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  • 1.
    Aasa, Björn
    et al.
    Department of Orthopaedics, Surgical and Perioperative Sciences, Umeå University, Norrlandsklinikens hälsocentral, Umeå.
    Berglund, Lars
    Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University.
    Michaelson, Peter
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Aasa, Ulrika
    Umeå University, Department of Community Medicine and Rehabilitation.
    Individualized Low-Load Motor Control Exercises and Education Versus a High-Load Lifting Exercise and Education to Improve Activity, Pain Intensity, and Physical Performance in Patients With Low Back Pain: A Randomized Controlled Trial2015Inngår i: Journal of Orthopaedic and Sports Physical Therapy, ISSN 0190-6011, E-ISSN 1938-1344, Vol. 45, nr 2, s. 77-85Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Study DesignRandomized controlled trial. BackgroundLow back pain is a common disorder. Patients with low back pain frequently have aberrant and pain-provocative movement patterns that often are addressed with motor control exercises. ObjectiveTo compare the effects of low-load motor control (LMC) exercise and those of a high-load lifting (HLL) exercise. MethodsSeventy participants with recurrent low back pain, who were diagnosed with nociceptive mechanical pain as their dominating pain pattern, were randomized to either LMC or HLL exercise treatments. Participants were offered 12 treatment sessions over an 8-week period. All participants were also provided with education regarding pain mechanisms. MethodsParticipants were assessed prior to and following treatment. The primary outcome measures were activity (the Patient-Specific Functional Scale) and average pain intensity over the last 7 days (visual analog scale). The secondary outcome measure was a physical performance test battery that included 1 strength, 3 endurance, and 7 movement control tests for the lumbopelvic region. ResultsBoth interventions resulted in significant within-group improvements in pain intensity, strength, and endurance. The LMC group showed significantly greater improvement on the Patient-Specific Functional Scale (4.2 points) compared with the HLL group (2.5 points) (P<.001). There were no significant between-group differences in pain intensity (P = .505), strength, and 1 of the 3 endurance tests. However, the LMC group showed an increase (from 2.9 to 5.9) on the movement control test subscale, whereas the HLL group showed no change (from 3.9 to 3.1) (P<.001). ConclusionAn LMC intervention may result in superior outcomes in activity, movement control, and muscle endurance compared to an HLL intervention, but not in pain intensity, strength, or endurance. Registered at ClinicalTrials.gov (NCT01061632).

  • 2.
    Aasa, Björn
    et al.
    Norrlandsklinikens hälsocentral, Umeå.
    Hellqvist, Jonas
    Umeå University, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Berglund, Lars
    Umeå University, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Michaelson, Peter
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering. peter.michaelson@ltu.se .
    Aasa, Ulrika
    Umeå University, Department of Community Medicine and Rehabilitation, Physiotherapy.
    A characterisation of pain, disability, kinesiophobia and physical capacity in patients with predominantly peripherally mediated mechanical low back pain2011Inngår i: Physiotherapy, ISSN 0031-9406, E-ISSN 1873-1465, Vol. 97, nr Suppl. 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: The specific objectives were to: 1) describe the level of pain intensity, disability, activity limitation, kinesiophobia and physical capacity in patients with predominantly peripherally mediated mechanical back pain, and 2) investigate whether differences between these patients in physical and psychosocial factors can be distinguished when the patients are further sub-grouped.Relevance: To improve assessment among patients with chronic low back pain (CLBP) it is important to investigate the prevalence of physical and psychosocial features in homogenous sub-groups.Participants: Seventy-one patients with CLBP, 20-60 years old, with peripherally mediated mechanical pain at the the moment for the study, were included and each patient was sub-classified into one of five sub-groups based on their pain behaviour and functional movement pattern (flexion n=20, flexion/lateral shift, n=11, active extension n=23 , passive extension n=8, and multidirectional pattern n=9).Methods: Data on pain intensity (Visual Analogue Scale), disability (the Roland and Morris Questionnaire), activity limitation (the Patient Specific Functional Scale), kinesiophobia (the Tampa Scale of Kinesiophobia) and physical capacity (lifting capacity and trunk extensor endurance) was collected.Analysis: Mean and standard deviation for parametric and median and interquartile range for non-parametric data were used for descriptive statistics. One-way ANOVA for normally distributed data and Kruskal-Wallis for non-normally distributed data were used for analyses of differences between the sub-groups. The subjects were also divided into two age-groups (20-40 and 41-60 years) and measures of physical capacity were compared to women and men at the ages of 34 and 50, respectively, in the general Swedish population using one sample T-test.Results: The patients reported low to moderate pain intensity (3.1/10±2.4), disability (RMDQ (7.27/24 ±4.2) and kinesiophobia (33.4/68 ±7) and these levels were lower than reported levels in other studies including more heterogenous groups of patients with CLBP. The patiens reported activity limitations (PSFS 13/30±23). Lifting capacity and trunk extensor endurance were significantly lower than in the general population in the youngest age-group. No significant differences in pain intensity, disability, kinesiophobia or physical capacity were found between the sub-groups.Conclusions: This research highlights that patients with predominantly peripherally mediated mechanical back pain may differ from other sub-groups of patients with CLBP (e.g., patients with central sensitization as dominating pain mechanism) regarding physical and psychosocial factors. The individual variation in pain intensity, disability, kinesiophbia and physical capacity among the patients indicates the importance to assess these factors in every patient. Due to the fact that there were few patients in the sub-groups, further research is necessary to explore whether there are differences, that we were not able to disingjish, between patients with different movement patterns.

  • 3.
    Aasa, Björn
    et al.
    Department of Orthopaedics, Surgical and Perioperative Sciences, Umeå University, Norrlandsklinikens hälsocentral, Umeå.
    Sandlund, Jonas
    Michaelson, Peter
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Aasa, Ulrika
    Umeå University, Department of Community Medicine and Rehabilitation.
    Low- versus high-load motor control exercise to reduce disability in patients with persistent peripherally mediated mechanical low back pain2012Inngår i: Rendez vous of hands and minds: 10th International Federation of Orthopaedic Manipulative Physical Therapists’ World conference, Quebec,  1-5 Oct 2012, 2012, nr 2Konferansepaper (Fagfellevurdert)
  • 4.
    Aasa, Ulrika
    et al.
    Umeå University, Department of Community Medicine and Rehabilitation.
    Aasa, Björn
    Department of Orthopaedics, Surgical and Perioperative Sciences, Umeå University, Norrlandsklinikens hälsocentral, Umeå.
    Michaelson, Peter
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Sandlund, Jonas
    Effects of low- and high-load motor control exercises on lumbar curvature during stance in patients with low back pain2012Inngår i: Rendez vous of hands and minds: 10th International Federation of Orthopaedic Manipulative Physical Therapists’ World conference, Quebec,  1-5 Oct 2012, 2012, nr 2Konferansepaper (Fagfellevurdert)
  • 5.
    Aaskoven, Mette
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Hietala, Ulrika
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Föräldrars upplevelse av att ha ett barn med diabetes typ 12019Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Bakgrund: Typ 1 diabetes är en sjukdom som mer än 500 000 barn och unga under 17 år lever med och kräver livslång behandling. För barnens föräldrar innebär detta en omställning i det dagliga livet och i deras föräldraskap. Föräldrarna kan ha behov av stöttning från vårdpersonal. Syfte: Att beskriva föräldrars upplevelse av att ha ett barn med typ 1 diabetes. Metod: Kvalitativ manifest innehållsanalys användes som analysmetod och 12 vetenskapliga artiklar med kvalitativ ansats ingick i resultatet. Analysen resulterade i fem slutgiltiga kategorier. Resultat: Föräldrar till ett barn med typ 1 diabetes kan uppleva att diagnosen förändrar livet. Vardagen styrs av kontroll och planering vilket leder till många känslor som är svåra att hantera. Föräldrarna behöver tillgänglighet från vårdpersonal och andra för att känna trygghet och för att kunna hantera livet med ett barn med diabetes typ 1. Slutsatser: För att sjuksköterskan ska kunna ge en god omvårdnad är det av betydelse att hen kan relatera till både patienter och anhöriga. Sjukvården har en viktig roll att genom stor tillgänglighet och uppbackning vara ett stöd och därmed vara en trygghet för familjerna i vardagen. Denna studies resultat kan ge en ökad förståelse för föräldrars upplevelse av att ha barn med diabetes typ 1. Det behövs mer kunskap inom området för att sjuksköterskor ska kunna bemöta och stötta familjerna vilket kan leda till förbättrad omvårdnad.

  • 6.
    Abbas, Maisaa
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Andersson, Elisa
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Personers upplevelser av att överleva ett hjärtstopp - ett litteraturstudie2019Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Hjärtstopp drabbar cirka 10 000 personer årligen i Sverige. Antalet personer som överlever ett hjärtstopp har ökat stadigt de sista åren, men fortfarande är det den vanligaste orsaken till plötslig död utanför sjukhus. För de personen som överlever innebär det att livet plötsligt förändras och fokus i det dagliga livet blir på händelsen och dess konsekvenser. Syftet med denna litteraturstudie var att beskriva de drabbades upplevelser av ett hjärtstopp. En kvalitativ design användes och nio vetenskapliga studier analyserades systematiskt med innehållsanalys. Analysen resulterade i fem kategorier: Att känna oro, att få ett nytt livsperspektiv, att kroppsliga begränsningar leder till känslor av rädsla och maktlöshet, att känna tacksamhet men vara i behov av stödsamtal, att vara i behov av information. Resultatet visade att personer som överlevt ett hjärtstopp hade många frågor och funderingar kring det inträffade men upplevde att de fick bristande information från sjukvården. Känslor som otrygghet, ångest och osäkerhet var vanligt samt oro inför framtiden. Resultatet från denna litteraturstudie kan användas för att öka kunskapen om hur personerna mår psykiskt och fysiskt, samt vilka behov de har för att hantera livet. Det behövs mer omvårdnadsforskning inom området med fokus på sjuksköterskors upplevelser av att vårda de drabbade personerna. Målet är att skapa trygghet hos sjukvårdspersonal så att de kan stötta dessa personer på bästa sätt och främja en läkning hos dem och anhöriga.

  • 7.
    Aghajan ghazi, Alice Lejla
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Nilsson, Elin
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Palliativ vård på ett hospice i ett utvecklingsland – en observationsstudie2018Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Background: The aim of palliative care is to keep the quality of life by integrating a person-centered care at the end of life. Palliative care and hospice care do not focus only on symptoms and medication. Self-esteem, dignity and support were major components for the patient at the end of life. Aim: The aim of this study was to describe how palliative care is given at a hospice in a developing country. Method: The used method was a qualitative participant observation study. The participants were health care staff at a hospice, they were chosen before the study began. The observation took place three times per week for six weeks. The researcher intertwined volunteering and observing at the same time. The data was analyzed with a qualitative content analysis. Result: The study resulted in six categories: environment, nursing records, nursing care, infection control and meals. Conclusion: The conclusion was that nature and safety had a big impact on the environment. The health care staff worked as a team to fulfill their goals.

  • 8.
    Ahlgren, Johanna
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Det korta mötet med barn i vården: En litteraturstudie om upplevelser hos sjuksköterskor2018Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Inledning: Den största anledningen till att barn kommer i kontakt med sjukvården är på grund av misstänkt fraktur, vilket innebär att röntgensjuksköterskor ofta möter barn i det dagliga arbetet på röntgenavdelningen. Trots det är dessa sällan utbildade i bemötande av barn, eller inom pediatrisk bildtagning. Vuxna som inte är vana vid att hantera barn kan känna viss tveksamhet eller rädsla inför att vårda ett barn. För att kunna förbättra mötet med barn är det viktigt att veta vilka känslor sjukvårdpersonal känner i mötet, och varför. Syfte: att beskriva vilka upplevelser sjukvårdpersonal känner i mötet med barn. Metod: Studien utfördes som en litteraturöversikt med 10 artiklar som granskades med en induktiv kvalitativ innehållsanalys. De 10 artiklarna var av kvalitativ ansats och intervjuade sjukvårdspersonal som bestod av ambulanspersonal, akutsjuksköterskor, allmänsjuksköterskor och radioterapeuter. Resultat: Fyra kategorier; bemötande, hanterbarhet, tiden har betydelse och föräldrar. Dessa beskriver i vilka situationer sjukvårdspersonal upplever både negativa och positiva känslor i mötet med barn. Slutsats: att identifiera vilka känslor som uppstår är grunden för fortsatta studier för att förbättra arbetsmiljön för såväl röntgensjuksköterskor som övrig sjukvårdspersonal. 

  • 9.
    Ahlgren, Linda
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Sjölander, Christina
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Arbetsterapeuters erfarenheter av att identifiera samt främja meningsfulla aktiviteter hos personer som är 80 år och äldre.2018Independent thesis Advanced level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syfte: Var att beskriva arbetsterapeuters erfarenheter av att identifiera samt främja meningsfulla aktiviteter hos personer som är 80 år och äldre, samt har hemsjukvård. Metod: Författarna valde en kvalitativ ansats för att beskriva arbetsterapeuternas subjektiva upplevelser. Åtta semistrukturerade intervjuer genomfördes och analyserades sedan utifrån kvalitativ innehållsanalys. Resultat: Data resulterade i tre kategorier varav en med två underkategorier dessa var: Identifiering av individuella behov för meningsfulla aktiviteter, Arbeta främjande mot meningsfulla aktiviteter, med underkategorierna: Problematik arbetsterapeuter möter hos de äldre samt Stöttande resurser för att bibehålla meningsfulla aktiviteter, samt kategorin Arbetsterapeuternas avsaknad av samt önskan om resurser för att arbeta mot meningsfulla aktiviteter. Slutsats: Studien visar att arbetsterapeuter inom hemsjukvården lägger fokus på att utgå ifrån patientens individuella livshistoria och att de ser en fara med generalisering vid arbetet med patienter som är 80 år och äldre. Arbetsterapeuternas erfarenhet visade även att mindre insatser samt att det sociala nätverket av anhöriga och vänner är av betydelse för att patienterna ska kunna utföra meningsfulla aktiviteter. Deltagarna i studien visade på ett stort engagemang i sitt arbete samtidigt som de uttrycker en önskan om att kunna göra mer för patienterna.

  • 10.
    Ahlmark, Daniel Innala
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Prellwitz, Maria
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Röding, Jenny
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nyberg, Lars
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Hyyppä, Kalevi
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    An Initial Field Trial of a Haptic Navigation System for Persons with a Visual Impairment2015Inngår i: Journal of Assistive Technologies, ISSN 1754-9450, E-ISSN 2042-8723, Vol. 9, nr 4, s. 199-206Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose– The purpose of this paper is to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment (VI). Design/methodology/approach– Six persons with a VI who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories. Findings– The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value– One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

  • 11.
    Ahlmark, Daniel Innala
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Prellwitz, Maria
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Röding, Jenny
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nyberg, Lars
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Hyyppä, Kalevi
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Virtuell vit käpp för den seende rullstolen2013Konferansepaper (Annet vitenskapelig)
  • 12.
    Ahlqvist, Anette
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Lindkvist, Maria
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Att vara förälder till barn med kronisk sjukdom - en litteraturstudie2018Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Att som förälder få uppleva att barnet drabbas av en kronisk sjukdom är en omvälvande händelse för många föräldrar. När ett barn blir sjuk är det oftast en hel familj som drabbas och i vården finns det en utmaning i att möta hela familjen som är i behov av stöd och vård. Syfte var att beskriva upplevelser av att vara förälder till barn med kronisk sjukdom. I denna litteraturstudie utgick vi från Graneheim och Lundmans metod för kvalitativ innehållsanalys med en manifest ansats. Resultat visar att diagnosen och sjukdomen upplevdes svår att hantera. Känslor som sorg, förtvivlan och skuld beskrevs komma i samband med sjukdomen. Känslan av att behöva stöd från hälso- och sjukvården upplevdes viktig av föräldrarna. Familjen upplevde svårigheter att hantera det vardagliga livet och få det att fungera. Mycket oro över det sjuka barnets framtid upplevdes. Fortsatt forskning som handlar om hur hälso- och sjukvården ska kunna ta hand om föräldrar till kroniskt sjukt barn bör utföras. Hälso- och sjukvårdspersonal behöver få tillgång till verktyg som hjälper dem att bemöta föräldrar till kroniskt sjuka barn.

    Nyckelord: Föräldrar, kroniskt sjuka barn, familjer, lidande, omvårdnad, upplevelser

  • 13.
    Ahlström, Elin
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Andersson, Elina
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Vårdpersonals upplevelser av att vårda personer med demenssjukdom2016Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Demenssjukdom är en av de mest vanligt förekommande sjukdomarna och det är främst äldre människor som drabbas. Detta kommer att leda till att antalet personer med demenssjukdom kommer att öka och deras komplexa sjukdomsproblematik kommer att leda till ökat behov av sjukhusvistelse och särskilt boende. Syftet med denna litteraturstudie var att beskriva vårdpersonals upplevelser av att vårda människor med demenssjukdom. En systematisk litteratursökning av vetenskaplig studier genomfördes inom området, vilket resulterade i tio studier som svarade på syftet. Studiernas innehåll analyserades med en kvalitativ manifest innehållsanalys med en induktiv ansats, som resulterade i fyra kategorier: Att vårdandet kan vara en utmaning, Att både ha kunskaps- och tidsbrist, Att vårdmiljön inte är utformad för personer med demenssjukdom och Att ha en god relation och kommunikation har stor betydelse. Studiens resultat diskuteras främst utifrån personcentrerad vård och hur ett personcentrerat förhållningsätt skulle kunna etableras inom vården av personer med demenssjukdom, i syfte att stärka personen med demenssjukdom utifrån dennes unika förutsättningar. Slutsatsen belyser vikten av att arbeta personcentrerat inom demensvården och att kunskap om demenssjukdomar kan underlätta svåra situationer. 

  • 14.
    Ahmed, Hamzah
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Relationship Between Crystal Structure and Mechanical Properties in Cocrystals and Salts of Paracetamol2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Oral tablets are convenient and widely administered drugdosage forms.The mechanical properties of a drug substance such as plasticity, ability to cohere into compacts and friction/adhesion are important in the development of a tablet formulation. Crystal engineering is an interesting and viabletool for improving or optimizing these technical properties of a drug substance.The creation of a lternative polymorphic forms, cocrystals, salts or hydrates of a drug substance can result in structural variations in the molecular packing of the crystals and, thereby, can alter the deformation behavior of the materials.Knowledge of the relationships between crystal modifications and the technical properties in multicomponent systems is limited, but represents a possibility to predict mechanical properties based on crystalstructure that facilitates engineering particles for the optimal processing performance. The overall objective of this thesis is thus to gain better understanding of the relationships between the crystal structure features and the mechanical properties of cocrystals and salts. Paracetamol form I, its cocrystals with oxalic acid and 4,4´-bipyridine, and its hydrochloride salt were selected as model systems in the study.The materials were scaled-up using rational crystallization methods and the physical purity was confirmed. The relevant properties of these powders were determined.Tablets were then made at applied pressures of50-250 MPa under controlled conditions.The tabletability and compactability of the powders were determined. The compression mechanics of the powders were the investigated according to a material classification protocol.Slip planes were identified by visually observing the crystal structures and based on the attachment energies calculated using different force fields in the materialsstudio.The tensile strengths of the powders increased with increasing pressure and the tabletability decreased in the order oxalic acid>paracetamol-hydrochloride salt≈paracetamol-oxalic acid>4,4´-bipyridine>paracetamol-4,4´-bipyridine.The tensile strength of the tablets decreased exponentially with increasing porosity,with some exceptions.Ingeneral, the cocrystals and the salt displayed intermediate compression characteristics as compared to the reference substances.The elastic recovery of the cocrystal and salt forms of paracetamol was not markedly different from that of paracetamol.It was found that slip plane prediction based on the attachment energies was not reliable. While it was possible to explain the improved tableting properties of powders based on the crystal features (i.e. the presence of slip planes and flat layers), no clear relationship was found with yield pressure. This may be attributed to possible brittle material characteristics and the surface energies of the crystals,which need to be further studied.Thus, cocrystallization and salt formation introduced structural features that were responsible for changes in the compaction and compression properties of drug substances. In future work, we intend to extend these studies to provide a clear picture of structure-mechanical property relationships in organic molecular crystals over multiple length scales;molecules to crystals to bulk powder.Key words Crystal engineering, solid forms, cocrystals, salts, tableting, crystal structure, mechanical properties, compression analysis

  • 15.
    Ahmed, Hamzah
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Shimpi, Manishkumar R.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Velaga, Sitaram P.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Relationship between mechanical properties and crystal structure in cocrystals and salt of paracetamol2017Inngår i: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 43, nr 1, s. 89-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives were to study mechanical properties of various solid forms of paracetamol and relate to their crystal structures. Paracetamol Form I (PRA), its cocrystals with oxalic acid (PRA-OXA) and 4,4-bipyridine (PRA-BPY) and hydrochloride salt (PRA-HCL) were selected. Cocrystals and salt were scaled-up using rational crystallization methods. The resulting materials were subjected to differential scanning solid-state characterization. The powders were sieved and 90-360 µm sieve fraction was considered. These powders were examined by scanning electron microscopy (SEM) and densities were determined. Tablets were made at applied pressures of 35-180 MPa under controlled conditions and the tablet height, diameter and hardness were measured. Tensile strength and porosity of the tablets were estimated using well known models. Crystal structures of these systems were visualized and slips planed were identified. Cocrystal and salt of PRA were physically pure. Sieved powders had comparable morphologies and particle size. The apparent and theoretical densities of powders were similar but no clear trends were observed. The tensile strengths of these compacts were increased with increasing pressure whereas tabletability decreased in the order oxalic acid > PRA-HCL ≈ PRA-OXA > BPY > PRA-BPY. Tablet tensile strength decreases exponentially with increasing porosity with the exception of PRY-BPY and BPY. Slip plane prediction based on attachment energies may not be independently considered. However, it was possible to explain the improved mechanical properties of powders based on the crystal structure. Cocrystallization and salt formation have introduced structural features that are responsible for improved tableting properties of PRA.

  • 16.
    Ahnlund, Andreas
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Tännström, Pontus
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Skjutning konstaterad! Ambulanssjuksköterskans förberedelser vid utlarmning till en plats där en patient blivit skottskadad2019Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Abstract

    Introduction: Social development in Sweden points to an environment where shootings with firearms become an increasingly common phenomenon among criminal groups. With the Terrorist attack of April 7, 2017, the Civil Protection and Preparedness Authority (MSB) has been commissioned by the government to investigate what needs to be resolved in order for society to be better prepared for events with ongoing fatalities. It is important that the experiences created by the staff exposed to these challenges are taken care of and that you can integrate and identify the best strategies that you can use to prepare yourself best for the mission. Aim: The aim was to identify the strategies used by ambulance nurses for preparation during the drive out in a situation where a patient has received a gunshot wound. Method: The study has been conducted with a descriptive qualitative approach. Semi-structured interviews were used to collect retrospective data from 10 ambulance nurses. The collected data was analyzed by critical incident technique and resulted in five final categories. Result: The results show that ambulance nurses use both mental and practical strategies to prepare for the care of a patient with a gunshot wound. The five final categories identified during the analysis were as follows: To talk to the colleague and to get a common strategy for structuring and distributing work, reviewing and repeating relevant algorithms, searching for a policy and thinking about safety, mental stability through calm and structured thoughts with an open mind, going through which equipment is the priority for a life-threatening bleeding and where it is located. Clinical implications: The result of this research project helps staff in the field of ambulance care receive different strategies that can be used to prepare for the care of patients who have been shot. The preparations are linked to their own mental strategies, collaboration with colleagues, collaboration with other actors and preparation for patient care. Key words: Preparation strategies, prehospital care, ambulance nurses, shot injury, critical incident technique.

  • 17.
    Aitken, Leanne M.
    et al.
    School of Nursing & Midwifery & NHMRC Centre of Research Excellence in Nursing (NCREN), Centre for Health Practice Innovation, Menzies Health Institute Queensland, Griffith University.
    Castillo, Maria I.
    School of Nursing & Midwifery & NHMRC Centre of Research Excellence in Nursing (NCREN), Centre for Health Practice Innovation, Menzies Health Institute Queensland, Griffith University.
    Ullman, Amanda
    School of Nursing & Midwifery & NHMRC Centre of Research Excellence in Nursing (NCREN), Centre for Health Practice Innovation, Menzies Health Institute Queensland, Griffith University.
    Engström, Åsa
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Cunningham, Kathryn
    Population Health Sciences, Medical Research Institute, University of Dundee.
    Rattray, Janice
    Population Health Sciences, Medical Research Institute, University of Dundee.
    What is the relationship between elements of ICU treatment and memories after discharge in adult ICU survivors?2016Inngår i: Australian Critical Care, ISSN 1036-7314, E-ISSN 1878-1721, Vol. 29, nr 1, s. 5-14Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    ObjectivesPatients admitted to an intensive care unit (ICU) often experience distressing memories during recovery that have been associated with poor psychological and cognitive outcomes. The aim of this literature review was to synthesise the literature reporting on relationships between elements of ICU treatment and memories after discharge in adult ICU survivors.Review method usedIntegrative review methods were used to systematically search, select, extract, appraise and summarise current knowledge from the available research and identify gaps in the literature.Data sourcesThe following electronic databases were systematically searched: PubMed, Ovid EMBASE, EBSCOhost CINAHL, PsycINFO and Cochrane Central Register of Controlled Trials. Additional studies were identified through searches of bibliographies. Original quantitative research articles written in English that were published in peer-review journals were included.Review methodsData extracted from studies included authors, study aims, population, sample size and characteristics, methods, ICU treatments, ICU memory definitions, data collection strategies and findings. Study quality assessment was based on elements of the Critical Appraisal Skills Programme using the checklists developed for randomised controlled trials and cohort studies.ResultsFourteen articles containing data from 13 studies met the inclusion criteria and were included in the final analysis. The relatively limited evidence about the association between elements of ICU treatment and memories after ICU discharge suggest that deep sedation, corticoids and administration of glucose 50% due to hypoglycaemia contribute to the development of delusional memories and amnesia of ICU stay.ConclusionsThe body of literature on the relationship between elements of ICU treatment and memories after ICU discharge is small and at its early stages. Larger studies using rigorous study design are needed in order to evaluate the effects of different elements of ICU treatment on the development of memories of the ICU during recovery.

  • 18.
    Albertsson, Ellenor
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Holmbom, Lina
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Personers upplevelser av att förändra sina levnadsvanor efter genomgången hjärtinfarkt: En litteraturstudie2016Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Hjärtinfarkt är i dag en av de största orsakerna till funktionsnedsättning och död runt om i världen. Egenvård är en stor del av behandlingen efter en hjärtinfarkt och innebär att personen på egen hand eller med hjälp av andra utför vissa delar av sin behandling. Syftet med denna litteraturstudie var att beskriva personers upplevelser av att förändra sina levnadsvanor efter genomgången hjärtinfarkt. Studien gjordes med fokus på ett inifrånperspektiv och är baserad på elva artiklar som analyserats med kvalitativ innehållsanalys med manifest ansats. Analysen resulterade i fyra kategorier; att stöd från andra ger trygghet till att genomföra förändringar, att rädsla hämmar och bidrar till förändring, att vilja ta hand om sig själv och att hindras från att kunna ta hand om sig själv. Resultatet visar att personer som genomgått en hjärtinfarkt behöver motivation för att kunna förändra sina levnadsvanor. Personerna har ett stort behov av information och kunskap för att kunna förstå sambandet mellan sjukdom och behovet av egenvård. Genom att personen har stöd ifrån ett socialt nätverk och från sjukvården upplever personen en trygghet i att genomföra och motiveras till att behålla de nya levnadsvanorna. Sjukvården bör fokusera på att ge en personcentrerad omvårdnad och kontinuerligt utvärdera hur personens motivation, behov och kunskap förändras över tid.

  • 19.
    Albertsson, Sophie
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Hjerpe, Caroline
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Den gravida kroppen - individens eller sjukvårdens ansvar?: En kvalitativ studie om kvinnors uppfattningar och erfarenheter.2018Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Bakgrund: Träning under en graviditet är viktigt både ur ett fysiologiskt samt psykologiskt perspektiv. Bristande fysisk aktivitet är en stor riskfaktor för hälsan. Livshändelser såsom graviditet och förlossning kan utgöra en större risk för bristande fysisk aktivitet hos kvinnor. Gravida kvinnor rekommenderas att vara fysiskt aktiva minst 30 minuter per dag. Informationen kring fysisk aktivitet och träning är ofta bristfällig inom mödrahälsovården varför det efterlyses ett närmare samarbete mellan till exempel barnmorskor och fysioterapeuter. Genom att förbättra kvantiteten och kvaliteten på informationen angående fysisk aktivitet hos gravida finns det en möjlighet att korrigera felaktiga uppfattningar och på så sätt främja en god hälsa. Syfte: Syftet var att beskriva kvinnors egen uppfattning om fysisk aktivitet och träning under och efter en graviditet samt upplevelse av mottagen information från sjukvården angående ämnet. Metod: En kvalitativ intervjustudie genomfördes med fem kvinnor, vilka rekryterades via ett strategiskt urval. Därefter genomfördes en innehållsanalys av intervjuerna. Resultat: Analysen av intervjutexterna resulterade i en huvudkategori “Den gravida kroppen - individens eller sjukvårdens ansvar?”. Huvudkategorin innehöll följande kategorier “Kunskapsinhämtning - individens ansvar” samt “Aktivitetsnivå - individens val” med tillhörande underkategorier. Konklusion: Studien visade positiva upplevelser och uppfattningar av fysisk aktivitet och träning i samband med graviditeten. De intervjuade kvinnorna upplevde bristande information från sjukvården gällande detta ämne. De råd som kvinnorna hade fått från sjukvården upplevdes som osäkra och väldigt generella, därför fanns en önskan om att individanpassa råden.

  • 20.
    Aldenlöv, Maria
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Lundbäck, Rebecca
    Luleå tekniska universitet, Institutionen för hälsovetenskap.
    Operationssjuksköterskors uppfattningar av operation med vaken patient: En kvantitativ enkätstudie2017Independent thesis Advanced level (degree of Master (One Year)), 40 poäng / 60 hpOppgave
    Abstract [sv]

    Att gå från att vara en person till att bli en patient innebär att livet kan förändras. Sårbarhet, utsatthet, förlust av kontroll, rädsla för det okända och stress är vanligt förekommande känslor i samband med operation. Patienter har beskrivit att de upplever operation som att balansera mellan att vara delaktig och osynlig, inte vilja störa men samtidigt bli sedd, samt att känna sig ensam, övergiven och exponerad. Som blivande operationssjuksköterskor är det viktigt att ha kunskap om patientens upplevelse, samt reflektera över det egna arbetet. Flertalet studier har fokuserat på patientens upplevelse och visar att personalens bemötande och kommunikation är avgörande för patientens upplevelse. Studies syfte var att kartlägga operationssjuksköterskors uppfattningar av operation med vaken patient. Studien var en tvärsnittsstudie med kvantitativ ansats, och tillämpade enkätformulär som datainsamlingsmetod med bekvämlighetsurval. Analysen genomfördes med deskriptiv analys, samt hypotesprövning för att stärka resultatet. Resultatet presenterades med tabeller, grafer och text. Den öppna kvalitativa frågan sammanställdes i kategorier och presenterades med citat. Resultatet visade att operationssjuksköterskor uppfattade att vid en operation med vaken patient skedde förändringar av kommunikationen och bemötandet, samt att operationssalen uppfattades lugnare och mer harmonisk när musik spelades. Författarna rekommenderar fortsatta studier för djupare förståelse av operationssjuksköterskors uppfattningar av förändringar av kommunikationen och bemötandet vid operation med vaken patient, samt musikens påverkan. Resultatet från denna studie kan användas som reflektionsstöd dels hos arbetsgivaren och dels hos den enskilda operationspersonalen, samt som stöd vid handledning av studenter och nyutbildade operationssjuksköterskor. 

  • 21.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Backman, Ylva
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Bergmark, Ulrika
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Gardelli, Åsa
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Hertting, Krister
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    ”Det ska vara kul att lära!”: Skolan som den bästa platsen för lärande2012Inngår i: Forskning om undervisning och lärande, ISSN 2000-9674, E-ISSN 2001-6131, Vol. 8, s. 41-49Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Inom ramen för denna artikel diskuterar vi såväl den psykosociala som den fysiska miljön i skolan. Vidare argumenterar vi för att skolans miljö är av betydelse för elevernas möjligheter att lära sig, likväl som för deras upplevelser av lärandesituationerna. Särskilt intressant blir då att lyssna till eleverna. Syftet med denna artikel är därför att synliggöra och diskutera elevers röster i förhållande till hur skolan kan bli den bästa platsen för lärande. Detta görs med utgångspunkt i forskningsprojektet ”Skolan suger” eller?, där drygt 200 elever i åldrarna 11–15 år deltog. Eleverna fick skriftligen reflektera över hur skolan ska bli en riktigt bra lärandemiljö. För att utveckla skolan till den bästa platsen för lärande uttryckte eleverna en önskan att kunna påverka sin lärandemiljö, att uppnå ömsesidighet och samspel, att kunna hantera tidsregleringen i skolan, samt att uppfylla behov för välbefinnande.

  • 22.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Backman, Ylva
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Bergmark, Ulrika
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Gardelli, Åsa
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Hertting, Krister
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    ”Skolan suger” ... eller?: Att ge röst åt barns och ungdomars erfarenheter av psykosocial hälsa i sin lärandemiljö2012Inngår i: Resultatdialog 2012, Stockholm: Vetenskapsrådet , 2012, s. 9-15Kapittel i bok, del av antologi (Annet (populærvitenskap, debatt, mm))
  • 23.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Bergmark, Ulrika
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Forsman, Arne
    Hertting, Krister
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Lasten hyvinvointi ell – näkökulmia aiheeseen2008Inngår i: Psykososiaalisen hyvinvoinnin edistäminen opetustyössä, Rovaniemi: Lapin yliopistokustannus , 2008, s. 39-46Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 24.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Bergmark, Ulrika
    Forsman, Arne
    Hertting, Krister
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Några perspektiv på psykosocial hälsa bland barn2008Inngår i: Barns trivsel i Nord: aktiviteter for psykososial trivsel fra skoler i Barentsregionen, Oslo: Gyldendal Norsk Folag AS , 2008, s. 39-45Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 25.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Bergmark, Ulrika
    Forsman, Arne
    Hertting, Krister
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Well-being among children: some perspectives from a Swedish viewpoint2008Inngår i: Crystals of schoolchildren's well-being: cross-border training material for promoting psychosocial well-being through school education, Rovaniemi: Lapland University of Applied Sciences, 2008, s. 39-46Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 26.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Forsman, Arne
    Öhrling, Kerstin
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Omvårdnad.
    Some research perspectives on the Arctichildren project from a Sweidsh horizon2006Inngår i: Abstract book: ArctiChildren conference : psychosocial well-being of schoolchildren in the Barents region 28-29th of September 2006, ArctiChildren Conference , 2006, s. 14-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    What can we do to improve our knowledge and understanding of school children health and well being? This question was raised when the ArctiChildren project started. The aim of this presentation is to share some methodological perspectives on research within schools. It is crucial to develop a number of different options of collaboration between researchers, teachers and students, as well as different possible methods. We will highlight the importance of developing collaboration between the researchers and the schools. We will also discuss projective methods, for example drawings, as one way to gain knowledge and understanding of schoolchildren's school experiences. Another method we will discuss is working on consulting basis with the staff in order to decrease bullying and harassment in school.

  • 27.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    A silent message is also a message2005Inngår i: A Nordic dimension in education and research - myth or reality?: NFPF/NERA 33rd congress, 2005, s. 83-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    "Dammed taxi cab!" A twelve year old student wrote these words in the margins of a questionnaire in school concerning psychosocial well-being. Within this paper they will serve as a point of departure for the discussion. Can the messages found on the sides of the squares intended for an X in a questionnaire be considered non-messages? Or are these expressions indeed messages that are made silent and therefore can be considered silent messages? Then one might wonder what the meanings of the silent messages are that often occurs in questionnaires? Can, or maybe should, we take notice of these silent messages? According to Polanyi every human being has silent and unexpressed dimensions within themselves, which acknowledge situations where we recognise that we know more than we can explain. This is also stressed by Merleau-Ponty, who argued that something exists beyond what is said, and Bateson emphasised that a non-message is also a message - the silence tells us something. Within this paper we will highlight and discuss the significance of silent messages of communication in general, and especially in questionnaires.

  • 28.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Beyond the boundaries of the classroom: Interpersonal relationships in thetransformation from (edu)room to (edu)roam2018Inngår i: NERA2018 - 46th Congress: Educational Research: Boundaries, Breaches and Bridges, 2018Konferansepaper (Fagfellevurdert)
  • 29.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    'Dammed taxi cab': how silent communication in questionnaires can be understood and used to give voice to children's experiences2011Inngår i: International Journal of Research and Method in Education, ISSN 1743-727X, E-ISSN 1743-7288, Vol. 34, nr 2, s. 117-130Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    'Dammed taxi cab' - a 12-year-old boy wrote these words in the margins of a questionnaire, and within this paper they will serve as a point of departure for the discussion of the use of questionnaires as a way to voice children's experiences. The overall aim of this paper is to enable understanding of and discuss the use of questionnaires as a way to voice children's experiences. An analysis in accordance with a life-world approach has provided the lens through which to explore messages that can occur in questionnaires. The key research questions that will be explored in an attempt to answer the overall aim are: (i) how can unanswered questions and notes in the margins of a questionnaire be understood? and (ii) why is a questionnaire not always completed, according to the intention of its creators? To develop an understanding of this we analysed a number of questionnaires with unanswered questions and notes in the margins using a life-world approach. During the analysis two themes emerged: silent messages and messages being silenced. Finally, we discuss the legitimacy of questionnaires in childhood research and possible implications for practice when using this method to give voice to children's experiences.

  • 30.
    Alerby, Eva
    et al.
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Pedagogik språk och Ämnesdidaktik.
    Kostenius, Catrine
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Silence for health and learning: a phenomenological reflection2011Konferansepaper (Annet vitenskapelig)
  • 31.
    Alexandrou, Constantia
    et al.
    Department of Physics, University of Cyprus.
    Constantinou, Martha
    Department of Physics, University of Cyprus.
    Korzec, Tomasz
    Institut fur Physik, Humboldt Universitat zu Berlin.
    Panagopoulos, Haralambos G.
    Department of Physics, University of Cyprus.
    Stylianou, Fotos
    Department of Physics, University of Cyprus.
    Renormalization constants for 2-twist operators in twisted mass QCD2011Inngår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 83, nr 1, artikkel-id 014503Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perturbative and nonperturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the nonperturbative evaluation of the one-derivative twist-2 vector and axial-vector operators. Nonperturbative results are obtained using the twisted mass Wilson fermion formulation employing two degenerate dynamical quarks and the tree-level Symanzik improved gluon action. The simulations have been performed for pion masses in the range of about 450-260 MeV and at three values of the lattice spacing a corresponding to β=3.9, 4.05, 4.20. Subtraction of O(a2) terms is carried out by performing the perturbative evaluation of these operators at 1-loop and up to O(a2). The renormalization conditions are defined in the RI⊃′-MOM scheme, for both perturbative and nonperturbative results. The renormalization factors, obtained for different values of the renormalization scale, are evolved perturbatively to a reference scale set by the inverse of the lattice spacing. In addition, they are translated to MS̄ at 2 GeV using 3-loop perturbative results for the conversion factors

  • 32.
    Alexandrou, Constantia
    et al.
    Department of Physics, University of Cyprus.
    Constantinou, Martha
    Department of Physics, University of Cyprus.
    Korzec, Tomasz
    Institut fur Physik, Humboldt Universitat zu Berlin.
    Panagopoulos, Haralambos G.
    Department of Physics, University of Cyprus.
    Stylianou, Fotos
    Department of Physics, University of Cyprus.
    Renormalization constants of local operators for Wilson type improved fermions2012Inngår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 86, nr 1, artikkel-id 014505Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perturbative and nonperturbative results are presented on the renormalization constants of the quark field and the vector, axial-vector, pseudoscalar, scalar, and tensor currents. The perturbative computation, carried out at one-loop level and up to second order in the lattice spacing, is performed for a fermion action, which includes the clover term and the twisted mass parameter yielding results that are applicable for unimproved Wilson fermions, as well as for improved clover and twisted mass fermions. We consider ten variants of the Symanzik improved gauge action corresponding to ten different values of the plaquette coefficients. Nonperturbative results are obtained using the twisted mass Wilson fermion formulation employing two degenerate dynamical quarks and the tree-level Symanzik improved gluon action. The simulations are performed for pion masses in the range of 480-260 MeV and at three values of the lattice spacing, a, corresponding to β=3.9, 4.05, 4.20. For each renormalization factor computed nonperturbatively we subtract its perturbative O(a2) terms so that we eliminate part of the cutoff artifacts. The renormalization constants are converted to MS̄ at a scale of μ=2GeV. The perturbative results depend on a large number of parameters and are made easily accessible to the reader by including them in the distribution package of this paper, as a Mathematica input file.

  • 33.
    Alhalaweh, Amjad
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Pharmaceutical cocrystals: formation mechanisms, solubility behaviour and solid-state properties2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The primary aim of pharmaceutical materials engineering is the successful formulation and process development of pharmaceutical products. The diversity of solid forms available offers attractive opportunities for tailoring material properties. In this context, pharmaceutical cocrystals, multicomponent crystalline materials with definite stoichiometries often stabilised by hydrogen bonding, have recently emerged as interesting alternative solid forms with potential for improving the physical and biopharmaceutical properties of a drug substance. There are, however, gaps in our understanding of the screening, scale-up and formulation operations required for effective use of cocrystals in drug product development. The objective of this thesis was to improve fundamental understanding of the formation mechanisms, solution behaviour and solid-state properties of pharmaceutical cocrystals. The solution chemistry and solubility behaviour of a diverse set of cocrystals were studied. It was found that the thermodynamic stability regions of the cocrystals and their components were defined by the phase solubility diagrams. Spray drying was introduced as a new method of preparing cocrystals; the formation mechanisms are illustrated. The cocrystals were more soluble than the respective drugs alone and the solubility-pH profiles were able to be predicted by mathematical models using a eutectic point determination approach. The cocrystal solubility was pH-dependent and could be engineered by the choice of coformers; this is valuable information for designing robust formulations. The solubility advantage of cocrystals was retained by the use of excipients that imparted kinetic and thermodynamic stability. The retention of drug-coformer association in processed cocrystals has been revealed, introducing a novel concept with potential implications for solid dosage form development. The final study demonstrated that the structure of the crystals and the particle engineering processes affected the solidstate and bulk particle properties of the cocrystals.This thesis contributes to the field of pharmaceutical science by advancing our understanding of crystallization processes and formulation development, thus enabling pharmaceutical cocrystals into drug products.

  • 34. Alhalaweh, Amjad
    et al.
    Ali, Hassan
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Effects of polymer and surfactant on the dissolution and transformation profiles of cocrystals in aqueous media2014Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 14, nr 2, s. 643-648Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Capturing solubility advantages of cocrystals is of great interest, and thus to understand the mechanism by which different excipients could maintain the supersaturation generated by cocrystals at the course of absorption in aqueous media is essential. To achieve this aim, the impact of different excipients on dissolution behavior of indomethacin-saccharin (IND-SAC) were monitored by measuring the concentrations of cocrystal components in the absence and presence of various concentration of excipients by HPLC, and solid phases were analyzed by differential scanning calorimetry after each experiment and the potential of Raman spectroscopy for monitoring phase transformations in situ was tested. No dissolution advantage was offered by cocrystals in the absence of any solution additive. The polymer and surfactant used in the study increased the solubility of IND but not SAC. This differential solubilization effect is believed to have stabilized the cocrystals for a relevant period for the absorption to take place. This could be attributed to either decreased gap between supersaturation and saturation of the drug or drug interaction with the additives. Understanding the effects of excipients type and concentration on the transformation profile is vital for designing enabling formulations for cocrystals. The eutectic constant may be useful in selecting excipients for stabilizing cocrystals.

  • 35.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Alzghoul, Ahmad
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Kaialy, Waseem
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Data mining of solubility parameters for computational prediction of drug–excipient miscibility2014Inngår i: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 40, nr 7, s. 904-909Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Computational data mining is of interest in the pharmaceutical arena for the analysis of massive amounts of data and to assist in the management and utilization of the data. In this study, a data mining approach was used to predict the miscibility of a drug and several excipients, using Hansen solubility parameters (HSPs) as the data set. The K-means clustering algorithm was applied to predict the miscibility of indomethacin with a set of more than 30 compounds based on their partial solubility parameters [dispersion forces , polar forces and hydrogen bonding ]. The miscibility of the compounds was determined experimentally, using differential scanning calorimetry (DSC), in a separate study. The results of the K-means algorithm and DSC were compared to evaluate the K-means clustering prediction performance using the HSPs three-dimensional parameters, the two-dimensional parameters such as volume-dependent solubility and hydrogen bonding , and selected single (one-dimensional) parameters. Using HSPs, the prediction of miscibility by the K-means algorithm correlated well with the DSC results, with an overall accuracy of 94%. The prediction accuracy was the same (94%) when the two-dimensional parameters or the hydrogen-bonding (one-dimensional) parameter were used. The hydrogen-bonding parameter was thus a determining factor in predicting miscibility in such set of compounds, whereas the dispersive and polar parameters had only a weak correlation. The results show that data mining approach is a valuable tool for predicting drug–excipient miscibility because it is easy to use, is time and cost-effective, and is material sparing.

  • 36.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    George, Sumod
    Basavoju, Srinivas
    Childs, S.L.
    Renovo Research, Atlanta, GA.
    Rizvi, S.A.A.
    College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Pharmaceutical cocrystals of nitrofurantoin: Screening, characterization and crystal structure analysis2012Inngår i: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 14, nr 15, s. 5078-5088Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The objective of this study was to screen and prepare cocrystals of the poorly soluble drug nitrofurantoin (NTF) with the aim of increasing its solubility. Screening for cocrystals of NTF using 47 coformers was performed by high-throughput (HT) screening using liquid assisted grinding (LAG) methods. Raman spectroscopy and powder X-ray diffraction (PXRD) were used as the primary analytical tools to identify the new crystalline solid forms. Manual LAG and reaction crystallization (RC) experiments were carried out to confirm and scale-up the hits. Seven hits were confirmed to be cocrystals. The cocrystals were characterized by PXRD, Raman and IR spectroscopy, thermal analysis (DSC and TGA) and liquid-state NMR or elemental analysis. The solution stability of the scaled-up cocrystals in water was tested by slurrying the cocrystals at 25 °C for one week. NTF forms cocrystals with a 1:1 stoichiometric ratio with urea (1), 4-hydroxybenzoic acid (2), nicotinamide (3), citric acid (4), l-proline (5) and vanillic acid (6). In addition, NTF forms a 1:2 cocrystal with vanillin (7). All but one of the NTF cocrystals transformed (dissociated) in water, resulting in NTF hydrate crystalline material or NTF hydrate plus the coformer, which indicates that the transforming cocrystals have a higher solubility than the NTF hydrate under these conditions. The crystal structures of 1:1 NTF-citric acid (4) and 1:2 NTF-vanillin (7) were solved by single-crystal X-ray diffraction. The crystal structures of these two cocrystals were analyzed in terms of their supramolecular synthons.

  • 37.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    George, Sumod
    Boström, Dan
    Department of Energy Technology and Thermal Process Chemistry, Umea University.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    1:1 and 2:1 urea-succinic acid cocrystals: structural diversity, solution chemistry, and thermodynamic stability2010Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 10, nr 11, s. 4847-4855Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this work was to study the crystal structures of 1:1 and 2:1 urea-succinic acid (U-SA) cocrystals and to investigate the role of solution chemistry in the formation and stability of different stoichiometric cocrystals. The structural diversity of other urea-dicarboxylic acid cocrystals is also discussed. The 1:1 U-SA cocrystal was stabilized by an acid-amide heterosynthon while acid-amide heterosynthons and amide-amide homosynthons stabilized the 2:1 cocrystals. The hydrogen bonding motifs in 1:1 and 2:1 U-SA cocrystals were consistent with other urea-dicarboxylic acid systems with similar stoichiometries. The 1:1 cocrystals were transformed to 2:1 cocrystals upon slurrying in various solvents at 25 °C. The phase solubility diagram was used to define the stability regions of different solid phases in 2-propanol at 25 °C. While no phase stability region for 1:1 cocrystal could be found, the stable regions for the 2:1 cocrystals and their pure components were defined by eutectic points. The solubility of the 2:1 cocrystals was dependent on the concentration of the ligand in the solution and explained by the solubility product and 1:1 solution complexation. The mathematical models predicting the solubility of the 2:1 cocrystals were evaluated and found to fit the experimental data

  • 38.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Kaialy, Waseem
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Buckton, Graham
    Department of Pharmaceutics, School of Pharmacy, University College London.
    Gill, Hardyal
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Nokhodchi, Ali
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Theophylline cocrystals prepared by spray drying: physicochemical properties and aerosolization performance2013Inngår i: AAPS PharmSciTech, ISSN 1530-9932, E-ISSN 1530-9932, Vol. 14, nr 1, s. 265-276Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and THF-SAC cocrystals were also used for comparison. The physical purity, particle size, particle morphology and surface energy of the materials were determined. The in vitro aerosol performance of the spray-dried cocrystals, drug-alone and a drug-carrier aerosol, was assessed. The spray-dried particles had different size distributions, morphologies and surface energies. The milled samples had higher surface energy than those prepared by spray drying. Good agreement was observed between multi-stage liquid impinger and next-generation impactor in terms of assessing spray-dried THF particles. The fine particle fractions of both formulations were similar for THF, but drug-alone formulations outperformed drug-carrier formulations for the THF cocrystals. The aerosolization performance of different THF cocrystals was within the following rank order as obtained from both drug-alone and drug-carrier formulations: THF-NIC > THF-URE > THF-SAC. It was proposed that micromeritic properties dominate over particle surface energy in terms of determining the aerosol performance of THF cocrystals. Spray drying could be a potential technique for preparing cocrystals with modified physical properties.

  • 39.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Roy, Lilly
    Department of Pharmaceutical Sciences, University of Michigan.
    Rodriguez-Hornedo, Nair
    Department of Pharmaceutical Sciences, University of Michigan.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    pH-dependent solubility of indomethacin-saccharin and carbamazepine-saccharin cocrystals in aqueous media2012Inngår i: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 9, nr 9, s. 2605-2612Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cocrystals constitute an important class of pharmaceutical solids for their remarkable ability to modulate solubility and pH dependence of water insoluble drugs. Here we show how cocrystals of indomethacin-saccharin (IND-SAC) and carbamazepine-saccharin (CBZ-SAC) enhance solubility and impart a pH-sensitivity different from that of the drugs. IND-SAC exhibited solubilities 13 to 65 times higher than IND at pH values of 1 to 3, whereas CBZ-SAC exhibited a 2 to 10 times higher solubility than CBZ dihydrate. Cocrystal solubility dependence on pH predicted from mathematical models using cocrystal K(sp), and cocrystal component K(a) values, was in excellent agreement with experimental measurements. The cocrystal solubility increase relative to drug was predicted to reach a limiting value for a cocrystal with two acidic components. This limiting value is determined by the ionization constants of cocrystal components. Eutectic constants are shown to be meaningful indicators of cocrystal solubility and its pH dependence. The two contributions to solubility, cocrystal lattice and solvation, were evaluated by thermal and solubility determinations. The results show that solvation is the main barrier for the aqueous solubility of these drugs and their cocrystals, which are orders of magnitude higher than their lattice barriers. Cocrystal increase in solubility is thus a result of decreasing the solvation barrier compared to that of the drug. This work demonstrates the favorable properties of cocrystals and strategies that facilitate their meaningful characterization.

  • 40.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Sokolowski, Anders
    Department of Pharmaceutical Chemistry, Uppsala University.
    Rodriguez-Hornedo, Nair
    Department of Pharmaceutical Sciences, University of Michigan.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Solubility behavior and solution chemistry of indomethacin cocrystals in organic solvents2011Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 11, nr 9, s. 3923-3929Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The main objective of this study was to investigate the solubility behavior and solution chemistry of indomethacin-saccharin (IND-SAC) cocrystals in organic media. We also evaluated previously proposed models of cocrystal solubility in organic solvents. In addition, the solubility behavior of IND-SAC cocrystals was compared with that of indomethacin-nicotinamide (IND-NIC) cocrystals using the eutectic constant approach. Phase solubility diagrams of IND-SAC cocrystals in various solvents were generated and the transition concentrations, at which drug and cocrystals are in equilibrium with the solvents, were determined. The solubility of IND-SAC cocrystals was explained by the solubility product and solution complexation. The tested models were found to fit the experimental data and to adequately explain the solubility behavior of the cocrystals. The solution complexation of IND and SAC is negligible in ethyl acetate and low in methanol and ethanol. The IND-NIC cocrystals were more soluble than the IND-SAC cocrystals in all the solvents studied. The eutectic constants predicted both the solubility and the stability of the cocrystals. Understanding the solubility behavior and solution chemistry of cocrystals has important implications for the screening, scale-up, and formulation development of this solid form. Further, the determination of eutectic constants is a simple and resource sparing means of obtaining key information on cocrystal stability and solution behavior

  • 41.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Formation of cocrystals by spray drying2010Inngår i: Journal of Pharmacy and Pharmacology (JPP), ISSN 0022-3573, E-ISSN 2042-7158, Vol. 62, nr 10 - Special issue, s. 1332-1333Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Spray drying is a widely used technique for material processing and scale-up. The cocrystals formation by spray drying is studied. In contrast to solvent evaporation method, spray drying of stiochiometric solutions of incongruently saturating cocrystals had generated pure cocrystals. The formation phenomena in spray drying could be kinetically controlled or mediated by glassy state.

  • 42.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Formation of cocrystals from stoichiometric solutions of incongruently saturating systems by spray drying2010Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 10, nr 8, s. 3302-3305Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spray drying is a well established technique for material processing and scale-up. This study investigated the formation of pharmaceutical cocrystals by spray drying. The cocrystal formation mechanisms in spray-drying and solution methods, based on triangular phase diagrams, are discussed. The solvent evaporation of stoichiometric solutions of incongruently saturating cocrystals resulted in a mixture of phases, as dictated by the thermodynamic phase diagram. In contrast, spray drying of similar solutions of incongruently saturating systems generated pure cocrystals. It is thus suggested that the formation of cocrystals by spray drying could be kinetically controlled and/or mediated by the glassy state of the material.

  • 43.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Vilinska, Annamaria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Gavini, Elisabetta
    University of Sassari.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Rassu, Giovanna
    University of Sassari.
    Surface thermodynamics of mucoadhesive dry powder formulation of zolmitriptan2011Inngår i: AAPS PharmSciTech, ISSN 1530-9932, E-ISSN 1530-9932, Vol. 12, nr 4, s. 1186-1192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Microparticle powders for nasal delivery were formulated to contain the model drug, zolmitriptan, and varying proportions of different polymers. The objective of the study was to investigate the effects of these formulative parameters on the surface chemistry of the spray-dried microparticles and their potential for adhesion to the tested substrates, porcine mucin, and nasal tissue. The polymers used were chitosans of varying ionization states and molecular weights and hydroxypropyl methyl cellulose. The surface energies of the surfaces of the microparticles were determined using contact angle measurements and the van Oss model. The theory of surface thermodynamics was applied to determine the theoretical potential for the different materials to adhere to the substrates. It was found that the drug or polymers alone, as well as the various formulations, were more likely to adhere to mucin than to nasal tissue. Further, there was a trend for higher molecular weight chitosans to adhere better to the substrates than lower molecular weight chitosans. Similarly, adhesion was improved for formulations with a higher content of polymers. These theoretical predictions may be compared with further experimental results and be of use in making informed decisions on the choice of formulations for future expensive bio-studies.

  • 44.
    AlHayali, Amani
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    In vitro-solubility and supersaturation behavior of supersaturating drug delivery systems2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The development of new pharmaceutical products has been challenged by the growing number of poorly water-soluble drugs, which often lead to suboptimal bioavailability. Various approaches, such as the use of amor-phous solid dispersions and cocrystals, have been used to improve the solu-bility, and subsequent bioavailability, of these drug molecules. Supersaturat-ing drug delivery systems (SDDSs) have potential for achieving adequate oral drug bioavailability by increasing the drug solubility and creating a su-persaturated state in the gastrointestinal tract. However, there is a need for better understanding of the supersaturation behavior in SDDSs and of the factors affecting supersaturation. The main objective of this thesis was to improve understanding of the supersaturation solubility behavior in SDDSs with a particular focus on rapidly dissolving solid forms (amorphous forms/cocrystals).

    In the course of the work, a new formulation for ezetimibe using an amorphous solid dispersion was prepared, cocrystals of tadalafil were pre-pared, and oral films of silodosin were formulated for the first time. These new formulations were thoroughly characterized using a number of solid-state and pharmaceutical characterization techniques.

    The dissolution and supersaturation behavior of the prepared SDDSs were studied. The effects of various factors on the supersaturation and precipita-tion characteristics were investigated. These factors included the preparation method, the temperature of the dissolution medium, the type of dissolution biorelevant medium (gastric/intestinal) used, the permeability of the relevant gastrointestinal membranes, the addition of polymers, and the addition of surfactants. The amorphous solid dispersions, cocrystals and oral films that were prepared represent new drug formulations that provide significantly higher dissolution rates and supersaturated solubility than crystalline drug forms. Solid dispersions prepared by the melting method had better super-saturation properties than those prepared by spray drying. The precipitation kinetics of the solid dispersion were faster at 37 ̊C than at 25 ̊C in bio-relevant media. Implementation of an absorption tool during in vitro evalua-tion of supersaturation levels could improve the prediction accuracy of su-persaturation and precipitation. A better understanding of the effects of ex-cipients on the supersaturation and precipitation behavior of these types of formulation was obtained in this thesis. The improvement in supersaturation solubility obtained by adding polymers and surfactants was not proportional to the amounts of excipient used.

    This thesis has made notable contributions to the field of pharmaceutical science by advancing our understanding of the supersaturation solubility behavior of the newly prepared SDDSs.

  • 45.
    Al-Hayali, Amani Ibraheem Younis
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Tavelin, Staffan
    Umeå university.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Dissolution and precipitation behavior of ternary solid dispersions of Ezetimibe in biorelevant media: AAPS annual meeting and Exposition2014 USA2014Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    PurposeTo prepare ternary solid dispersions of Ezetimibe (EZ) and investigate their powder dissolution and precipitation behavior(supersaturation) in simulated gastric and intestinal fluidsMethodsTernary solid dispersions of EZ were prepared with PVPK30 and Poloxamer 188 at different ratios. Spray drying and meltquenching methods were used for the preparation of these solid dispersions. The solid dispersions were characterized bybasic to advanced solid-state tools including Modulated differential scanning calorimetry (MDSC), Powder X-ray diffractionand Fourier transform infrared spectroscopy .Biorelevant simulated media (FaSSIF pH 6.5 and FaSSGF pH1.6) were used tostudy the supersaturating solubility of the ternary solid dispersions. HPLC was used to determine the drug concentrationsResultsTernary solid dispersions were successfully prepared by spray drying and melt quench methods. All prepared soliddispersions showed broadening of the XRD peaks indicating amorphous nature. MDSC analysis revealed disappearance ofthe melting peak of Ezetimibe indicating that molecular dispersion of the drug in polymer matrix. The solid dispersions withhigher PVPK30 content showed single Tg at 158.54 °C (spray drying) and 169.32 °C (melt quench). About 10 folds increasein the apparent solubility was observed for solid dispersions prepared by both methods. However, melt quenched soliddispersions had maintained the supersaturation solubility in FaSSIF longer than spray dried solid dispersions. Dissolutionstudies in FaSSGF are ongoingConclusionAmorphous ternary solid dispersions of Ezetimibe containing PVP K30 and Poloxamer 188 could be prepared by spraydrying and melt quenching methods. These solid dispersions showed improved solubility and prolonged supersaturation inbiorelevant media

  • 46.
    Al-Hayali, Amani Ibraheem Younis
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Tavellin, Staffan
    Departments of Pharmacology and Clinical Neuroscience, Umeå university.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Dissolution and precipitation behavior of ternary solid dispersions of ezetimibe in biorelevant media2017Inngår i: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 43, nr 1, s. 79-88Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effects of different formulations and processes on inducing and maintaining the supersaturation of ternary solid dispersions of ezetimibe (EZ) in two biorelevant media fasted-state simulated intestinal fluid (FaSSIF) and fasted-state simulated gastric fluid (FaSSGF) at different temperatures (25˚C and 37˚C) were investigated in this work. Ternary solid dispersions of EZ were prepared by adding polymer PVP-K30 and surfactant poloxamer 188 using melt-quenching and spray-drying methods. The resulting solid dispersions were characterized using scanning electron microscopy, differential scanning calorimetry, modulated differential scanning calorimetry, powder X-ray diffraction and Fourier transformation infrared spectroscopy. The dissolution of all the ternary solid dispersions was tested in vitro under non-sink conditions. All the prepared solid dispersions were amorphous in nature. In FaSSIF at 25˚C, the melt-quenched (MQ) solid dispersions of EZ were more soluble than the spray-dried solid (SD) dispersions and supersaturation was maintained. However, at 37˚C, rapid and variable precipitation behavior was observed for all the MQ and SD formulations. In FaSSGF, the melting method resulted in better solubility than the spray-drying method at both temperatures. Ternary solid dispersions show potential for improving solubility and supersaturation. However, powder dissolution experiments of these solid dispersions of EZ at 25˚C may not predict the supersaturation behavior at physiologically relevant temperatures.  

  • 47.
    AlHayali, Amani
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Selo, Mohammed Ali
    School of Pharmacy and Pharmaceutical Sciences and Trinity Biomedical Sciences Institute, Trinity College, Dublin. Faculty of Pharmacy, University of Kufa, Al-Najaf, Iraq.
    Ehrhardt, Carsten
    School of Pharmacy and Pharmaceutical Sciences and Trinity Biomedical Sciences Institute, Trinity College, Dublin.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Investigation of supersaturation and in vitro permeation of the poorly water soluble drug ezetimibe2018Inngår i: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 117, s. 147-153Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The interplay between supersaturation, precipitation and permeation characteristics of the poorly water-soluble drug ezetimibe (EZ) was investigated. Supersaturation and precipitation characteristics of EZ in the presence of Caco-2 cells were compared to those in a cell-free environment. The effect of the water-soluble polymer polyvinyl pyrrolidone (PVP-K30) on the supersaturation, precipitation and transport of EZ was also investigated and the amount of drug taken up by Caco-2 cells was quantified.

    A one-compartment setup without Caco-2 cells (i.e. in the wells of cell-culture plates) was used to mimic a non-sink in vitro dissolution chamber. The two-compartment Caco-2 cell monolayer setup (with apical and basolateral compartments) was used to investigate how the absorption of EZ affects supersaturation. EZ in varying degrees of supersaturation (DS; 10, 20, 30 and 40) was introduced into the one-compartment setup or the apical chamber of the two-compartment setup. Samples were collected at specific times to determine supersaturation, precipitation and permeation. At the end of the study, Caco-2 cells were lysed and the intracellular amount of EZ was quantified.

    In the one-compartment setup, a high DS was associated with rapid precipitation. Supersaturation was maintained for longer time periods and precipitation was lower in the presence of Caco-2 cells. There were no significant differences in the absorption rate of the drug, even at high concentrations on the apical side. Permeability coefficients for all supersaturated solutions (i.e. DS 10–40) were significantly (p < 0.05) different from those when EZ was present in crystalline form. Both concentrations of PVP-K30 (i.e. 0.05% and 0.1% w/v) improved solubility and supersaturation of EZ when added to the apical side, however, the increase in absorption at the higher concentration was not proportional. The amount of intracellular EZ increased with increasing DS in the apical side, until the saturation limit was reached in the cells (i.e. at DS 30 and higher).

    This study demonstrated that precipitation of EZ could be overestimated when supersaturation was investigated without the implementation of an absorption compartment in vitro, both in the absence and in the presence of polymer.

  • 48.
    Al-Hayali, Amani
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Selo, Mohammed Ali
    School of Pharmacy and Pharmaceutical Sciences , Trinity College Dublin .
    Ehrhardt, Carsten
    School of Pharmacy and Pharmaceutical Sciences , Trinity College Dublin .
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Investigation of supersaturation and permeation of a poorly water soluble drug Ezetimibe: Systems approaches to drug discovery, development and clinical usage2017Inngår i: Future Medicines For One World, 2017Konferansepaper (Fagfellevurdert)
  • 49.
    AlHayali, Amani
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap. College of Pharmacy, University of Mosul, Mosul, Iraq.
    Vuddanda, Parameswara Rao
    Research Centre for Topical Drug Delivery and Toxicology, Department of Clinical and Pharmaceutical Sciences, School of Life and Medical Sciences, University of Hertfordshire, UK.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Silodosin oral films: Development, physico-mechanical properties and in vitro dissolution studies in simulated saliva2019Inngår i: Journal of Drug Delivery Science and Technology, ISSN 1773-2247, Vol. 53, artikkel-id 101122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sublingual film dosage forms for drugs used for fast symptomatic treatment have promise because they allow a rapid onset of action. The aim of this study was to prepare films of silodosin intended for sublingual administration for the symptomatic treatment of benign prostatic hyperplasia in men. Hydroxypropyl methylcellulose (HPMC) or hydroxypropyl methylcellulose acetate succinate (HPMC-AS) were used as film-forming polymers. The effects of the polymers and the surfactant tocopherol polyethylene glycol succinate (TPGS) on the physico-mechanical properties and dissolution behavior of the films in simulated saliva were investigated. The eight silodosin oral films developed (F1–F8) contained 8 mg silodosin per 6 cm2 film and HPMC or HPMC-AS in drug:polymer ratios of 1:5 or 1:3, while four also contained TPGS (0.5% w/w). The films were characterized using DSC, TGA, SEM, and PXRD and the mechanical properties were investigated by measuring tensile strength, elongation at break and Young's modulus. The mechanical properties of the films were dependent on the ratio of polymer used. The in vitro dissolution and drug release studies indicated that HPMC-AS films disintegrated more quickly than HPMC films. Silodosin was shown to be dispersed within the polymers. Despite silodosin being submicronized in the HPMC films, the dissolution and drug release rate (time for 80% release) from HPMC films was significantly faster than from HPMC-AS films. TPGS increased the drug release rate to a greater extent with HPMC than with HPMC-AS. The degree of saturation of formulation F4 was >1, which shows potential for improving oral absorption of silodosin.

  • 50.
    Ali, Hassan
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Alhalaweh, Amjad
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Mendes, N.F.C.
    Ribeiro-Claro, Paulo
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Solid-state vibrational spectroscopic investigation of cocrystals and salt of indomethacin2012Inngår i: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 14, nr 20, s. 6665-6674Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Knowledge and control of the solid forms of active pharmaceutical ingredients are important aspects of drug development in the pharmaceutical industry. In this paper, the process of the molecular self-assembly of saccharin cocrystals and the 2-amino-5-methylpyridine salt of indomethacin, in terms of the hydrogen bonding patterns, has been studied in the solid-state using vibrational spectroscopy (Raman and infrared). Interaction patterns in the respective crystalline states were obtained from the single crystal data. The effects of cocrystal and salt formation on the frequencies of the vibrational modes of motion were explained by vibrational spectroscopy and supported by quantum chemical calculations at the density functional theory level, leading to unambiguous assignment of the vibrational spectra of the starting materials and their respective products. Both Raman and infrared spectroscopies were useful, reliable tools for characterizing and distinguishing the indomethacin cocrystals and salt.

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