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  • 1.
    Alhalaweh, Amjad
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Andersson, Staffan
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Preparation of Zolmitriptan-Chitosan microparticles by spray drying for nasal delivery2009In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 38, no 3, p. 206-214Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to use spray drying to prepare mucoadhesive dry powders of the antimigraine drug, zolmitriptan, in combination with the natural polymer, chitosan, for nasal administration. The effect of type, molecular weight, and proportion of chitosan on the powder and particle characteristics was also studied. Solutions containing different proportions of chitosans were prepared and spray dried. The chemical stability and content of the drug were determined by HPLC. The morphology and size range of the microparticles were also determined. Solid-state analysis was undertaken using thermal methods (DSC/MDSC and TGA), powder X-ray diffraction (PXRD), and Fourier transform infra-red spectroscopy (FT-IR). The drug release profiles were investigated and the time required to reach maximum solution concentrations (Tmax) was used for comparison. The drug was chemically stable, with a 93-105% loading in the microparticles. The microparticles were spherical with a narrow size distribution, irrespective of the formulation. Phase separation was observed for formulations containing less than 90% (w/w) chitosan, irrespective of the type. In contrast, in the formulation containing 90% (w/w) chitosan, the drug was molecularly dispersed. FT-IR studies showed that the bands corresponding to intermolecular hydrogen bonding were broader and more diffuse when zolmitriptan was amorphous. The formation of a hydrogen bond between drug and chitosans was also observed. Tmax increased as the proportion of chitosan decreased, and was proportional to the molecular weight of the chitosan in the formulation containing 90% (w/w) chitosan. Spray drying is a suitable technique for making mucoadhesive dry powders of zolmitriptan and chitosan for nasal application. The dispersion and release of the drug was affected by the properties and composition of the chitosan.

  • 2.
    AlHayali, Amani
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    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 University of Technology, Department of Health Sciences, Medical Science.
    Investigation of supersaturation and in vitro permeation of the poorly water soluble drug ezetimibe2018In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 117, p. 147-153Article in journal (Refereed)
    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.

  • 3.
    Catalan-Figueroa, Johanna
    et al.
    Department of Pharmaceutical Science and Technology, School of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile. Department of Biochemistry, School of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile. Centro de Nanotecnología Aplicada, Universidad Mayor, Santiago, Chile.
    Boisset, Constanza B
    Department of Pharmaceutical Science and Technology, School of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile.
    Jara, Miguel O
    Department of Pharmaceutical Science and Technology, School of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile.
    Flores, Mario E
    Instituto de Ciencias Químicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
    Moreno-Villoslada, Ignacio
    Instituto de Ciencias Químicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
    Fiedler, Jenny L
    Centro de Nanotecnología Aplicada, Universidad Mayor, Santiago, Chile.
    Morales, Javier O.
    Luleå University of Technology, Department of Health Sciences, Medical Science. Department of Pharmaceutical Science and Technology, School of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile. Advanced Center for Chronic Diseases (ACCDiS), Santiago, Chile.
    A mechanistic approach for the optimization of loperamide loaded nanocarriers characterization: Diafiltration and mathematical modeling advantages2018In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 125, p. 215-222Article in journal (Refereed)
    Abstract [en]

    Oral bioavailability of loperamide is restricted by its limited absorption in the gastrointestinal tract due to its poor aqueous solubility and its P-glycoprotein (Pgp) substrate characteristic. In addition, ammonium methacrylate copolymers have shown to have mucoadhesive properties, whereas poloxamer 188, has been suggested as a Pgp inhibitor. Thus, in this work, we evaluate conditions that affect physicochemical parameters of ammonium methacrylate/poloxamer 188-based nanocarriers loaded with loperamide hydrochloride. Nanocarriers were synthesized by nanoprecipitation, enhancing loperamide encapsulation efficiency by modifying the aqueous phase to basic pH. The isolation of the non-encapsulated drug fraction from the nanocarriers-incorporated fraction was conducted by centrifugation, ultrafiltration, vacuum filtration and diafiltration. The last method was effective in providing a deeper understanding of drug-nanocarrier loading and interactions by means of modeling the data obtained by it. Through diafiltration, it was determined an encapsulation efficiency of about 93%, from which a 38% ±6 was shown to be reversibly (thermodynamic interaction) and a 62% ±6 irreversibly (kinetic interaction) bound. Finally, release profiles were assessed through empirical and semi-empirical modeling, showing a biphasic release behavior (burst effect 11.34% and total release at 6 h = 33% ±1). Thus, encapsulation efficiency and release profile were shown to have a strong mathematical modeling-based correlation, providing the mechanistic approach presented in this article a solid support for future translational investigations.

  • 4.
    Padrela, Luis
    et al.
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Rodrigues, Miguel A.
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Matos, Henrique A.
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Azevedo, Edmundo Gomes de
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Formation of indomethacin-saccharin cocrystals using supercritical fluid technology2009In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 38, no 1, p. 9-17Article in journal (Refereed)
    Abstract [en]

    The main objective of the present work is to check the feasibility of supercritical fluid (SCF) technologies in the screening and design of cocrystals (novel crystalline solids). The cocrystal formation tendencies in three different SCF techniques, focusing on distinct supercritical fluid properties - solvent, anti-solvent and atomization enhancer - were investigated. The effect of processing parameters on the cocrystal formation behaviour and particle properties in these techniques was also studied.A recently reported Indomethacin-Saccharin (IND-SAC) cocrystalline system was our model system. A 1:1 molar ratio of indomethacin (γ-form) and saccharin was used as a starting material. The SCF techniques employed in the study include the CSS technique (Cocrystallization with Supercritical Solvent), the SAS technique (Supercritical Anti-Solvent), and the AAS technique (Atomization and Anti-Solvent). The resulting cocrystalline phase was identified using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier Transform-Raman (FT-Raman). The particle morphologies and size distributions were determined using scanning electron microscopy (SEM) and aerosizer, respectively.The pure IND-SAC cocrystals were obtained from SAS and AAS processes, while partial to no cocrystal formation occurred in the CSS process. However, no remarkable differences were observed in terms of cocrystal formation at different processing conditions in SAS and AAS processes. Particles from CSS processes were agglomerated and large, whilst needle-to-block-shaped and spherical particles were obtained from SAS and AAS processes, respectively. The particle size distribution of these particles was 0.2 μm to 5 μm.Particulate IND-SAC cocrystals with different morphologies and sizes (nano-to micron) were produced using supercritical fluid techniques. This work demonstrates the potential of SCF technologies as screening methods for cocrystals with possibilities for particle engineering.

  • 5.
    Rao Vuddanda, Parameswara
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Montenegro-Nicolini, Miguel
    Department of Pharmaceutical Sciences and Technology, University of Chile, Santiago.
    Morales, Javier O.
    Department of Pharmaceutical Sciences and Technology, University of Chile, Santiago.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Effect of plasticizers on the physico-mechanical properties of pullulan based pharmaceutical oral films2017In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 96, p. 290-298Article in journal (Refereed)
    Abstract [en]

    The effect of different plasticizers (glycerol, vitamin E TPGS and triacetin) and their concentrations on the physico-mechanical properties of pullulan based oral films was studied. A full factorial (32) design of experiments was used. Elastic modulus, tensile strength, elongation at break and disintegration time were selected as response variables. Modulated differential scanning calorimeter (MDSC) was used for determining glass transition temperature (Tg) of pullulan films. The surface morphology of films was evaluated by SEM, while ATR-FTIR was used to obtain a molecular level understanding of polymer-plasticizer interactions. The DoE analysis allowed for the modelling of tensile strength and elongation at break. The highest elongations were observed in glycerol at 20% w/w. Majority of the films disintegrated within one minute without significant differences. ATR-FTIR spectra of pullulan alone and different plasticizer blend films show characteristic molecular interactions. The present study concluded that glycerol is suitable plasticizer compared to others for manufacturing pullulan based oral films.

  • 6.
    Rao Vuddanda, Parameswara
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Montenegro-Nicolini, Miguel
    Department of Pharmaceutical Sciences and Technology, University of Chile.
    Morales, Javier O.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Effect of surfactants and drug load on physico-mechanical and dissolution properties of nanocrystalline tadalafil-loaded oral films2017In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 109, p. 372-380Article in journal (Refereed)
    Abstract [en]

    The aim of the present work was to prepare tadalafil (TDF) nanocrystals-loaded oral polymeric films (OFs) and investigate the effect of hydrophilic surfactants and drug loads on the physico-mechanical and dissolution properties. The nanosuspensions of TDF were prepared by high shear homogenization. HPMC based placebo casting film gel was prepared and mixed with TDF nanosuspensions. Films were casted using an automated film applicator and dried at 60 °C for 45 min. Particle size (PS), polydispersity index (PDI), and zeta potential (ZP) of TDF nanosuspensions were measured in a Zetasizer. The films were characterized using SEM, AFM, DSC, TGA and PXRD. The mechanical properties and in vitro drug release were determined using standard methods. TDF existed in crystalline form and the particles remained in the nano-range in redispersed films. TDF nanocrystals were embedded in the polymeric matrix and the drug loaded films were rough on the surface. Mechanical properties of the films varied with changes in drug load and surfactant. Significant changes in the disintegration times were noticed in films containing surfactants compared to surfactant-free films. About 80% of the drug release was observed between 3 and 30 min. TPGS showed better TDF release from the films at different drug loads

  • 7. Velaga, Sitaram
    et al.
    Bergh, Stefan
    Uppsala university, Department of Pharmacy.
    Carlfors, Johan
    Uppsala university, Department of Pharmacy.
    Stability and aerodynamic behaviour of glucocorticoid particles prepared by a supercritical fluids process2004In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 21, no 4, p. 501-9Article in journal (Refereed)
    Abstract [en]

    Particle processing techniques using supercritical fluids (SF) are potential alternative technologies to design particles for inhalation. Powders of budesonide and flunisolide were prepared using solution enhanced dispersion by supercritical fluids (SEDS) process. The aim was to determine thermodynamic stability of different polymorphs of flunisolide including new forms from SEDS technology and to characterise micronisedand SEDS produced powders of budesonide and flunisolide for their suitability as inhalation powders. Acetone and methanol solutions of budesonide and flunisolide, with a concentration of 2.5 mg/ml, were used for the particle preparation. The pressure was 100 bar and temperatures were 60 degrees C or 80 degrees C. The flow rates of CO(2) and drug solution were 9 ml/min and 0.3 ml/min, respectively. Chemical purity of different polymorphs of flunisolide was estimated using high performance liquid chromatography (HPLC) and thermal behaviour was determined using differential scanning calorimetry (DSC). Particle morphology and surface examination were performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The particle size distribution and density of the powders were determined with the help of Coulter Counter and helium pycnometer respectively. The in vitro deposition of the powders was studied using multistage liquid impinger (MLI). From the stability study, it was found that the two forms of flunisolide, polymorphs II and hemihydrate, were the most stable. Flunisolide form III was transformed to hemihydrate during the stability study. The chemical purity of the material was increased after SEDS processing. SEDS produced powders of budesonide and flunisolide form III from acetone showed narrow volumetric particle size distributions with 90% of the particles below 4 microm and geometric mean size around 3 microm.However, in the MLI study, budesonide powder obtained from SEDS with acetone showed favorable deposition in the lower stages with a mass median aerodynamic diameter (MMAD) of around 3 microm whilst the flunisolide form III was preferentially deposited in the higher stages of the MLI with MMAD of over 5 microm, due to aggregation of the particles. Particles of budesonide and flunisolide, in the size range, suitable for inhalation, were reproducibly produced using SEDS.

  • 8.
    Velaga, Sitaram
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Djuris, Jelena
    Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy.
    Cvijic, Sandra
    Department of Pharmaceutical Technology and Cosmetology, University of Belgrade-Faculty of Pharmacy.
    Rozou, Stavroula
    Elpen Pharmaceutical Co..
    Russo, Paola
    Department of Pharmacy, University of Salerno.
    Colombo, Gaia
    Department of Life Sciences and Biotechnology, University of Ferrara.
    Rossi, Alessandra
    Food and Drug Department, University of Parma.
    Dry powder inhalers: An overview of the in vitro dissolution methodologies and their correlation with the biopharmaceutical aspects of the drug products2018In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 113, p. 18-28Article in journal (Refereed)
    Abstract [en]

    In vitro dissolution testing is routinely used in the development of pharmaceutical products. Whilst the dissolution testing methods are well established and standardized for oral dosage forms, i.e. tablets and capsules, there are no pharmacopoeia methods or regulatory requirements for testing the dissolution of orally inhaled powders. Despite this, a wide variety of dissolution testing methods for orally inhaled powders has been developed and their bio-relevance has been evaluated.

    The review provides an overview of the in vitro dissolution methodologies for dry inhalation products, with particular emphasis on dry powder inhaler, where the dissolution behavior of the respirable particles can have a role on duration and absorption of the drug. Dissolution mechanisms of respirable particles as well as kinetic models have been presented. A more recent bio-relevant dissolution set-ups and media for studying inhalation biopharmaceutics were also reviewed. In addition, factors affecting interplay between dissolution and absorption of deposited particles in the context of biopharmaceutical considerations of inhalation products were examined.

  • 9.
    Vuddanda, Parameswara Rao
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science. Department of Pharmaceutics, UCL School of Pharmacy, University College London, London, United Kingdom.
    Alomari, Mustafa
    Department of Pharmaceutics, UCL School of Pharmacy, University College London.
    Dodoo, Cornelius C.
    Department of Pharmaceutics, UCL School of Pharmacy, University College London.
    Trenfield, Sarah J.
    Department of Pharmaceutics, UCL School of Pharmacy, University College London.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Basit, Abdul W.
    Department of Pharmaceutics, UCL School of Pharmacy, University College London.
    Gaisford, Simon
    Department of Pharmaceutics, UCL School of Pharmacy, University College London.
    Personalisation of warfarin therapy using thermal ink-jet printing2018In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 117, p. 80-87Article in journal (Refereed)
    Abstract [en]

    Warfarin is a widely used anticoagulant that is critical in reducing patient morbidity and mortality associated with thromboembolic disorders. However, its narrow therapeutic index and large inter-individual variability can lead to complex dosage regimes. Formulating warfarin as an orodispersible film (ODF) using thermal ink-jet (TIJ) printing could enable personalisation of therapy to simplify administration. Commercial TIJ printers are currently unsuitable for printing the milligram dosages, typically required for warfarin therapy. As such, this study aimed to modify a commercial TIJ printing system to formulate personalised warfarin ODFs containing therapeutic dosages. A TIJ printer was modified successfully with the printer functionality intact; the substrate (paper) rolling mechanism of the printer was replaced by printing onto a stationary stage. Free film substrates were composed of hydroxypropyl methylcellulose (20%w/w) and glycerol (3%w/w). The resulting ODFs were characterised for morphology, disintegration, solid-state properties and drug content. Printed film stability was assessed at 40 °C/75% relative humidity for 30 days. Therapeutic warfarin doses (1.25 and 2.5 mg) were successfully printed onto the film substrates. Excellent linearity was observed between the theoretical and measured dose by changing the warfarin feed concentration (R2 = 0.9999) and length of the print objective, i.e. the Y-value, (R2 = 0.9998). Rapid disintegration of the ODFs was achieved. As such, this study successfully formulated personalised warfarin ODFs using a modified TIJ printer, widening the range of applications for TIJ printing to formulate narrow therapeutic index drugs.

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