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  • 1.
    Ahmed, Hamzah
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Shimpi, Manishkumar R.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Velaga, Sitaram P.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Relationship between mechanical properties and crystal structure in cocrystals and salt of paracetamol2017In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 43, no 1, p. 89-97Article in journal (Refereed)
    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.

  • 2.
    Alhalaweh, Amjad
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Alzghoul, Ahmad
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    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 miscibility2014In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 40, no 7, p. 904-909Article in journal (Refereed)
    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.

  • 3.
    Al-Hayali, Amani Ibraheem Younis
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Tavellin, Staffan
    Departments of Pharmacology and Clinical Neuroscience, Umeå university.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Dissolution and precipitation behavior of ternary solid dispersions of ezetimibe in biorelevant media2017In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 43, no 1, p. 79-88Article in journal (Refereed)
    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.  

  • 4.
    Ali, Hassan
    et al.
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Alhalaweh, Amjad
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Vibrational spectroscopic investigation of polymorphs and cocrystals of indomethacin2013In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 39, no 5, p. 625-634Article in journal (Refereed)
    Abstract [en]

    Context:Identification of optimal solid form of an active pharmaceutical ingredient and form control are very important in drug development. Thus, the structural information of these forms and in-depth insight on the modes of molecular interactions are necessary, and vibrational spectroscopic methods are well suited for this purpose.Objective:In-depth structural analysis of different solid forms of indomethacin (IND) using Raman and infrared (IR) spectroscopy is the objective. We have investigated the modes of molecular interactions in polymorphs (α and γ), amorphous and discovered cocrystals of IND with nicotinamide (NIC) and trans-cinnamic acid (CIN) coformers.Materials and methods: The solid forms of IND have been prepared; their purity has been verified by differential scanning calorimetry and powder X-ray diffractometry and then studied in the solid-state by Raman and IR spectroscopy. The modes of the interactions were closely investigated from the vibrational data.Results: The key vibrational features of IND solid forms have been specified. The IR (C=O) band at 1713 cm−1 attributed to cyclic acid dimer of γ IND has disappeared in IND–NIC/CIN whilst retained in IND–SAC cocrystal.Discussion:IND cocrystallizes in different conformations and crystal lattices with different coformers. The cyclic acid dimer of IND has been kept on its cocrystallization with saccharin and it could have been broken with NIC and CIN.Conclusions: The complementary nature of Raman and IR spectroscopy allowed unambiguous investigation of the chemical composition of pharmaceutical materials which is of particular importance in the absence of detailed structural information, as in the case of IND–NIC and IND–CIN.

  • 5.
    Morales, Javier O.
    Department of Pharmaceutical Science and Technology School of Chemical and Pharmaceutical Sciences University of Chile.
    Remington: Essentials of Pharmaceutics. By Linda Felton,Pharmaceutical Press, Gurnee, IL, 2013, 784 pages, ISBN:97808571110502015In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 41, no 4, p. 529-Article, book review (Other academic)
  • 6.
    Morales, Javier O.
    et al.
    College of Pharmacy, University of Texas at Austin .
    Joks, Gero M
    bPharmazeutischeTechnologie, Pharmazeutisches Institut der Universität Bonn.
    Lamprecht, Alf
    bPharmazeutischeTechnologie, Pharmazeutisches Institut der Universität Bonn.
    Ross, Alistair C
    Controlled Therapeutics (Scotland) Ltd.
    McConville, Jason T
    College of Pharmacy, University of Texas at Austin.
    A design of experiments to optimize a new manufacturing process for high activity protein-containing submicron particles2013In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 39, no 11, p. 1793-1801Article in journal (Refereed)
    Abstract [en]

    A novel method for the manufacture of protein/peptide-containing submicron particles was developed in an attempt to provide particles with increased activity while using high energy input technologies. The method consists of antisolvent co-precipitation from an aqueous solution containing both an amino acid core material (e.g. D,L-valine), and either bovine serum albumin (BSA) or lysozyme (Lys) as model proteins. The aqueous solution was added to the organic phase by means of a nebulizer to increase the total surface area of interaction for the precipitation process. Sonication proved to be an effective method to produce small particle sizes while maintaining high activity of Lys. The use of a polysorbate or sorbitan ester derivatives as stabilizers proved to be necessary to yield submicron particles. Particles with very high yields (approximately 100%) and very high activity after manufacture (approximately 100%) could be obtained. A particle size of 439.0 nm, with a yield of 48.8% and with final remaining activity of 98.7% was obtained. By studying various factors using a design of experiments strategy (DoE) we were able to establish the critical controlling factors for this new method of manufacture.

  • 7.
    Morales, Javier O.
    et al.
    Department of Pharmaceutical Science and Technology, School of Chemical and Pharmaceutical Sciences, University of Chile.
    McConville, Jason T
    College of Pharmacy, University of New Mexico, Albuquerque, NM.
    Novel strategies for the buccal delivery of macromolecules2014In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 40, no 5, p. 579-590Article in journal (Refereed)
    Abstract [en]

    For years now, the delivery of small molecules through the buccal mucosal route has been described in the literature, but it has only been over the past decade that investigations into macromolecule delivery via the buccal route have sharply increased. The administration of macromolecules such as proteins and peptides, antibodies, or nucleic acids by buccal administration would be greatly enhanced due to the avoidance of the gastrointestinal conditions, rapid uptake into systemic circulation, as well as the potential for controlled drug delivery. Since macromolecules are faced with a number of specific challenges related to permeation through the epithelium, several strategies have been employed historically to improve their buccal absorption and subsequent bioavailability. Several conventional strategies to improve macromolecule penetration include the use of chemical permeation enhancers, enzyme inhibitors and the use of mucoadhesive materials acting as carriers. More recent approaches include the incorporation of the macromolecule as part of nanostructured delivery systems to further enhance targeting and delivery. This review focuses on the different permeation enhancing strategies as well as formulation design that are tailored to meet the challenges of active macromolecule delivery using the buccal mucosal route of administration.

  • 8.
    Morales, Javier O.
    et al.
    Department of Pharmaceutical Sciences and Technology, University of Chile.
    McConville, Jason T
    College of Pharmacy, University of New Mexico, Albuquerque, NM.
    Preface for buccal drug delivery theme issue2014In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 40, no 5, p. 577-578Article in journal (Refereed)
    Abstract [en]

    During the past years, buccal drug delivery has attracted the attention of researchers looking for alternative delivery routes of administration. As an alternative to oral drug delivery, the buccal mucosal route avoids the passage through the acidic gastric environment, intestinal and bacterial enzymatic activity, absorption issues associated with the intestinal epithelium (e.g. P-glycoprotein efflux), and the first pass metabolism of the liver. Therefore, the buccal route could be a good delivery route for macromolecules and other drugs not compatible with the gastrointestinal tract environment. This "Buccal Drug Delivery" special edition of Drug Development and Industrial Pharmacy aims to bring together a range of different aspects relevant to the growing field of buccal drug delivery. The special edition includes thorough reviews of the literature, as well as original research articles touching on most prominent features related to buccal drug delivery systems, such as the move toward the use of nanotechnology in different ways to facilitate buccal drug delivery with the potential to prompt future product developments.

  • 9.
    Padrela, Luis
    et al.
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Azevedo, Edmundo Gomes de
    Department of Chemical and Biological Engineering, Instituto Superior Técnico, Lisboa.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Powder X-ray diffraction method for the quantification of cocrystals in the crystallization mixture2012In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 38, no 8, p. 923-929Article in journal (Refereed)
    Abstract [en]

    Context: The solid state purity of cocrystals critically affects their performance. Thus, it is important to accurately quantify the purity of cocrystals in the final crystallization product.Objective: The aim of this study was to develop a powder X-ray diffraction (PXRD) quantification method for investigating the purity of cocrystals. The method developed was employed to study the formation of indomethacin-saccharin (IND-SAC) cocrystals by mechanochemical methods.Materials and methods: Pure IND-SAC cocrystals were geometrically mixed with 1:1 w/w mixture of indomethacin/saccharin in various proportions. An accurately measured amount (550 mg) of the mixture was used for the PXRD measurements. The most intense, non-overlapping, characteristic diffraction peak of IND-SAC was used to construct the calibration curve in the range 0–100% (w/w). This calibration model was validated and used to monitor the formation of IND-SAC cocrystals by liquid-assisted grinding (LAG).Results: The IND-SAC cocrystal calibration curve showed excellent linearity (R2 = 0.9996) over the entire concentration range, displaying limit of detection (LOD) and limit of quantification (LOQ) values of 1.23% (w/w) and 3.74% (w/w), respectively. Validation results showed excellent correlations between actual and predicted concentrations of IND-SAC cocrystals (R2 = 0.9981).Discussion: The accuracy and reliability of the PXRD quantification method depend on the methods of sample preparation and handling. The crystallinity of the IND-SAC cocrystals was higher when larger amounts of methanol were used in the LAG method.Conclusion: The PXRD quantification method is suitable and reliable for verifying the purity of cocrystals in the final crystallization product.

  • 10. Velaga, Sitaram
    et al.
    Carlfors, Johan
    Uppsala university, Department of Pharmacy.
    Supercritical Fluids Processing of Recombinant Human Growth Hormone2005In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 31, no 2, p. 135-49Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to investigate the feasibility of precipitating recombinant human growth hormone (hGH) from aqueous solutions using conventional and modified techniques of solution-enhanced dispersion (SEDS) by supercritical fluids. The study investigated the effect on hGH stability of adding isopropanol either as a cosolvent with the original aqueous protein solution (conventional process) or to the supercritical carbon dioxide before mixing with the aqueous protein solution (modified process). The influence of the addition of sucrose (with or without isopropanol) on the precipitation behavior and stability of the protein was also studied. Experiments were performed under various processing conditions (pressure 100-200 bars and temperature 40-50°C), and with various flow rates and solution compositions (CO2/isopropanol and protein solution). Bioanalytical characterization of the resulting powders involved spectrophotometry, sodium dodecyl sulfate-polycrylamide gel electrophoresis, reverse-phase high performance liquid chromatography (RP-HPLC), and size exclusion chromatography. Solid-state characterization was performed using differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, and Karl Fischer techniques. Results showed that with both conventional and modified methods, under optimum processing conditions, the presence of sucrose in the solution decreased the destabilizing effects of the solvent and/or process on the structure of hGH. More hGH was dissolved from the precipitated powders containing sucrose than from those containing only isopropanol. Reverse-phase HPLC indicated that about 94% of the hGH was recovered in its native form. The proportion of dimers and oligomers was reduced in the presence of sucrose; about 92% of the soluble protein was present in monomer form under optimal conditions. The remaining undissolved protein was in monomeric form. The precipitated powders were amorphous, containing particulate aggregates in the size range 1-6 µm with 5-10% residual moisture content. In conclusion, hGH was successfully precipitated from aqueous solution using SEDS technology. The presence of sucrose in the protein solution promoted the precipitation of hGH and reduced aggregation and improved dissolution

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