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No revestimento por solidificação de material fundido o agente de revestimento é aplicado em seu estado liquefeito e se solidifica na superfície do substrato, formando a cobertura desejada, eliminando o uso de solventes. O presente trabalho teve como objetivo estudar dois tipos de processo: revestimento de partículas grandes em leito de jorro e revestimento de partículas finas em leito fluidizado, e avaliar a influência de parâmetros do processo sobre propriedades físicas e farmacotécnicas das partículas revestidas, assim como usá-las no preparo de comprimidos. As partículas grandes foram revestidas com PEG 4000, sendo o estudo do processo feito através de um planejamento fatorial completo 23 com triplicatas no ponto central. As variáveis estudadas foram pressão do ar de atomização, vazão de atomização e altura do bico de atomização. Para as partículas revestidas foram determinados a distribuição granulométrica, o fator de Hausner e o índice de Carr. Os comprimidos destas partículas foram submetidos a ensaios de dissolução in vitro, para avaliação dos perfis de liberação de paracetamol. As partículas finas foram revestidas com uma dispersão sólida de PEG 4000 e curcumina, sendo o estudo do processo feito através de um planejamento fatorial completo 23, seguido de um planejamento Box-Behnken. As variáveis estudadas foram pressão do ar de atomização, vazão de atomização e quantidade de dispersão sólida. Para as partículas revestidas foram determinados a distribuição granulométrica, densidades aparente e compactada, fator de Hausner, capacidade de compactação, porosidade total, além de serem submetidas a microscopia eletrônica de varredura e a análise por DSC. A dispersão sólida também foi caracterizada através de análise por DSC, espectroscopia no infravermelho, difração de raios X, sendo também feita a determinação da solubilidade da curcumina em água. Os comprimidos destas partículas foram caracterizados através da obtenção do diagrama de Heckel, curvas de dureza em função da pressão de compressão aplicada e ensaio de dissolução in vitro. Para as partículas grandes, o estudo do processo sugeriu que a vazão de atomização foi o fator de maior influência sobre o tamanho das partículas, influenciando o grau de aglomeração durante o processo. Uma menor vazão de atomização resultou em um menor grau de aglomeração das partículas. A caracterização da dispersão sólida mostrou que houve um aumento da solubilidade da curcumina e que ela interage com PEG 4000. Para as partículas finas, o estudo do processo sugeriu que a pressão do ar de atomização foi fator de maior influência sobre o tamanho das partículas, sendo o seu revestimento favorecido quando se operou com o altos valores de pressão. Ambos os tipos de partículas revestidas resultaram em comprimidos com características adequadas. / The hot-melting coating is a solvent-free technique used to coat pharmaceutical solid dosage forms. The coating agent is applied in its melted state, and after its solidification, the coating is formed. The objective of this present work was to study two types of processes: coarse particle coating in spouted bed and fine particle coating in fluidized bed, evaluate the influence of process parameters on particle size and flow properties, as well as their tableting. Coarse particles were coated with PEG 4000, and the process study followed a full factorial design 23 with triplicates in the central point. The factors studied were atomization air pressure, atomization rate, and vertical position of the spray nozzle. Particle size distribution, Hausner factor and Carr index were determined for coated particles. Tablets of these particles were submitted to dissolution tests to obtain their release profile of paracetamol. Fine particles were coated with a solid dispersion of PEG 4000 and curcumin, in a study of the process that followed a full factorial design 23, and a Box-Behnken design. The factors studied were air atomization pressure, atomization rate, and the PEG 4000 content. Coated particles were characterized by their bulk and tapped densities, particle size distribution, Hausner factor, ability to settle, total porosity, scanning electron microscopy and DSC analysis. Solid dispersion was also characterized by DSC analysis, infrared spectroscopy, X-ray diffraction, being also made the determination of the curcumin solubility in water. Heckel´s plot, hardness as function of the applied pressure and in vitro dissolution tests were used to characterize the tablets. The study of the coating process of coarse particles suggested that the atomization rate was the most significant factor, influencing the particle agglomeration degree during the process. The lower the atomization rate, the lower the degree of particles agglomeration. Curcumin in the solid dispersion showed an increase in water solubility and also showed an interaction with PEG 4000 by hydrogen bounding. The study of the fine particles coating process showed that the atomization air pressure was the most significant factor on particle size. All tablets prepared from both types of coated particles showed adequate characteristics.

No revestimento por solidificação de material fundido o agente de revestimento é aplicado em seu estado liquefeito e se solidifica na superfície do substrato, formando a cobertura desejada, eliminando o uso de solventes. O presente trabalho teve como objetivo estudar dois tipos de processo: revestimento de partículas grandes em leito de jorro e revestimento de partículas finas em leito fluidizado, e avaliar a influência de parâmetros do processo sobre propriedades físicas e farmacotécnicas das partículas revestidas, assim como usá-las no preparo de comprimidos. As partículas grandes foram revestidas com PEG 4000, sendo o estudo do processo feito através de um planejamento fatorial completo 23 com triplicatas no ponto central. As variáveis estudadas foram pressão do ar de atomização, vazão de atomização e altura do bico de atomização. Para as partículas revestidas foram determinados a distribuição granulométrica, o fator de Hausner e o índice de Carr. Os comprimidos destas partículas foram submetidos a ensaios de dissolução in vitro, para avaliação dos perfis de liberação de paracetamol. As partículas finas foram revestidas com uma dispersão sólida de PEG 4000 e curcumina, sendo o estudo do processo feito através de um planejamento fatorial completo 23, seguido de um planejamento Box-Behnken. As variáveis estudadas foram pressão do ar de atomização, vazão de atomização e quantidade de dispersão sólida. Para as partículas revestidas foram determinados a distribuição granulométrica, densidades aparente e compactada, fator de Hausner, capacidade de compactação, porosidade total, além de serem submetidas a microscopia eletrônica de varredura e a análise por DSC. A dispersão sólida também foi caracterizada através de análise por DSC, espectroscopia no infravermelho, difração de raios X, sendo também feita a determinação da solubilidade da curcumina em água. Os comprimidos destas partículas foram caracterizados através da obtenção do diagrama de Heckel, curvas de dureza em função da pressão de compressão aplicada e ensaio de dissolução in vitro. Para as partículas grandes, o estudo do processo sugeriu que a vazão de atomização foi o fator de maior influência sobre o tamanho das partículas, influenciando o grau de aglomeração durante o processo. Uma menor vazão de atomização resultou em um menor grau de aglomeração das partículas. A caracterização da dispersão sólida mostrou que houve um aumento da solubilidade da curcumina e que ela interage com PEG 4000. Para as partículas finas, o estudo do processo sugeriu que a pressão do ar de atomização foi fator de maior influência sobre o tamanho das partículas, sendo o seu revestimento favorecido quando se operou com o altos valores de pressão. Ambos os tipos de partículas revestidas resultaram em comprimidos com características adequadas. / The hot-melting coating is a solvent-free technique used to coat pharmaceutical solid dosage forms. The coating agent is applied in its melted state, and after its solidification, the coating is formed. The objective of this present work was to study two types of processes: coarse particle coating in spouted bed and fine particle coating in fluidized bed, evaluate the influence of process parameters on particle size and flow properties, as well as their tableting. Coarse particles were coated with PEG 4000, and the process study followed a full factorial design 23 with triplicates in the central point. The factors studied were atomization air pressure, atomization rate, and vertical position of the spray nozzle. Particle size distribution, Hausner factor and Carr index were determined for coated particles. Tablets of these particles were submitted to dissolution tests to obtain their release profile of paracetamol. Fine particles were coated with a solid dispersion of PEG 4000 and curcumin, in a study of the process that followed a full factorial design 23, and a Box-Behnken design. The factors studied were air atomization pressure, atomization rate, and the PEG 4000 content. Coated particles were characterized by their bulk and tapped densities, particle size distribution, Hausner factor, ability to settle, total porosity, scanning electron microscopy and DSC analysis. Solid dispersion was also characterized by DSC analysis, infrared spectroscopy, X-ray diffraction, being also made the determination of the curcumin solubility in water. Heckel´s plot, hardness as function of the applied pressure and in vitro dissolution tests were used to characterize the tablets. The study of the coating process of coarse particles suggested that the atomization rate was the most significant factor, influencing the particle agglomeration degree during the process. The lower the atomization rate, the lower the degree of particles agglomeration. Curcumin in the solid dispersion showed an increase in water solubility and also showed an interaction with PEG 4000 by hydrogen bounding. The study of the fine particles coating process showed that the atomization air pressure was the most significant factor on particle size. All tablets prepared from both types of coated particles showed adequate characteristics.

Thesis (M. Pharm. (Pharmaceutics)) -- University of Limpopo, 2019 / Various approaches have been developed to retain dosage forms in the gastrointestinal tract. One of the commonly used approaches is the use of microspheres. Due to their intrinsic low density and small size, they are distributed throughout the gastrointestinal tract which improves drug absorption thus improving bioavailability. Ranitidine hydrochloride, an antiulcer drug is poorly absorbed from the lower gastrointestinal tract and has a short half-life of 2.5-3 hours. The aim of this study was to formulate and evaluate gastroretentive microspheres of ranitidine hydrochloride in order to extend gastric retention in the upper gastrointestinal tract, which may result in enhanced absorption and thus improved bioavailability. Pre-formulation studies were conducted to develop and validate the analytical method to identify and quantify ranitidine hydrochloride; to select the suitable polymers for further formulation development and; to determine the compatibility of the chosen polymers with ranitidine hydrochloride. The analytical method was validated and found to be sensitive, linear, precise and accurate. Preliminary formulations lead to the selection of ethyl cellulose and PEG 4000 as polymers and solvent evaporation as the method of manufacture. Compatibility studies were determined by DSC/TGA, FTIR and short-term accelerated studies and no incompatibilities were observed. Two prototype formulations of the preliminary formulations F24 and F26 were manufactured comprised of varying drug: polymer concentration. The microspheres were evaluated for morphology, particle size, flow properties, percentage yield, buoyancy and in vitro drug release. Both formulations resulted in spherical microspheres with good flow properties, high yield and buoyancy studies revealed that the microspheres would float immediately upon contact with the dissolution media and floating would continue for more than 8 hours. In vitro drug release studies revealed that polymer concentration greatly affected drug release. Dissolution kinetic studies revealed that formulation F24 and v F26 were best described by the Korsmeyer-Peppas and Higuchi kinetic models respectively. Formulation F26 was considered the best formulation, which comprised of a drug: PEG 4000 ratio of 1:2 w/w, as it yielded better in better drug encapsulation, better buoyancy results and had complete drug release.

Yes / Several contributions in answering granulation challenges including the use of computer simulation and well thought out experimental analyses are being researched. Using a twin screw granulator (TSG) by design of experiments (DoE), comparisons on 1) equipment similarities i.e., continuous and 2) shear forces, are made to previous literature on continuous equipment and a Cyclomix. This study proposes that equipment specific DoE, better explains the contribution of parameters than investigating an identified parameter from the experimental findings from a specific equipment. Granule strength and structure are presented together with the contribution of process parameters, speed, temperature, and binder content. Seeded structures are present in all but the Extrudomix. Longer residence times within the Cyclomix facilitates seeded structures. Granule crushing strengths are higher in TSG than all other continuous equipment. Optimum condition for the formation of stronger granules with least variation is around 65.4 °C. / The authors would like to acknowledge the support from the CCIP grant (Collaboration, Capacity and IP Development) fund from the University of Bradford for ordering cunsumables and equipment.