Birendra Srivastava

Spherical crystallization: A technique use to reform solubility and flow property of active pharmaceutical ingredients

Tablets have been choice of manufacturers over the years due to their comparatively low cost of manufacturing, packaging, shipping, and ease of administration; also have better stability and can be considered virtually tamper proof. A major challenge in formulation development of the tablets extends from lower solubility of the active agent to the elaborated manufacturing procedures for obtaining a compressible granular material. Moreover, the validation and documentation increases, as the numbers of steps increases for an industrially acceptable granulation process. Spherical crystallization (SC) is a promising technique, which encompass the crystallization, agglomeration, and spheronization phenomenon in a single step. Initially, two methods, spherical agglomeration, and emulsion solvent diffusion, were suggested to get a desired result. Later on, the introduction of modified methods such as crystallo-co-agglomeration, ammonia diffusion system, and neutralization techniques overcame the limitations of the older techniques. Under controlled conditions such as solvent composition, mixing rate and temperature, spherical dense agglomerates cluster from particles. Application of the SC technique includes production of compacted spherical particles of drug having improved uniformity in shape and size of particles, good bulk density, better flow properties as well as better solubility so SC when used on commercial scale will bring down the production costs of pharmaceutical tablet and will increase revenue for the pharmaceutical industries in the competitive market. This review summarizes the technologies available for SC and also suggests the parameters for evaluation of a viable product.

Extended release promethazine HCl using acrylic polymers by freeze-drying and spray-drying techniques: formulation considerations

O presente trabalho compreendeu estudo de um novo sistema de liberacao prolongada de cloridrato de prometazina (PHC) com polimeros acrilicos Eudragit RL100 e Eudragit S100 em diferentes proporcoes em massa (1:1 e 1:5) e em combinacao (0,5+1,5), utilizando tecnicas de liofilizacao e de secagem por aspersao As dispersoes solidas foram caracterizadas por espectrofotometria no infravermelho por transformada de Fourier (FT-IR), calorimetria diferencial de varredura (DSC), difratometria de raios X (PXRD), Ressonância Magnetica Nuclear (RMN), microscopia eletronica de varredura (SEM) e, tambem, por estudos de solubilidade e de dissolucao in vitro em HCl 0,1 N (pH 1,2), agua bidestilada e tampao fosfato (pH 7,4). Realizaram-se, tambem, testes de adsorcao da solucao do farmaco nos polimeros solidos. Desenvolveu-se sistema de dispersao solida exclusiva dentro das capsulas, que foi avaliado por meio de estudos de dissolucao in vitro. Relacionou-se o desaparecimento progressivo de picos do farmaco em perfis termotropicos de dispersoes secas por spray a quantidade aumentada de polimero, enquanto os estudos de SEM sugeriram dispersao homogenea do farmaco no polimero. O Eudragit RL100 apresentou maior capacidade de adsorcao do que o Eudragit S100 e, dessa forma, a combinacao de (0,5+1,5) para S100 e para RL100 mostrou taxa de dissolucao maior, com liberacao de 94,17% de farmaco em 12 horas. Entre as varias formulacoes, as capsulas preparadas pela combinacao de polimeros acrilicos utilizando secagem por aspersao (0,5+1,5) apresentou liberacao prolongada do farmaco em 12 horas, com 96,78% de liberacao, seguindo cinetica de ordem zero (r2 = 0,9986)

Nanomedicine to improve drug delivery outcomes [Retracted]

The early genesis of the concept of nanomedicine sprang from the visionary idea that tiny nanorobots and related machines could be designed, manufactured, and introduced into the human body to perform cellular repairs at the molecular level. Nanomedicine today has branched out in hundreds of different directions, each of them embodying the key insight that the ability to structure materials and devices at the molecular scale can bring enormous immediate benefits in the research and practice of medicine. The integration of nanotechnology with biology and medicine has given birth to a new field of science called Nanomedicine. Research into the rational delivery and targeting of pharmaceutical, therapeutic, and diagnostic agents is at the forefront of projects in nanomedicine. These involve the identification of precise targets (cells and receptors) related to specific clinical conditions and choice of the appropriate nanocarriers to achieve the required responses while minimizing the side effects. Mononuclear phagocytes, dendritic cells, endothelial cells, and cancers (tumor cells as well as tumor neovasculature) are key targets. The ultimate goal of nanomedicine is to develop well-engineered nanotools for the prevention, diagnosis, and treatment of many diseases. Nanomedicine today has branched out in hundreds of different directions, each of them embodying the key insight that the ability to structure materials and devices at the molecular scale can bring enormous immediate benefits in the research and practice of medicine.

In Vitro and In Vivo Evaluations of Ketoprofen Extended Release Pellets Prepared using Powder Layering Technique in a Rotary Centrifugal Granulator

In the present study, an extended release pellet dosage form of ketoprofen was prepared using powder layering technique. A combination of ethyl cellulose (45 cps) and shellac polymers was used as a binder (12% w/w polymer) during drug layering and an extended release coating (1:3 ratio at 2%, 4% and 7% w/w polymer) within the same apparatus. The coated pellets were characterized for sphericity, Hardness-Friability Index, and drug content, and also underwent scanning electron microscopy. In vitro dissolution was performed in 900 mL of phosphate buffer (pH 6.8) using paddle apparatus at 100 rpm. Ethyl cellulose and shellac when used as binders during drug loading did not extend ketoprofen release beyond 3 h. However, coating of the drug loaded pellets using ethyl cellulose and shellac resulted in an extended release profile of about 10 h. Using Higuchi’s model and the Korsmeyer equation, the drug release mechanism from the pellets was found to be an anomalous type involving diffusion and erosion. Scanning electron microscopy was used to visualize the pellet morphology and drug release mechanism during dissolution testing. In vivo evaluations of the extended release pellets in rats indicated a significant increase in the time to reach maximum concentration (tmax) and extent of absorption (AUC0-∞) compared to the ketoprofen immediate release tablet blend dispersed and dosed. In conclusion, extended release pellets of ketoprofen could perform therapeutically better than conventional dosage forms, leading to improved efficacy for a prolonged period.