floating microspheres

The present study was to formulate and characterize oral floating microspheres of Pramipexole to sustain the gastric residence time and to target gastritis. The floating microspheres were prepared by ionotropic gelation technique. Sodium alginate was used as polymer, sodium bicarbonate as gas generating agent, calcium chloride as cross-linking agent, HPMC K4, as rate retarding agent. Microspheres were characterized for the Micromeretic properties, incorporation efficiency, buoyancy test, SEM analysis, FTIR, and in vitro diffusion studies. The diffusion studies were carried out in 0.1N HCl and the results were applied to various kinetic models.  Among the total 14 formulations F12 was found to be optimized on the basis of different evaluation parameters. The % yield of F12 formulation was found to be 98.58%. On the basis of optical microscopy, the particle size was 65.12±0.04µm. The % buoyancy, % entrapment efficiency and swelling index of F12 formulation was 98.12%, 96.56% and 97.10, respectively. The Cumulative % drug release of F12 formulation was 98.3±5.10% in 12h.  SEM studies showed the particles were in spherical shape. On the basis of obtained results, Floating microspheres were of good candidate for targeting to GIT.

Over the years, different formulation technologies for gastroretentive dosage delivery were investigated and patented. Well-designed controlled drug delivery system can overcome the problems of conventional therapy and enhance the therapeutic efficacy of a drug. There are various approaches in delivering a therapeutic substance to target site in a sustained controlled release fashion. One such approach is using multiparticulate as carriers for drugs. Such systems have advantages over single-unit dosage forms as they avoid the all-or-none gastric emptying nature of single-unit systems. However, multiparticulate dosage forms are gaining favor because of potential benefits like predictable gastric emptying, no risk of dose dumping, flexible release patterns and increased bioavailability with less inter- and intra-subject variability. The purpose of writing this review on method of prepare floating multiparticulate is to compile the recent literature with special focus on the classification and formulation aspects, principal mechanism of floatation to achieve gastric retention, characterization of floating multiparticulate system. Keywords- multiparticulate system, design and method of preparation, floating microspheres, beads, granules.    

One of the most feasible approaches for achieving a prolonged and predictable drug delivery profiles in the GIT is to control the gastric residence time (GRT) using gastroretentive dosage forms. The aim of the present study is to prepare the floating microspheres of ketoprofen to sustain the drug release for longer time to overcome the short half life of the drug. The microspheres were prepared by emulsification-solvent evaporation technique using ethyl cellulose and heat denaturation technique using egg albumin as a natural polymer. The optimization of microspheres was carried out based on pentagonal design using response surface methodology. The floating microspheres were evaluated for micromeritic properties, particle size, percentage yield, in-vitro buoyancy, entrapment efficiency, drug polymer compatibility, scanning electron microscopy and in-vitro drug release studies. The prepared microspheres exhibited prolonged drug release (> 9 h) and remained buoyant for > 24 h. The mean particle size increased and the drug release rate decreased at higher polymer concentration. The optimized formulation of ethyl cellulose microspheres (KEC-OP) exhibited prolonged drug release of 88.31 % up to 10 h demonstrating zero order kinetics and Case II transport release mechanism where as optimized formulation of egg albumin (KEA-OP) showed drug release of 96.78 % up to 9 h demonstrating peppas kinetics and Case II transport release mechanism.