FORMULATION AND EVALUATION OF ALGINATE-CELLULOSE FLOATING MICROSPHERES OF CEFIXIME TRIHYDRATE

Abstract

Gastro retentive floating microspheres is a type of dosage form used as an efficient means of enhancing the bioavailability controlled delivery of many drugs that are mainly absorbed from the stomach and upper part of the intestine. Floating microspheres of cefixime trihydrate were prepared using polymers to prolong gastric residence time and increase drug bioavailability with decreased gastro intestinal side effects. The floating micro carriers were prepared by ionotropic gelation method by dispersing cefixime trihydrate with calcium carbonate and sodium bicarbonate separately into a mixture of anionic sodium alginate, as primary polymer with copolymers namely, HPMC K4M, HPMC K15M and ethyl cellulose into a solution of calcium chloride containing acetic acid. The prepared microparticles were evaluated for drug entrapment efficiency, particle size, buoyancy and in vitro drug release studies. As the amount of gas forming agents increased, the size and floating properties increased. The NaHCO3 loaded microspheres were large compared to those produced with CaCO3 but more buoyancy was shown by the microspheres formulated with CaCO3. The formulations without gas forming agents showed maximum entrapment efficiency. Drug release rate increased proportionally with addition of NaHCO3 but the increase in the concentration of CaCO3 did not make any change in the amount of drug release. From these studies we can conclude that CaCO3 is a more powerful gas forming agent than NaHCO3. The microspheres formulated with CaCO3 show increased buoyancy and controlled drug release which makes it excellent in floating drug delivery systems (FDDS).