FORMULATION AND EVALUATION OF EXTENDED RELEASE MUCOADHESIVE MICROSPHERES OF ATORVASTATIN

The objective of the present study was to prepare and evaluate the mucoadhesive microspheres of Atorvastatin. Atorvastatin microspheres were prepared by orifice- ionotropic gelation method using polymers such as HPMC (K 100 M), Carbopol 940P, Sodium CMC, Guar gum, Sodium Alginate, Ethyl Cellulose, Methyl Cellulose and Xanthan gum. Totally 15 different formulations of Atorvastatin were prepared by using the above polymers. The microspheres were characterized for drug content, entrapment efficiency, mucoadhesive property by in vitro washoff test and in-vitro drug release. The formulation F10 was selected as an ideal formulation based on the in vitro release profile which shows an extended drug release of 96.11% upto 8 hours in phosphate buffer of pH 7.0. Surface morphology (SEM analysis) and drug-polymer interaction studies (FT-IR analysis) were performed only for the ideal formulation (F10). The microspheres were smooth and elegant in appearance showed no visible cracks as confirmed by SEM and FT-IR studies indicated the lack of drug-polymer interactions in the ideal formulation (F10). The in vitro release data of all microsphere formulations were plotted in various kinetic equations to understand the mechanisms and kinetics of drug release. The ideal formulation (F10) followed Higuchi kinetics and value of "n," is calculated to be 0.86 indicated that the drug release shows non-fickian diffusion.” Key Words: SEM, FT-IR, Carbopol 940,HPMC (K 100 M),orifice- ionotropic gelation method, Atorvastatin, Sodium Alginate , Sodium CMC.