stability studies.

The aim of the present investigation was to design a mucoadhesive liposomal system of Repaglinide for the treatment of type - 2 diabetes mellitus that is capable of delivering entrapped drug over an extended period of time. Mucoadhesive liposomal formulations were prepared by using different ratio of lecithin and cholesterol by thin film hydration technique followed by coating of liposomes by 0.1 % w/v and 0.3 % w/v of chitosan and were evaluated for entrapment efficiency, particle size, zeta potential, surface morphology and in-vitro drug release. Particle size and zeta potential of the F2 and C2F2 formulation was found to be 413.5 nm, 830.9 nm and -40.9 mV, -46.8 mV respectively. Coating of liposomes resulted increase in particle size and also increases the zeta potential.  Highest entrapment efficiency was observed in F1, CF1 and C2F2 90%, 95% and 94%. The percent drug release from F1-F3, CF1-CF3 and C2F1-C2F3 was observed as follows F1- 79.04%, F2- 76.77%, F3- 64.32%, CF1-66.65%, CF2- 62.12%, CF3- 56.54% and C2F1- 59.1%, C2F2-56.56%, C2F3- 53.45% which follows first order drug release and non-Fickian diffusion mechanism. And mucoadhesive strength from CF2- 60%, C2F2- 74%.

The Present study was undertaken with an aim to formulate delayed release enteric coated tablets of Tenatoprazole to avoid the degradation in stomach, as it is an acid labile drug and to improve bioavailability. The method adopted for development was direct compression. Different core tablets were prepared by using approved excipients and evaluated for parameters like hardness, friability, thickness and disintegration time. Sub coating was done for the optimized formulation (F5) by using Hydroxy propyl methyl cellulose 5cps with buildup of 3%w/w and finally enteric coating was done by using polymers like Hydroxy propyl methyl cellulose phthalate (HPMCP), Eudragit L30 D55 and Hydroxy propyl methyl cellulose acetate succinate (HPMCAS) with an average weight build up of 5%, 8% & 10% w/w. All the formulations were evaluated for their physicochemical parameters and compared with marketed sample. Results indicated that all the tablets prepared possess good integrity, desirable for enteric coated tablets. At the end it was found that prepared formulation gave satisfactory results compared with market sample dissolution profile. Among the polymers studied, the methacrylic acid polymers exhibited better dissolution rate than the cellulose polymers. The selected formulation (F5h with 8% w/w) was subjected for stability studies as per ICH guidelines and were found to be stable, as no significant change was observed in the evaluated parameters. Hence prepared formulation by-pass the degradation of Tenatoprazole by enteric coating and thus a pharmaceutically equivalent, robust formulation of Tenatoprazole enteric coated tablet was developed.