Development and characterization of buccoadhesive bilayer famotidine tablets

The buccoadhesive controlled release tablets for delivery of Famotidine were prepared by direct compression of hydroxyl propyl methyl cellulose (HPMC K100), sodium carboxy methyl cellulose (SCMC), poly vinyl pyrrolidone (PVP K30) with carbomer (CP 934) and ethyl cellulose (EC) was used as impermeable baking layer. The prepared formulations were evaluated for their physicochemical characteristics, swelling index, surface pH, ex vivo buccoadhesive strength and in vitro drug release studies. The distinguishable differences in the results were shown to be dependent on characteristics and composition of bioadhesive materials used and the results are reproducible. Stability studies were performed in natural human saliva and accelerated conditions showed no significant differences in physical appearance, drug content, buccoadhesive strength. Ex vivo muco irritation by histological examination reveals, the administration site of buccal tablet should not cause any irritation and inflammation. Ex vivo permeation studies reveals that there was no significant difference between in vitro and ex vivo permeation. Drug diffusion from buccal tablets showed apparently zero order kinetics and release mechanism was diffusion controlled after considerable swelling evidenced by kinetic models.