Objective: Bilayer gastric retentive floating tablets (BGRFT) with ranitidine HCl and clarithromycin using natural gums have been developed to prolong the gastric residence time and increase drug bioavailability. Literature review revealed no published studies on the present study.Methods: Immediate release (IR) layer prepared by using different diluents and super disintegrants like sodium starch glycolate, crosscarmellose sodium and crospovidone. Controlled released (CR) layer prepared by using neem gum, damar gum and copal gum. Prepared tablets were evaluated for in vivo and in vitro buoyancy, in vitro dissolution studies and fourier transformation-infrared spectroscopy (FTIR). Drug release was evaluated with zero and first order for release kinetics, Higuchi, Hixson-Crowell erosion models for release mechanism.Results: Prepared IR layer followed first order rate kinetics and CR layer followed zero order rate kinetics with non-Fickian diffusion mechanism. BGRFT also showed similar results as that of the individual layer. Optimized formulations were characterized by FTIR studies and found no interactions between drug and polymer.Conclusion: The results demonstrate the feasibility of the model in the development of BGRFT. BGRFT enhanced the drug release and finally the bioavailability of clarithromycin when compared with commercial tablet (Biomycin 250). The present study could establish the suitability of neem gum as CR polymer in the design of BGRFT
