DEVELOPMENT, FORMULATION AND EVALUATION OF A BILAYER GASTRIC RETENTIVE FLOATING TABLETS OF RANITIDINE HCL AND CLARITHROMYCIN USING NATURAL POLYMERS

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

FORMULATION AND EVALUATION OF METFORMIN HYDROCHLORIDE AND GLICLAZIDE SUSTAINED RELEASE BILAYER TABLETS: A COMBINATION THERAPY IN MANAGEMENT OF DIABETES

Objective: The main objective of the present investigation is to develop a sustained-release (SR) formulation to optimize the postprandial elevation of glucose level in type 2 Diabetic subjects using combination therapy. In the present research work, bilayer sustained release formulation of metformin hydrochloride (MFH) and gliclazide (GLZ), based on monolithic-matrix technology was developed and evaluated. Methods: The formulations of metformin hydrochloride layer and gliclazide layer that contain polyox WSR coagulant and different viscosity grades of hydroxyl propyl methylcellulose (HPMC) as sustained-release matrix were prepared by direct compression and wet granulation method respectively. The bilayer tablets were prepared after carrying out the optimization of metformin layer and evaluated for various pre-compression and post-compression parameters. For the best formulation selected on basis of in vitro evaluation of tablets, Fourier-transform infrared spectroscopy (FT-IR) studies and comparison of in vitro dissolution profile of developed formulation with the innovator were performed. Results: Metformin hydrochloride and gliclazide showed sustained release of drug by diffusion mechanism and followed first-order kinetics. The best formulation of metformin hydrochloride (M7) and gliclazide (G8) show 99.93% and 99.65% of drug release in 24 h respectively. The similarity factor (f2) was 79.95 for metformin hydrochloride and 73.62 for gliclazide when compared with the innovator. Conclusion: The monolith diffusion-controlled bilayer tablets of metformin hydrochloride and gliclazide offer improved patient compliance and convenience with better postprandial hyperglycemic control with once-a-day dosing. The sustained release of the drug up to 24 h regulate antidiabetic activity round the clock with minimal side effects