Original Articles: 2012 Vol: 4 Issue: 4
Development and Evaluation of Gastroretentive Controlled Release Polymeric Suspensions Containing Ciprofloxacin and Carbopol Polymers
Considering the importance of drug release pattern from polymers, controlled release oral formulations of Ciprofloxacin were prepared using two grades of Carbopol polymer such as C934 and C940. The objective of the present study was to design and compare the release characteristics of those suspensions. The results indicated that the dissolution of Ciprofloxacin was faster in acidic buffer of pH 1.2 than in phosphate buffer of pH 7.2. In the acidic buffer, the values of the regression coefficient suggested that both the formulations followed Korsmeyer Peppas model release kinetics whereas those values, in the phosphate buffer, indicated that the release kinetics of the formulation containing C934 (F1) were according to Korsmeyer Peppas model and the formulation containing C940 (F2) followed first order release kinetics. Considering the n values for Peppas model, both the formulations showed Fickian diffusional release pattern in acidic buffer suggesting usual molecular diffusion of the drug due to a chemical potential gradient indicating diffusional controlled drug release. However, release of Ciprofloxacin from F2 in phosphate buffer was attributed mainly to polymer relaxation followed by diffusion of the drug, while the release of the drug from F1 was probably controlled by the swelling and relaxation of the polymers indicating super case II transport.