Design, Development and Evaluation of Amlodipine Besylate IR and Metformin HCl SR Bilayer Floating System.

ABSTRACTThe scenario of pharmaceutical drug delivery is rapidly changing. Conventional pharmaceutical dosage forms are being replaced by new drug delivery systems. These new drug delivery systems are having border over conventional ones in terms of many biopharmaceutical parameters. One such drug delivery system is bilayer floating sustained release drug delivery system. The research envisaged in the present study is an attempt towards developing a formulation of anti-diabetics and anti-hypertensive drug in a single dosage form. The main aim of present study is to formulate and evaluate bilayer tablets of Amlodipine Besylate as IR and Metformin Hydrochloride SR combination tablets for effective treatment of type II diabetes mellitus and hypertension. Preformulation studies including drug excipient compatibility were conducted for both drugs. Different formulations of sustained release, floating Metformin HCl tablets were prepared by using hydrophilic polymers like HPMC K100M, HPMC K4M etc., were evaluated. Amlodipine immediate release formulations were prepared using sodium starch glycolate as superdisintegrant and starch as disintegrant and were evaluated. Based on the in vitro dissolution data F6 and F3 were selected as the best formulations from Metformin and Amlodipine formulations respectively. From the bilayer tablet Amlodipine layer disintegrated within 5min , Metformin layer started floating after 5 min and showed total floating time ?12 hrs with good swelling index, good post compression parameters. In vitro dissolution study of bilayer tablet was done in USP type II along with UV spectrophotometer bestowed cumulative % drug release of Amlodipine as 98.75% at 30 min and 99.32 % of Metformin at 12 hrs. From the study it was found that, HPMC K100M showed good sustained release for 12 hrs. Among the disintegrants used sodium starch glycolate and starch showed good disintegration of Amlodipine layer. Overall this FDC formulation could be more effective, conveni