Chem. Pharm. Bull. 50(11) 1495—1498 (2002)

glycemic agents belonging to biguanide group and secondgeneration sulphonyl urea respectively. Generally, they are individually used in the treatment of type II non-insulin dependent diabetes mellitus. The combination of both the drugs are also available and it is reported to be effective than individual therapy. Metformin acts by decreasing hepatic glucose production and improves insulin sensitivity by increasing peripheral glucose uptake. Because of its shorter and variable biological half-life of 1.5—4.5 h, it should be repeatedly administered (500 mg thrice a day) to maintain effective plasma concentration. Gliclazide reduces the glucose level by direct stimulation of insulin release from beta cells of pancreatic islet. Relatively Gliclazide is having longer biological half-life (6—15 h) depending upon individual and the dose is 80 mg two-three times a day with meals. Combination of Metformin-500 mg and Gliclazide-80 mg per tablet is available in India and it is to be taken two to three times a day to get required effect. In the present study, we attempted to formulate Metformin/Gliclazide extended release tablet by using Eudragit NE30D aqueous dispersion, with an intention to extend the drug release over a period of 8—12 h, hence it can be taken once a day. The formulated tablets were analysed for drug content by a validated HPLC technique developed in our laboratory and characterized by various physicochemical parameters such as disintegration time, hardness, friability, thickness, weight variation and in vitro drug release.