FORMULATION AND EVALUATION OF SUSTAINED RELEASE TABLETS OF MEFENAMIC ACID USING HYDROPHILIC POLYMERS

Abstract

Mefenamic acid is a non-steroidal anti-inflammatory drug used to treat pain, including menstrual pain. It has a dose of 250 mg 4 times daily. It has a very short half-life of 2 hours and thus controlling the release would be beneficial. In the present study, mefenamic acid 250 mg controlled release matrices were prepared by direct compression and in-vitro drug dissolution studies were performed to find out the drug release rate and patterns. Hydroxypropylmethylcellulose, Hydroxypropylcellulose and Hydroxyethylcellulose were used as rate controlling polymers. Hydroxypropylmethylcellulose was used as primary rate controlling polymer and effects of addition of Hydroxypropyl cellulose and Hydroxyethylcellulose on in-vitro drug dissolution were studied.  Tablets were formulated using total polymer content as 30, 35 and 40 percent with 20 percent standard polymer content of Hydroxypropyl methylcellulose in all batches and varying the concentration of Hydroxypropyl cellulose and Hydroxyethylcellulose in the range of 10, 15 and 20 percent. In-vitro drug release was carried out using USP Type II at 50 rpm in 900 ml of acidic dissolution medium (pH 1.2) for 2 hours, followed by 900 ml alkaline dissolution medium (pH 7.4) up to 12 hours. Several kinetic models were applied to the dissolution profiles to determine the drug release kinetics.

KEYWORDS: Mefenamic acid , Hydroxypropyl methylcellulose, Hydroxypropyl cellulose, Hydroxyethyl cellulose, Release Kinetics.