PREPARATION AND IN-VITRO EVALUATION OF MEFENAMIC-ACID SUSTAINED-RELEASE BEADS

Sustained release beads of mefenamic acid were prepared by a capillary method using cellulose acetate phthalate, surfactants (Tween 80 and Span 80), and polymers (K 100 M Methocel and K 100 LV Methocel). These beads were then formulated into capsule dosage form. The beads did not disintegrate in simulated gastric fluid; however, they disintegrated in simulated intestinal fluid. The dissolution profiles of mefenamic acid beads and capsule dosage form were conducted in phosphate buffer (pH 7.2) at 37 degrees C. The beads containing Span 80 and a mixture of K 100 M and A 4 M Methocel resulted in prolonged drug release. The formulations prepared with Tween 80 and K 100 LV Methocel released over 90% of the drug in 2 hours indicating no sustained release properties. The beads in capsule dosage form yielded slower dissolution profiles compared to the beads alone. Aging for six months had no effect on dissolution of mefenamic acid beads. The release of mefenamic acid seems to be combination of diffusion and leaching. The release of mefenamic acid from beads can be modified by varying the polymer composition and their concentration.