Stabilization and sustained-release effect of Misoprostol with Methacrylate copolymer

The use of ammonio methacrylate copolymer (Eudrgit RS, RL) to form a sustai ned-release solid dispersion of Misoprostol can improve and enhance two imp ortant physical and chemical properties of Misoprostol. First, the solid di spersion matrix formed by the copolymer can protect Misoprostol from being degraded by water so that its stability is improved. Second, Misoprostol ca n be slowly released by diffusion from the copolymer matrix. Accelerated st ability studies of Misoprostol-Eudragit solid dispersion after storing at v arious temperatures for different time periods were carried out. According to high performance liquid chromatography (HPLC) analyses: the stability of Misoprostol in a series of Eudragit appeared significantly improved at dif ferent ratios. The Misoprostol-Eudragit dispersion can be used in a powder form, filled in capsules, or compressed into tablets. The dissolution profi les of Misoprostol-Eudragit solid dispersion and its tablets in;water, pH 1 .2, 4.5 and 6.8, dissolution media show that this stable solid dispersion i s a sustained-release type. (C) 2000 Elsevier Science B.V. All rights reser ved.