Effect of montmorillonite on drug release from polymeric matrices.

Drug release from matrices of polyvinyl alcohol was affected by molecular weight and solubility of the drugs (either sodium salicylate or papaverine hydrochloride), and by the matrix loading. - Montmorillonite addition to the matrix formulation modified only the release constant of papaverine hydrochloride owing to drug interaction with the clay by an ionic exchange process. The kinetics exponent was affected a little bit by interaction of the drug with montmorillonite, whereas the influence of the matrix loading was more remarkable.