Dissolution Behavior of Probucol from Solid Dispersion Systems of Probucol-Polyvinylpyrrolidone

Solid dispersion systems of probucol-polyvinylpyrrolidone (PVP) K25, K30 and K90 were prepared in various weight ratios by co-evaporation of the drug and PVP ethanolic solution. The observation of solid dispersion systems by powder X-ray diffraction spectra and differential scanning calorimeter indicated that probucol in the systems did not exhibit its crystalline property. The solubility of probucol in water at 25°C was 5 ng/ml at most, and its dissolution was markedly increased in the solid dispersion systems in the JP XII disintegration media No. 1 (pH 1.2) and No. 2 (pH 6.8) at 37°C. Probucol concentrations after the dissolution of the solid dispersion systems showed hypersaturation. The solid dispersion system of 1 : 9 (probucol : PVP K 30 in weight ratio) showed the best dissolution of probucol among the systems prepared in the study.