抄録
Coprecipitates were prepared in various ratio of tolbutamide-polyvinylpyrrolidone (PVP). The X-ray diffraction spectra indicated that tolbutamide in the coprecipitate did not exhibit its crystalline property. Comparative studies were made on the in vitro dissolution and the in vivo absorption of tolbutamide from the coprecipitate and the drug alone. The dissolution rate of tolbutamide was markedly increased in the tolbutamide-PVP coprecipitates in the pharmacopeial disintegration media at pH 1.2 and 7.5. In vivo absorption study of each preparation was carried out by determining the plasma level of tolbutamide following the oral administration to rabbits. Bioavailability of tolbutamide was improved in the coprecipitate 1.37 time as much as tolbutamide alone. It was shown that the drug was rapidly and completely absorbed following the oral administration of the coprecipitate. Quantitative analysis of PVP in the solution was also studied by the determination of the fluorescence of the complex of PVP and 8-anilino-1-naphthalenesulfonic acid sodium salt.
