DISSOLUTION BEHAVIOUR OF PROPYLTHIOURACIL POLYVINYLPYRROLIDONE SOLID DISPERSIONS

Abdel-Rahman, S. I.; El-Sayed, A. M.; Aboutaleb, A. E.

doi:10.21608/bfsa.1988.73520

DISSOLUTION BEHAVIOUR OF PROPYLTHIOURACIL POLYVINYLPYRROLIDONE SOLID DISPERSIONS

Document Type : Original Article

Authors

Department of Industrial Pharmacy, Faculty of Pharmacy, Assiut University, Assiut, Egypt

10.21608/bfsa.1988.73520

Abstract

The objective of the present study was to investigate the influence of variation of the molecular weight and the proportion of polyvinylpyrrolidone (PVPs) on the dissolution of propylthiouracil (Pt) as a model of sparingly soluble drugs dispersed in highly soluble polymers. Solid dispersions of Pt-PVP were prepared by the solvent method. The dissolution behavior was determined as a function of the molecular weight of PVP and the drug-to-carrier ratio. Three PVP molecular weight fractions were used, namely, PVP 10.000, PVP 40.000 and PVP 360.000. The drug-PVP percentages used were 10, 20, 40, 60 and 90%w/w. Enhancement of dissolution rate was observed for all solid dispersion systems compared to the drug alone or the physical mixtures. The dissolution rate was increased with increasing the proportion of PVP to the drug. Generally, the enhancement of the dissolution rate was decreased in the order: PVP 10.000 > PVP 40.000 > PVP 360.000. Differential scanning calorimetry (DSC) reveals a decrease in the melting point of Pt due to retardation of drug nucleation in the PVP matrix. X-ray diffractometry of the highest dissolution rate solid dispersion indicates the presence of Pt in an amorphous state in the carrier.