Physicochemical characterization and solubility enhancement studies of allopurinol solid dispersions

Authors

  • Jagdale Swati Changdeo Maharashtra Institute of Pharmacy
  • Musale Vinod Maharashtra Institute of Pharmacy
  • Kuchekar Bhanudas Shankar Maharashtra Institute of Pharmacy
  • Chabukswar Anuruddha Rajaram Maharashtra Institute of Pharmacy

DOI:

https://doi.org/10.1590/S1984-82502011000300009

Keywords:

Allopurinol, Polyethylene glycol 6000, Solid dispersions, Closed melting method, Dissolution enhancement

Abstract

Allopurinol is a commonly used drug in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. One of the major problems with the drug is that it is practically insoluble in water, which results in poor bioavailability after oral administration. In the present study, solid dispersions of allopurinol were prepared by solvent evaporation, kneading method, co-precipitation method, co-grinding method and closed melting methods to increase its water solubility. Hydrophilic carriers such as polyvinylpyrrolidone, polyethylene glycol 6000 were used in the ratio of 1:1, 1:2 and 1:4 (drug to carrier ratio). The aqueous solubility of allopurinol was favored by the presence of both polymers. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, powder X-ray diffraction, UV and Fourier Transform Infrared spectroscopy. Solid state characterizations indicated that allopurinol was present as an amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure allopurinol, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. Solid dispersion prepared with polyvinylpyrrolidone showed highest improvement in wettability and dissolution rate of allopurinol. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer-Peppas model and the drug release kinetics primarily as Non-Fickian diffusion. Therefore, the present study showed that polyvinylpyrrolidone and polyethylene glycol 6000 have a significant solubilizing effect on allopurinol.

Downloads

Download data is not yet available.

Downloads

Published

2011-09-01

Issue

Section

Articles

How to Cite

Physicochemical characterization and solubility enhancement studies of allopurinol solid dispersions . (2011). Brazilian Journal of Pharmaceutical Sciences, 47(3), 513-523. https://doi.org/10.1590/S1984-82502011000300009