The Influence of Polyvinylpyrrolidone on the Dissolution of Allopurinol

Dissolution rates of allopurinol have been determined in non-disintegrating discs prepared from physical mixtures and from co-precipitates of allopurinol incorporating polyvinylpyrrolidone (P.V.P.). Four different molecular weight species of P.V.P., K-15, K-30, K-90 and Plasdone, were used. The results obtained indicate that the dissolution rate of allopurinol is not affected by changes in the amount of P.V.P. in the discs or by the molecular weight of the P.V.P. incorporated into the disc.Dissolution rates of allopurinol into aqueous solutions of P.V.P. were less than those in solvent alone. The effect of P.V.P. in the dissolution media appears to be due almost entirely to the increase in bulk viscosity of the dissolution media.