Dissolution of Suppositories V: Influence of Aging on Aspirin Release from Polyethyleneglycol Suppositories with and Without Crospovidone

Abstract

This report details the effect of aging on release of aspirin from four PEG blends containing crospovidone as a disintegrant in concentrations of 0, 0.5, 1 and 5%. It has been reported in the literature that release from suppository formulations is often altered upon aging. In this experiment, suppositories containing 350 mg aspirin were dissolved in 1,000 mls of pH 8.0 dissolution fluid, at 37.5° with an agitation rate of 50 rpm. Suppositories were designated as fresh (less than 10 days old), 4 months old and 6 months old. Aspirin was assayed at 265 nm. Dissolution profiles as well as dissolution half-times were reported. Aging had little effect on Base A and Base B. However, Ease C exhibited an ambiguous effect in that the dissolution half-times were inconsistent. Base D exhibited a dramatic change in release upon aging in that the dissolution half-times increased from 23 minutes to 55 minutes with 1/22 crospovidone. It is hypothesized that Base D stabilized when larger amounts of crospovidone are used although the exact mechanism of this stabilization is unknown