Studies of the dissolution characteristics of norethindrone-mestranol tablets

Abstract

Using a simple and sensitive HPLC method, dissolution studies have been performed on norethindrone-mestranol combination tablets in de-aerated water and in 30% isopropanol-water. The rate and extent of dissolution in the hydroalcoholic medium were much greater than in water. However, in a comparison of the dissolution data of products of the same dosage strengths from different manufacturers, the same rank order relationships existed for data obtained in de-aerated water and hydroalcoholic media. This would suggest that even for highly insoluble drugs an aqueous dissolution medium may be used. In these studies each component of the tablet exhibited its own dissolution rate in de-aerated water although these differences were not detected in the hydroalcoholic medium. Manufacturers should therefore exercise caution in monitoring the dissolution of only one component for quality control purposes.