Overcoming Limitations in Dissolution Testing of Poorly Water Soluble Racecadotril

Abstract

The conventional dissolution test, particularly the USP apparatus I and II, remains an important tool in the field of the pharmaceutical product development. For accurate dissolution characterization, sink conditions, where saturation solubility of a drug in the dissolution medium is at least three times more than the drug concentration, are significant. These conditions can be difficult to maintain with formulations containing poorly soluble active pharmaceutical ingredients. This research summarizes the role of the excipients to enhance dissolution of racecadotril and facilitate the achievement of sink. The dissolution model utilizes various media (0.1N HCl, Acetate buffer pH 4.5 and Phosphate buffer pH 6.8) with surfactant to improve the dissolution limitation of racecadotril. Crucially, the acetate buffer pH 4.5 with 0.75% SLS does allow sink conditions to be maintained and hence the experiment will yield complete dissolution.