Biopharmaceutical properties of adapalene loaded biocompatible microemulsions

Abstract

Adapalene (ADA) belongs to the group of retinoids, synthetic analogs of retinol, and it is used as a first line therapy of mild to moderate acne, with a few exceptions (1). However, dermal availability of ADA is limited due to its poor aqueous solubility. In order to enhance the drug penetration into target areas (i.e. hair follicles and epidermis), several strategies, such as liposomes, microemulsions (MEs), solid lipid microparticles, nanostructured lipid carriers etc., were proposed recently. MEs have been reported as a promising tool for topical drug delivery because they combine several advantages over conventional formulations, including ease of manufacture, high solubilization potential for poorly soluble drugs, reduced side effects, long-term stability and improved drug penetration through/into the skin (2).