Percutaneous Penetration Enhancement Potential of Microemulsion-Based Organogels

Abstract

The skin, and particularly the most outer layer stratum corneum, is an effective barrier for molecules administered by conventional topical formulations (i.e., ointments, creams, hydrogels). Therefore, vehicles and carriers that enhance percutaneous penetration of active pharmaceutical and cosmetic ingredients are of great interest. Microemulsion-based gels (MBGs) are gel-like systems derived from microemulsions, with growing relevance regarding dermal and transdermal delivery. MBGs are thermodynamically stable, viscoelastic, and thermoreversible transparent or opaque systems, depending on their composition and microstructure. MBGs attracted interest in the development of topical formulations with a view to improve drug permeation through the skin for systemic delivery or to achieve its accumulation in the skin for dermal delivery. This chapter focuses on several biocompatible types of MBGs, i.e., lecithin organogels (LOs), pluronic/lecithin organogels (PLOs), gelatin-stabilized MBGs, and lecithin-linker MBGs, which are at various stages of development toward dermal application, from preliminary in vitro experiments to clinical studies, providing a global view of lecithin-based and gelatin-containing MBGs with special focus on their potential for improvement of cutaneous drug delivery.