Comparison of Rheological Properties, Follicular Penetration, Drug Release, and Permeation Behavior of a Novel Topical Drug Delivery System and a Conventional Cream

The study introduced a novel adapalene-loaded solid lipid microparticle (SLMA) dispersion for topical drug delivery and compared it with a conventional cream. The SLMA dispersion demonstrated lower complex viscosity at 20 °C and higher at 32 °C, with a consistently larger phase angle than the cream. Both formulations showed similar follicular penetration and deposition capabilities. However, the SLMA dispersion exhibited superior drug release in sebum, minimal release in stratum corneum (SC) lipids, and no permeation for either formulation. The glyceride matrix of the SLMA, similar to sebum components, potentially enhanced targeted drug delivery into sebum, improving follicular penetration.