Development, Formulation, and Characterization of an Adapalene-Loaded Solid Lipid Microparticle Dispersion for Follicular Penetration

In 2014, researchers developed a novel solid lipid microparticle (SLM) dispersion containing adapalene, a model retinoid, aimed at enhancing the delivery of the active pharmaceutical ingredient into hair follicle orifices. They conducted a series of analyses, including solid-state characterization of the lipid matrix, design space analysis, stability studies for particle size and thermal behavior, and structural analysis using various microscopy techniques. The SLM dispersion maintained a constant mean particle size of 4.2 μm over 24 weeks and had a melting point of approximately 56 °C. In vitro studies using porcine ear skin and artificial human skin lipids demonstrated the formulation's potential for dermal application through follicular penetration and targeted erosion or dissolution in sebum.