Application of the human stratum corneum lipid-based mimetic model in assessment of drug-loaded nanoparticles for skin administration

A lipid-based permeation assay (PVPA(SC)) with a lipid composition similar to Human stratum corneum layer has been previously reported. The aim of this study was to further characterize the PVPA(SC) model in the presence of co-solvents and to determine its applicability to evaluate drug permeability with drug-loaded nanoparticles. Data obtained from PVPA(SC) model were compared with results from isolated SC from pig ear skin. The characterization revealed that the PVPA(SC) barriers retain integrity and calcein permeability when stored up to 12 weeks at -20 degrees C, in the presence of different co-solvents, and under a skin environment pH range. The permeation profile of calcein in the lipid-based barrier correlated well with data obtained for the isolated SC model and revealed higher reproducibility. Cyclosporine A (CsA) was selected as a model drug, given its relevance for skin-inflammatory diseases and two types of lipid nanoparticles were used to assess the permeability of the PVPA(SC) model. It was possible to distinguish the permeability between free and nanoparticles' loaded cyclosporine. Data obtained with CsA-loaded nanoformulations indicated a higher permeation rate than the obtained for the solid lipid nanoparticles or the free drug. The PVPA(SC) model could be applied as a cost-effective alternative for skin early drug development.