Cyclosporin A in skin samples from in vitro penetration studies may be assayed by a simple HPLC method

RESUMO

A simple High Perfomance Liquid Chromatography method with UV detection was developed for quantification of Cyclosporin A (CysA) in skin sample after in vitro penetration studies. The peptide was recovered from two different layers of skin, the stratum corneum and the epidermis plus dermis ([E+D]), by vortex homogenization and bath sonication in an organic solvent (methanol). Recovery of CysA from skin was about 85 percent and CysA was estimated by HPLC using a RP-18 column, UV detection at 210 nm and acetronitrile water (6733 v/v) as the mobile phase. The quantification limit was 105ng/mL. The assay was linear from 0.15-500 µg/mL. The within-day and between-day assay precision and accuracy were studied at three concentration levels (1, 10 and 20 µg/mL)...