Development and validation of a liquid chromatographic method for in vitro mupirocin quantification in both skin layers and percutaneous penetration studies.

A simple, rapid, and sensitive reversed-phase high-performance liquid chromatographic (HPLC) method for the measurement of mupirocin concentrations in both skin layers and percutaneous samples has been developed. Mupirocin was extracted from skin layers using PBS-acetonitrile (90:10, v/v). The method is sufficiently sensitive and repeatable to be used in percutaneous penetration studies. The samples were chromatographed on a 250 mm x 4 mm C(8) LiChrospher Select B (5 microm). The mobile phase composition was a mixture of acetonitrile-ammonium acetate 0.05 M (27.5:72.5, v/v) adjusted to pH 6.3 with acetic acid. The analyte was detected at 228 nm and the run time was 11 min. Linearity was confirmed in the concentration range 0.2-20 microg/ml and the limit of detection was 9.5 ng/ml.