Determination of 6-hydroxychlorzoxazone and chlorzoxazone in porcine microsome samples

A simple, accurate and sensitive HPLC method for the in vitro determination of 6-hydroxychlorzoxazone and chlorzoxazone in porcine microsome samples is described. Chromatography was performed on a YMC-Pack ODS-AQ column using a mobile phase of 0.05% phosphoric acid pH 3–methanol (60:40, v/v). UV detection was carried out at 287 nm. The detector response was linear over the concentration range 25–2000 ng/ml. This assay produced quick, accurate, and repeatable results.