A simple and easy method for determination of meloxicam in rat muscle and plasma

The aim of this paper is to provide a simple and easy method for determination of meloxicam in rat muscle and plasma, based on dissolution of tissue samples with SolvableTM and measurement with a column-switching high performance liquid chromatographic system. After tissue and plasma samples were extracted with SolvableTM and methanol, samples were injected into a precolumn (Hypersil ODS) in 0.05 M phosphate buffer (pH 3), and after clean-up and enrichment the analytes were transferred to an analytical column (YMC Pack Pro C18) by backflushing with 0.05 M phosphate buffer (pH 6)-methanol (60:40, v/v). The eluate was monitored with a UV-detector set at 360 nm. Coefficients of determination (r2) for muscle and plasma were both more than 0.999. The limits of quantification (LOQ) in muscle and plasma were 50 ng/g and 20 ng/mL, respectively. The accuracy and precision were achieved in the range of 50-2500 ng/g in muscle and 20-2500 ng/mL in plasma. Our method could be successfully applied to evaluate the pharmacokinetics of topically administrated meloxicam.