de Jager A D, Ellis H, Hundt H K, Swart K J, Hundt A F
FARMOVS Research Centre for Clinical Pharmacology and Drug Development, University of the Orange Free State, Bloemfontein, South Africa.
J Chromatogr B Biomed Sci Appl. 1999 Jun 11;729(1-2):183-9. doi: 10.1016/s0378-4347(99)00169-3.
After repeated topical application of a piroxicam gel preparation to the knee, piroxicam was quantified in plasma, subcutaneous tissue, synovial capsule and synovial fluid, using specimens obtained during knee surgery. Electrochemical detection was used and the limit of quantification (LOQ) was 0.72 ng/ml in plasma at a signal-to-noise ratio of 10:1. The chromatographic method was optimised to determine piroxicam in all four matrices, and the analyte was quantified using a calibration line constructed from plasma calibration standards. Levels in subcutaneous tissue, synovial capsule and synovial fluid were compared to plasma steady-state levels and expressed as a ratio, in order to ascertain bioavailability.
