Piroxicam concentrations in plasma and synovial fluid after a single dose of piroxicam-beta-cyclodextrin
Bannwart, B.; Bertin, P.; Péhourcq, F.; Schaeverbeke, T.; Gillet, P.; Lefrançois, G.; Trèves, R.; Dehais, J.; Netter, P.; Gaucher, A.
International Journal of Clinical Pharmacology and Therapeutics 39(1): 33-36
2001
ISSN/ISBN: 0946-1965 PMID: 11204935 Document Number: 535026
Aims: The efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) in rheumatic diseases depends on their concentrations within the joint. We determined piroxicam concentrations in plasma and synovial fluid (SF) after a single oral dose of 20 mg in the form of one tablet of piroxicam-beta-cyclodextrin. Methods: 45 patients, aged 21 to 84 years, presenting with an effusion of the knee, related to degenerative or inflammatory joint disease, were included in this study after having given their written consent. One blood and one SF sample were drawn concomitantly in each patient from 0.5 to 48 h after NSAID administration. Piroxicam assays were performed by high performance liquid chromatography. Pharmacokinetic parameters were obtained from the mean plasma and synovial concentrations measured at various sampling times. Results: The peak concentration was higher in plasma (2.51 +- 0.25 mug/ml) than in SF (1.31 +- 0.76 mug/ml), but the elimination half-life was much longer in SF (90.7 h) than in plasma (32.5 h). The SF/plasma area under the concentration-time curve ratio (evaluating the quantity of NSAID transferred from the blood to the joint) was equal to 0.39. Conclusions: Piroxicam contained in piroxicam-beta-cyclodextrin diffused well into the SF where its pharmacokinetic profile corresponded to that of a long half-life NSAID.