Abstract：Objective To investigate the drug transport of transdermal delivery of piroxicam through observing its pharmacokinetic process and distribution characteristics.Methods Three doses of piroxicam(2,4 and 6 mg) were administered to right shoulders of rats.The concentrations of piroxicam in plasma and joint fluid were determined by high-pressure liquid chromatography(HPLC) and pharmacokinetic parameters were calculated by DAS 1.0 software.Results At 2,4 and 6 hours after topical application of 4 mg piroxicam,the drug concentrations were(427±82),(2 015±184) and(1 317±224)μg·L-1in plasma,and(119±26),(1 538±358) and(1 349±320)ng·g-1in joint fluid,respectively.The ratio of joint fluid to plasma in piroxicam concentrations ranged from 0.28 to 1.02.The plasma concentrations of the three doses of piroxicam reached peaks at 4 hours and maximum concentrations were(925±118),(1 980±135) and(2 644±337)μg·L-1,respectively.Area under the plasma concentration-time curve(AUC0-∞) was(29 976±10 845),(63 871±58 534) and(85 389±15 352)μg·L-1·h-1,respectively.There was a linear increase in Cmax and AUC0-∞ with increasing doses of piroxicam patches.Conclusion Topically applied piroxicam can reach local deep tissues such as joint by direct permeation and have higher concentrations,and the dynamic factor is a linear increase from 2 to 6 mg.
2012, Vol. 52 
