Enhanced efficacy by percutaneous absorption of piroxicam from the poloxamer gel in rats.

The pharmacokinetics and anti-inflammatory activity of piroxicam from the poloxamer 407 gel were determined to investigate percutaneous absorption of piroxicam from poloxamer gels in rats. The poloxamer 407 gel containing 1% piroxicam showed significant inhibition of carragenin-induced rat foot swelling when compared to the control group. The extent of inhibition of swelling (%) showed a linear relationship with the logarithm of piroxicam dose within approximately 0.4-3.2 mg/kg. The enhancing effect of polyoxyethylene-2-oleyl ether, non-ionic surfactant on the percutaneous absorption of piroxicam from poloxamer 407 gel was evaluated in rats. The piroxicam gel containing polyoxyethylene-2-oleyl ether increaesd the relative bioavailability approximately 1.8-fold compared with the gel without enhancer. Percutaneous administration of piroxicam gel containing polyoxyethylene-2-oleyl ether to rats showed a relatively constant, sustained blood concentration with minimal fluctuation.