Preparation of Piroxicam nanosuspensions by high pressure homogenization and evaluation of improved bioavailability

Objective: Inflammation is a natural response of the organism, involving events responsible for releasing chemical mediators and requiring treatments of symptoms such as pain, redness, heat, swelling, and loss of tissue function. Piroxicam (PRX) is a non-steroidal anti-inflammatory drug with the effect of nonselective COX inhibitor activity; however, it shows poor bioavailability caused by the poor and slow water solubility. In this study, we developed PRX nanosuspensions with 200-500 nm in diameter to increase the bioavailability of PRX by improving its solubility.Methods: PRX nanosuspensions were fabricated by High pressure homogenization method with PVA, SDS and Tween 80. The nanosuspensions were characterized by XRD, FTIR, DSC, and in vitro release. In vivo pharmacokinetic properties and anti-inflammatory effects were also investigated in rabbits.Results: PRX nanosuspensions significantly increased the solubility (14.89 +/- 0.03 mg/L for pure PRX and 16.75 +/- 0.05 mg/L for PRX nanosuspensions) and dissolution rate as compared to the pure PRX (p < 0.05). Orally administered PRX nanosuspension (AUC 0-t is 49.26 +/- 4.29 mu g/mL x h) significantly improved the bioavailability of PRX (AUC 0-t is 28.40 +/- 12.11 mu g/mL x h). The anti-inflammatory effect of PRX nanosuspension was also investigated in rabbits and it was observed that PRX nanosuspension treatment significantly improved the inhibition of COX-2 and NF kappa B expression as compared to the PRX treatment (p < 0.05).Conclusions: The results in this study indicate that PRX nanosuspension is a promising nanomedicine for enhancing the anti-inflammatory activity of PRX and has a high potential for the treatment of inflammation.