Nanoemulsifying drug delivery system to improve the bioavailability of piroxicam.

OBJECTIVE The aim of this study is to develop and characterize self-nanoemulsifying drug delivery system (SNEDDS) of piroxicam in liquid and solid forms to improve its dissolution, absorption and therapeutic efficacy. MATERIALS AND METHODS The generation of liquid SNEDDS (L-SNEDDS) was composed of soybean or coconut oil/Tween 80/Transcutol HP (12/80/8%w/w) and it was selected as the optimized formulation based on the solubility study and pseudo-ternary phase diagram. Optimized L-SNEDDS and liquid supersaturatable SNEDDS (L-sSNEDDS) preparations were then adsorbed onto adsorbents and formulated as directly compressed tablets. RESULTS AND DISCUSSION The improved drug dissolution rate in the solid supersaturatable preparation (S-sSNEDDS) may be due to the formation of a nanoemulsion and the presence of drug in an amorphous state with hydrogen bond interaction between the drug and SNEDDS components. In vivo pharmacokinetic studies on eight healthy human volunteers showed a significant improvement in the oral bioavailability of piroxicam from S-sSNEDDS (F12) compared with both the pure drug (PP) and its commercial product (Feldene®) (commercial dosage form (CD)). The relative bioavailability of S-sSNEDDS (F12) relative to PP or CD was about 151.01 and 98.96%, respectively. CONCLUSION The obtained results ratify that S-sSNEDDS is a promising drug delivery system to enhance the oral bioavailability of piroxicam.