Development and validation of a stability indicating HPLC method for the determination of buprenorphine in transdermal patch

A rapid and sensitive stability indicating HPLC method has been developed and validated for the determination of buprenorphine (BPN) in transdermal patch. Chromatographic separation was achieved isocratically on an XBridge(superscript TM) Shield RP18 column with a mobile phase of acetonitrile/0.063 M ammonium bicarbonate buffer (pH 9.5) (58:42, v/v) at the flow rate of 1.5 mL/min with UV absorbance monitoring at 230 nm. The system performance was evaluated and the result showed that BPN and degradation products were separated. Buprenorphine was subjected to neutral, acidic and basic hydrolysis as well as chemical oxidation to evaluate the specificity. The calibration curve of buprenorphine was linear in the range of 30~70 μg/mL (r=0.9999, n=5). The values of RSD (%) for the intra-day and inter-day precision ranged from 0.04 to 0.22 and 0.65 to 0.88%, respectively. The average of the recovery percentage ranged from 98.86 to 99.36%. The detection limit (DL) and quantitation limit (QL) for buprenorphine were 0.008 and 0.024 μg/mL, separately. The robustness of this method was also evaluated on the small fluctuations of pH in the mobile phase, the mobile phase compositions, and the flow rate. The results of stability studies showed the hydrolysis reaction of buprenorphine followed zero-order kinetics model in acidic and basic environment and followed first-order kinetics model in the presence of hydrogen peroxide. This analytical method was successfully applied to the determination of buprenorphine in transdermal patch and can be used for routine quality control work.