A quantitative nuclear magnetic resonance (qNMR) method to measure the content of Orlistat in tablets was studied and found to be efficient, accurate, reliable, and simple. In this paper, phloroglucinolanhydrous and dimethylsulfoxide-d₆ (DMSO-d₆) served as the internal standard and solvent, respectively. The qNMR methodology, including the linearity, range, the limit of detection (LOD) and quantification (LOQ), stability, precision, and accuracy, was validated seriatim, and the results were very favorable. The content determination results of three batches of Orlistat in tablets were almost identical upon comparing the qNMR method and the high-performance liquid chromatography (HPLC) method. The recommended method authentically compensated the deficiencies of the current HPLC method for determining Orlistat content, and proved to be a method complementary to traditional analysis for the purity measurement of Orlistat in some pharmaceutical preparations.
Keywords: Orlistat; internal standard method; methodology validation; qNMR.