Simultaneous determination of tricaprylin, DPPG and DEPC in propofol liposomes by a methyl esterification method and GC-FID analysis

Abstract

As a novel injection preparation, propofol liposomes have extensive application prospects in clinical practice, and lipid components in them need to be quantified for quality control. In this study, a simple and accurate GC-FID method coupled with a methyl esterification pretreatment was developed for simultaneous determination of three main excipients (tricaprylin, TA; dipalmitoyl phosphatidylglycerol, DPPG; 2-dierucoyl-sn-glycero-3-phosphocholine, DEPC) in propofol liposomes with stearic acid used as the internal standard (IS). Response surface methodology was utilized for optimizing three factors of the methyl esterification reaction (the temperature, BF₃ concentration and reaction time were optimized to be 75.0 °C, 14.5% and 6.5 min, respectively). Under optimum conditions, the average methyl esterification rate of the three analytes reached 96.43 ± 0.16% (n = 3). Moreover, multiple sample solutions could be simultaneously prepared, which would promote the efficiency and accuracy of quantitative analysis. Three calibration curves had good linear regression (r > 0.9999) within the tested ranges, the average recoveries ranged from 98.64% to 102.44% and the RSDs of the precision, repeatability, stability and recoveries were all below 1.53%. Finally, the validated method was successfully applied to the quantitative analysis of the three analytes in six batches of propofol liposomes.