A simple and reliable reverse-phase high-performance liquid chromatographic procedure for determination of paclitaxel (taxol) in human serum

A simple, fast, and reliable isocratic (mobile phase: acetonitrile/methanol/water [48/11/41]), reverse-phase (C18 column) high-performance liquid chromatography method for the determination of paclitaxel concentration in human serum is presented. The procedure uses a new and convenient one-step sample-purification procedure that requires only 400 mu l of sample and uses N-heptylbenzamide as an internal standard. Paclitaxel is detected by UV absorbance measurement at 227 nm. The method has a broad linear range (0.01 to 10 mg/l, or 0.012 to 11.7 mu mol/l; r > 0.999), and the detection limit is 0.01 mg/l (0.012 mu mol/l). The deviation from target value is less than or equal to 1.5%, and coefficients of variation are less than or equal to 13.8% within runs and less than or equal to 15.3% between runs. Recovery of paclitaxel is greater than or equal to 92.6%. No interferences were observed from endogenous compounds or from more than 30 drugs that may be administered with paclitaxel. Docetaxel, which is not concurrently administered, coeluted with paclitaxel. Compared with previously published high-performance liquid chromatography procedures for the determination of paclitaxel, the particular advantage of the method presented here is its simple and rapid single-step sample-purification procedure, which makes a high recovery of paclitaxel from serum samples possible and results in a pure extract, avoiding interferences from endogenous compounds. The method is suitable for pharmacological studies and routine analysis.