LC AND LC-MS STUDY ON STRESS DECOMPOSITION BEHAVIOR OF PACLITAXEL AND ESTABLISHMENT OF VALIDATED STABILITY-INDICATING ASSAY METHOD

Abstract

Paclitaxel was subjected to different ICH prescribed stress conditions of thermal stress, hydrolysis, oxidation and photolysis. In total, six major degradation products were detected by LC and to elucidate the degradation products of Paclitaxel we develop a rapid and systematic strategy based liquid chromatography–mass spectrometry (LC–MS) profiling and liquid chromatography–tandem mass spectrometry (LC–MS–MS) sub structural technique. For establishment of stability-indicating assay, the reaction solutions in which different degradation products were formed were mixed, and the separation was optimized by varying the LC conditions. An acceptable separation was achieved using a C-18 column and a mobile phase comprising of 65:35 buffer (2 mM ammonium acetate, pH 6.9): acetonitrile held isocratic for 26 min followed by a 25 min linear gradient to 20:80 (buffer–acetonitrile) at a flow-rate of 2.0 ml/min. The degradation products appeared at relative retention times (RRT) of 0.14 (side chain methyl ester), 0.16 (baccatin III), 0.43 (10-deacetyl Paclitaxel), 0.52 (Paclitaxel isomer), 0.67 (oxetane ring opened) and 1.33 (7-epi Paclitaxel). The validation studies established a linear response of the drug at concentrations between 50ng/ml and 1000ng/ml. The mean value (±R.S.D.) of correlation coefficient was 0.9998 (±0.01). The mean R.S.D. values for Paclitaxel inter-day precision were 0.24 and 0.90, respectively. The recovery of the drug ranged between 99.42 and 100.58%, when it was spiked to a mixture of solutions in which sufficient degradation was observed.