Isolation of oxidative degradation products of atorvastatin with supercritical fluid chromatography

Abstract

The isolation of four oxidative degradation products of atorvastatin using preparative high-performance liquid chromatography applying at least two chromatographic steps is known from the literature. In this paper it is shown that the same four impurities could be isolated from similarly prepared mixtures in only one step using supercritical fluid chromatography. The methods for separation were developed and optimized. The preparation of the mixtures was altered in such a way as to enhance the concentration of desired impurities. Appropriate solvents were applied for collection of separated impurities in order to prevent degradation. The structures of the isolated impurities were confirmed and their purity determined. The preparative supercritical fluid chromatography has proven to be superior to preparative HPLC regarding achieved purity of standards applying fewer chromatographic as well as isolation steps.

Spectroscopic studies on photodegradation of atorvastatin calcium

“…A topic that has attracted a lot of attention lately in the field of drugs is their photodegradation, when toxic compounds can be formed, and the therapeutic activity of these pharmaceutical compounds can be much diminished 13 . Various photodegradation pathways of ATC 14 and development of various methods for the isolation of degradation products of ATC 15 were reported. Until now, the method used for the study of the degradation products of atorvastatin was HPLC 16 , 17 , LC–MS 18 and nuclear magnetic resonance (NMR) 19 .…”