Estimation of impurity profiles of drugs and related materials Part 18. Impurities and degradation products of mazipredone

Chemical and analytical characterization of related organic impurities in drugs

“…Impurities 4 and 5 in hydrocortisone and prednisolone can be by-products of the microbiological hydroxylation but they are also among the several oxidative degradation products of these drugs [37]. A similar degradation pathway was found for the 21-(N-methylpiperazinyl) analogue of prednisolone (mazipredone) [1,65]. The diketopiperazine derivatives 11 and 14 are impurities of enalapril and lisinopril, respectively.…”

“…If TLC is used, reflection UV spectra are similarly easily available [9]. Although UV spectroscopy is the least effective among the spectroscopic techniques, often very important information is obtainable for the structure elucidation [17,34,36,37,41,43,44,45,46,47,49,58,65,66,69,70].…”

“…More typically, at least one more step is necessary and this is usually mass spectrometry [15,35,36,37,40,43,44,46,47,48,49,52,55,56,57,58,65,66]. Due to its high sensitivity, small samples obtained from the TLC plate or analytical HPLC fraction are suitable to take good quality spectra in the off-line mode.…”

“…The following on-line techniques of GC-MS [18,36,37,46,52,57] and HPLC-MS are more developed. The latter is in our time the most generally used hyphenated method in impurity profiling [19,37,41,46,65,71]. The importance of CE-MS [12] and CEC-MS [20] is increasing.…”

Recent Advances in the Analysis of Steroid Hormones and Related Drugs

“…Six synthesis-related impurities were identified in prednisolone. 239 Several synthesis-related impurities 240,241 and degradants 242,243 (mainly products of intramolecular oxido-reduction reactions were identified in the course of the stress stability test of mazipredone (21-deoxy-21-N-methylpiperazinyl derivative of prednisolone). Among minor impurities the 9α-bromo analogue of the parent drug was found as the main impurity in triamcinolone acetonide.…”