Die Pharmazie is published by IMR Press from Volume 81 Issue 1 (2026). Previous articles were published by another publisher under the CC-BY licence, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement.
Identification, isolation and characterization of potential degradation products in pioglitazone hydrochloride drug substance
K. Ramulu 1, T. Thilak Kumar 1, S. Radha Krishna 1, R. Vasudev 2, M. Kaviraj 2, B. M. Rao 3, N. Someswara Rao 4
Affiliations
Article Info
1 Analytical Research, Custom Pharmaceutical Services, Visakhapatnam, India
2 Analytical Research Department, Discovery Research, Dr. Reddy's Laboratories Ltd., Visakhapatnam, India
3 Andhra University, Visakhapatnam, India
4 Andhra University, Visakhapatnam, 530 003, India, Email: drbmrao@hotmail.com
Abstract
During stress degradation studies of pioglitazone hydrochloride, one major unknown oxidative degradation impurity and two major unknown base degradation impurities were identified by LC-MS. These impurities were isolated using preparative liquid chromatography. Based on the spectral data (1H NMR, 13C NMR, MS and IR), oxidative degradation impurity, base degradation impurity-1 and base degradation impurity-2 were characterized as pioglitazone N-oxide, 3-(4-(2-(5-ethylpyridine-2yl) ethoxy) phenyl)-2-mercaptopropanoic acid and 2-(1-carboxy-2-{4-[2-(5-ethylpyridine-2yl)-ethoxy] phenyl}-ethyl disulfanyl)-3-{4-[2-(5-ethylpyridine-2yl)-ethoxy] phenyl propanoicacid, respectively. The formation and mechanism of these impurities were discussed and presented.