Analysis of diltiazem and its related substances by HPLC and HPLC/MS

Diltiazem (DTZ) is an optically active calcium channel blocker having a benzodiazepine structure. The drug used in therapy is (+)-cis-diltiazem with configuration (2S, 3S). To describe the analytical profile of DTZ different stationary phases (RP-18, RP-8, monolithic support) were tested. The best separation of DTZ from A, 13, E and F was obtained using as stationary phase a RP-8 or a monolithic RP-18. The characterization of impurities was carried out using two analytical systems, HPLC and HPLC/MS. (c) 2004 Elsevier B.V. All rights reserved.