Analysis of Carbamazepine, Oxcarbazepine, Their Impurities, and Non-Labeled Interfering Substances by Stability Indicating UPLC/MS/MS Method: Studying Method's Greenness Profile

Research Abstract

Carbamazepine (CBZ) and Oxcarbazepine (OX) are highly effective anti-psychotic drugs. In USP, it is stated that CBZ has several impurities including, iminodibenzyl (IDB), iminostilbene (IMS), and 9-methylacridine (MA). While, for OX, it is reported to have impurities like, CBZ, IMS and 9-methylacridine (MA). Presence of such impurities in various forms may lead to reduce in efficacy and increase side effects. It is declared that CBZ (Tegretol®) and OX (Trileptal®) oral suspensions contain methylparaben, propylparaben, and sorbic acid as preservatives. For the first time, CBZ and OX were determined with their impurities and formulation excipients with a highly selective and sensitive ecofriendly LC/MS/MS method using methanol: water containing 0.1 % formic acid (95:5, v/v) as a mobile phase. Mass spectrometric quantitation was carried out in positive and negative-ion modes. Application of the proposed method to quantify CBZ and OX in their tablets and oral suspensions were successfully done. The results obtained by the suggested method and the reported methods for both drugs agreed well. The developed method has advantages of being ecofriendly using simple green mobile phase. Unlike other published methods, it is successfully applied to quantify the impurities and excipients along with parent drugs within limits recommended by USP guidelines.

Research Keywords

LC/MS/MS; Carbamazepine; Oxcarbazepine; Impurities; Formulation Excipients; Greenness profile.