Quantitative determination of Levomepromazine in pharmaceuticals by spectrophotometric method as its sulfoxide

The oxidative derivatization method using Diperoxyazelaic acid for the indirect spectrophotometric determination of Levomepromazine hydrochloride is presented. Diperoxyazelaic acid is introduced as a derivatizing agent for Levomepromazine, yielding the sulfoxides. This reaction product was successfully used for the spectrophotometric determination of the Levomepromazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Levomepromazine hydrochloride in the concentration range of 3-150 µg/mL. The limit of quantification, LOQ (10S) is 2.85 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Levomepromazine in Tisercin Solution for Injection 25mg/mL was demonstrated. The present method is precise, accurate and other excipients: anhydrous citric acid, monothioglycerol, sodium chloride did not interfere. RSD = 1.24 % (δ = –0.02 %)