Simultaneous Determination of Levomepromazine Hydrochloride and Its Sulfoxide by UV‐Derivative Spectrophotometry and Bivariate Calibration Method

Abstract

Two spectrophotometric methods are proposed for the simultaneous quantification of levomepromazine hydrochloride (LV) and its main degradation product levomepromazine sulfoxide (LV‐SO). One of them is based on the first order derivative spectra generated by the Savitzky‐Golay algorithm (third‐order polynomial degree, Δλ=10 nm). Determination of levomepromazine hydrochloride and its sulfoxide was realized by measurements of amplitudes of derivative spectra at 332 nm and 278 nm, respectively. The Beer law was obeyed in the concentration range 1.5–50 µg/mL for LV and 2.5–50 µg/mL for LV‐SO. The second of the proposed methods utilized the bivariate calibration algorithm. The determination was performed at 302 nm for levomepromazine and at 334 nm for sulfoxide. The elaborated methods allowed determination of LV in the concentration range 1.0–25 µg/mL while LV‐SO was determined in the concentration range 2.0–50 µg/mL.

Keywords:

• Levomepromazine hydrochloride
• levomepromazine sulfoxide
• derivative spectrophotometry
• bivariate calibration
• simultaneous determination