Determination of Promethazine Hydrochloride via Area under Curve

Abstract

Promethazine hydrochloride was determined by developing a simple, sensitive, and economical spectrophotometric method. The method was based on calculating the area under the curve of the zero-order spectrum and obeyed the Beer-Lambert law over a range of concentrations (5-45 μg/mL). The Rec% in the method was 101.413-99.13043. In the area under the peak method, the recovery percentage (Rec%) ranged from 98.85714% to 102.0916%, while the relative standard deviation percentage (RSD%) ranged from 0.3288% to 0.7443%. In the accuracy and consistency test of the method, the Rec% value ranged from 99.7942% to 100.838%, while the RSD% value ranged from 0.3288% to 0.7443% for the drug. In the application of the method, the Rec% value ranged from 99.1725% to 101.983%, while the RSD% ranged from 0.584265% to 0.900128%. In the standard addition method, the Rec% value was between 99.06859-102.4576%, while the RSD% ranged between 0.1941-0.7412% and the limits of detection were 0.0478, while the limits of quantification were 0.0628 for Promethazine hydrochloride. The method was successfully applied to estimate the drug in its pure form and in pharmaceutical preparations.