Abstract
Two simple, selective and accurate methods were developed for the determination of Labetalol hydrochloride in pure form and pharmaceutical tablets. Both methods are based on derivatization of the studied drug with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBDCl) in alkaline medium (pH7.5).The reaction product was measured spectrofluorimetrically at 540nm after excitation at 476nm (method I) or spectrophotometrically at 480nm (method II). The calibration graphs were rectilinear over the concentration ranges of 0.10–2.0 and 1.0–11.0μgmL−1 for methods I and II, respectively. The proposed methods were successfully applied to the analysis of commercial tablets without interference from common excipients. Furthermore, the spectrofluorimetric method was utilized for the in vitro determination of labetalol in spiked human plasma, with a percent mean recovery (n=3) of 97.80±1.29%. Moreover, the spectrofluorimetric method was extended to examine the stability study of LBT under different stress conditions such as alkaline, acidic, oxidative, photolytic and a thermal degradation.
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•Spectrofluorimetric and spectrophotometric analytical methods for Labetalol hydrochloride was developed.•The methods are based on derivatization of the studied drug with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBDCl) in alkaline medium (pH7.5).•Validation of the proposed methods according to ICH and USP XXV validation guidelines was done.•Analysis of investigated drug in pharmaceutical dosage form was performed.•Analysis of the investigated drug in spiked human plasma was performed.