Determination of Thiomersal, Lidocaine and Phenylepherine in their Ternary Mixture

Nada S Abdelwahab

doi:10.4172/2157-7064.1000199

Abstract

This work is concerned with the development and validation of two accurate, precise and specific spectrophotometric and chromatographic methods for analysis of Phenylepherine (PE), Lidocaine (LC) and Thiomersal (TM) in their ternary mixture and in Chromoderm® solution. The developed spectrophotometric method is the mean centering of ratio spectra (MCR) spectrophotometric method that depends on using the mean centered ratio spectra in two successive steps which eliminates the derivative steps and therefore the signal to noise ratio is enhanced. On the other hand, the developed chromatographic method isocratic RP-HPLC method that depends chromatographic separation on Zorbax C18 column using a mobile phase consisting phosphate buffer: acetonitrile: triethylamine (40:60:0.1, by volume pH=6 with orthophosphoric acid). The flow rate was 0.6 mL min-1 and the eluent was monitored at 245 nm. Factors affecting the developed methods were studied and optimized. Moreover, they have been validated as per ICH guidelines. The developed methods have been successfully applied for determination of PE, LC and TM in different laboratory mixtures and in solution dosage form. Also, Statistical analysis of the results of the two developed methods with each other using F and student’s t tests showed no significant difference

Highlights

Phenylepherine (PE), chemically known as 3-[(1R)-1-hydroxy-2(methylamino) ethyl] phenol [1]
Due to the pharmaceutical importance of the studied drugs and the lacking in the methods developed for their determination in ternary mixture, this work aims to develop and validate accurate and precise spectrophotometric and chromatographic methods for determination of PE, LC and TM in their ternary mixture with the application to Chromoderm® solution which is used as analgesic, astringent, anaesthetic and antiseptic in minor surgery and wound infection
The developed MCR method depends on the mean centering of ratio spectra, it eliminates the derivative steps and signal- tonoise ratio is enhanced [35]

Summary

Introduction

Phenylepherine (PE), chemically known as 3-[(1R)-1-hydroxy-2(methylamino) ethyl] phenol [1]. Lidocaine (LC), is chemically designated as (2-(diethyl amino)N-(2,6-dimethyl phenyl)acetamide [1] It is an official drug in BP [2] and USP [3]. It is used topically to relieve itching, burning, pain from skin inflammations [9] and is used as a local anesthetic for minor surgery [4,9,10,11]. It is characterized by rapid onset of action and intermediate duration of efficacy [12,13,14]

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Conclusion