Sequential Spectrophotometric Method for the Simultaneous Determination of Amlodipine, Valsartan, and Hydrochlorothiazide in Coformulated Tablets

Hany W Darwish,Maissa Y Salem,Said A Hassan,Badr A El-Zeany

doi:10.1155/2013/273102

Hany W Darwish, Maissa Y Salem + Show 2 more

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https://doi.org/10.1155/2013/273102

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Abstract

A new, simple and specific spectrophotometric method was developed and validated in accordance with ICH guidelines for the simultaneous estimation of Amlodipine (AML), Valsartan (VAL), and Hydrochlorothiazide (HCT) in their ternary mixture. In this method three techniques were used, namely, direct spectrophotometry, ratio subtraction, and isoabsorptive point. Amlodipine (AML) was first determined by direct spectrophotometry and then ratio subtraction was applied to remove the AML spectrum from the mixture spectrum. Hydrochlorothiazide (HCT) could then be determined directly without interference from Valsartan (VAL) which could be determined using the isoabsorptive point theory. The calibration curve is linear over the concentration ranges of 4–32, 4–44 and 6–20 μg/mL for AML, VAL, and HCT, respectively. This method was tested by analyzing synthetic mixtures of the above drugs and was successfully applied to commercial pharmaceutical preparation of the drugs, where the standard deviation is <2 in the assay of raw materials and tablets. The method was validated according to the ICH guidelines and accuracy, precision, repeatability, and robustness were found to be within the acceptable limits.

Highlights

Many analytical methods have been introduced for the analysis of mixtures among which the molecular absorption spectroscopy was the most simple, fast, and applicable in laboratories
This paper describes the development and subsequent validation of a novel, simple, and rapid spectrophotometric method “Sequential Spectrophotometry” for simultaneous quantitation of ternary mixtures
Few methods were reported for the simultaneous estimation of AML, VAL, and HCT in their ternary mixture [23,24,25,26] and only one spectrophotometric method was developed for the determination of this mixture [27]

Summary

Introduction

Many analytical methods have been introduced for the analysis of mixtures among which the molecular absorption spectroscopy was the most simple, fast, and applicable in laboratories. Molecular absorption spectroscopy has been extensively used for the determination of drugs in pharmaceutical preparations with a view to the development of analytical methods. Valsartan (VAL) (chemically described as N-[p-(o-1Htetrazol-5-ylphenyl)benzyl]-N-valeryl-L-valine [10] Figure 1), is a potent and specific competitive antagonist of the angiotensin-II AT1-receptor. It is used for treatment of hypertension, heart failure, and post-myocardial infarction [12]. Few methods were reported for the simultaneous estimation of AML, VAL, and HCT in their ternary mixture [23,24,25,26] and only one spectrophotometric method was developed for the determination of this mixture [27]. The authors developed derivative and chemometric methods for the analysis of the same mixture [28]

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