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

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.

Mean centering of double divisor ratio spectra, a novel spectrophotometric method for analysis of ternary mixtures

“…There are reported methods for the determination of AML, ALI or HCT in different dosage forms [27][28][29][30][31]. AML, ALI and HCT were simultaneously determined in their ternary mixture by HPLC and capillary electrophoresis [32,33].…”

“…Ternary mixtures suffer a higher degree of difficulty in spectrophotometric resolution than binary mixtures, due to the severe overlap usually noticed in their spectra. Many methods have been developed for resolution of the overlapped spectra of ternary mixtures using different spectrophotometric and chemometric techniques [1][2][3][4][5][6][7][8].…”

Simultaneous Determination of Amlodipine Besylate, Valsartan, and Its Related Substances in Their Film-Coated Tablets Dosage form by RP-HPLC Method

“…AML and VAL are official in BP and USP [2,3]. Literature review showed that few analytical methods have been described for the estimation of AML and VAL including spectrophotometric [4][5][6][7], highperformance liquid chromatography (HPLC) [8][9][10][11][12][13][14], spectrofluorimetric method [15][16][17], electrochemical and voltammetric methods [18][19][20][21][22] had been reported for the estimation of AML and VAL in pure or in dosage forms. According to the best of my knowledge, there is no Stability indicating new-RP-HPLC method for simultaneous determination of Amlodipine Besylate, Valsartan and its related substances in their film-coated tablets dosage form.…”

Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study

“…There are reported methods for the determination of BIS or HCT in different dosage forms [47][48][49][50] and in their binary mixtures [45,[51][52][53][54][55].…”

“…Many reported methods were reported for the determination of AML, ALI or HCT in different dosage forms [57][58][59][60][61][62]. HPLC and capillary electrophoresis methods were reported for simultaneous determination of this ternary mixture [63,64].…”