Abstract
Three simple UV spectrophotometric methods were established and validated for the concurrent estimation of a ternary mixture of an antihypertensive formulation consisting of amlodipine (AMD), hydrochlorothiazide (HCZ) and telmisartan (TEL) using 50% v/v ethanol-water as solvent. The first method was based on the determination of AMD using zero-order spectra (371.0 nm), whereas, HCZ and TEL were quantified by measuring the peak height at zero crossing wavelength of the second derivative of ratio spectra (279.4 nm and 314.7 nm). The second procedure was accomplished by determining the absorption difference between peak and trough at two different wavelengths of double devisor ratio spectra (369.4 nm-297.5 nm for AMD; 272.1 nm-241.5 nm for HCZ; 297.2 nm-272.7 nm for TEL) The third method involved the measurement of the peak amplitude of maxima or minima of first derivative spectra of double devisor ratio spectra. (390.4 nm for AMD, 278.9 nm for HCZ 288.1 nm for TEL) All the drugs showed good linearity with an acceptable correlation coefficient in all the three proposed methods. Further accuracy, precision, sensitivity, robustness, recovery studies and selectivity were determined according to the ICH strategies and the results were in agreement with the acceptable range. In addition, the proposed techniques were applied effectively for quantification of AMD, HCZ and TEL from the solid dosage form. The comparison of assay outcomes, using the student's t-test and F test, revealed that there is no significant change among the proposed UV and the reported HPLC procedures. The manipulation of UV spectra is simple, fast, and the proposed methods were environment friendly and economical when compared to very expensive chromatographic methods. Hence, these procedures can be employed for the routine quality control examination in industries and laboratories. (C) 2020 Elsevier B.V. All rights reserved.