Different spectrophotometric and TLC-densitometric methods for determination of olmesartan medoxomil and hydrochlorothiazide and their degradation products

Abstract

In this work, multivariate calibration models and TLC-densitometric methods have been developed and validated for quantitative determination of olmesartan medoxomil (OLM) and hydrochlorothiazide (HCZ) in presence of their degradation products, olmesartan (OL) and salamide (SAL), respectively. In the first method, multivariate calibration models including principal component regression (PCR) and partial least square (PLS) were applied. The wavelength range 210-343 nm was used and data was auto-scaled and mean centered as pre-processing steps for PCR and PLS models, respectively. These models were tested by application to external validation set with mean percentage recoveries 99.78, 100.01, 100.41 and 100.46% for OLM, HCZ, OL and SAL, respectively, for PLS model and also, 100.22, 100.40, 102.25 and 100.13% for them, respectively, for PCR model. The second method is TLC-densitometry at which the chromatographic separation was carried out using silica gel 60F254 TLC plates and the developing system consisted of a mixture of ethyl acetate:chloroform:methanol: formic acid:tri-ethylamine (60:40:4:4:1, by volume) with UV-scanning at 254 nm. The developed methods were successfully applied for determination of OLM and HCZ in their pharmaceutical dosage form. Also, statistical comparison was made between the developed methods and the reported method using student’s-t test and F-test and results showed that there was no significant difference between them concerning both accuracy and precision.

Universal procedures for spectrophotometric determination of anticoccidial drugs; application to multi-ingredient veterinary formulation and computational investigations for multivariate analysis

“…2021 -European Journal of Chemistry -CC BY NC -DOI: 10.5155/eurjchem.12.4.368-376.2144 For both PLS-2 and PCR, the concentration residuals were plotted against the actual concentrations of the prepared mixtures (Figures 7 and 8), and the residuals for all samples were found to be randomly distributed around zero [25][26][27][28][29][30][31][32][33]. The average recoveries of each drug using PLS-2 and PCR methods are summarized in Table 2.…”

“…The validation set is composed of 5 laboratory-prepared mixtures containing different proportions of AMP, SQX, and DVD (Table 1). In addition, the concentrations of AMP, SQX, and DVD in the veterinary formulation extract were calculated using the optimized PLS-2 or PCR calibration model after being recorded in the same specified lambda range [25][26][27][28][29][30][31][32][33].…”