Determination of Benazepril HCl and Hydrochlorothiazide in Pharmaceutical Preparations Using UV-Visible Spectrophotometry and Genetic Multivariate Calibration Methods
Durmus Özdemir1* and Erdal Dinc2
1.Department of Chemistry, Faculty of Science, İzmir Institute of Technology, 35430 Urla-İzmir, Turkey
2.Department of Analytical Chemistry, Faculty of Pharmacy, University of Ankara, 06100 Tandoğan-Ankara, Turkey
(Received: February 16, 2005; Accepted: June 14, 2005)
ABSTRACT
Simultaneous determination of binary mixtures of benazepril and hydrochlorothiazide in pharmaceutical tablets using U V-visible spectrophotometry, classical least squares (CLS) and three genetic algorithms (GA) based multivariate calibration methods was demonstrated. The three genetic multivariate calibration methods are Genetic C lassical Least Squares (GCLS), Genetic Inverse Least Squares (GILS) and Genetic Regression (GR). The sample data set contains the U V- spectra of 28 synthetic mixtures of benazepril (12~36μg/mL) and hydrochlorothiazide (10~22 μg/mL) and 16 tablets containing both compounds. The spectra cover the range from 210 to 360 nm in 0.1 nm intervals. Several calibration models were built with the four methods. The root mean square error of calibration (RMSEC) and validation (RMSEV) for the synthetic data were in the range of 0.19 and 0.34 μg/mL for all the genetic algorithm based methods. The root mean square error of Prediction (RMSEP) values for the tablets were in the range of 0.04~0.20 mg/tablets. A comparison of genetic algorithm selected wavelengths for each component was also included.
Key words: U V-visible spectrophotometry, multivariate calibration, genetic algorithms, genetic regression