Determination of Losartan Potassium and Hydrochlorothiazide Mixture by AUC-CM and DRS1 Spectrophotometric Methods

Abstract

Determination of losartan potassium LOS and hydrochlorothiazide HCTZ by two methods in raw material and tablets formulations. The first method is the area under the curve correction method (AUC-CM). The second one is the first derivative of the ratio spectra method (DRS₁). The determination by (AUC-CM) was at the wavelength’s ranges (245 - 255) nm for LOS and (312 - 320) nm for HCTZ. The LOS linearity was to be between (2.00 – 48.00) µg/mL with R² = 0.99994, while the HCTZ linearity was to be between (7.50 – 100.00) µg/mL with R² = 0.99987. By using (DRS₁), wavelengths of 237.0 nm and 270.0 nm, used for the determination of LOS and HCTZ, respectively. The LOS linearity was to be between (1.50 – 50.00) µg/mL with R² = 0.99998, while the HCTZ linearity was to be between (1.00 – 20.00) µg/mL with R² = 0.99996.  The validation of the two methods was estimated as linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, robustness, recovery and specificity. The two methods were successfully applied for the determination of LOS and HCTZ in tablets formulations in one Syrian pharmaceutical product LOTID in two doses (50/12.5 and 100/25) mg/tab. The proposed methods are not complicated, available in spectrophotometer programming, direct, and sensitive and does not require any pre- extraction process. Thus, the two methods could be ready to use in routine analysis and quality control.