New sensitive turbidimetric method for determination of losartan potassium in pharmaceutical formulations using flow injection combined with homemade turbidimeter

Abstract

This paper is describing a rapid and sensitive method for determination of Losartan potassium (LOS-K) in pure and drug forms. The method is based on the reaction of LOS-K with potassium hexacyanoferrate (III) in acidic medium to form a yellow precipitate. The precipitated product was monitoring and measurements using homemade (Ayah 6Sx1-T-2D solar cell) analyzer that combined with a continuous flow injection technique. Chemical and physical factors such as reagent concentration, acid medium, flow rate, sample volume, purge duration, and delay coil reaction were investigated and optimized. The linear dynamic range of LOS-K was 0.1-2 mmol/L with linearity percentage (r2%) 98.41%. Limit of detection (LOD) at a minimum concentration in the calibration graph was 5.8 µg/sample and limit of quantitation was LOQ=38.3 µg/sample. A comparison of developed method with reference methods (UV-Spectrophotometry at λmax= 232) was also made. These results indicate that the proposed method- which was successfully applied for determination of LOS-K in the pharmaceutical samples, can be used as an alternative for classical methods.