Cloud-Point Extraction and Flame Atomic Absorption Spectrometric Determination of Valsartan in Pure Form and Its Pharmaceutical Preparations

Abstract

To determine Valsartan in pure form and its pharmaceutical preparations, a new method using UV-Vis and Flam atomic absorption spectrophotometry (FAAS) has been used. This is done by cloud point extracting (CPE) method using active surface Triton X-114 as a non-ionic surfactant. The (CPE) method involves the formation of two complex, the first is based on the formation of a complex between valsartan and para-bromoaniline in the presence of para-dimethyl  amino benzaldehyde (Mannich complex)  at 438 nanometers , While the second  complex is formed between valsartan and Fe(III) at 441 nanometers , and another method (FAAS) was applied to estimate Valsartan using second complex . A number of conditions were established such as the volume of a non-ionic surfactant, temperature , effect of time on complex formation, reagent volume, and metal ion concentration . the optimal conditions used being the same in UV_Vis and FAAS where 75 °C was the best temperature for cloud point extraction . Ethanol was the best solvent for extracting the two complexes, and Beer's law range was 0.8 _7.2 µg/ml for (UV_Vis) and 0.5-4.5 µg/ml for (FAAS), The samples' average recoveries were found to range between 99.88-101.042%. The relative standard deviation (RSD) for1.6 µg/mL of VAL was ˂ 2.5% The limits of detection and quantification were 0.004210 and 0.01047 µg/mL respectively. The method has been validated and successfully applied to pharmaceutical valsartan preparations, and from the obtained results and recovery ratios, we found it to be a good, highly sensitive, inexpensive, non-toxic, and environmentally friendly method.