Spectrophotometric Measurement of Fluoxetine in Drug Formulation after Cloud Point Extraction

In this research study, Cloud point extraction is a powerful technique for preconcentration and separation of the fluoxetine in pharmaceutical formulation before its measurement by spectrophotometry (UV-vis). The fluoxetine was first reacted with NQS (1,2-naphthacinone-4-sulfonate) in an alkaline medium and the color product was extracted and preconcentrated using the triton X-114 surfactant. The effective parameters including, the solution pH, reagent concentration, surfactant concentration, temperature and reaction time were optimized to improve the extraction of the proposed method. In optimum conditions, a linear range of 50 to 1000 ng/L was obtained with a correlation coefficient of 0.9998 and a limit of detection of 30 ng/L. The relative standard deviation (RSD) was calculated as 1.35% for five repeated measurements of concentration of 500 ng/L of fluoxetine. The concentration factor was obtained 10 and enhancement factor was found to be 4.05. The proposed method was successfully used for pre-concentration and measurement of fluoxetine in pharmaceutical formulation. The advantages of this method are the simple performance, high speed and low cost, which are easily applicable in quality control and clinical laboratories and would be a proper alternative to expensive methods such as chromatography.