Selective Cloud Point Extraction for the Spectrophotometric Determination of Cetylpyridinium Chloride in Pharmaceutical Formulations

Abstract

In this work, we developed a simple and selective method for separation and spectrophotometric determination of trace amounts of cetylpyridinium chloride (CPC) in pharmaceutical products using cloud point extraction (CPE) technique. The method is based on cloud point extraction of the CPC in alkali conditions using of nonionic surfactant Triton X-114. Under selected conditions, the calibration graph was linear in the range of 0.50-30 µg/mL of CPC with r=0.9993 (n=10). Average recoveries for spiked samples were determined to be between 95–104%. The relative standard deviation (RSD) for 5.0 µg/mL of CPC was 1.86 % (n=10). Also, the use of micellar extraction for extracting CPC was enhanced the molar absorptivity (ε) from 1.83103 L/mol.cm in aqueous solution to 1.539104 L/mol.cm in surfactant-rich phase. The proposed method was applied for the determination of CPC in a commercial mouth washer product