Cloud-point extraction and spectrophotometric determination of clonazepam in pharmaceutical dosage forms

Abstract

Aneco-friendly, simple and very sensitive method was developed for preconcentration and determination of clonazepam (CLO) in pharmaceutical dosage forms using cloud point extraction (CPE) technique. The method is based on cloud point extraction of product from oxidative coupling between reduced CLO and phloroglucinol (PHG) using Triton X-114 as surfactant. The product was extracted by micelles of the non-ionic surfactant (TritonX-114) and subsequently detected spectrophotometrically at specific 543 nm. Under optimal conditions, the linearity of calibration curve was in the range of 0.3-25 µg/mL of CLO (r = 0.9994). Average recoveries for samples were determined to be between 96-101%. The relative standard deviation (RSD) for 3.0 µg/mL of CLO was (2.5%). The limits of detection and quantification were 0.11 and 0.37 µg/mL respectively. The suggested method was applied successfully for determination of CLO in commercial tablets.

KEY WORDS: Clonazepam, Cloud point extraction, Triton X-114

Bull. Chem. Soc. Ethiop. 2017, 31(3), 373-382.

DOI: http://dx.doi.org/10.4314/bcse.v31i3.2