Spectrophotometric Determination of Chlorprothixene with Eriochrome Cyanine R

 Two spectrophotometric methods are described for the determination of chlorprothixene (CPT). The first method is based on the extraction of the ion-association compound of CPT with eriochrome cyanine R (ECR) into butanol. The extracted compound in the organic solvent obeys Beer’s law in the range 5–80 μg mL ⁻¹. The second method is based on the measuring of the absorbance of the aqueous solution of the compound of CPT with ECR in presence of methylcellulose. Conformity with Beer’s law was evident in the range 0.7–10 μg mL ⁻¹ of chlorprothixene. The methods were applied for the determination of chlorprothixene contents in pharmaceuticals. Received July 30, 1998. Revision July 20, 1999.