Spectrophotometric determination of chlorprothixene with eriochrome cyanine R

Two spectrophotometric methods are described for the determination of chlor prothixene (CPT). The first method is based on the extraction of the ion-as sociation 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 mu g mL(-1). The second method is based on the measuring of the absorban ce of the aqueous solution of the compound of CPT with ECR in presence of m ethylcellulose, Conformity with Beer's law was evident in the range 0.7-10 mu g mL(-1) of chlorprothixene. The methods were applied for the determinat ion of chlorprothixene contents in pharmaceuticals.