Spectrophotometric determination of some thioxanthene derivatives

الملخص EN

A simple charge-transfer spectrophotometric method is described for the assay of some thioxanthene derivatives namely, chlorprothixene, thiothixene and methylene hydrochloride.

The method is based on the interaction of these drugs, as n-electron-donors, with either 2, 3- dichloro-5, 6-dicyano-p-benzoquinone (DDQ) or chloranilic acid, as p-acceptors, to give a highly colored radical anions.

The absorbance–concentration plot is linear over the ranges 8-40 µg/ml and 5-40 µg/ml for thiothixene and methylene, respectively with (DDQ) and 10-60, 8-60 and 10-70 µg/ml for chlorprothixene, thiothixene and methylene, respectively with chloranilic acid.

The drug: DDQ molar ratios was found to be 1:2 and the drug : chloranilic acid was found1 : 1.

The proposed method has been successfully applied for the determination of the examined drugs in tablets containing them the percentage recoveries ranges from 99.74-103.15.

The assay results were in accord with the pharmacopeia results.