Procedures utilizing a direct spectrophotometric measurement (such as described in the British Pharmacopoeia) for the analysis of trifluoperazine tablets suffer from several disadvantages. The possibility of excipient interference is not precluded and this factor, coupled with use of a fixed reference absorptivity value, can sometimes lead to erroneous results. Therefore, alternative assay procedures are required to assess accurately the drug content. Two such methods are described. The first is the acid-dye type and involves the partitioning of a trifluoperazinebromocresol purple complex between an aqueous buffer pH 6 and benzene containing 1 2 isoamyl alcohol and subsequent measurement of the yellow-colored organic phase at 410 mp. Acidic and neutral compounds as well as the common excipients do not interfere. The second method employs an alkaline siliceous earth column through which the drug is eluted into a chloroform-methanol-HCI system and the absorbance measured at 259 mp. The precision and accuracy of the alternative methods, as well as the pharmacopeial procedure are compared using commercial dosage forms and simulated drug-excipient mixtures.