Solubility of the picrates, picrolonates and styphnates of several kinds of antihistaminics was examined and quantitative determinations were carried out to determine whether these salts could be used for analyses. It was shown that the picrates and picrolon-ates of diphenylhydramine and N-(dimethylaminoethyl)-phenothiazine, picrate of Tripelennamine, and the styphnate of N-(2-dimethylaminopropyl)-phenothiazine could be used for determinations but none of the salts of thonzylamine and doxylamine were suitable for such use.