A series of specific physical criteria, by which four amine-containing antiparkinson agents and a newer amine-containing skeletal muscle relaxant, currently in popular clinical application, can be identified and differentiated, is presented. Twentythree derivatives of these compounds were prepared using a variety of characterizing agents which included picric acid, ammonium reineckate, sodium tetraphenylborate, chloroplatinic acid, and methyl iodide. By the use of microcrystal tests, and formation of derivatives, it is possible to differentiate biperiden, cycrimine, procyclidine, trihexyphenidyl, and phenyramidol. Photomicrographs are presented as a supplemental and additional parameter for characterization purposes.
ARIOUS techniques for the identification of V t r i h e x y phenidy 1, cycrimine, and procyclidine hydrochloride salts have appeared in the literature. These include microcrystal tests and color spot tests (I), chromatographic studies (2-4), published infrared spectra (5), and derivatization (6-9).
A few isolated derivatives have been reported for phenyramidol hydrochloride (10-12) and those can be used as a n aid to identification. No method for the qualitative estimation of biperiden hydrochloride could be found in the literature.
All of these preparations are potent systemic drugs and are intended for oral or parenteral administration; hence reliable criteria for their identification and differentiation are of great importance to the forensic chemist and toxicologist. It is the purpose of this investigation to develop a comprehensive series of several physical reference criteria which can be utilized to positively identify these compounds in the least amount of time.
EXPERIMENTAL
Apparatus.-Fisher-Johns melting point apparatus; Beckman IR-5A infrared spectrophotometer; Bausch & Lomb biological microscope; Metrohm potentiograph model E336.