DSC studies on the polymorphism and pseudopolymorphism of pharmaceutical substances

A complex system including thermoanalytical methods, infrared spectroscopy and X-ray powder diffraction for studying physico-chemical behaviour of binary mixtures is described. This system has been tested by investigating binary mixtures of amphetamine hydrochloride salts.These studies have proved that among the selected compounds the primary and secondary amine hydrochloride salts exhibit conglomerate forming tendency, while the tertiary amine hydrochloride salts form molecular compounds (racemates). For thep-fluoro amphetamine hydrochloride the existence of two polymorphic modifications has been detected.The authors are grateful to D. Kozma (Department of Organic Chemical Technology) for the thermoanalytical data of compound III, to Prof. E. Fogassy for the fruitful discussion.