Physical studies of detomidine hydrochloride, a new drug substance
Laine, E.; Tuominen, V.; Kahela, P.; Liponkoski, L.; Sjöholm, R.
Acta Pharmaceutica Suecica 20(6): 451-460
1983
ISSN/ISBN: 0001-6675 PMID: 6675424 Document Number: 207221
Solid-solid and solid-liquid transitions of a new drug substance, detomidine (4-(2,3-dimethylbenzyl)-imidazole) hydrochloride , were studied by temperature controlled X-ray diffractometry (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) and IR and 13C NMR spectroscopy. Detomidine hydrochloride has 2 crystalline forms, an anhdyrate and a hydrate. The thermal analysis showed that the water was loosely bonded in the hydrous crystals. The amount of water in this structure as determined by TG suggests that it is a monohydrate. The results of the 13C NMR studies show that in solution the water in the hydrate is bonded via its O atom to the imidazole cation. Evidently the water is bonded mainly to N-3 in the imidazole ring.