Racemic compound and conglomerate of anhydrous sibutramine hydrochloride: a rare case of relative stability

Abstract

The thermal behaviours of racemic sibutramine hydrochloride monohydrate as well as that of the anhydrous state were investigated by DSC. A new anhydrous solid was then put in evidence and its crystal structure was solved from XRPD data. This new phase was found to be the conglomerate. Depending on the heat treatment, the initial anhydrous racemic compound may be completely resolved. DSC analyses have shown that the anhydrous conglomerate melts at a higher temperature than the anhydrous racemic compound.