Steroid polymorphism. I: Androsterone

Clarification of the crystalline forms of androsterone

“…The melting onset of 185 uC (DH melt 5 85.57 J g 21 ) indicates that the hemihydrate does transform to form 1 on dehydration, as suggested by B&DB. 9 However, between the dehydration and the melting events a further small endotherm was observed with onset 150 uC (Fig. 3) which may correspond to the event reported by B&DB in crystals grown from ether, although the temperature of the event differs from that reported by B&DB (165 uC).…”

“…The unit cell previously assigned to a polymorphic 'form 2' of androsterone, 8,9 has been identified as a hemihydrate, which is also the hydrated form identified in the literature by thermal microscopy. 7 This has clarified the literature regarding the crystalline state of this fundamental steroid.…”

“…Single crystal X-ray data sets were measured on a Bruker SMART APEX diffractometer, using Mo Ka (l 5 0.71073 A ˚) radiation with a graphite monochromator. Bruker SMART 9 software was used for the data collection and the data were integrated using Bruker SAINT+. 10 The structures were solved by direct methods using SHELXS-97, 9 and SHELXL-97 11 was used for structural refinement.…”

“…Bruker SMART 9 software was used for the data collection and the data were integrated using Bruker SAINT+. 10 The structures were solved by direct methods using SHELXS-97, 9 and SHELXL-97 11 was used for structural refinement. An absorption correction was applied using SADABS.…”

Structural characterisation of two pharmaceutically important steroids by solid-state NMR

“…Kuhnert-Brandsta¨tter and Grimm 7 identified a hydrate of androsterone by thermal microscopy and reported that it desolvated at 80 1C. Bouche´and Draguet-Brughmans (B & D-B) 8 replicated the desolvation using crystals grown by evaporation from 70% aqueous ethanol at room temperature and reported the unit cell parameters (CSD code AN-DOON01). Banerjee 9 postulated the existence of another form of androsterone, and reported a unit cell (CSD code AN-DOON02) different from that of Form 1.…”