Sweet pharmaceutical salts of stanozolol with enhanced solubility and physical stability

Different solid forms of stanozolol (STAN), including two polymorphs, one monohydrate, and a large number of solvates and cocrystals had been reported previously. In this contribution, two pharmaceutical salts of STAN with artificial sweeteners, saccharin (SAC) and acesulfame (AH), were obtained and reported for the first time. Both salts were fully characterized by a variety of analytical methods, including single-crystal and powder X-ray diffraction (XRD), solid state NMR, differential scanning calorimetry (DSC) as well as dynamic vapour sorption (DVS). Though a similar functional group (OC–N–SO2) existed in SAC and AH, different annular R33(9) heterosynthons were observed for the two salts. The new salts are non-hygroscopic and resistant to STAN hydrate formation under high relative humidity (RH) conditions (95%). Additionally, dissolution studies indicate that the apparent solubilities and intrinsic dissolution rates (IDRs) of the salts are dramatically improved compared to those of pure STAN. All of these favourable properties make the salt forms more attractive for further pharmaceutical application.