Hola!
Parece ser que hay 3 formas de CB, no se si eso puede influir también:
https://patents.google.com/patent/EP2503004A1
The crystalline form I of 17α-propionate is preferably obtained through crystallisation from tert-butylmethylether. The concentration of 17α-propionate in said solvent is in the range of 0.9 to 1.1 g in 9-11 ml of tert-butylmethylether preferably 1g in 10 ml. Said crystalline form I is characterised by a melting point in the range of about 133 to 135°C and/or a DRX as in Fig. 1 and/or a DSC as shown in Fig. 2 and/or an IR as shown in Fig. 3.
[0034]
The crystalline form II of 17α-propionate is preferably obtained through crystallisation from diisopropylether. The concentration in said solvent is preferably in the range of 0.9 to 1.1 g in 54-66 ml of diisopropylether.
[0035]
Said crystalline form II is characterised by a melting point in the range of about 114 to 116°C and/or a DRX as in Fig. 4 and/or a DSC as shown in Fig. 5 and/or an IR as shown in Fig. 6.
[0036]
The crystalline form III of 17α-propionate is preferably obtained through crystallisation from a mixture of dichloromethane/n-hexane preferably in a ratio of about 1/30, acetone/n-hexane preferably in a ratio of about 1/8, or ethanol/water mixture preferably in a ratio of about 1/2.
[0037]
The melting point of said crystalline forms III could not be determined.
[0038]
The crystalline form III obtained from dichloromethane/n-hexane has a DRX as shown in Fig. 7 and/or a DSC as shown in Fig. 8 and/or an IR as shown in Fig. 9. The crystalline form III obtained from acetone/n-hexane has a DRX as shown in Fig. 10 and/or a DSC as shown in Fig. 11 and/or an IR as shown in Fig. 12.
[0039]
The crystalline form III obtained from ethanol/water has a DRX as shown in Fig. 13 and/or a DSC as shown in Fig. 14 and/or an IR as shown in Fig. 15.