1. A process for the preparation of crystalline Form III of Cortexolone 17α-propionate
of formula (I)
2. The process as claimed in Claim 1, wherein the amount of ethanol used for
providing a solution of cortexolone 17α-propionate in ethanol in step a) is about 3 ml
per gram of cortexolone 17α-propionate.
3. The process as claimed in Claim 1, wherein ethanol and n-hexane are used in the
25 ratio of about 1:2.
4. The process as claimed in Claim 1, wherein the water content of the mixture is less
than about 10%.
5. The process as claimed in Claim 1, wherein the mixture obtained in step b) is cooled
to a temperature of about 0 oC (± 2 oC), maintained at a temperature of 0 oC (± 2 oC)
and stirred for 30 minutes at 0 oC (± 2 o 10 C).
6. The process as claimed in Claim 1, wherein the crystalline Form III of cortexolone
17α-propionate is isolated by filtration and is further washed with n-hexane.
15 7. The process as claimed in Claim 6, wherein the isolated crystalline Form III of
cortexolone 17α-propionate is dried at temperatures from about 40°C to about 50°C,
under a vacuum for a time between about 7 hours and about 9 hours.
8. The process as claimed in Claim 1, wherein the crystalline Form III of Cortexolone
20 17α-propionate is stable and has a purity of greater than 99.0%, wherein stable
means that after 2 months at 25±2°C and 60±5% relative humidity or at 2-8°C all
impurities are below 1.0%.
9. The process as claimed in Claim 1, wherein the crystalline Form III of cortexolone
25 17α-propionate is characterized by a powder x-ray diffraction pattern as substantially
depicted in FIG. 1.
10. The process as claimed in Claim 1, wherein the crystalline Form III of cortexolone
17α-propionate is characterized by a powder x-ray diffraction pattern having peaks
30 at about 6.35, 12.71, 14.18, 14.4, 16.1, 22.5, and 23.8 degrees 2 theta (±0.2°).