Abiraterone Acetate Formulation

1 . A method for producing a composition comprising nanoparticles of abiraterone acetate, the method comprising:

dry milling a composition comprising abiraterone acetate, a millable grinding compound, a facilitating agent and one or both of an antioxidant and a sequestering agent in a mill comprising a plurality of milling bodies, for a time period sufficient to produce a composition comprising fine particles of the abiraterone acetate,

wherein the particle size of the grinding matrix and the particle size of the abiraterone acetate is reduced by dry milling.

2 . The method of claim 1 , wherein [D 90 ] of the abiraterone acetate in the composition comprising fine particles of abiraterone acetate is greater than 100 nm and less than one of: 1100 nm, 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, and 200 nm.

3 . The method of claim 1 , wherein the milling takes place in the presence of one or both of an antioxidant and a sequestering agent.

4 . The method of claim 3 , wherein the antioxidant is selected from ascorbic acid, BHA and BHT.

5 . The method of claim 3 , wherein the sequestering agent is selected from fumaric acid, tartartic acid and citric acid.

6 .- 20 . (canceled)

21 . A method of treating castration resistant prostate cancer comprising administering a daily dose of 100-900 mg of abiraterone acetate wherein the abiraterone acetate has a [D 50 ] of greater than 100 nm and less than one of: 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, and 200 nm.

22 . The method of claim 21 comprising administering 200-500 mg of abiraterone acetate.

23 . The method of claim 21 comprising administering 300-500 mg of abiraterone acetate.

24 . (canceled)

25 . The method of any of claims 21 - 23 comprising administering a glucocorticoid.

26 . The method of claim 25 wherein the glucorticoid is prednisone.

27 . The method of claim 25 wherein the glucorticoid is prednisolone.

28 . The method of claim 25 wherein the glucorticoid in methylprednisolone.

29 . A pharmaceutical composition comprising abiraterone acetate, wherein the [D 90 ] of the abiraterone acetate in the composition is greater than 100 nm and less than one of: 1100 nm, 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, and 200 nm.

30 . The pharmaceutical composition of claim 29 , wherein the [D 50 ] of the abiraterone acetate greater than 100 nm and is less than 700 nm, less than 600 nm, less than 500 nm, or less than 400 nm.

31 . The pharmaceutical composition of claim 29 or claim 30 , wherein the [D 4,3 ] of the abiraterone acetate in the composition is greater than 100 nm and less than one of: 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, and 300 nm.

32 . A pharmaceutical composition prepared by a method comprising the method of claim 1 .