Extended release venlafaxine besylate tablets

1. An extended release coated pharmaceutical tablet comprising:

(a) a tablet core, which comprises at least 70% venlafaxine besylate; and

(b) a coating over said tablet core which comprises an ammonio methacrylate copolymer component, wherein said coating is in an amount within the range of 3% to 25% of the weight of said tablet core.

2. The extended release tablet according to claim 1 , wherein said tablet core comprises 75-99% venlafaxine besylate.

3. The extended release tablet according to claim 2 , wherein said tablet core contains 80-95% venlafaxine besylate.

4. The extended release tablet according to claim 1 , wherein said ammonio methacrylate copolymer component comprises at least 50% of said coating.

5. The extended release tablet according to claim 4 , wherein said ammonio methacrylate copolymer component comprises 7 mol % to 14 mol % ammonio methacrylate units.

6. The extended release tablet according to claim 5 , wherein said ammonio methacrylate copolymer component comprises 8 mol % to 12 mol % ammonio methacrylate units.

7. The extended release tablet according to claim 4 , wherein said ammonio methacrylate copolymer component comprises 65-100% of a Type A ammonio methacrylate copolymer and 35-0% of a Type B ammonio methacrylate copolymer.

8. The extended release tablet according to claim 7 , wherein said ammonio methacrylate copolymer component comprises 85-100% of a Type A ammonio methacrylate copolymer and 15-0% of a Type B ammonio methacrylate copolymer.

9. The extended release tablet according to claim 1 , wherein said tablet core is free from extended release matrix excipients.

10. The extended release tablet according to claim 9 , wherein said tablet core further comprises a lubricant and optionally a filler selected from the group consisting of sugars, microcrystalline cellulose, calcium phosphates, and mixtures thereof.

11. The extended release tablet according to claim 10 , wherein said tablet core contains 150 to 300 mg of said venlafaxine besylate.

12. The extended release tablet according to claim 11 , wherein said coating is in an amount within the range of 5% to 15% of the weight of said tablet core; said ammonio methacrylate copolymer component comprises at least 50% of said coating; and said ammonio methacrylate copolymer component comprises 85-100% of a Type A ammonio methacrylate copolymer and 15-0% of a Type B ammonio methacrylate copolymer.

13. The extended release tablet according to claim 1 , wherein said tablet core further comprises a matrix material.

14. The extended release tablet according to claim 13 , wherein said matrix material is a lipophilic matrix material.

15. The extended release tablet according to claim 14 , wherein said matrix material is co-processed calcium phosphate and fatty acid wax having a ratio within the range of 85:15 to 65:35, respectively.

16. The extended release tablet according to claim 15 , wherein said tablet core comprises 10-20% of said co-processed calcium phosphate and fatty acid wax excipient and 0.2 to 2% of a lubricant.

17. The extended release tablet according to claim 16 , wherein said coating is in an amount within the range of 5% to 25% of the weight of said tablet core; said ammonio methacrylate copolymer component comprises at least 50% of said coating; and said ammonio methacrylate copolymer component comprises 70-100% of a Type A ammonio methacrylate copolymer and 30-0% of a Type B ammonio methacrylate copolymer.

18. The extended release tablet according to claim 17 , wherein said tablet core comprises 50 to 150 mg of said venlafaxine besylate.

19. The extended release tablet according to claim 1 , wherein said tablet exhibits a dissolution profile within the following ranges:

Time

Venlafaxine

2 hours

<30%

4 hours

30-55%

8 hours

55-80%

12 hours 

65-90%

24 hours 

>80%

in USP 2 apparatus using SGF, pH 1.2, medium for hours 0-2 and then SIF, pH 6.8, medium for hours 2-24.