Hydrocodone base and methods for its purification
A method of recovering a highly pure hydrocodone base from an impure hydrocodone preparation includes contacting the impure hydrocodone preparation with a weak acid in water to form a solution and adding a strong base to the solution in an amount sufficient to precipitate the pure hydrocodone base product. A highly pure hydrocodone base comprises less than 0.0025 wt % codeinone.
1. A method of recovering a highly pure hydrocodone base from an impure hydrocodone preparation, the method comprising:
contacting the impure hydrocodone preparation with a weak acid in water to form a solution;
charging the solution with an organic solvent before the addition of the strong base;
adding a strong base to the solution in an amount sufficient to precipitate the highly pure hydrocodone base.
2. The method of claim 1 , wherein the organic solvent is an alcohol.
3. The method of claim 2 , wherein the alcohol is selected from the group consisting of: methanol, ethanol, propanol, isopropanol, butanol, tert-butyl alcohol, or a mixture of any of the foregoing.
4. The method of claim 2 , wherein the alcohol is ethanol or butanol.
5. The method of claim 1 , where the highly pure hydrocodone base comprises less than 0.05 wt % 6α-tetrahydrothebaine (6a-THT).
6. The method of claim 1 , where the highly pure hydrocodone base comprises less than 0.05 wt % 6,7-dihydrothebaine.
7. The method of claim 1 , where the highly pure hydrocodone base comprises less than 0.05 wt % 6β-tetrahydrothebaine base.
8. The method of claim 1 , where the highly pure hydrocodone base comprises less than 0.0025 wt % codeinone.
9. The method of claim 1 , wherein the highly pure hydrocodone base has a purity of about 99.9% area as measured by high performance liquid chromatography.