Formulations and methods for lyophilization and lyophilates provided thereby
The present invention provides compositions, methods for lyophilizing compounds and making pharmaceutical compositions, and kits providing solutions and lyophilized formulations of compounds. The compositions, methods, and kits are particularly useful in pharmaceutical applications involving therapeutic agents that have low solubility at low pH and medium pH values. Certain embodiments provide methods for lyophilizing compounds in liquid solutions, which include the steps of: a) preparing aqueous solutions of a compound of interest in the absence of buffer; b) adjusting the pH to high values of pH in order to increase the solubility of the compound of interest; and c) freeze-drying the solution to provide a lyophilized solid composition. Aqueous solutions including buffer are also disclosed. Lyophilized formulations, including micronized and non-micronized powders, are provided.
1. A method for lyophilizing glibenclamide to provide a lyophilized solid glibenclamide composition having less than about 1% w/w buffer, comprising:
a) preparing an aqueous solution of said glibenclamide in the absence of buffer,
b) adding to the solution one or more substantially pharmaceutically inert compounds as a bulking agent,
c) adjusting the pH of the solution to greater than about pH 8 effective to increase the solubility of the glibenclamide,
d) adding additional glibenclamide to the solution, and
e) freeze-drying the solution to provide a lyophilized solid composition that comprises glibenclamide and less than about 1% w/w buffer, and a weight of substantially pharmaceutically inert compounds that comprises at least about 10 times the weight of glibenclamide in the lyophilized solid glibenclamide composition.
2. The method of claim 1 , comprising a further step of adjusting the pH of the solution following the step of adding additional glibenclamide.
3. The method of claim 1 , wherein the pH is adjusted to greater than about pH 10.
4. The method of claim 1 , wherein the glibenclamide concentration in the aqueous solution is greater than about 0.5 mg/mL.
5. The method of claim 1 , wherein said one or more substantially pharmaceutically inert compounds are independently selected from a sugar and a salt.
6. The method of claim 1 , wherein the weight of said substantially pharmaceutically inert compounds comprises at least about 30 times the weight of glibenclamide in the lyophilized solid glibenclamide composition.
7. The method of claim 1 , wherein the weight of said substantially pharmaceutically inert compounds comprises at least about 100 times the weight of glibenclamide in the lyophilized solid glibenclamide composition.
8. The method of claim 1 , wherein said one or more substantially pharmaceutically inert compounds are independently selected from glucose, fructose, mannose, galactose, mannitol, sorbitol, lactose, trehalose, sucrose, sodium chloride, and potassium chloride.
9. The method of claim 1 , wherein a substantially pharmaceutically inert compound is mannitol.
10. The method of claim 1 , wherein a substantially pharmaceutically inert compound is mannitol, wherein the weight of mannitol comprises at least about 30 times the weight of glibenclamide in the lyophilized solid glibenclamide composition.
11. The method of claim 1 , wherein a substantially pharmaceutically inert compound is mannitol, wherein the weight of mannitol comprises at least about 100 times the weight of glibenclamide in the lyophilized solid glibenclamide composition.
12. The method of claim 1 , wherein said adjusting the pH comprises adding an alkali base to the solution, wherein the alkali base is sodium hydroxide or potassium hydroxide.
13. The method of claim 12 , wherein one of the substantially pharmaceutically inert compounds is mannitol and the alkali base is sodium hydroxide.
14. The method of claim 1 , wherein said lyophilized solid glibenclamide composition is a solid pharmaceutical composition suitable for pharmaceutical use.
15. The method of claim 1 , wherein said lyophilized solid glibenclamide composition is substantially free of agents that enhance the solubility of glibenclamide.
16. The method of claim 2 , wherein the glibenclamide concentration in the aqueous solution is greater than about 0.5 mg/mL.
17. The method of claim 2 , wherein said adjusting the pH comprises adding an alkali base to the solution, wherein the alkali base is sodium hydroxide or potassium hydroxide.
18. The method of claim 2 , wherein said lyophilized solid glibenclamide composition is substantially free of agents that enhance the solubility of glibenclamide.