RIFAXIMIN COMPOSITIONS AND METHOD OF USE
Forms of rifaximin (INN) antibiotic, such as the poorly crystalline form named rifaximin γ are described, along with the production of medicinal preparations containing rifaximin for oral and topical use.
1 . A composition comprising substantially amorphous rifaximin.
2 . The composition of claim 1 , wherein the composition has a water content of less than about 2%.
3 . The composition of claim 1 , wherein the composition has a water content of about 1.5%.
4 . The composition of claim 1 , wherein the composition has a water content between about 1% to about 2%.
5 . The composition of claim 1 , wherein the composition is in a capsule.
6 . The composition of claim 1 , wherein the composition is in tablet form.
7 . The composition of claim 1 , wherein the composition is a medicinal composition.
8 . The composition of claim 1 , wherein the composition is in powder form.
9 . The composition of claim 7 , wherein the medicinal composition is for oral use.
10 . The composition of claim 7 , wherein the medicinal composition is for topical use.
11 . The composition of claim 9 , wherein the medicinal composition comprises excipients.
12 . The composition of claim 9 , wherein the medicinal composition comprises binding agents.
13 . The composition of claim 9 , wherein the medicinal composition comprises lubricating agents.
14 . The composition of claim 9 , wherein the medicinal composition comprises disintegrating agents.
15 . The composition of claim 9 , wherein the medicinal composition comprises flavoring agents.
16 . A closed container, comprising a medicinal composition for oral use comprising substantially amorphous rifaximin.
17 . The composition of claim 16 , wherein the composition has a water content of less than about 2%.
18 . The composition of claim 16 , wherein the composition has a water content of about 1.5%.
19 . The composition of claim 16 , wherein the composition has a water content between about 1% to about 2%.
20 . The closed container of claim 16 , wherein the medicinal composition comprises excipients.
21 . The closed container of claim 20 , wherein the excipients comprise mannitol, lactose or sorbitol.
22 . A method of preparing substantially amorphous rifaximin, comprising:
providing dried rifaximin;
heating the rifaximin in the presence of an alcohol to result in dissolution of the rifaximin;
precipitating the rifaximin; and
drying the precipitate to have a water content of less than 2% to form substantially amorphous rifaximin.
23 . The method of claim 22 , comprising drying the precipitate to have a water content of about 1.5%.
24 . The method of claim 22 , comprising drying the precipitate to have a water content of between about 1% and 2%.
25 . The method of claim 22 , wherein the alcohol is ethyl alcohol.
26 . The method of claim 22 , wherein precipitating the rifaximin comprises precipitating the rifaximin with demineralized water.
27 . The method of claim 22 , wherein the rifaximin is cooled to 0° C. prior to the drying step.
28 . The method of claim 22 , wherein drying the precipitate comprises drying the precipitate under vacuum.