Nitrofurantoin crystals
AssigneeProcter & Gamble Pharmaceuticals, Inc.
InventorsFrederick D. Cazer, Michael J. Kane, Barry L. Scott, Vijay Shahi
Life of this patent
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Abstract
Nitrofurantoin particulates comprising discrete particulates of nitrofurantoin wherein: (a) said particulates are larger than about 200 mesh size; and (b) the BET surface area of said particulates is at least about 0.2 M.sup.2 /g. Preferably, the surface of said particulates consists essentially of nitrofurantoin monohydrate. Also preferably, said particulates comprise at least about 5%, more preferably at least about 50% of nitrofurantoin monohydrate. Preferred compositions of this invention comprise these nitrofurantoin particulates in an aqueous suspension. The nitrofurantoin particulates of this invention are highly efficacious for the delivery of nitrofurantoin in oral dosage forms.
Claims10
Nitrofurantoin particulates, wherein:
- (a) said particulates are larger than about 200 mesh size;
- (b) the BET surface area of said particulates is at least about 0.2 M.sup.2 /g;
- (c) the surface of said particulates consists essentially of nitrofurantoin monohydrate crystalline forms;
- and
- (d) the remaining, inner portion of said particulates is comprised of anhydrous nitrofurantoin, nitrofurantoin monohydrate, or mixtures thereof.
A method of making nitrofurantoin particulates, wherein said particulates are larger than about 200 mesh size, the BET surface area of said particulates is at least about 0.2 M.sup.2 /g, and the surface of said particulates consists essentially of nitrofurantoin monohydrate crystalline forms, comprising the steps of:
- (a) preparing a saturated aqueous solution of nitrofurantoin monohydrate;
- (b) adding to said solution anhydrous nitrofurantoin having a particle size larger than about 200 mesh;
- (c) mixing said solution for at least about 5 minutes;
- and
- (d) filtering said solution.
Dependencies are inferred from the claim text.