Patent ID: 9533052
Date: 2017-01-03
CPC Classifications: A61K,A61P

Claim:
1. A process of preparing an aqueous suspension of crystalline rebamipide comprising (1) a water-soluble salt of rebamipide; (2) hydroxypropylmethyl cellulose (HPMC) or polyvinylpyrrolidone (PVP); (3) hydrochloric acid; and (4) water; comprising: (a) mixing an aqueous solution comprising a polymer selected from HPMC or PVP with hydrochloric acid and purified water to form a hydrochloric acid-HPMC/PVP solution; (b) dissolving rebamipide in an aqueous solution comprising NaOH to form a sodium hydroxide-rebamipide solution; (c) adding the sodium hydroxide-rebamipide solution of step (b) to the hydrochloric acid-HPMC/PVP solution step (a) to deposit crystalline rebamipide; (d) stirring the suspension of step (c) to complete the crystallization; and (e) adjusting the pH of the aqueous suspension of step (d) to 5-7 with sodium hydroxide; wherein the shape of crystalline rebamipide is a regular crystal having a long gage length of less than 1000 nm and a short gage length of less than 60 nm, provided that the ratio between the long gage length and short gage length is not less than 4.