Claims for Patent: 4,904,769

Summary for Patent: 4,904,769

Title:	Highly pure acarbose
Abstract:	A purified acarbose which contains less than 10% by weight of sugar-like secondary components is obtained by column chromatograph of a solution of prepurified acarbose with a pH 4 to 7. The column contains as a packing material a weakly acid cation exchanger which has carboxyl groups and is based on dextran, agarose and cellulose or exchangers which are derived from the latter with the addition of polyamide.
Inventor(s):	Rauenbusch; Erich (Wuppertal, DE)
Assignee:	Bayer Aktiengesellschaft (Leverkusen, DE)
Application Number:	06/940,713
Patent Claims:	1. A purified acarbose composition which, apart from water, has an acarbose content of about 93-98% by weight. 2. An acarbose composition according to claim 1, which, apart from water, contains 2 to 5% by weight of sugar-like secondary components. 3. An acarbose composition according to claim 1, which, apart from water, contains less than 2% by weight of sugar-like secondary components. 4. A process for the preparation of a purified acarbose composition according to claim 1, comprising applying a prepurified acarbose in a 1 to 20% by weight aqueous solution with a pH of 3.5 to 7 to a column which contains as packing material a weekly acid cation exchanger which has carboxyl groups and is based on dextran, agarose and cellulose or exchangers which are derived from the latter with the addition of polyamide, eluting the column exclusively with degassed, distilled water and isolating the purified acarbose composition from the eluate. 5. A process according to claim 4, wherein the volume of prepurified acarbose solution which is applied corresponds to the filling volume of the column. 6. A process according to claim 4, wherein the volume of prepurified acarbose solution is less than 60% of the column volume. 7. A process according to claim 4, wherein the pH of the prepurified acarbose solution is 3.5 to 6.0. 8. A process according to claim 4, wherein the pH of the prepurified acarbose solution is 4.0 to 5.5. 9. A process according to claim 4, wherein the prepurified acarbose solution is applied at temperatures up to room temperature, and, the column is heated to 25.degree. to 95.degree. C. after the salts and coloring constituents have been eluted therefrom. 10. A process according to claim 9, wherein the prepurified acarbose solution is applied at temperatures in the range from 4.degree. to 25.degree. C., and, after the salts and coloring constituents have been eluted, the column is heated to 40.degree. to 70.degree. C. 11. A pharmaceutical composition comprising an effective amount of an acarbose composition according to claim 1, said acarbose, apart from water, contains less than 10% by weight of sugar-like secondary components and a pharmaceutically acceptable excipient therefor.