Composition for pH dependent controlled release of active ingredients and methods for producing it
US5656292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1995 |
| Grant date | Aug 12, 1997 |
| Priority date | — |
| Expiry date | Jul 5, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B31/04
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The present invention is related to a composition for pH dependent or pH regulated controlled release of active ingredients especially drugs. The composition consists of a compactible mixture of the active ingredient and starch molecules substituted with acetate and dicarboxylate residues. The preferred dicarboxylate acid is succinate. The average substitution degree of the acetate residue is at least 1 and 0.2-1.2 for the dicarboxylate residue. The starch molecules can have the acetate and dicarboxylate residues attached to the same starch molecule backbone or attached to separate starch molecule backbones. The present invention also discloses methods for preparing said starch acetate dicarboxylates by transesterification or mixing of starch acetates and starch dicarboxylates respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.