Ether-ester derivatives of cellulose and their applications
US4226981A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1978 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | Sep 20, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/835
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A novel cellulose derivative provided in this invention is a mixed ester of an alkoxy or hydroxyalkoxy substituted cellulose ether, prepared by the esterification reaction of the ether with succinic anhydride and an anhydride of an aliphatic monocarboxylic acid. The cellulose derivatives are advantageous because of their capability of producing enteric coatings having sufficient flexibility without the use of a plasticizer as well as by their chemical and physical stability against moisture, and also by easy purification after completion of the esterification reaction. The coatings produced from the derivatives have a similar chemical and physical stability. The cellulose derivatives are useful for the enteric coating of pharmaceutical dosage forms and also for providing halation-preventing layers on photographic films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.