Biodegradable oxidized cellulose esters
AssigneeUniversity of Iowa Research Foundation
InventorsVijay Kumar, Yang Dong
Life of this patent
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Abstract
The present invention relates to the preparation of a series of oxidized cellulose esters suitable for use as a drug carrier in the development of biodegradable controlled and/or sustained release pharmaceutical, agricultural, and veterinary compositions, such as films, compacts, microspheres, and pellets. The esters are prepared by acylation of oxidized cellulose having at least 3% carboxyl groups. The resulting oxidized cellulose esters are soluble in aqueous alkaline solutions, water, and a variety of organic solvents.
Claims1
A biodegradable, oxidized cellulose ester having the following general formula I or II:
- wherein:
- X is selected from the group consisting of H, Na, K, Ca, NH4, and NEt3H;
- whereby R is (CH2)nCOOH, where n is 2 to 4;
- w is 0.1-1.0;
- x is 0.1-2.0;
- and
- n is 30-1500
- and
- wherein:
- X is selected from the group consisting of H, Na, K, Ca, NH4, and NEt3H;
- R′ and R″ are each selected from the group consisting of:
- H;
- CF3;
- (CH2)nCH3, where n is from 0 to 18;
- (CH2)nCOOH, where n is from 1 to 8;
- CY═CZCOOH, where Y and Z are independently selected from the group consisting of hydrogen, methyl, branched alkyl having from 1 to 20 carbon atoms and from one to three cis or trans double bonds;
- branched alkenyl having from 1 to 20 carbon atoms and having from one to three cis or trans double bonds;
- CY—CH2, where Y is H, methyl, or phenyl;
- CH═CHY, where Y is C6H5;
- CH═CYCOOH, where Y is H or CH3;
- (CH2)8CH═CH(CH2)8CH3;
- or C6H(2-6)(COOH)0-4, CH2CH(COOH)CH2—COOH;
- w is 0.1-1.0;
- x′ is 0.1-1.9;
- y is 0.1-1.9;
- and
- n is 30-850.
Dependencies are inferred from the claim text.