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US7595392: Biodegradable oxidized cellulose esters


Filing Information

Inventor(s) Vijay Kumar · Yang Dong ·
Assignee(s) University of Iowa Research Foundation ·
Attorney/Agent(s) McKee, Voorhees & Sease, P.L.C. ·
Primary Examiner Shaojia Anna Jiang ·
Assistant Examiner Everett White ·
Application Number US10007866
Filing date 12/06/2001
Issue date 09/29/2009
Prior Publication Data
Predicted expiration date 01/31/2022
Patent term adjustment 56
U.S. Classifications 536/63  · 536/69  · 536/68  · 536/67  · 536/32  · 514/54  · 536/64  ·
International Classifications C08B300  · C08B306  ·
Kind CodeB2
1 Claims, No Drawings


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.

Independent Claims | See all claims (1)

  1. 1. 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.

References Cited

U.S. Patent Documents

Document NumberAssigneesInventorsIssue/Pub Date
US2379917 DU PONT Herman et al. Jul 1945
US4590265* Eastman Kodak Company Bogan et al. May 1986
US5008385* Akzo N.V. Diamantoglou Apr 1991
US5970988 Eastman Kodak Company Buchanan et al. Oct 1999
US5973139 Eastman Chemical Company Lee et al. Oct 1999
US5981738 Eastman Chemical Company Cook et al. Nov 1999
* cited by examiner

Other Publications

Chemical Abstracts, vol. 51, No. 1, Jan. 10, 1957, Columbus, Ohio, US; Abstract No. 701g, Toshikazu Fujimura et al.: “The acetylation of oxycellulose” XP002210935 abstract & Chem. High Polymers, vol. 12, 1955, pp. 315-321, XP008007015.

Referenced By

Document NumberAssigneeInventorsIssue/Pub Date
US7879994 Eastman Chemical Company Charles Michael Buchanan et al. Feb 2011
US8816066 --

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