Biodegradable oxidized cellulose esters and their uses as microspheres

• US 7,649,089 B2
• Filed: 10/28/2004
• Issued: 01/19/2010
• Est. Priority Date: 12/06/2001
• Status: Expired due to Fees

• Current Assignee: University of Iowa Research Foundation
• Original Assignee: University of Iowa Research Foundation
• Inventors: Dong, Yang, Kumar, Vijay
• Primary Examiner(s): Jiang; Shaojia Anna
• Assistant Examiner(s): WHITE, EVERETT NMN
• Application Number:
  US10/975,248
• Publication Number:
  US 20050131225A1
• Time in Patent Office: 1,909 Days
• Field of Search: 536/63, 536/64, 536/67, 536/68, 536/69, 536/32, 514/54
• US Class Current: 536/63
• CPC Class Codes: A61K 9/1652 Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin homeopathic globules A61K9/1623
• CPC Class Codes: A61K 9/5042 Cellulose; Cellulose derivatives, e.g. phthalate or acetate succinate esters of hydroxypropyl methylcellulose
• CPC Class Codes: C08B 15/00 Preparation of other cellulose derivatives or modified cellulose , e.g. complexes
• CPC Class Codes: C08B 3/00 Preparation of cellulose esters of organic acids rendering cellulose suitable for esterification C08B1/02

Abstract

A new cellulose excipient, OCCAE, suitable for use as a binder, filler, and/or disintegrant in the development of solid dosage forms and as a bodying agent or a drug carrier in the preparation of topical formulations is described. The cellulose excipient is formed by reacting an oxidized cellulose ester with an alcohol in the presence of a catalyst. The invention also describes the formation of controlled release microspheres using OCCAE and/or oxidized cellulose esters that may be used to control the release of drug in a patient over a time period of several hours to several days.

Claims

1. A biodegradable, oxidized cellulose carboxylated alkyl/aryl ester (OCCAE) having one of the following general formulas I or II, the general formula:

2. An OCCAE according to claim 1 that is present in a product selected from the group consisting of a pharmaceutical, an agricultural product, and a veterinary composition.

3. An OCCAE according to claim 1 that is soluble in at least one solvent selected from the group consisting of water, ketones, esters, glycol ethers, glycol ether acetates, alcohols, methylene chloride, halogenated solvents, and aprotic solvents.

4. An OCCAE according to claim 3 whereby the aprotic solvents are selected from the group consisting of DMSO, DMA, DMF, and n-methyl-2-pyrrolidone.

5. A pharmaceutical comprising the OCCAE of claim 1.

6. The pharmaceutical of claim 5 comprising microspheres.

7. The pharmaceutical of claim 6 comprising controlled release microspheres.

8. The pharmaceutical of claim 6 further comprising a drug.

9. The pharmaceutical of claim 8 comprising drug that is released over a time period of between about 150 days to 6 months or longer.

10. The OCCAE according to claim 1 having one of the following general formulas I or II the general formula:

11. A pharmaceutical comprising the OCCAE of claim 1, said pharmaceutical comprising microspheres.

12. The pharmaceutical of claim 11 comprising controlled release microspheres.

13. The pharmaceutical of claim 11 further comprising a drug.

14. The pharmaceutical of claim 13 comprising drug that is released over a time period of between about 150 days to 6 months or longer.

15. A pharmaceutical comprising:

controlled release microspheres comprising at least one oxidized cellulose ester.

16. The pharmaceutical of claim 15 comprising a drug that is released over a time period of between about 24-150 hours.

17. The pharmaceutical of claim 15 comprising from about 1-10% by weight of a drug.