Claims for Patent: 5,002,769

Summary for Patent: 5,002,769

Title:	Compositions for the sustained-release of chlorhexidine
Abstract:	The present invention pertains to biodegradable sustained-release compositions capable of achieving the sustained release of chlorhexidine. The compositions can be formed into implant devices which may be used to treat a wide variety of diseases and conditions. The implants are especially useful in treating diseases such as periodontal disease which require prolonged drug release.
Inventor(s):	Friedman; Michael (Jerusalem, IL)
Assignee:	Yissum Research Development Company of the Hebrew University of Jerusalem (Jerusalem, IL)
Application Number:	07/324,505
Patent Claims:	1. A sustained-release composition for permitting the sustained release of chlorhexidine in a periodontal pocket wherein said composition comprises an essentially two-dimensional implant specially adapted for implantation in a periodontal pocket of a patient, said implant comprising: (1) an effective amount of chlorhexidine digluconate, wherein said effective amount of chlorhexidine digluconate is an amount sufficient for the treatment of periodontal disease; (2) a plasticizer selected from the group consisting of a phthalate ester, a phosphate ester, glycerin, and sorbitol, wherein said plasticizer is present in an amount sufficient to effect brittleness but not so great a concentration as to prevent the release of said chlorhexidine digluconate; and (3) a cross-linked water insoluble protein matrix wherein said protein is selected from the group consisting of gelatin, collagen, albumin, an enzyme and fibrinogen, wherein said protein is cross-linked with a cross-linking agent selected from the group consisting of an aldehyde, aluminum, chromium, titanium zirconium, bisdiazobenzidine, phenol 2,4-disulfonyl chloride, 1,5-difluoro-2,4-dinitrobenzene, urea, 3,6-bis(mercurimethyl)-dioxane urea, dimethyl adipimidate and N,N'-ethylene-bis-(iodo-acetamide), and wherein said protein is present in said composition at about 14-93%. 2. The composition of claim 1 wherein said cross-linking agent is present in an amount sufficient to render said protein insoluble but not in an amount which prevents the release of the active agent from the composition. 3. The composition of claim 1 wherein said cross-linking agent is present in said composition in an amount of from about 0.01% to about 26%. 4. The composition of claim 1 wherein said cross-linking agent is an aldehyde selected from the group consisting of formaldehyde and glutaraldehyde. 5. The composition of claim 4 wherein said cross-linking agent is glutaraldehyde. 6. The composition of claim 1 wherein said cross-linked protein is cross-linked by incubation in the presence of cross-linking means, said means being selected from the group consisting of: heat, pressure and radiation. 7. The composition of claim 6 wherein said cross-linked protein is cross-linked to an extent sufficient to render said protein insoluble but not to an extent which prevents the release of said chlorhexidine digluconate from the composition. 8. The composition of claim 1 wherein said protein is present at a concentration sufficient to provide said composition with structural stability, but not at so great a concentration as to render said composition (i) incapable of biodegradation, or (ii) incapable of permitting the release of said chlorhexidine digluconate. 9. The composition of claim 1 wherein said protein is gelatin. 10. The composition of claim 9 wherein said gelatin is hydrolyzed gelatin. 11. The composition of claim 1 wherein said plasticizer is selected from the group consisting of: glycerin and sorbitol. 12. The composition of claim 11 wherein said plasticizer is glycerin. 13. The composition of claim 1 wherein said plasticizer is present at a concentration of from about 0.01% to about 52%. 14. The composition of claim 1 wherein said film is from about 3 to about 10 mm in length, and from about 1 to about 5 mm in width, and from about 0.01 to 0.5 mm in depth. 15. A composition of claim 1 wherein said chlorhexidine digluconate and said protein are present at a relative weight ratio which ranges from about 0.01:7 to about 3:1. 16. The composition of claim 1 wherein said plasticizing agent and said protein are present at a relative weight ratio which ranges from about 0.01:7 to about 4:7. 17. The composition of claim 1 wherein said composition has a flexibility which ranges from about 0.1 kg/mm.sup.2 to about 50 kg/mm.sup.2. 18. A method of administering chlorhexidine digluconate to a patient in need of such an agent, which comprises providing to said patient an essentially two-dimensional implant adapted for implantation in a periodontal pocket of a patient, said implant comprising: (1) an effective amount of chlorhexidine digluconate, wherein said effective amount of chlorhexidine digluconate is an amount sufficient for the treatment of periodontal disease; (2) a plasticizer selected from the group consisting of a phthalate ester, a phosphate ester, glycerin, and sorbitol, wherein said plasticizer is present in an amount sufficient to effect brittleness but not so great a concentration as to prevent the release of said chlorhexidine digluconate; and (3) a cross-linked water insoluble protein matrix wherein said protein is selected from the group consisting of gelatin, collagen, albumin, an enzyme and fibrinogen, wherein said protein is crosslinked with a cross-linking agent selected from the group consisting of an aldehyde, aluminum, chromium, titanium zirconium, bisdiazobenzidine, phenol 2,4-disulfonyl chloride, 1,5-difluoro-2,4-dinitrobenzene, urea, 3,6-bis(mercurimethyl)-dioxane urea, dimethyl adipimidate and N,N'-ethylene-bis-(iodo-acetamide), and wherein said protein is present in said composition at about 14-93%. 19. The method of claim 18 wherein said composition additionally contains a cross-linking agent. 20. The method of claim 18 wherein said patient suffers from the condition the pericoronitis. 21. The method of claim 18 wherein said administration is an adjunct to endodontic treatment. 22. The method of claim 18 wherein said administration is an adjunct to a tooth implantation procedure. 23. The method of claim 18 wherein said administration is an adjunct to an epiectomy.