Claims for Patent: 6,214,331

Summary for Patent: 6,214,331

Title:	Process for the preparation of aqueous dispersions of particles of water-soluble polymers and the particles obtained
Abstract:	The invention is a process for the preparation of crosslinked water-swellable polymer particles. First, an aqueous polymer solution containing a water-soluble polymer having at least one functional group or charge, is combined with aqueous medium. The aqueous polymer solution is then mixed under moderate agitation with an oil medium and an emulsifier to form an emulsion of droplets of the water-soluble polymer. A crosslinking agent capable of crosslinking the functional groups and/or charges in the water-soluble polymer is then added to the emulsion to form crosslinked water-swellable polymer particles. The invention also includes the particles formed by the process and aqueous dispersions containing the particles which are useful for administering to an individual. The particles of the invention are useful for implantation, soft tissue augmentation, and scaffolding to promote cell growth.
Inventor(s):	Vanderhoff; John W. (Bethlehem, PA), Lu; Cheng Xun (Somerset, NJ), Lee; Clarence C. (Lilburn, GA), Tsai; Chi-Chun (Lawrenceville, GA)
Assignee:	C. R. Bard, Inc. (Murray Hill, NJ) Lehigh University (Bethlehem, PA)
Application Number:	08/989,888
Patent Claims:	1. A process for the preparation of crosslinked water-swellable polymer particles comprising the steps of: combining an aqueous polymer solution comprising at least one water-soluble polymer having at least one functional group or charge and an aqueous medium with an oil phase comprising an inert hydrophobic liquid and at least one emulsifier under moderate agitation so as to form an emulsion of droplets of the water-soluble polymer; and adding to the emulsion at least one crosslinking agent capable of crosslinking the functional groups or charges on the water-soluble polymer so as to form crosslinked water-swellable polymer particles. 2. The process of claim 1 wherein the emulsifier has an HLB value of less than about 8. 3. The process of claim 1, wherein the emulsifier is selected from the group consisting of hexadecyl sodium phthalate, sorbitan monostearate, SPAN 60, and a metal soap. 4. The process of claim 1, further comprising the step of inverting the emulsion of crosslinked water-swellable polymer particles in an excess of water to provide an aqueous dispersion of crosslinked water-swellable polymer particles. 5. The process of claim 4, further comprising the step of recovering the crosslinked water-swellable polymer particles. 6. The process of claim 1, wherein the ratio of the weight of the water-soluble polymer to that of the crosslinking agent is from about 0.1 to about 10. 7. The process of claim 1, wherein crosslinked water-swellable polymer particles have a size between about 10 micrometers in diameter and about 250 micrometers in diameter. 8. The process of claim 1, wherein crosslinked water-swellable polymer particles have a size greater than about 10 micrometers in diameter and less than about 212 micrometers in diameter. 9. The process of claim 1, wherein crosslinked water-swellable polymer particles have a size greater than about 10 micrometers in diameter and less than about 150 micrometers in diameter. 10. The process of claim 1, further comprising the step of adjusting the pH of the aqueous polymer solution above or below pH 7 so as to reduce the rate of the reaction of the crosslinking agent with the water-soluble polymer, and after the emulsion is formed, adjusting the pH is to approximately pH 7. 11. The process of claim 1, wherein the water-soluble polymer has at least one functional group selected from the group consisting of hydroxyl groups, thiol groups, carboxyl groups, sulfonic acid groups, sulfate groups, phosphate groups, amino groups, aldehyde groups, and sulfonyl halide groups. 12. The process of claim 1, wherein the water-soluble polymer is selected from the group consisting of proteins, polysaccharides, peptidoglycans, glycoproteins, proteoglycans, celluloses, teichoic acids, lipopolysaccharides, and synthetic hydrophilic polymers, sodium alginate, poly(N-vinyl pyrrolidone), methyl cellulose, chitin, chitosan, agarose, dextrans, poly(vinyl alcohol), chondroitin sulfate, xanthans, dermatan sulfate, keratin sulfate, amylose, amylopectin, carrageenans, glycogen, starch, heparin sulfate, limit dextrans and fragments thereof, emulsan, gellan, curdlan, hyaluronic acid, poly(ethylene oxide), bovine serum albumin, human gamma globulin, and mixtures thereof. 13. The process of claim 12, wherein the water-soluble polymer is a polysaccharide. 14. The process of claim 13, wherein the polysaccharide is selected from the group consisting of hyaluronic acid, sodium alginate, chondroitin sulfate, celluloses, chitin, chitosan, agarose, dextrans, xanthans, dermatan sulfate, keratin sulfate, amylose, emulsan, gellan, curdlan, amylose, carrageenans, amylopectin, dextrans, glycogen, starch, heparin sulfate, and limit dextrins or fragments thereof. 15. The process of claim 1, wherein the crosslinking agent is selected from the group consisting of pentaerythritol-tris-, XAMA-7, epichlorhydrin, divinyl sulfone, glutaraldehyde, p-toluene sulfonic acid, carbodiimides, diepoxides, polyepoxides, and ammonium persulfate. 16. The process of claim 1, wherein the inert hydrophobic liquid is a hydrocarbon or mixture of hydrocarbons. 17. The process of claim 16 wherein the hydrocarbon is selected from the group consisting of toluene, o-xylene, and isooctane. 18. A crosslinked water-swellable polymer particle preparation wherein the particles are substantially homogeneous in size, wherein the particles are between about 10 micrometers in diameter and about 250 micrometers in diameter, and wherein at least 80% of the particles are spherical. 19. The polymer particle preparation of claim 18, wherein the particles are greater than about 10 micrometers in diameter and less than about 212 micrometers in diameter. 20. The polymer particle preparation of claim 18, wherein the particles are greater than about 10 micrometers in diameter and less than about 150 micrometers in diameter. 21. The polymer particle preparation of claim 18, wherein the crosslinking is provided by covalent bonds. 22. The polymer particle preparation of claim 18, wherein the particles comprise at least one water-soluble polymer having at least one functional group selected from the group consisting of hydroxyl groups, thiol groups, carboxyl groups, sulfonic acid groups, sulfate groups, phosphate groups, amino groups, aldehyde groups, and sulfonyl halide groups. 23. The polymer particle preparation of claim 18, wherein the particles comprise at least one water-soluble polymer selected from the group consisting of proteins, polysaccharides, peptidoglycans, glycoproteins, proteoglycans, celluloses, teichoic acids, lipopolysaccharides, and synthetic hydrophilic polymers, sodium alginate, poly(N-vinyl pyrrolidone), methyl cellulose, chitin, chitosan, agarose, dextrans, poly(vinyl alcohol), chondroitin sulfate, xanthans, dermatan sulfate, keratin sulfate, amylose, amylopectin, carrageenans, glycogen, starch, heparin sulfate, limit dextrans and fragments thereof, emulsan, gellan, curdlan, hyaluronic acid, poly(ethylene oxide), bovine serum albumin, human gamma globulin, and mixtures thereof. 24. The polymer particle preparation of claim 23, wherein the particles comprise at least one water-soluble polymer which is a polysaccharide. 25. The polymer particle preparation of claim 24, wherein the polysaccharide is selected from the group consisting of hyaluronic acid, sodium alginate, chondroitin sulfate, celluloses, chitin, chitosan, agarose, dextrans, xanthans, dermatan sulfate, keratin sulfate, amylose, emulsan, gellan, curdlan, amylose, carrageenans, amylopectin, dextrans, glycogen, starch, heparin sulfate, and limit dextrins or fragments thereof. 26. The polymer particle preparation of claim 18, wherein the particles are formed by the process of claim 1. 27. The polymer particle preparation of claim 18, further comprising a bioactive agent. 28. An aqueous dispersion of crosslinked water-swellable polymer particles, wherein the particles are substantially homogeneous in size, wherein the particles are between about 10 micrometers in diameter and about 250 micrometers in diameter, and wherein at least 80% of the particles are spherical. 29. The aqueous dispersion of claim 28, wherein the aqueous dispersion is extrudable through a 20 gauge hypodermic syringe needle.

Details for Patent 6,214,331

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Grifols Therapeutics Llc	ALBUKED, PLASBUMIN-20, PLASBUMIN-25, PLASBUMIN-5	albumin (human)	For Injection	101138	10/21/1942		2015-06-06
Baxalta Us Inc.	BUMINATE, FLEXBUMIN	albumin (human)	Injection	101452	03/03/1954		2015-06-06
Csl Behring Ag	ALBURX	albumin (human)	Injection	102366	07/23/1976		2015-06-06