Claims
- 1. In a solvent extraction process for preparing microspheres of an antigen containing biodegradable poly(DL-lactide-co-glycolide), the improvement comprising:
- preparing a lyophilized antigen-sucrose matrix; adding acetonitrile solvent to the antigen-sucrose matrix to form a solution;
- preparing a solution of a biodegradable poly (DL-lactide-co-glycolide) polymer by adding acetonitrile solvent to the polymer;
- adding the biodegradable poly (DL-lactide-co-glycolide)polymer acetonitrile solution to the antigen-sucrose acetonitrile solution;
- adding an oil to the poly (DL-lactide-co-glycolide)polymer-sucrose-antigen solution to form an emulsion having a controlled viscosity, that corresponds to a predetermined average particle size of distributions of microspheres of poly (DL-lactide-co-glycolide) biodegradable polymers of from about 0.5 to about 7.0 micrometers;
- centrifuging the emulsion of controlled viscosity and removing a supernatant to obtain microspheres of the predetermined range of particle size distributions.
- 2. The process of claim 1, wherein the oil is selected with a predefined viscosity to form the microspheres.
- 3. The process of claim 1, wherein a thickening agent is added to the oil to increase its viscosity.
- 4. The process of claim 1, wherein the oil is prediluted with an extractant solvent.
- 5. The process of claim 1, wherein the oil is a paraffin oil in which the viscosity is adjusted by preheating to a temperature of desired viscosity.
- 6. The process of claim 1, wherein relative ratios between the lactide and glycolide is 50:50.
- 7. The process of claim 1, wherein the average particle size distribution is from about 1.0 to about 2.0 micrometers.
I. CROSS REFERENCE
This application is a continuation-in-part of U.S. patent application Ser. No. 07/867,301 filed Apr. 10, 1992, now U.S. Pat. No. 5,417,986, which in turn is a continuation-in-part of U.S. patent application Ser. No. 07/805,721, filed Nov. 21, 1991, now abandoned, which in turn is a continuation-in-part of U.S. patent application Ser. No. 07/690,485 filed Apr. 24, 1991, now abandoned, which in turn is a continuation-in-part of U.S. patent application Ser. No. 07/521,945 filed May 11, 1990, now abandoned, which in turn is a continuation-in-part of U.S. patent application Ser. No. 07/493,597 filed Mar. 15, 1990, now abandoned, which in turn is a continuation-in-part of U.S. patent application Ser. No. 06/590,308 filed Mar. 16, 1984, pending.
II. GOVERNMENT INTEREST
The invention described herein may be manufactured, licensed and used by or for governmental purposes without the payment of any royalties to us thereon.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4384975 |
Fong |
May 1983 |
|
4530840 |
Tice et al. |
Jul 1985 |
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Continuation in Parts (6)
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Number |
Date |
Country |
Parent |
867301 |
Apr 1992 |
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Parent |
805721 |
Nov 1991 |
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Parent |
690485 |
Apr 1991 |
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Parent |
521945 |
May 1990 |
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Parent |
493597 |
Mar 1990 |
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Parent |
590308 |
Mar 1984 |
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