Encapsulation of bioactive agents
AssigneeMicrobiological Research Authority
InventorsGraham Henry Farrar, Anne Margaret Tinsley-Bown, David Hugh Jones
Life of this patent
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Abstract
Bioactive agent is encapsulated in a polymer microparticle in a (water-in-oil)-in-water emulsion-based method, and using a solvent that comprises ethyl acetate. Also described are microparticles comprising low inherent viscosity (i.v.) PLG, some with i.v. less than 0.5dl/g, and methods for their preparation. DNA release is modified through use of low i.v. PLG. A particle production method for scale-up uses a blender that avoids excessive shear damage to DNA being encapsulated.
Claims15
A method for encapsulating DNA in a polymer microparticle, comprising:
- dissolving polymer in a solvent to form a polymer solution;
- preparing an aqueous solution of DNA;
- combining the polymer and aqueous solutions with agitation to form a water-in-oil emulsion;
- adding the water-in-oil emulsion to a further aqueous phase with agitation to form a (water-in-oil)-in-water emulsion;
- adding the (water-in-oil)-in-water emulsion to excess of an aqueous phase to extract the solvent, thereby forming polymer microparticles of a size up to 10 microns in diameter, said microparticles containing DNA in aqueous solution;
- wherein the solvent comprises ethyl acetate.
A method for encapsulating a bioactive agent in a polymer microparticle, comprising:
- dissolving polymer in a solvent to form a polymer solution;
- preparing an aqueous solution of a bioactive agent;
- combining the polymer and aqueous solutions with agitation to form a water-in-oil emulsion;
- adding the water-in-oil emulsion to a further aqueous phase with agitation to form a (water-in-oil)-in-water emulsion;
- adding the (water-in-oil)-in-water emulsion to excess of an aqueous phase to extract the solvent, thereby forming polymer microparticles of a size up to 10 microns in diameter said microparticles containing bioactive agent in aqueous solution;
- wherein the solvent comprises ethyl acetate, wherein the ratio of solvent:aqueous phase in formation of the water-in-oil emulsion is in the range of 5:1 to 12:1 (volume:volume).
A method for encapsulating DNA in a polymer microparticle, comprising:
- dissolving polymer in a solvent to form a polymer solution;
- preparing an aqueous solution of DNA;
- combining the polymer and DNA solutions with agitation to form a water-in-oil emulsion;
- adding the water-in-oil emulsion to a further aqueous phase with agitation to form a (water-in-oil)-in-water emulsion;
- adding the (water-in-oil)-in-water emulsion to excess of an aqueous phase to extract the solvent, thereby forming polymer microparticles of a size up to 10 microns in diameter, said microparticles containing DNA in aqueous solution;
- wherein the DNA comprises a coding sequence that is expressed in a recipient following oral administration, and wherein the solvent comprises ethyl acetate.
A method for encapsulating a bioactive agent in a polymer microparticle, comprising:
- dissolving polymer in a solvent to form a polymer solution;
- preparing an aqueous solution of a bioactive agent;
- combining the polymer and aqueous solutions with agitation to form a water-in-oil emulsion;
- adding the water-in-oil emulsion to a further aqueous phase with agitation to form a (water-in-oil)-in-water emulsion;
- adding the (water-in-oil)-in-water emulsion to excess of an aqueous phase to extract the solvent, thereby forming microparticles of a size up to 10 microns in diameter, said microparticles containing bioactive agent in aqueous solution;
- wherein the agitation steps comprise agitating the solutions or emulsions in the blending compartment of a blender, and using a blending blade which both blends and mixes the contents of the blending compartment.
Dependencies are inferred from the claim text.