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US 12,569,441 B2Granted
Microparticles and nanoparticles having negative surface charges
AssigneeCytodigm, Inc.
InventorBin Wu
Life of this patent
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Abstract
This invention provides methods for producing a polymer particle which contains unusually high negative charges on the surface of the particle. Preferably, the polymer is pharmaceutically acceptable. The negative charges can be conferred by chemical groups such as carboxyl, sulfonate, nitrate, fluorate, chloride, iodide, persulfate, and many others, with carboxyl group being preferred. The invention also provides polymer particle produced by the methods of the invention.
Claims8
A method for preparing PLGA microparticles or nanoparticles having negative surface charges, said method comprising:
- (1) dissolving an active pharmaceutical ingredient (API) in an inner aqueous solvent to form an API solution;
- (2) dissolving a pharmaceutically acceptable PLGA polymer having an average molecular weight of from about 1,000 to about 1,000,000 Da, in an organic solvent to form a polymer solution, wherein the organic solvent is not miscible or is partially miscible in the inner aqueous solvent;
- (3) emulsifying the API solution in the polymer solution;
- (4) dissolving a pharmaceutically acceptable polyacrylic acid and a surfactant;
- (5) emulsifying the solution of step (3) in the outer aqueous solution to form an emulsion;
- and
- (6) removing the organic solvent to form said PLGA microparticles or nanoparticles having negative surface charges;
- wherein the microparticles or nanoparticles have a zeta potential of from about −15 mV to −100 mV and wherein the pharmaceutically acceptable polyacrylic acid is incorporated onto and at least partially into the PLGA microparticles.
5 more elements
Dependencies are inferred from the claim text.