Process for preparing microparticles through phase inversion phenomena
AssigneeBrown University Foundation
InventorsEdith Mathiowitz, Donald Chickering, III, Yong S. Jong, Jules S. Jacob
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Abstract
A process for preparing nanoparticles and microparticles is provided. The process involves forming a mixture of a polymer and a solvent, wherein the solvent is present in a continuous phase and introducing the mixture into an effective amount of a nonsolvent to cause the spontaneous formation of microparticles.
Claims31
A method for microencapsulating an agent to form a microencapsulated product, comprising:
- dissolving a polymer in an effective amount of a solvent,
- dissolving or dispersing said agent in said effective amount of said solvent, wherein said polymer, said agent and said solvent form a mixture having a continuous phase and wherein the solvent is said continuous phase, and
- introducing said mixture into an effective amount of a nonsolvent to cause the spontaneous formation of said microencapsulated product, wherein said solvent and said nonsolvent are miscible and 0<.delta. solvent -.delta. nonsolvent <6 wherein the nonsolvent and solvent are used in effective amounts, wherein the effective amount of nonsolvent and solvent is an effective amount when the solvent:nonsolvent volume ratio is between 1:40 and 1:1,000,000.
A method for microencapsulating an agent to form a microencapsulated product, comprising:
- dissolving a polymer in a solvent at a concentration of less than 10% weight/volume,
- dissolving or dispersing said agent in said solvent, wherein said polymer, said agent and said solvent form a mixture having a viscosity of less than 3.5 centipoise, and
- introducing said mixture into a nonsolvent, wherein the volume ratio of solvent:nonsolvent is at least 1:40, to cause the spontaneous formation of said microencapsulated product, wherein said solvent and said nonsolvent are miscible and 0<.delta. solvent -.delta. nonsolvent <6.
A method for microencapsulating an agent to form a microencapsulated product, comprising:
- dissolving a polymer in an effective amount of a solvent,
- dissolving or dispersing an agent in the effective amount of the solvent by freezing the mixture of the solvent, the polymer, and the agent to form a frozen mixture and drying by vacuum the frozen mixture, wherein the polymer, the agent and the solvent in the frozen mixture have a continuous phase,
- redissolving the continuous phase frozen mixture in a solvent, and
- introducing the mixture into an effective amount of a nonsolvent to cause the spontaneous formation of microencapsulated product, wherein the solvent and the nonsolvent are miscible and 0<.delta. solvent -.delta. nonsolvent <6.
Dependencies are inferred from the claim text.