Process for preparing microparticles through phase inversion phenomena
AssigneeBrown University Research 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.
Claims37
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 said effective amount of said solvent, wherein said polymer, said agent and said solvent form a mixture having a continous 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 a microencapsulated product, wherein said step of introducing does not include emulsification, agitation, and/or stirring, wherein said solvent and said nonsolvent are miscible and the difference in solubility parameter of solvent/nonsolvent pairs or the solubility parameter of the nonsolvent/solvent pairs is less than 6, wherein the nonsolvent and solvent are used in effective amounts, wherein the effective amount per volume of nonsolvent is at least tenfold greater than the amount per volume of solvent.
A method for microencapsulating an agent to form a microencapsulated product, comprising:
- dissolving a polymer in an effective amount of a solvent,
- dissolving a dispersing and 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 microencapsulated product, wherein said step of introducing does not include emulsifacation, agitation, and/or stirring, wherein said solvent and said nonsolvent are a hydrophilic solvent/nonsolvent pair, wherein the nonsolvent and solvent are used in effective amounts, wherein the effective amount per volume of nonsolvent is at least tenfold greater than the amount per volume of solvent.
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 between 1:40 and 1:1,000,000, to cause the spontaneous formation of said microencapsulated product, wherein said solvent and said nonsolvent are miscible and the difference in solubility parameter of solvent/nonsolvent pairs or the solubility parameter of the nonsolvent/solvent pairs is less than 6.
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 between 1:40 and 1:1,000,000, to cause the spontaneous formation of said microencapsulated product, wherein said solvent and said nonsolvent are a hydrophilic solvent/nonsolvent pair.
Dependencies are inferred from the claim text.