Abstract: The present invention provides methods for producing composite particles using supercritical fluid as a plasticizing and extracting agent, composite particles formed in accordance with the methods and an apparatus for carrying out the methods. In accordance with the methods of the invention, a polymer, a wax and/or a lipid that is a solid at standard temperature and pressure is contacted with a supercritical fluid to form a melt, either before or after the polymer, wax and/or lipid has been contacted with a solution comprising a solute dissolved in a solvent. The supercritical fluid plasticizes the polymer, wax and/or lip and extracts the solvent from the solution, resulting in the formation of a two-fraction system including a first melt-rich fraction that includes the plasticized melt and fine particles of precipitated solute that are dispersed in the melt, and a second fraction that includes the supercritical fluid and the solvent.

Abstract: The present invention provides methods for purifying polymers. In each embodiment of the invention disclosed herein, a supercritical fluid is contacted with an organic solution that includes a polymer to be purified dissolved in an organic solvent. The supercritical fluid extracts the organic solvent from the organic solution. Impurities such as residual monomers and process solvents are removed with the organic solvent and supercritical fluid, thereby purifying the polymer. The methods of the invention are particularly suitable for use in the purification of biodegradable polymers for use in pharmaceutical applications.

Abstract: A method for producing micro and/or nanoparticles by contacting an emulsion with a supercritical fluid. The method can be used to produce an aqueous suspension of particles that include a drug encapsulated in a polymer. The drug and polymer are dissolved in an organic solvent to form an organic solution. The organic solution is pumped into contact with an aqueous solution in an in-line homogenization device to form an emulsion. Immediately after the emulsion in the in-line homogenization device, the emulsion contacts the supercritical fluid. The supercritical fluid extracts the organic solvent from the oil droplets of the emulsion, causing the drug and polymer to precipitate into the aqueous phase of the emulsion and thereby form an aqueous suspension of particles that include a drug encapsulated in a polymer.

Abstract: Emulsions for use in precipitating water-insoluble drug nanoparticles. The continuous phase of the emulsions include water and an external surfactant. The discontinuous phase of the emulsions include butyl lactate, a co-solvent, an internal surfactant and a water-insoluble drug that is solubilized in the discontinuous phase. The emulsions allow for the precipitation of nanoparticles of water-insoluble drugs that are otherwise difficult or impossible to precipitate using conventional emulsion techniques.

Abstract: A method and apparatus for producing particles, the apparatus includes a solution source that supplies a solution, and a fluid source that supplies a fluid. The solution includes a solvent and a solute. A mixer receives the solution and the fluid from the sources, and mixes the solution and the fluid together to form a mixture. The mixture is supplied from the mixer to an expansion assembly at first pressure. The expansion assembly sprays and expands the mixture substantially simultaneously to form frozen droplets, and preferably to form a low-density powder of frozen droplets. A freeze-dry apparatus sublimes the solvent from the particles. A high mass-transfer rate and a uniform open-structure of the powder bed enhances the freeze-drying process. Solid particles having a controlled size distribution are obtained. The particles preferably have a hollow or porous morphology suitable for differing drug delivery applications to include aerosol formulations.