摘要:
The present invention provides methods and apparatus for producing particles via supercritical fluid processing. In one embodiment, the method includes expanding a supercritical fluid plasticized melt across a pressure drop to form solid composite particles that are simultaneously dispersed, foamed and cooled, and milling the solid particles produced to achieve the desired size distribution. In another embodiment, a pressure vessel containing a supercritical fluid plasticized melt is depressurized to form a cooled solid porous mass, which is then milled to obtain solid composite particles.
摘要:
A method of producing solid composite lipid/drug nanoparticles that includes the steps of: (1) dissolving a lipid and a drug in a suitable organic solvent to form a solution; (2) emulsifying the solution in a liquid to form an emulsion having a discontinuous phase of micelles comprising the organic solvent, the drug and the lipid, and a continuous phase comprising the liquid; and (3) contacting the emulsion with a supercritical fluid under conditions suitable to keep the supercritical fluid in a supercritical state, whereby the supercritical fluid extracts the organic solvent from the micelles, causing them to precipitate as organic-solvent free solid composite lipid/drug nanoparticles suspended or dispersed in the liquid.
摘要:
A method of producing microparticles and nanoparticles of a solute via the extraction of solvent, having the solute dissolved therein, from an emulsion using a supercritical fluid. The solute to be precipitated is dissolved in the solvent to form a solution, and the solution is dispersed in an immiscible or partially miscible liquid to form an emulsion. The particles are produced via the extraction of the solvent from the emulsion using the supercritical fluid. The process can produce an aqueous suspension of particles that are substantially insoluble in water, and the solvents used in the process to form the emulsion initially can be recovered and recycled.
摘要:
A method for producing composite particles using a supercritical fluid extraction technique on an emulsion. First and second materials (for example; a polymer and a biologically active material) are dissolved or suspended in a preferably solvent to form a solution or dispersion. The solution or dispersion is emulsified in a polar solvent to form an oil-in-water or water-in-oil-in-water emulsion. The emulsion is contacted with a supercritical fluid to extract the solvent. Removal of the solvent by the supercritical fluid from the emulsion supersaturates at least the first material in the solution causing the first material to precipitate out of the solution as composite particles that include both the first and second materials.
摘要:
A method of producing solid composite lipid/drug nanoparticles that includes the steps of: (1) dissolving a lipid and a drug in a suitable organic solvent to form a solution; (2) emulsifying the solution in a liquid to form an emulsion having a discontinuous phase of micelles comprising the organic solvent, the drug and the lipid, and a continuous phase comprising the liquid; and (3) contacting the emulsion with a supercritical fluid under conditions suitable to keep the supercritical fluid in a supercritical state, whereby the supercritical fluid extracts the organic solvent from the micelles, causing them to precipitate as organic-solvent free solid composite lipid/drug nanoparticles suspended or dispersed in the liquid.
摘要:
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.
摘要:
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. Expansion of the first fraction across a pressure drop results in the formation of composite particles that include the polymer, wax and/or lipid and the solute.
摘要:
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.
摘要:
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.
摘要:
The present invention provides a method of forming particles that involves contacting a solution, which includes a solute and/or other material to be precipitated dissolved or dispersed in a solvent, with a first compressed or liquefied gas at an initial temperature to form a mixture. The mixture is then expanded at a first temperature to form droplets. Depending upon the composition of the droplets and the first temperature, the droplets may be in a solid state or a liquid state. The droplets are then contacted with an extracting fluid at a second temperature to extract the solvent from the droplets. The method can be used to produce micro and nanoparticles suitable for various drug delivery systems.