Patents by Inventor Keith P. Johnston

Keith P. Johnston has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6974593
    Abstract: Particles of water insoluble biologically active compounds, particularly water-insoluble drugs, with an average size of 100 nm to about 300 nm, are prepared by dissolving the compound in a solution then spraying the solution into compressed gaz, liquid or supercritical fluid in the presence of appropriate surface modifiers.
    Type: Grant
    Filed: June 9, 2003
    Date of Patent: December 13, 2005
    Assignees: Jagotec AG, Board of Regents, The University of Texas System
    Inventors: Inge B Henriksen, Awadesh K. Mishra, Gary W. Pace, Keith P. Johnston, Simon Mawson
  • Patent number: 6918946
    Abstract: A method for the production of a robust, chemically stable, crystalline, passivated nanoparticle and composition containing the same, that emit light with high efficiencies and size-tunable and excitation energy tunable color. The methods include the thermal degradation of a precursor molecule in the presence of a capping agent at high temperature and elevated pressure. A particular composition prepared by the methods is a passivated silicon nanoparticle composition displaying discrete optical transitions.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: July 19, 2005
    Assignee: Board of Regents, The University of Texas System
    Inventors: Brian A. Korgel, Paul Thurk, Keith P. Johnston
  • Patent number: 6862890
    Abstract: The present invention provides a system and a method for the production of microparticles and nanoparticles of materials that can be dissolved. The system and method of the present invention provide quicker freezing times, which in turn produces a more uniform distribution of particle sizes, smaller particles, particles with increased porosity and a more intimate mixing of the particle components. The system and method of the present invention also produce particles with greater surface area than conventional methods. One form of the present invention provides a method for the preparation of particles. An effective ingredient is mixed with water, one or more solvents, or a combination thereof, and the resulting mixture is sprayed through an insulating nozzle located at or below the level of a cryogenic liquid. The spray generates frozen particles.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: March 8, 2005
    Assignee: Board of Regents, University of Texas System
    Inventors: Robert O. Williams, III, Keith P. Johnston, Timothy J. Young, True L. Rogers, Melisa K. Barron, Zhongshui Yu, Jiahui Hu
  • Patent number: 6846565
    Abstract: A method for the production of a robust, chemically stable, crystalline, passivated nanoparticle and composition containing the same, that emit light with high efficiencies and size-tunable and excitation energy tunable color. The methods include the thermal degradation of a precursor molecule in the presence of a capping agent at high temperature and elevated pressure. A particular composition prepared by the methods is a passivated silicon nanoparticle composition displaying discrete optical transitions.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: January 25, 2005
    Assignee: Board of Regents, The University of Texas System
    Inventors: Brian A. Korgel, Keith P. Johnston
  • Patent number: 6756062
    Abstract: A method for preparing poorly water soluble drug particles is disclosed. The method comprises dissolving a drug in at least one organic solvent to form a drug/organic mixture, spraying the drug/organic mixture into an aqueous solution, and concurrently evaporating the organic solvent in the presence of the aqueous solution to form an aqueous dispersion of the drug particles. The resulting drug particles are in the nanometer to micrometer size range and show enhanced dissolution rates and reduced crystallinity when compared to the unprocessed drug.
    Type: Grant
    Filed: March 14, 2001
    Date of Patent: June 29, 2004
    Assignee: Board of Regents University of Texas System
    Inventors: Keith P. Johnston, Robert O. Williams, Timothy J. Young, Xiaoxia Chen
  • Publication number: 20040067251
    Abstract: A method for preparing poorly water soluble drug particles is disclosed. The method comprises dissolving a drug in at least one organic solvent to form a drug/organic mixture, spraying the drug/organic mixture into an aqueous solution and concurrently evaporating the organic solvent in the presence of the aqueous solution to form an aqueous dispersion of the drug particles. The resulting drug particles are in the nanometer to micrometer size range and show enhanced dissolution rates and reduced crystallinity when compared to the unprocessed drug. The present invention additionally contemplates products and processes for new drug formulations of insoluble drug particles having high dissolution rates and extremely high drug-to-excipient ratios.
    Type: Application
    Filed: October 8, 2002
    Publication date: April 8, 2004
    Applicant: Dow Chemical Company
    Inventors: Keith P. Johnston, Robert O. Williams, Xiaoxia Chen
  • Publication number: 20040022861
    Abstract: The present invention provides a system and a method for the production of microparticles and nanoparticles of materials that can be dissolved. The system and method of the present invention provide quicker freezing times, which in turn produces a more uniform distribution of particle sizes, smaller particles, particles with increased porosity and a more intimate mixing of the particle components. The system and method of the present invention also produce particles with greater surface area than conventional methods. One form of the present invention provides a method for the preparation of particles. An effective ingredient is mixed with water, one or more solvents, or a combination thereof, and the resulting mixture is sprayed through an insulating nozzle located at or below the level of a cryogenic liquid. The spray generates frozen particles.
    Type: Application
    Filed: October 18, 2002
    Publication date: February 5, 2004
    Inventors: Robert O. Williams, Keith P. Johnston, Timothy J. Young, True L. Rogers, Melisa K. Barron, Zhongshui Yu, Jiahui Hu
  • Publication number: 20040018229
    Abstract: Particles of water insoluble biologically active compounds, particularly water-insoluble drugs, with an average size of 100 nm to about 300 nm, are prepared by dissolving the compound in a solution then spraying the solution into compressed gaz, liquid or supercritical fluid in the presence of appropriate surface modifiers.
    Type: Application
    Filed: June 9, 2003
    Publication date: January 29, 2004
    Inventors: Inge B. Henriksen, Awadesh K. Mishra, Gary W. Pace, Keith P. Johnston, Simon Mawson
  • Patent number: 6576264
    Abstract: Particles of water insoluble biologically active compounds, particularly water-insoluble drugs, with an average size of 100 nm to about 300 nm, are prepared by dissolving the compound in a solution then spraying the solution into compressed gaz, liquid or supercritical fluid in the presence of appropriate surface modifiers.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: June 10, 2003
    Assignees: SkyePharma Canada Inc., Board of Regents, The University of Texas System
    Inventors: Inge B Henriksen, Awadesh K. Mishra, Gary W. Pace, Keith P. Johnston, Simon Mawson
  • Publication number: 20030041602
    Abstract: The present invention provides a system and a method for the production of microparticles and nanoparticles of materials that can be dissolved. The system and method of the present invention provide quicker freezing times, which in turn produces a more uniform distribution of particle sizes, smaller particles, particles with increased porosity and a more intimate mixing of the particle components. The system and method of the present invention also produce particles with greater surface area than conventional methods. One form of the present invention provides a method for the preparation of particles. An effective ingredient is mixed with water, one or more solvents, or a combination thereof, and the resulting mixture is sprayed through an insulating nozzle located at or below the level of a cryogenic liquid. The spray generates frozen particles.
    Type: Application
    Filed: January 30, 2002
    Publication date: March 6, 2003
    Inventors: Robert O. Williams, Keith P. Johnston, Timothy J. Young, True L. Rogers, Melisa K. Barron, Zhongshui Yu, Jiahui Hu
  • Publication number: 20030003300
    Abstract: A method for the production of a robust, chemically stable, crystalline, passivated nanoparticle and composition containing the same, that emit light with high efficiencies and size-tunable and excitation energy tunable color. The methods include the thermal degradation of a precursor molecule in the presence of a capping agent at high temperature and elevated pressure. A particular composition prepared by the methods is a passivated silicon nanoparticle composition displaying discrete optical transitions.
    Type: Application
    Filed: March 28, 2002
    Publication date: January 2, 2003
    Inventors: Brian A. Korgel, Keith P. Johnston
  • Publication number: 20020188160
    Abstract: A process is provided for catalyzing an organic reaction to form a reaction product by placing reactants and a catalyst for the organic reaction, the catalyst of a metal complex and at least one ligand soluble within one of the phases of said aqueous biphasic system, within an aqueous biphasic system including a water phase, a dense phase fluid, and a surfactant adapted for forming an emulsion or microemulsion within the aqueous biphasic system, the reactants soluble within one of the phases of the aqueous biphasic system and convertible in the presence of the catalyst to a product having low solubility in the phase in which the catalyst is soluble; and, maintaining the aqueous biphasic system under pressures, at temperatures, and for a period of time sufficient for the organic reaction to occur and form the reaction product and to maintain sufficient density on the dense phase fluid, the reaction product characterized as having low solubility in the phase in which the catalyst is soluble.
    Type: Application
    Filed: November 18, 1999
    Publication date: December 12, 2002
    Inventors: GUNILLA B. JACOBSON, WILLIAM TUMAS, KEITH P. JOHNSTON
  • Patent number: 6479708
    Abstract: A process is provided for catalyzing an organic reaction to form a reaction product by placing reactants and a catalyst for the organic reaction, the catalyst of a metal complex and at least one ligand soluble within one of the phases of said aqueous biphasic system, within an aqueous biphasic system including a water phase, a dense phase fluid, and a surfactant adapted for forming an emulsion or microemulsion within the aqueous biphasic system, the reactants soluble within one of the phases of the aqueous biphasic system and convertible in the presence of the catalyst to a product having low solubility in the phase in which the catalyst is soluble; and, maintaining the aqueous biphasic system under pressures, at temperatures, and for a period of time sufficient for the organic reaction to occur and form the reaction product and to maintain sufficient density on the dense phase fluid, the reaction product characterized as having low solubility in the phase in which the catalyst is soluble.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: November 12, 2002
    Assignee: The Regents of the University of California
    Inventors: Gunilla B. Jacobson, William Tumas, Keith P. Johnston
  • Publication number: 20020081334
    Abstract: A method for preparing poorly water soluble drug particles is disclosed. The method comprises dissolving a drug in at least one organic solvent to form a drug/organic mixture, spraying the drug/organic mixture into an aqueous solution, and concurrently evaporating the organic solvent in the presence of the aqueous solution to form an aqueous dispersion of the drug particles. The resulting drug particles are in the nanometer to micrometer size range and show enhanced dissolution rates and reduced crystallinity when compared to the unprocessed drug.
    Type: Application
    Filed: March 14, 2001
    Publication date: June 27, 2002
    Inventors: Keith P. Johnston, Robert O. Williams, Timothy J. Young, Xiaoxia Chen
  • Patent number: 5733964
    Abstract: Heterogeneous polymer mixtures comprising a polymer in liquid or supercritical CO.sub.2 are stabilized by employing a poly(propylene oxide) or poly(butylene oxide) based surfactant. These surfactants are especially well suited for stabilizing heterogeneous polymer mixtures formed by micronizing techniques as well as by precipitation of a compressed fluid antisolvent applications.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: March 31, 1998
    Assignees: Board of Regents, The University of Texas System, Air Products and Chemicals, Inc.
    Inventors: Keith P. Johnston, Steven Paul Wilkinson, Mark Leonard O'Neill, Lloyd Mahlon Robeson, Simon Mawson, Richard Henry Bott, Carrington Duane Smith