Patents by Inventor Guohua Chen

Guohua Chen 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).

  • Publication number: 20070077304
    Abstract: An injectable depot formulation includes a biocompatible polymer, an organic solvent combined with the biocompatible polymer to form a viscous gel, and a small molecule drug incorporated in the viscous gel such that the formulation exhibits an in vivo release profile having Cmax to Cmin ratio less than 200 and lag time less than 0.2.
    Type: Application
    Filed: September 26, 2006
    Publication date: April 5, 2007
    Applicant: ALZA Corporation
    Inventors: Andrew Luk, Gunjan Junnarkar, Guohua Chen
  • Publication number: 20070015689
    Abstract: Formulations and methods are provided for improving the stability upon exposure to aqueous media of polypeptides present in non-aqueous suspension vehicles. In particular aspects of the invention, formulations are provided that comprise a complex of a metal ion and a polypeptide suspended in a non-aqueous, biocompatible suspension vehicle. Aggregation of individual polypeptide molecules is reduced when aqueous media is introduced to such formulations, serving to stabilize the polypeptide.
    Type: Application
    Filed: June 21, 2006
    Publication date: January 18, 2007
    Applicant: ALZA CORPORATION
    Inventors: Catherine Rohloff, Guohua Chen, Zhongli Ding, Stephen Berry, Latha Narayanan, Michael Desjardin
  • Publication number: 20060193918
    Abstract: A nonaqueous, single-phase vehicle that is capable of suspending an active agent. The nonaqueous, single-phase vehicle includes at least one solvent and at least one polymer and is formulated to exhibit phase separation upon contact with an aqueous environment. The at least one solvent may be selected from the group consisting of benzyl benzoate, decanol, ethyl hexyl lactate, and mixtures thereof and the at least one polymer may be selected from the group consisting of a polyester, pyrrolidone, ester of an unsaturated alcohol, ether of an unsaturated alcohol, polyoxyethylenepolyoxypropylene block copolymer, and mixtures thereof. In one embodiment, the at least one solvent is benzyl benzoate and the at least one polymer is polyvinylpyrrolidone. A stable, nonaqueous suspension formulation that includes the nonaqueous, single-phase vehicle and an active agent, and a method of forming the same, are also disclosed.
    Type: Application
    Filed: February 3, 2006
    Publication date: August 31, 2006
    Inventors: Catherine Rohloff, Guohua Chen, Andrew Luk, Rupal Ayer, Paul Houston, Michael Desjardin, Pauline Zamora, Stan Lam
  • Publication number: 20060165800
    Abstract: Methods and compositions for systemically or locally administering by implantation a beneficial agent to a subject are described, and include, for example, depot gel compositions that can be injected into a desired location and which can provide controlled release of a beneficial agent over a short duration of time. The compositions include a low molecular weight biocompatible polymer, a biocompatible solvent having low water miscibility that forms a viscous gel with the polymer and limits water uptake by the implant, and a beneficial agent.
    Type: Application
    Filed: April 3, 2006
    Publication date: July 27, 2006
    Inventors: Guohua Chen, David Priebe
  • Publication number: 20060140988
    Abstract: The present invention relates to methods and depot emulsion compositions for delivery of visco-supplements.
    Type: Application
    Filed: December 19, 2005
    Publication date: June 29, 2006
    Inventors: Guohua Chen, Edwin Chan, Joel Rosenblatt
  • Publication number: 20060141040
    Abstract: The present invention relates generally to compositions and methods for administering a biologically active agent, and more specifically to injectable non-aqueous suspensions.
    Type: Application
    Filed: December 19, 2005
    Publication date: June 29, 2006
    Inventors: Guohua Chen, Paul Houston, Andrew Luk
  • Publication number: 20060142234
    Abstract: The present invention relates generally to compositions and methods for administering a biologically active agent, and more specifically to injectable non-aqueous suspensions.
    Type: Application
    Filed: December 19, 2005
    Publication date: June 29, 2006
    Inventors: Guohua Chen, Paul Houston, Andrew Luk
  • Publication number: 20050281879
    Abstract: Injectable depot gel compositions and kits that provide an excipient for modulating a release rate and stabilizing beneficial agents are provided. Methods of administering and preparing such systems are also provided. The gel compositions comprise biodegradable, bioerodible polymers and water-immiscible solvents in amounts effective to plasticize the polymers and form gels with the polymers. Suitable excipients include pH modifiers, reducing agents, and antioxidants.
    Type: Application
    Filed: November 10, 2004
    Publication date: December 22, 2005
    Inventors: Guohua Chen, David Priebe
  • Publication number: 20050281877
    Abstract: Osmotic delivery system semipermeable body assemblies that control the delivery rate of a beneficial agent from an osmotic delivery system incorporating one of the semipermeable body assemblies are provided. A semipermeable body assembly or plug includes a semipermeable body which is positionable in an opening of an osmotic delivery system. The semipermeable body has a hollow interior portion having a size selected to obtain a predetermined liquid permeation rate through the semipermeable body. Because the beneficial agent in the osmotic delivery system is delivered at substantially the same rate, the osmotic agent imbibes liquid which has permeated through the plug from a surrounding environment, and the liquid permeation rate through the plug controls the delivery rate of the beneficial agent from the osmotic delivery system.
    Type: Application
    Filed: August 2, 2005
    Publication date: December 22, 2005
    Inventors: Guohua Chen, Scott Lautenbach, Keith Dionne, Scott Jordan, Steve Berry, Craig Rodenberger, Rupal Ayer
  • Patent number: 6923800
    Abstract: Osmotic delivery system semipermeable body assemblies that control the delivery rate of a beneficial agent from an osmotic delivery system incorporating one of the semipermeable body assemblies are provided. A semipermeable body assembly or plug includes a semipermeable body which is positionable in an opening of an osmotic delivery system. The semipermeable body has a hollow interior portion having a size selected to obtain a predetermined liquid permeation rate through the semipermeable body. Because the beneficial agent in the osmotic delivery system is delivered at substantially the same rate, the osmotic agent imbibes liquid which has permeated through the plug from a surrounding environment, and the liquid permeation rate through the plug controls the delivery rate of the beneficial agent from the osmotic delivery system.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: August 2, 2005
    Assignee: ALZA Corporation
    Inventors: Guohua Chen, Scott D. Lautenbach, Keith E. Dionne, Scott D. Jordan, Steve A. Berry, Craig I. Rodenberger, Rupal Ayer
  • Publication number: 20050107772
    Abstract: In one aspect, the present invention is directed to an osmotic pump that automatically provides an ascending release rate of active agent as the osmotic pump functions in an environment of operation and may be designed for implantation within a desired animal or human subject. An osmotic pump according to the present invention includes a reservoir, a rate controlling membrane, an expandable osmotic composition, an active agent formulation and an exit orifice. Once administered to an environment of operation, water passes through the rate controlling membrane and into the osmotic composition, which causes the osmotic composition to expand and expel the active agent formulation through the exit orifice at a rate that is directly proportional to the rate at which water passes through the rate controlling membrane.
    Type: Application
    Filed: September 29, 2004
    Publication date: May 19, 2005
    Inventors: Guohua Chen, Rupal Ayer, Scott Lautenbach
  • Publication number: 20050106214
    Abstract: Injectable depot gel compositions and kits that provide an excipient for modulating a release rate and stabilizing beneficial agents are provided. Methods of administering and preparing such systems are also provided. The gel compositions comprise biodegradable, bioerodible polymers and water-immiscible solvents in amounts effective to plasticize the polymers and form gels with the polymers. Suitable excipients include pH modifiers, reducing agents, and antioxidants.
    Type: Application
    Filed: November 10, 2004
    Publication date: May 19, 2005
    Inventor: Guohua Chen
  • Publication number: 20050079202
    Abstract: Methods and compositions for systemically or locally administering a beneficial agent to a subject are described, and include, for example, implantable elastomeric depot compositions that can be injected into a desired location and which can provide controlled release of a beneficial agent over a prolonged duration of time. The compositions include a biocompatible, elastomeric polymer, a biocompatible solvent having low water miscibility that forms an elastomeric viscous gel with the polymer and limits water uptake by the implant, and a beneficial agent.
    Type: Application
    Filed: May 28, 2004
    Publication date: April 14, 2005
    Inventors: Guohua Chen, Paul Houston, Lothar Kleiner, Aruna Nathan, Joel Rosenblatt
  • Publication number: 20040151753
    Abstract: Methods and compositions for systemically or locally administering a beneficialagent to a subject are described, and include, for example, depot gel compositions that can be injected into a desired location and which can provide controlled release of a beneficial agent over a prolonged duration of time. The compositions include a biocompatible polymer, a biocompatible solvent having low water miscibility that forms a viscous gel with the polymer and limits water uptake by the implant, and a beneficial agent.
    Type: Application
    Filed: November 4, 2003
    Publication date: August 5, 2004
    Inventors: Guohua Chen, Paul Houston, Roy Bannister, Teresa Kameda, David Priebe, Lothar Kleiner
  • Publication number: 20040109893
    Abstract: Drug delivery systems and kits are provided that release an anesthetic, such as bupivacaine, over a short duration. Methods of administering and preparing such systems are also provided. Drug delivery systems include a short duration gel vehicle and an anesthetic dissolved or dispersed in the gel vehicle. The gel vehicle comprises a low molecular weight bioerodible, biocompatible polymer and a water-immiscible solvent in an amount effective to plasticize the polymer and form a gel with the polymer. In some instances, a component solvent is used along with the water-immiscible solvent. An efficacy ratio, which is one way to measure the efficacy of a delivery system, can be controlled based on, for example, the construction of the gel vehicle to achieve a desired release profile.
    Type: Application
    Filed: October 31, 2003
    Publication date: June 10, 2004
    Inventors: Guohua Chen, David T. Priebe, Roy Bannister, Paul Houston, Lothar Walter Kleiner
  • Publication number: 20040024069
    Abstract: Injectable depot compositions are provided that include a bioerodible, biocompatible polymer, a solvent having a miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith, a thixotropic agent, and a beneficial agent. The solvent comprises an aromatic alcohol, an ester of an aromatic acid, an aromatic ketone, or mixtures thereof. The compositions have substantially improved the shear thinning behavior and reduced injection force, rendering the compositions readily implanted beneath a patient's body surface by injection.
    Type: Application
    Filed: November 14, 2002
    Publication date: February 5, 2004
    Inventors: Guohua Chen, Paul R. Houston, Lothar Walter Kleiner, John J. Spaltro
  • Publication number: 20040022859
    Abstract: Injectable depot compositions are provided that include a polymer matrix having a plurality of bioerodible, biocompatible polymers wherein wherein each polymer of the plurality of polymers has a specified weight average molecular weight; and the polymer matrix has a broad molecular weight distribution of the plurality of polymers; a solvent having a miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith; and a beneficial agent. The compositions are have substantially improved the shear thinning behavior and reduced injection force, rendering the compositions readily implanted beneath a patient's body surface by injection.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 5, 2004
    Inventors: Guohua Chen, Paul Houston, Lothar Kleiner, Jeremy Wright
  • Publication number: 20040001889
    Abstract: Methods and compositions for systemically or locally administering by implantation a beneficial agent to a subject are described, and include, for example, depot gel compositions that can be injected into a desired location and which can provide controlled release of a beneficial agent over a short duration of time. The compositions include a low molecular weight biocompatible polymer, a biocompatible solvent having low water miscibility that forms a viscous gel with the polymer and limits water uptake by the implant, and a beneficial agent.
    Type: Application
    Filed: June 25, 2003
    Publication date: January 1, 2004
    Inventors: Guohua Chen, David Priebe
  • Publication number: 20030180364
    Abstract: Catheter injectable depot compositions are provided that include a bioerodible, biocompatible polymer, a solvent having miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith, a thixotropic agent, and a beneficial agent. The solvent comprises an aromatic alcohol, an ester of an aromatic acid, an aromatic ketone, or mixtures thereof. The compositions are have substantially improved the shear thinning behavior and reduced injection force, rendering the compositions readily implanted beneath a patient's body surface by injection.
    Type: Application
    Filed: November 14, 2002
    Publication date: September 25, 2003
    Inventors: Guohua Chen, Paul R. Houston, Lothar Kleiner, John Spaltro
  • Publication number: 20030170289
    Abstract: Injectable depot compositions are provided that include a bioerodible, biocompatible polymer, an aromatic alcohol having miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith, and a beneficial agent. The composition may additionally contain an ester of an aromatic acid, or an aromatic ketone. The compositions are readily implanted beneath a patient's body surface by injection, as the aromatic alcohol not only facilitates solubilization of the polymer, but also acts as a thixotropic agent, substantially increasing the shear thinning behavior of the composition.
    Type: Application
    Filed: November 14, 2002
    Publication date: September 11, 2003
    Inventors: Guohua Chen, Paul R. Houston, Lothar Walter Kleiner, Jeremy Corwin Wright