Patents by Inventor Nienyuan J. Chang

Nienyuan J. Chang 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: 5296228
    Abstract: Sustained release pharmaceutical compound delivery compositions and methods for their production are disclosed wherein ion exchange resin particles are loaded with releasably bound pharmaceutical compounds and incorporated in an aqueous reversibly gelling polymeric solution. The pores of the ion exchange resin are sufficiently small to lock in the pharmaceutical compound without exposure to the large polymer molecules. The pharmaceutical compound remains bound within the pores of the ion exchange resin particles until after administration to a target tissue site where small ions migrate into the pores and initiate an exchange reaction.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: March 22, 1994
    Assignee: Allergan, Inc.
    Inventors: Nienyuan J. Chang, Kenneth J. Himmelstein
  • Patent number: 5292517
    Abstract: pH sensitive, reversible gelling erodible drug delivery compositions and methods for their production are disclosed. The compositions are liquid solutions of poly(methylvinylether/maleic acid) having pharmaceutical compounds incorporated therein. The poly(methylvinylether/maleic acid) solutions increase in viscosity with increases in pH. Thus, when the compositions are formulated at a pH lower than physiological pH's, and then delivered to a target physiological site, the liquid solution becomes viscous and adheres to the tissue for a length sufficient to provide prolonged bioavailability of the pharmaceutical compound.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: March 8, 1994
    Assignee: Allergan, Inc.
    Inventor: Nienyuan J. Chang
  • Patent number: 5275820
    Abstract: Sustained release pharmaceutical compound delivery compositions and methods for their production are disclosed wherein ion exchange resin particles are loaded with releasably bound pharmaceutical compounds prior to incorporation in an erodible polymeric matrix to form microparticulates. The microparticulates are suspended in a fluid medium where the encapsulating polymeric matrix shields the drug loaded ion exchange resin from solvent interaction. Administration to a target tissue site initiations erosion of the polymer matrix and release of the loaded pharmaceutical compound.
    Type: Grant
    Filed: December 27, 1990
    Date of Patent: January 4, 1994
    Assignee: Allergan, Inc.
    Inventor: Nienyuan J. Chang
  • Patent number: 5066414
    Abstract: Shelf-stable/biodegradable fabric softening compositions are provided comprising mixtures of a quarternary ammonium salt containing at least one ester linkage, a linear alkoxylated alcohol, and a liquid carrier. These biodegradable compositions have improved product stability and dispersability, as well as excellent fabric softening characteristics.
    Type: Grant
    Filed: March 6, 1989
    Date of Patent: November 19, 1991
    Assignee: The Procter & Gamble Co.
    Inventor: Nienyuan J. Chang
  • Patent number: 4789491
    Abstract: Disclosed is a method for preparing fabric softening compositions containing quarternized di-esters or di-isopropanol amines. When formulated using the disclosed procedure, including the use of narrowly-defined pH and temperature ranges, the resulting compositions are both biodegradable and storage stable.
    Type: Grant
    Filed: August 7, 1987
    Date of Patent: December 6, 1988
    Assignee: The Procter & Gamble Company
    Inventors: Nienyuan J. Chang, Darlene R. Walley