Patents by Inventor Chung H. Cheng

Chung H. Cheng 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).

  • Methods and compositions for topical delivery of retinoic acid
    Patent number: 5955109
    Abstract: Retinoic acid compositions intended for topical application are incorporated in novel formulations in which they are retained as impregnants inside the pores of porous solid particles or microspheres. The pores form a continuous network open to the exterior of the particles, permitting outward diffusion of the retinoic acid impregnant at a controlled rate depending on the pore size. The impregnated particles are prepared by impregnation of preformed particles with the retinoic acid.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: September 21, 1999
    Assignee: Advanced Polymer Systems, Inc.
    Inventors: Richard Won, Martin A. Katz, Chung H. Cheng, Sergio Nacht
  • Methods and compositions for topical delivery of benzoyl peroxide
    Patent number: 5879716
    Abstract: Benzoyl peroxide intended for topical application is incorporated in novel formulations in which it is retained as impregnants inside the pores of porous solid particles or microspheres. The pores form a continuous network open to the exterior of the particles, permitting outward diffusion of the benzoyl peroxide impregnant at a controlled rate depending on the pore size. The impregnated particles are prepared by impregnation of preformed particles with the benzoyl peroxide.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: March 9, 1999
    Assignee: Advanced Polymer Systems, Inc.
    Inventors: Martin A. Katz, Chung H. Cheng, Sergio Nacht