Chung Li Cheng

US Patent:

58797165, Mar 9, 1999

Filed:

Jun 14, 1993

Appl. No.:

8/076824

Inventors:

Martin A. Katz - Menlo Park CA
Chung H. Cheng - San Jose CA
Sergio Nacht - Los Altos CA

Assignee:

Advanced Polymer Systems, Inc. - Redwood City CA

International Classification:

A61K 916

US Classification:

424501

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.

US Patent:

59551097, Sep 21, 1999

Filed:

Jun 17, 1993

Appl. No.:

8/079220

Inventors:

Richard Won - Palo Alto CA
Martin A. Katz - Menlo Park CA
Chung H. Cheng - San Jose CA
Sergio Nacht - Los Altos CA

Assignee:

Advanced Polymer Systems, Inc. - Redwood City CA

International Classification:

A61K 916

US Classification:

424501

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.