Adsorption of sebum

• US 4,000,317 A
• Filed: 05/06/1974
• Issued: 12/28/1976
• Est. Priority Date: 11/22/1972
• Status: Expired due to Term

• Current Assignee: Colgate-Palmolive Company
• Original Assignee: Colgate-Palmolive Company
• Inventors: Menda, William Carl, Mehaffey, Robert James
• Primary Examiner(s): Friedman, Stanley J.
• Application Number:
  US05/466,937
• Time in Patent Office: 967 Days
• Field of Search: 424/127, 424/357, 424/69, 424/347, 424/356
• US Class Current: 514/770
• CPC Class Codes: A61K 2800/412 Microsized, i.e. having sizes between 0.1 and 100 microns
• CPC Class Codes: A61K 8/25 Silicon; Compounds thereof
• CPC Class Codes: A61Q 19/008 Preparations for oily skin
• CPC Class Codes: A61Q 19/10 Washing or bathing preparations

Abstract

Sebum, the oily material secreted by the sebaceous glands, especially on the human face, is adsorbed by a thin layer of a pyrogenic colloidal silica of spherical shape and very small particle size. The pyrogenic colloidal silica has a high capacity for adsorbing the sebum and preventing it from exerting its oily effects on the skin. Free flow of sebum from the sebaceous gland is allowed but even in the cases of persons whose sebaceous glands are overactive, the skin is not excessively oily, due to the adsorption effects of the pyrogenic colloidal silica. The appearance of the facial skin of a user is improved, the surface of the skin is less apt to support harmful bacterial and fungal growth and, if make-ups containing dyes or pigments are employed, they are less apt to undergo color changes, due to the effects of oil thereon.

Compositions that may be employed to apply the pyrogenic colloidal silica to the skin are non-oily, aqueous, alcoholic or aqueous alcoholic suspensions of the pyrogenic colloidal silica in certain ranges of concentrations thereof, which may include minor proportions of non-oily adjuvants, such as thickeners, solvents, emollients, pH modifiers, bactericides, drying agents and exfoliants.

By use of a small amount of such a composition, sebum adsorption can be effected over daytime periods of from 4 to 12 hours, with no re-application required and the pyrogenic colloidal silica composition can be used in such small quantities as to be essentially invisible on the skin. Heavier applications may be employed overnight, when unobtrusiveness of the product is not as important.

Claims

1. A method of slowing the development of oily skin which comprises applying to skin which normally becomes oily an oil-free suspension of pyrogenic colloidal silica in an aqueous-alcoholic medium, the particles of silica having at least 90% thereof with diameters between 2 and 20 millimicrons, said suspension containing from 0.5 to 10% by weight of the pyrogenic colloidal silica, 20 to 70% by weight water, 25 to 75% by weight of an aliphatic monohydric alcohol having from 2 to 4 carbon atoms, and 0.2 to 5% by weight of an organic thickening agent, said suspension being applied to the skin in a layer of a thickness corresponding to from 5 ×

10^-5 to 1 ×

10^-5 gram of silica per square centimeter of skin, said suspension being free of oil.

2. A composition for slowing the development of oily skin which consists essentially of an oil-free suspension of pyrogenic colloidal silica in an aqueous-alcoholic medium, the particles of silica having at least 90% thereof with diameters between 2 and 20 millimicrons, said suspension containing from 0.5 to 10% by weight of the pyrogenic colloidal silica, 20 to 70% by weight of water, 25 to 75% by weight of an aliphatic monohydric alcohol having from 2 to 4 carbon atoms, and 0.2 to 5% by weight of an organic thickening agent.