Drug – bio-affecting and body treating compositions – Anti-perspirants or perspiration deodorants
Reexamination Certificate
2001-12-19
2003-09-09
Dodson, Shelley A. (Department: 1616)
Drug, bio-affecting and body treating compositions
Anti-perspirants or perspiration deodorants
C424S078020, C424S078080, C424S400000, C424S401000
Reexamination Certificate
active
06616921
ABSTRACT:
FIELD OF INVENTION
This invention relates to the field of antiperspirant deodorant products. More specifically, it relates to antiperspirant deodorant products comprising an antiperspirant salt and a water soluble polymer that comprises Brnsted acid groups and acts as a co-gellant for the antiperspirant salt when mixed therewith in the presence of water.
BACKGROUND OF INVENTION
Cosmetic antiperspirant and deodorant products are known. Typical antiperspirant products comprise topically acceptable compositions containing a metal salt, such as an astringent aluminium or aluminium/zirconium salt, in combination with a cosmetically suitable vehicle. Typical deodorant products comprise topically acceptable compositions containing one or more agents that mask or inhibit the formation of unpleasant body odours; antimicrobial agents are widely used for this purpose. Such cosmetic antiperspirant and deodorant products may be available in a variety of product forms, for example as sticks, creams, soft-solids, roll-on lotions, aerosols, pump sprays and squeeze sprays.
Whilst such compositions provide a degree of antiperspirancy and malodour reduction, there can be problems associated with their use and there is always a desire for improved performance. A problem encountered by some people, is that the application of high levels of astringent antiperspirant salts leads to skin irritation. Others find similar problems with certain antimicrobial agents. Other problems include formulation difficulties with the high levels of active ingredients sometimes required. It has long been desirable to achieve excellent protection from body malodour without the use of high concentrations of conventional antiperspirant or deodorant agents. This could lead to antiperspirant and deodorant products being cheaper, easier to formulate (by virtue of the reduced amount of antiperspirant active used), or generally having improved sensory properties. Other benefits of requiring lesser amounts of conventional antiperspirant or deodorant agents include the reduced concentration on the body of such ‘foreign’ agents and the reduced impact on the environment, in terms of chemical usage and processing.
The above problems have been addressed in a number of ways in the past, examples including the use of certain polymers as antiperspirant actives. WO 93/24105 (Tranner) describes the use of particular water-insoluble film-forming polymers, with conventional antiperspirant salts being non-essential, optional components in the compositions of the invention. The examples given that include antiperspirant salt also comprise co-polymers of octylacrylamide/acrylates or PVP/acrylates. No reference is made to interactions between the antiperspirant salts and the polymers. References to film-forming polymers are also made in JP 2290810 (Nakagawa et al) and WO 95/27473 (Causton and Baines). An alternative approach is described in EP 701812 (Abrutyn et al), where porous polymer beads are claimed to be capable of absorbing sweat components.
Polymers have also been used to enhance the performance of antiperspirant salts by increasing the residual amount of antiperspirant salt on the skin. Thus, EP 222580 (Klein and Sykes) describes the use of dimethyldiallyl ammonium chloride (DMDAAC) polymers for this purpose.
The use of DMDAAC/acrylic acid-type co-polymers to thicken personal care products is described in EP 266,111 (Boothe et al) and EP 478,327 (Melby and Boothe). The latter of these patents discusses the thickening of metal-containing aqueous compositions by said co-polymers.
Aqueous compositions comprising an acrylic acid containing polymer and an antiperspirant salt are described in WO 98/50005 and WO 98/48768 (Ron et al). In these patents, the proposed invention relates to the reverse thermal viscosifying benefit of the polymer.
U.S. Pat. Nos. 5,194,262 and 5,271,932 (Goldberg et al) describe antiperspirant compositions containing microcapsules comprising an antiperspirant salt encapsulated within a water-soluble shell possessing a bioadhesive. Polyacrylic acid is disclosed as a possible component of both the water-soluble shell and the bioadhesive.
SUMMARY OF INVENTION
We have discovered that the performance of conventional antiperspirant salts can be improved by the addition of polymers that are capable of interacting with the antiperspirant salts on contact with the skin.
Thus, according to a first aspect of the present invention, there is provided an antiperspirant product comprising an antiperspirant salt and a water soluble polymer, characterised in that:
(i) the polymer comprises Brnsted acid groups and acts as a co-gellant for the antiperspirant salt when mixed therewith in the presence of water; and
(ii) the polymer is physically separate from antiperspirant salt prior to application.
According to a second aspect of the present invention, there is provided a cosmetic method of achieving an antiperspirancy and/or deodorancy benefit, said method comprising the topical application to the human body of an antiperspirant product as defined in the first aspect of the invention.
According to a related aspect of the invention, there is provided a cosmetic method of achieving an antiperspirancy and/or deodorancy benefit, said method comprising bringing together on the surface of the human body an antiperspirant salt and a water soluble polymer comprising Brnsted acid groups which, in the presence of water, acts as a co-gellant for the antiperspirant salt.
According to a third aspect of the present invention, there is provided a method for the manufacture of an antiperspirant composition, comprising the mixing, in a fluid carrier material, of an antiperspirant salt and a water soluble polymer, wherein said polymer comprises Brnsted acid groups and acts as a co-gellant for the antiperspirant salt, when mixed therewith in the presence of water, and wherein the polymer is physically separate from antiperspirant salt in the composition.
DETAILED DESCRIPTION OF THE INVENTION
The interaction between the antiperspirant (AP) salt and the polymer, on application to the human body, is an essential factor in this invention. The interaction between the components is chemical in nature and results in a thickened or gelled state of matter. It is desirable that the interaction between the components does not occur significantly before they are brought into contact with the human body. Such premature interaction can result in numerous problems including unwanted thickening of the product, poor dispensing, poor sensory properties, and poor antiperspirancy and/or deodorancy performance. Avoidance of premature interaction involves keeping the polymer physically separate from the AP salt. This may be achieved by co-application of the components from independent compositions; such co-application being done concurrently or consecutively, with either the AP salt or the polymer being applied first.
Alternatively, a composition comprising a non-interacting mixture of the AP salt and the polymer may be employed. Such compositions comprise the polymer physically separate from the AP salt. Non-interacting mixtures of this kind are ones where intimate contact between the AP salt and the polymer is not possible. Mixtures of this kind include co-dispersions of the AP salt and the polymer in a non-solvent carrier material. Examples of mixtures that do not meet this criterion include a true solution comprising both AP salt and the polymer and mixtures comprising AP salt encapsulated by the polymer.
In a particular aspect of the present invention, compositions comprising a non-interacting mixture of the AP salt and the polymer are essentially non-aqueous compositions. Essentially non-aqueous compositions comprise less than 10% by weight of water, preferably less than 5% by weight of water, and most preferably less than 1% by weight of water, excluding any water of hydration associated with the AP salt. In addition to being essentially non-aqueous, many compositions comprising both the AP salt and the polymer comprise less than 20% or even less than 10% by weig
Rieley Hugh
Smith Ian Karl
Dodson Shelley A.
Stein Kevin J.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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