Drug – bio-affecting and body treating compositions – Anti-perspirants or perspiration deodorants
Reexamination Certificate
2001-04-20
2002-01-29
Dodson, Shelley A. (Department: 1616)
Drug, bio-affecting and body treating compositions
Anti-perspirants or perspiration deodorants
C424S066000, C424S068000, C424S078020, C424S078080, C424S400000, C424S401000
Reexamination Certificate
active
06342210
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the formation of enhanced antiperspirant salts containing (1) aluminum or (2) aluminum and zirconium polymeric species, the salts themselves and cosmetic compositions formulated with such salts. In particular, the use of a glass-forming step for the antiperspirant active is useful in forming actives with lower refractive indices. This results in (1) a clearer final formulation, especially with a selected polyamide gelling agent; and (2) an ability to obtain suspension products which have the appearance of a clear gel without the wetness frequently associated with traditional gels.
BACKGROUND OF THE INVENTION
In an earlier and co-pending case assigned to the same assignee as this application, U.S. Ser. No. 9/597,322 filed Jun. 19, 2000, it was disclosed that certain grinding techniques which resulted in antiperspirant actives in a certain micron particle size range have shown improved efficacy in traditional screening tests. It has now been found that if an antiperspirant salt is first dissolved in water, made into a glass by evaporation of the water, and then subjected to the grinding process as described in that earlier case, an improved salt can be obtained with a surprising new property of a lower refractive index.
By way of general background, antiperspirant salts, such as aluminum chlorohydrex (also called aluminum chlorohydrex polymeric salts and abbreviated here as “ACH”) and aluminum zirconium glycine salts (abbreviated here as “ZAG”, “ZAG complexes” or “AZG”), are known to contain a variety of polymeric and oligomeric species with molecular weights (MW) ranging from 100-500,000. It has been clinically shown that, in general, the smaller the species, the higher the efficacy for reducing sweat.
In an attempt to increase the quality and quantity of smaller aluminum and/or zirconium species, a number of efforts have focused on (1) how to select the components of ACH and ZAG which affect the performance of these materials as antiperspirants and deodorants; and (2) how to manipulate these components to obtain and/or maintain the presence of smaller types of these components. These attempts have included the development of analytical techniques. Size exclusion chromatography (“SEC”) or gel permeation chromatography (“GPC”) are methods frequently used for obtaining information on polymer distribution in antiperspirant salt solutions. With appropriate chromatographic columns, at least five distinctive groups of polymer species can be detected in a ZAG, appearing in a chromatogram as peaks 1, 2, 3, 4 and a peak known as “5”. Peak #1 is the larger Zr species (greater than the pore size of column materials, (particularly greater than 120-125 Angstroms). Peak 2 is the larger aluminum species (particularly greater than 120-125 Angstroms). Peak 3 is the medium species. Peak 4 is the smaller aluminum species (aluminum oligomers), and has been particularly correlated with enhanced efficacy for both ACH and ZAG salts. Peak 5 (sometimes referred to as Peak 5-6) is the smallest aluminum species. The retention time (“Kd”) for each of these peaks varies depending on the experimental conditions. Various analytical approaches for characterizing the peaks of ACH and various types of ZAG actives are found in “Antiperspirant Actives-Enhanced Efficacy Aluminum-Zirconium-Glycine (AZG) Salts” by Dr. Allan H. Rosenberg (Cosmetics and Toiletries Worldwide, Fondots, D. C. ed., Hartfordshire, UK: Aston Publishing Group, 1993, pages 252, 254-256). Using GPC, Rosenberg describes four peaks identified as Al Kd 0.0; 0.24; 0.40; and 0.60. Activated ACH is identified as material having an enriched Al Kd 0.4 content. Spray drying AZG within a prescribed time frame to fix the desired distributions of the 4 peaks in a powder has also been suggested in the same reference Rosenberg, A., “New Antiperspirant Salt Technology” (
Cosmetics and Toiletries Worldwide,
Fondots, D. C. ed., Hartfordshire, UK: Aston Publishing Group, 1993, pages 214-218).
Other techniques have been developed as well such as size exclusion chromatography (“SEC”) sometimes referred to as gel permeation chromatography (“GPC”) (depending on the type of column used) which can utilize SEC columns in HPLC systems. A combination system combining inductively coupled plasma (“ICP”) with SEC for an SEC-ICP system has also been developed. Such techniques can be used to investigate whether zirconium and aluminum species co-elute at similar retention times or elute separately from the column at different retention times. In a particular method the SEC and ICP equipment are linked to characterize and monitor the zirconium and aluminum content and species in an aqueous solution of zirconium and aluminum, especially ZAG solutions. This is useful to investigate whether zirconium and aluminum species co-elute at similar retention times or elute separately from the column at different retention times.
Attempts to activate antiperspirant salts with improved efficacy have included developing processes for obtaining better types of ACH such as by heating solutions of ACH with or without elevated pressure in order to depolymerize larger aluminum species into Peak 4 species. Examples can be found in U.S. Pat. No. 4,359,456 to Gosling et al. Since ACH solutions may be used as starting materials for aluminum zirconium glycine (ZAG or AZG) salts, heating ACH solutions has also been used to enrich Peak 4 oligomers before spray drying.
U.S. Pat. No. 4,775,528 to Callaghan et al describes the formation of a solid antiperspirant composition having an Al:Zr atomic ratio from 6:1 to 1:1; the GPC profile of the antiperspirant in solution gave a ratio of at least 2:1 for peak 4/peak 3. This reference specifies that the zirconyl hydrochloride be mixed with the aluminum chlorhydroxide solution before the drying step is completed.
U.S. Pat. No. 4,871,525 to Giovamuiello, et al. also teaches a method to activate ZAG by thermally enriching the Al Kd 0.4 content in aqueous solutions.
The dilution/heating process that is normally used to activate the aluminum species involves heating a dilute aqueous solution of the antiperspirant salt and then spray drying the material to a powder form. Aside from activity issues, the refractive indices of such salts are in the range of 1.49-1.52 for aluminum salts and in the range of 1.55-1-57 for aluminum zirconium salts which makes it difficult to obtain clear products with good skin feel at reasonable cost.
Further references include European patent Application 0 499 456 A2 assigned to Bristol-Myers Squibb Company describes a ZAG complex and a process for making the complex comprising mixing zirconium hydroxychloride, a selected aluminum chloro species and an amino acid in aqueous solution and, optionally drying the aqueous solution to obtain a dry ZAG salt.
European Patent Application EP 0 653 203 A1 to Rosenberg et al describes a process for making ZAG salt with high antiperspirant activity. According to this reference, glycine is added to Zr starting materials at ambient temperature, and the mixed Zr/glycine is admixed with the aluminum chlorohydrate starting material immediately prior to spray drying in a continuous or semi-continuous operation.
U.S. Pat. No. 4,871,525 to Giovanniello et al describes a solid powder of aluminum zirconium hydroxyl halide glycinate complex having improved antiperspirant activity wherein the glycine is used to prevent gel formation. The ratio of Zr to glycine is less than 1:1.
In general, it has been found that large or medium size aluminum polymeric species (Peak 2 and Peak 3 species) in antiperspirant salts can be converted to smaller ones (Peak 4) by diluting an aqueous solution of the salt to a concentration of about 2-20% (w/w), and heating the diluted solution to a temperature of about 90° C. for a period of time. (Peak 5 or Peak 5-6 has not usually been mentioned because chemical equilibrium factors in aqueous solutions have limited the ability to increase this peak.) However, there has been no thermal activation method available to convert large zir
Cai Heng
Fan Aixing
Tang Xiaozhong
Colgate-Palmolive Company
Dodson Shelley A.
Miano Rosemary M.
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