Antiperspirant suspensions containing finely divided...

Details Antiperspirant suspensions containing finely divided... Antiperspirant suspensions containing finely divided...

2000-05-26

2003-02-11

Dees, Jose′ G. (Department: 1616)

Drug, bio-affecting and body treating compositions

Anti-perspirants or perspiration deodorants

C424S066000, C424S068000, C424S401000, C424S682000, C424S685000

Reexamination Certificate

active

06517819

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject of the present invention is complexes containing finely-divided aluminium and zirconium in the form of a suspension, which effect particularly good perspiration reduction on human skin, and a process for their synthesis.
2. Description of the Related Art
The prior art already includes a series of patents for the synthesis of aluminium and zirconium complexes that can be used as active ingredients for antiperspirants.
In U.S. Pat. No. 2,814,584 and U.S. Pat. No. 2,814,585 (Daley), for the first time aluminium/zirconium/buffer complexes were described in which urea and glycine act as buffer components. These complexes are also known as ZAG in the case of glycine. Aluminium chlorohydrate (ACH) and ZrOCl
2
solutions were taken as the starting point. In U.S. Pat. No. 2,854,382 (Grad), the possibility of using a solution of ZrO(OH)Cl as the Zr source instead of ZrOCl
2
is also described. Although a broad range of Al:Zr molar ratios would have been possible, Daley only invokes a ratio of between 1.5:1 and 3.5:1. In the case of Grad, the molar ratio can lie between 0.5:1 and 3.0:1. In U.S. Pat. No. 2,906,688, Beekman et al. describe a further process for the synthesis of stable aluminium/zirconium complexes which is characterised in that it involves heating an aqueous mixture containing ZrOCl
2
×8H
2
O and aluminium hydroxychloride (ACH) or aluminium trichloride/Al metal. Stable non-gelling solutions with an Al/Zr molar ratio of between 2 and 8 and a pH value of over 3 are obtained.
In their patent GB-2 144 992, Callaghan and Phipps describe the synthesis of active aluminium/zirconium complexes (ZAGs) in which they heated aqueous mixtures containing ZrO(OH)Cl, ACH and glycine with an Al/Zr/glycine ratio of 4:1:4 to 50° C., and thus produced a ZAG complex. The composition of such a complex was given by the formula (Al
2
(OH)
6-y
X
y
)
a
(ZrO(OH)
x
Cl
2-x
)
b
neutral amino acid. The designation “activated” is supported by a newly introduced analytical method. This constitutes the usual method in polymer chemistry for determining molecular weight distribution using size-exclusion chromatography. The molecular weight distributions (polymer species distributions) thus determinable differ with the complexes according to Callaghan and Phipps from those in the aforesaid process and indicate, in the eyes of the inventors, the chemical difference of the new complexes.
A series of further patents (U.S. Pat. No. 4,775,528, U.S. Pat. No. 5,114,705, U.S. Pat. No. 5,298,640 and U.S. Pat. No. 5,486,347) were published by Callaghan et al., and include additional process parameters for the heating of the aqueous ZrO(OH)Cl, ACH and glycine mixtures, such as the separate heating of the ACH solution to shift the polymer species distribution (“activation”) and to dry the reaction solutions.
The concept that the polymer species distribution could be important for effectiveness as an antiperspirant was also applied by Rosenberg et al. to the zirconium components utilised as the product in the patent AU 68983/94. The process described by him is characterised by the following steps:
Firstly, an aqueous mixture of a zirconium salt and glycine is made with a particular polymer species distribution. Next, an activated ACH solution (AACH) is made and reacted with the zirconium solution. This solution was then immediately dried by spray drying.
The table below provides an overview of the ZAG complexes that are registered for the cosmetics industry. The table was issued by the FDA in 1982 as Tentative Final Monograph for Antiperspirant Drug Products for
1
.
TABLE 1
Complexes without glycine
Name
Me/Cl ratio
Al/Zr ratio
Glycine
Aluminium zirconium
2.1 to 1.5
2 to 6 
None
trichlorohydrate (Al/Zr-3)
Aluminium zirconium
1.5 to 0.9
2 to 6 
None
tetrachlorohydrate (Al/Zr-4)
Aluminium zirconium
2.1 to 1.5
6 to 10
None
pentachlorohydrate (Al/Zr-5)
Aluminium zirconium
1.5 to 0.9
6 to 10
None
octachlorohydrate (Al/Zr-8)
1
Translators note: This sentence, the last part of which is already in English in the German patent text, ends as reproduced here.
TABLE 2
Complexes containing glycine as a buffer
Name
Me/Cl ratio
Al/Zr ratio
Glycine
Aluminium zirconium
2.1 to 1.5
2 to 6 
Variable
trichlorohydrex complex (ZAG-3)
Aluminium zirconium
1.5 to 0.9
2 to 6 
Variable
tetrachlorohydrex complex
(ZAG-4)
Aluminium zirconium
2.1 to 1.5
6 to 10
Variable
pentachlorohydrex complex
(ZAG-5)
Aluminium zirconium
1.5 to 0.9
6 to 10
Variable
octachlorohydrex complex
(ZAG-8)
It is known that the aluminium chlorohydrate complexes (ACH) have a polymer structure. These compounds are not particularly effective, i.e. they produce only a slight sweat reduction. They can, however, be altered by heat or chemical additions such that partial depolymerisation of the highly polymerised species takes place. Aluminium chlorohydrate complexes treated in this manner show enhanced effectiveness. It is possible to follow this level of depolymerisation (the “activation” level) with the aid of size-exclusion chromatography (HPLC). According to known teaching, the presence of particular bands in the HPLC spectrum provides information as to whether these compounds have particularly good sweat-reducing properties. In this context, the presence of the so-called Band 3 (or Kd=0.4-0.5) has proved to be particularly important. If Band 3 is large, it was taken that these compounds were particularly effective. In the ensuing period, the ratio of Band 2 to Band 3 was also regarded as an important criterion for assessing effectiveness.
In determining the degree of activation or the sweat reduction capability of Al/Zr compounds, attempts were made to transfer experience gained and methods used in the field of AACH compounds. Al/Zr compounds also show a characteristic band distribution in an HPLC chromatogram.
Some researchers have also used Raman and IR spectroscopy to be able to give the bonding details and the effectiveness of these complexes.
Apart from these physical methods, the best means for determining the activation level and effectiveness is the in vitro method—the so-called “hot-room” test, various versions of which are described (A. J. Parisse, in Cosmetic Science and Technology Series, vol. 8, “Clinical Safety and Efficacy Testing of Cosmetics”, p. 163-223). Commercially available activated Al/Zr complexes (antiperspirant powders) have better effectiveness than the Zr-free ACH types, although the sweat reduction values achievable are too low for the users' requirements. There was therefore a need for more effective types. There was also a need for stable Al/Zr antiperspirant active agents in a fluid, though not aqueous, form.
In the processing of the known powder-type, activated Al/Zr active agents, problems arose due to the strong tendency of the finely divided powders towards relatively severe dust formation. Therefore, in the further processing of the powder into cosmetic formulations, observing the dust limit values is an important point in preventing any endangering of the health of workers engaged in it.
It has, therefore, not previously been possible to fulfil all the cosmetic industry's requirements with the complexes available.
SUMMARY OF THE INVENTION
Surprisingly, it was discovered that particularly effective aluminium and zirconium-containing antiperspirant agents are obtained if these active ingredients comply with the following formulae and conditions:
Al
a
(OH)
(3-b)
X
b
(ZrO)
c
(OH)
(2-d)
X
d
(amino acid)
e
where X=a halogen, especially chlorine
and a/c=2.0 to 10.0
(a+c)/(b+d)=0.9 to 2.1
e/c=0 to 2.0
such that at least 60% of the zirconium content can be directly titrated after dissolving in about 0.1 n HCl with EDTA at pH 0.8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
These antiperspirant agents comprise non-aqueous suspensions which are characterised in that the non-aqueous phase consists of a largely unpolarised organic liquid that is not miscible with water, belonging to the substance group al

Affiliated with

Also associated with

Rating

Antiperspirant suspensions containing finely divided... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Antiperspirant suspensions containing finely divided..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antiperspirant suspensions containing finely divided... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3132317