Note: Descriptions are shown in the official language in which they were submitted.
CA 02433343 2003-06-26
WO 02/096371 PCT/US02/16766
COSMETIC COMPOSITIONS CONTAINING ROSEMARY EXTRACT AND DHA
Field of the Invention
The invention relates to cosmetic compositions. More specifically, the
invention
relates to self-tanning cosmetic compositions.
Background of the Invention
With sun exposure being recognized as a significant health risk, the
desirability of
sitting for hours to develop a deep tan has diminished considerably in recent
years. However,
the desire to have that bronze glow has not diminished in a large portion of
the population.
The solution for most prudent consumers is the use of self-tamzing products.
These products
typically employ the compound dihydroxyacetone(DHA), which interacts with the
proteins on
the skin to produce a brown color approximating a sun-derived tan. In the
early days of self-
tanners, there were a number of problems which prevented widespread
acceptance, the
primary one being the unnatural orange color that would develop on some users.
However,
self-tanners have iinproved tremendously in recent years, and most products
currently
available produce natural and fairly long-lasting color on the user. There is
one remaining
issue with self-tanners that continues to reduce their acceptability to the
consumer: after
application, inany users detect a malodor that lingers for up to 24 hours. The
unpleasant odor
apparently arises as a result of compounds generated on the skin upon
application of the self-
tanner. The only solution known to date is the incorporation of fragrance or
oils that mask the
odor to some extent; however, the addition of fragrance is not always an
acceptable option to
every product, and in any event does not address the root of the problem,
i.e., neutralizing the
coinpounds generated on the skin. To date, this problem continues to affect
self-tanners, and
therefore, may prevent their more frequent usage. The present invention now
provides a
solution for the odor generated upon application of the self-tanner to the
slcin.
Summary of the Invention
The present invention relates to a cosmetic composition comprising DHA in
combination with an effective ainount of a rosemary extract or active
component thereof. As
used herein, the term "cosmetic composition" is intended to encompass any
composition
containing DHA intended for topical application to the skin, which may also
include
compositions that are used in therapeutic applications, for example, in
conjunction with PUVA
therapy.
CA 02433343 2007-09-19
The invention also relates to a method of preventing or reducing the
generation of
malodor on the skin resulting from application of a DHA-containing self-
tanner, comprising
applying to the sldn a composition comprising DHA combined with an effective
amount of
rosemary extract.
Detailed Description of the Invention
It has been unexpectedly discovered that the addition of rosemary extract to
compositions containing DHA will prevent or reduce the typical malodor
associated with the
application of DHA compositions to the skin. Rosemary extract is a natural and
known
material extracted from the rosemary plant, and having established properties
as an
antioxidant: However, notwithstanding its known properties, in the present
case, where the
problem seems not to arise in degradation of the formula, but rather due to a
reaction on the
sldn about which very little is known, it was quite unexpected that the
rosemary extract
performed so remarkably.
Rosemary extract is a generic term describing a number of different chemical
compositions that may contain several different active components. Among the
common
components that are found in rosemary exhact are carnosol, carnosic acid,
methoxy carnosic
acid, rosmarinic acid, rosmanol and rosmaridiphenol, in different proportions
depending on
the individual extract. Numerous rosemary extracts are available commercially,
and any one
can be used in the present invention. However, particularly preferred for use
is the "Guardian"
rosemary extract available from 13arth Supplied Products. This extract
contains, in a base of
lecitbin, acetylated hydrogenated vegetable glycerides and propylene glycol,
an active
rosemary extract, in an amount of from about 12-30%, containing a minitnum of
5% phenolic
diterpenes. In particular, the active portion contains a minimum of 50%
carnosic acid,
camosol in an amount of 20-35%, and methoxy carnosic acid in an amount of from
about 5-
15%, with minor amounts of rosmanol, rosmarinic acid and rosmaridiphenol. It
will be
understood that the term "rosemary extract" as used herein shall encompass not
only a
rosemary extract per se, but also a composition to which the individual active
components,
such as are noted above, are added to the composition individually, or in
individual
combinations, from synthetic or natural sources, either from rosemary or from
starting
material other than rosemary, in amounts equivalent to those described in the
use of the
rosemary extract.
The active rosemary extract can be used in the DHA formulation in an amount of
from
about 0.0001 to about 50% by weight of the total composition. However, the
extract is
2
CA 02433343 2003-06-26
WO 02/096371 PCT/US02/16766
extremely efficacious, requiring only small amounts to achieve reduction in
odor, so the
preferred range of use of the extract is about 0.1 to about 10% by weight of
the composition.
The extract can be added to any type of formulation in which DHA is ordinarily
applied, for
example, creams, lotions, sprays, sticks and the like, and may be aqueous,
water and oil or
anhydrous. The amount of DHA employed will be in line with the typical use of
this material,
which is generally in the range of from about 1-10%. Anotller unexpected
result of the use of
the rosemary extract is its lack of adverse effect on color development with
DHA. DHA is a
relatively unstable material, and is subject to alterations in its performance
when in the
presence of other incoinpatible materials. However, surprisingly, rosemary
extract has no
adverse effect on the color development, and in some cases even seemed to
improve it.
The invention will be further understood by reference to the following non-
limiting
examples.
EXAMPLES
Example 1
Initial studies were perfonned to identify compounds which might assist in
reducing
the malodor associated with DHA application on the skin. A first attempt
tested compounds
generally known to have odor-reducing properties, namely, dipropylene glycol,
zinc acetate,
choline, and aloe vera gel. No consistent positive results were obtained with
any of these
compounds.
A secondary experiment was conducted on a new raw material: `Guardian'
Rosemary
Extract produced by Earth Supplied Products. The influence of Rosemary Extract
(RME) on
odor formation on 14 panelists using aqueous solutions of DHA and Rosemary
Extract was
investigated. Color and odor'were tested on the panelists to determine any
differences in the
reaction of DHA in the presence of Rosemary Extract.
Results and Discussions:
I) Clinical Study: Applications ofAqueous Solutions of DHA alone and DHA witlz
R1VIE to
the sltin
In the presence of RME, significant odor improvement was observed on 13 / 14
panelists (0.25% RME). One panelist did not produce any malodor when DHA was
applied.
The iinprovement in odor was most evident at 24 hours after the application to
the skin..
Under these conditions we observed greater than 90% reduction in malodor
formation.
3
CA 02433343 2003-06-26
WO 02/096371 PCT/US02/16766
When the color development was compared between test and control compositions,
we
observed that in the presence of RME, no difference in color was evident. (In
some cases, the
color development was slightly improved) Therefore, while using RME
significantly reduced
the malodor - there was no inhibition of the DHA color reaction as was seen
previously with
other ingredients tested.
Example 2
The following illustrates a composition, a water and oil emulsion, of the
invention:
Material Weight %
Cyclomethicone 11.00
Cetyl Diinethicone copolyol 1.00
Cyclomethcone/PEG/PPG-18/18
dimethicone 5.00
Tocopheryl acetate 0.20
Polysilicone 7/cyclomethicone 1.50
Fragrance 0.40
Deionized water QS
DHA 4.00
Glycerin 8.00
Sodium chloride 0.80
Lactic acid 0.50
Pantethine 0.02
Cyclomethicone 2.00
Blaclc Iron oxide 0.02
Iron oxide/alumina 0.38
Mica/titanium dioxide/iron oxides/
dimethicone 0.22
Mica/iron oxides 0.14
Preservative 0.50
Rosemary extract 0.25
Cyclomethicone .1.00
Cyclomethicone/dimethicone/vinyl dimethicone
crosspolymer 3.50
4
