Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Patent
1999-02-22
2000-10-31
Page, Thurman K.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
424 62, A61K 600, A61K 700, A61K 7135
Patent
active
061398543
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to the field of skin lightening. Specifically, the present invention relates to novel compositions comprising a liquid crystal which enhance skin penetration effect of specific hydroquinone derivatives for skin lightening.
BACKGROUND OF THE INVENTION
The specific hydroquinone as shown in formula (I) is known as a skin lightening compound. See WO9523780. ##STR2## wherein Z is oxygen or sulfur.
The combination of the specific hydroquinone derivatives and penetration enhancers is disclosed in WO9523780.
WO9523780 describes that penetration enhancers are disclosed in Mahjour, M., B. Mauser, Z. Rashidbaigi & M. B. Fawzi, "Effect of Egg Yolk Lecithins and Commercial Soybean Lecithins on In Vitro Skin Permeation of Drugs", Journal of Controlled Release, Vol. 14 (1990), pp. 243-252. The journal discloses Lecithin as a penetration enhancer. However, there is no description of a liquid crystal comprising specific hydroquinone derivatives and lecithin which have penetration enhancing effect.
It is an object of the present invention to provide compositions for lightening mammalian skin which has a good penetration effect, so that the specific hydroquinone derivatives which are skin lightening actives can penetrate effectively and work effectively.
SUMMARY OF THE INVENTION
The present invention relates to a skin lightening composition comprising ##STR3## wherein Z is oxygen or sulfur. (b) an average polarity solvent (f) and (g) forms a liquid crystal.
DETAILED DESCRIPTION OF THE INVENTION
The compound of the formula(I) have a good skin lightening effect in mammals, however it is expected to strengthen the penetration effect of the compound of formula (I) to mammal's skin. It has been unexpectedly found that the subject composition achieve good penetration in mammals' skin of the compounds of formula (I).
As used herein, "topical application" means directly laying on or spreading on outer skin.
As used herein, "skin lightening" means decreasing melanin in skin, including one or more of overall lightening of basal skin tone, lightening of hyperpigmented lesions including age spots, melasma, chloasma, freckles, post inflammatory hyperpigmentation or sun-induced pigmented blemishes.
As used herein, "solid" means solid form at the temperature of 25.degree. C., and "liquid" means liquid form at the temperature of 25.degree. C.
As used herein, all percentages are by weight unless otherwise specified.
The typical examples of the compound of fonnula(I) is as follows.
A skin lightening composition of the present invention comprises preferably from about 0.001% to about 10%, more preferably from about 0.01% to about 80/%, still more preferably from about 0.1% to about 5%, most preferably from about 0.5% to about 3% of the compound of the formula(I) as an active agent in a topical composition.
Use of subject compositions comprising over 3% of an active is preferred for lightening of hyperpigmented lesions and other areas where substantial lightening is desired.
In order to dissolve the compounds of formula(I), since the compounds of formula(I) are molecules of average polarity being neither soluble in very polar solvents nor very non polar solvents, it is necessary to be dissolved in an average polarity solvent. The average polarity solvents could preferably be solvents which have the ratio of Organicity and Inorganicity (Organicity/Inorganicity) of 0.2 to 3.6, more preferably be solvents which have the ratio of Organicity and Inorganicity (Organicity/Inorganicity) of 0.5 to 3.5. The ratio of Organicity and Inorganicity (Organicity/Inorganicity) is described in Pharmaceutical Bulletin Vol. 2, No. 2, 163 (1954); and The Field of Chemical (Kagaku no Ryoiki) Vol. 11, No. 10, October 1957. The average polarity solvents include liquid triglycerides such as castor oil, olive oil, and capric/caprylic triglyceride; cosmetically acceptable ester oil such as isopropyl palmitate, oleyl oleate, 2-octyidodecyl myristate and neopentyl glycol dioctoanate (trade name: Cosmol 525 manufactured
REFERENCES:
Mahjour et al., "Effect of Egg Yolk Lecithins and Commercial Soybean Lecithins on In Vitro Skin Permeation of Drugs", Journal of Controlled Release, vol. 14, pp. 243-252 (1990).
Hilton Michael E.
Howard S.
Kendall Dara M.
Page Thurman K.
The Procter & Gamble & Company
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