| PATENT ASSIGNEE'S COUNTRY | USA |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 07.11.2000 |
| PATENT TITLE |
Method and composition for hair removal |
| PATENT ABSTRACT |
The present invention provides a method for removing hair from a selected skin area comprising the steps of (a) applying a liposome composition comprising a photosensitizer to the selected skin area so that the composition is introduced into hair follicle ducts of the skin area, wherein the photosensitizer is present in the composition in an amount effective to undergo a reaction and damage the hair follicles upon application to the skin area of light at an appropriate wavelength, energy and duration to penetrate the skin and activate the photosensitizer; (b) removing from the skin area substantially all of the liposome composition which is not introduced into the hair follicle ducts; and (c) applying light to the skin area at an appropriate wavelength, energy and duration to penetrate the skin and cause the photosensitizer to undergo a reaction to damage the hair follicles. The present invention also provides a composition useful for hair removal. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | February 27, 1996 |
| PATENT REFERENCES CITED |
Li, et al., entitled "The Feasibility Of Targeted Selective Gene Of The Hair Follicle, " Nature Medicine, vol. 1, No. 7, pp. 705-706 Jul. (1995). Grossman, et al., entitled "PDT For Hirsutism, " Lasers In Surgery And Medicine, Supplement 7, p. 44 (1995). |
| PATENT CLAIMS |
What is claimed: 1. A method for removing hair from a selected skin area comprising the steps of: (a) applying a liposome composition comprising a phthalocyanine to the selected skin area so that the composition is introduced into hair follicle ducts of the skin area, wherein the phthalocyanine is present in the composition in an amount effective to undergo a reaction and damage the hair follicles upon light activation of the phthalocyanine; (b) removing from the skin area substantially all of the liposome composition which is not introduced into the hair follicles; and (c) applying light to the skin area at the appropriate wavelength, energy, and duration to penetrate the skin and cause the phthalocyanine to undergo a reaction to damage the hair follicles; wherein the light is applied for about 5 minutes to about 6 hours, at a wavelength between about 500 and about 900 nm, and at an energy between about 20 and about 800 J/cm.sup.2 skin area. 2. The method of claim 1, wherein the phthalocyanine is an aluminum, germanium, gallium, tin, or silicon phthalocyanine; a sulfonated aluminum, germanium, gallium, tin, or silicon phthalocyanine; or a nitrated aluminum, germanium, gallium, tin, or silicon phthalocyanine. 3. The method of claim 2, wherein the phthalocyanine is a sulfonated aluminum phthalocyanine. 4. The method of claim 3, wherein the sulfonated aluminum phthalocyanine is aluminum tetrasulfophthalocyanine or aluminum disulfophthalocyanine. 5. The method of claim 2, wherein the phthalocyanine is a silicon phthalocyanine. 6. The method of claim 5, wherein the silicon phthalocyanine is hydroxysiloxydimethylpropyl-N-dimethyl silicon phthalocyanine. 7. The method of claim 1, wherein the effective amount of phthalocyanine applied is between about 5 and about 20 .mu.g phthalocyanine per cm.sup.2 skin area. 8. The method of claim 1, wherein the effective amount of phthalocyanine applied is between about 7 and about 14 .mu.g phthalocyanine per cm.sup.2 skin area. 9. The method of claim 1, wherein the light is applied at a wavelength between about 600 and about 700 nm. 10. The method of claim 1, wherein the light is applied at an energy between about 400 and about 600 J/cm.sup.2 skin area. 11. The method of claim 1, wherein the light is applied at a wavelength between about 600 and about 700 nm, and at an energy between about 400 and about 600 J/cm.sup.2 skin area. 12. The method of claim 1, wherein the light is applied for about 5 minutes to about 2 hours, at a specific wavelength corresponding to the maximum absorption of the phthalocyanine, and at an energy between about 20 and about 90 J/cm.sup.2 skin area. 13. The method of claim 1, wherein the light is applied for about 5 minutes to about 45 minutes at a specific wavelength corresponding to the maximum absorption of the phthalocyanine, and at an energy between about 40 and about 80 J/cm.sup.2 skin area. 14. A liposome composition comprising a phthalocyanine in an amount effective to undergo a reaction to damage hair follicles upon introduction of the composition into hair follicle ducts and application of light at an appropriate wavelength, energy, and duration to penetrate skin and activate the phthalocyanine, wherein the effective amount of phthalocyanine in the composition is between about 50 and about 200 .mu.g phthalocyanine per ml composition. 15. The composition of claim 14, wherein the effective amount of phthalocyanine in the composition is between about 70 and about 140 .mu.g phthalocyanine per ml composition. 16. The composition of claim 14, wherein the phthalocyanine is an aluminum, germanium, gallium, tin, or silicon phthalocyanine; a sulfonated aluminum, germanium, gallium, tin, or silicon phthalocyanine; or a nitrated aluminum, germanium, gallium, tin, or silicon phthalocyanine. 17. The composition of claim 14, wherein the phthalocyanine is a sulfonated aluminum phthalocyanine. 18. The composition of claim 17, wherein the sulfonated aluminum phthalocyanine is aluminum tetrasulfophthalocyanine or aluminum disulfophthalocyanine. 19. The composition of claim 14, wherein the phthalocyanine is a silicon phthalocyanine. 20. The composition of claim 19, wherein the silicon phthalocyanine is hydroxysiloxydimethylpropyl-N-dimethyl silicon phthalocyanine. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
BACKGROUND OF THE INVENTION Currently, the most common methods for hair removal involve the use of hair removal creams, as well as shaving, waxing and electrolysis. Although creams and shaving are popular because they can be readily used at home, they are inadequate because they must be used on a regular basis. Waxing and electrolysis offer longer term hair removal. Both methods, however, can be time-consuming and are often quite painful. For example, removing a typical mustache which contains 1,000 to 2,000 hairs by electrolysis may take up to 50 visits before the hair removal is complete. More recently, lasers alone or in conjunction with topical formulations containing carbon particles, hair dyes, hematoporphin derivatives or aminolevulinic acid have been used for hair removal (See, U.S. Pat. Nos. 5,226,907 and 5,425,728; Grossman, M. et al. Lasers Surg. Med. Suppl. 7:44 (1995)). Such treatments are generally not selective in that they result in only partial destruction of hair follicles and may promote skin reaction. Accordingly, there exists a need for selectively removing hair that is not time consuming, painful and damaging to the skin, and results in hair removal which is long lasting, and more permanent than conventional hair removal methods. The present invention satisfies this need. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for removing hair that requires little time, is relatively painless and does not damage or irritate the skin. It also is an object of the present invention to provide a method for removing hair that is long lasting, and more permanent than conventional hair removal methods. It is a further object of the present invention to provide a liposome composition useful for removing hair. Additional objects of the present invention will be apparent from the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B and 1C provide photographs of the histological sections of skin from mice 3 months after treatment with: 1A) control, no light, no dye; 1B) light exposure of 600-700 nm at 400 J/cm.sup.2 3 hours after application of AlPcS.sub.2a liposome formulation; and 1C) light exposure of 600-700 nm at 400 J/cm.sup.2 6 hours after application of AlPcS.sub.2a liposome formulation. FIGS. 2A, 2B and 2C provide photographs of mice 1 month after treatment with: 2A) control, no light, no dye; 2B) light exposure of 600-700 nm at 100 J/cm.sup.2 30 minutes after application of Pc 4 liposome formulation; and 2C) light exposure of 600-700 nm at 200 J/cm.sup.2 30 minutes after application of Pc 4 liposome formulation. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for removing hair from a selected skin area of the body. As used herein "selected skin area" includes any area of the body which contains hair that is desirous of being removed. Such areas include but are not limited to parts of the body to which hair removal is typically desired, such as the face, the female underarms and legs, as well as the hair surrounding the female genital area (i.e. the hair commonly removed in bikini waxes). The method of the present invention also may be used for removing hair from individuals with hirsutism, i.e. excess hair growth over all parts of the body. In the method of the present invention, a liposome composition comprising a photosensitizer is first applied to the skin area so that the composition is introduced into hair follicle ducts of the skin area. The composition is left on the skin until such time the composition is introduced into the hair follicle ducts, which may vary between about 5 minutes and 6 hours depending upon the choice and concentration of the photosensitizer. The skin area also may be shaved before application of the liposome composition, or left unshaved. Preferably, the skin is shaved before application of the liposome composition. The liposome composition may be formulated with the photosensitizer by mixing the desired amount of the photosensitizer with the liposome composition. Suitable methods for preparing liposome compositions include but are not limited to the preparations described in U.S. Pat. Nos. 4,224,179, 4,235,871, 4,708,861 and 4,900,566, which are hereby incorporated by reference in their entirety. The liposome composition also may include a pharmaceutically acceptable topical carrier known in the art such as creams, gels, oils and the like. Suitable photosensitizers include but are not limited to phthalocyanines, porphyrins, purpurins, psoralens, bergaptens, angelicins, chlorins and flavins, which can be activated by light at wavelengths that are sufficient to penetrate into skin to reach the hair follicles (i.e. wavelengths.gtoreq.500). Particularly preferred photosensitizers are those compounds which absorb in the red region of the visible spectrum such as phthalocyanines. Suitable phthalocyanines include but are not limited to phthalocyanines containing a central atom of aluminum, germanium, gallium, tin or silicon such as silicon phthalocyanine (i.e. hydroxysiloxydimethylpropyl-N-dimethyl silicon phthalocyanine, "Pc 4")), as well as sulfonated or nitrated forms of such pthalocyanines, such as sulfonated aluminum phthalocyanine (i.e. aluminum tetrasulfo-phthalocyanine ("AlPcS.sub.4 ") or aluminum disulfophthalocyanine ("AlPcS.sub.2a "). Such phthalocyanines and others are described in Spikes, J. Photochemistry and Photobiology 43:691-699 (1986); Ben-Hur, E. and Rosenthal, I. Int. J. Radiat. Biol. 47:145-147 (1985); Moser, F. H. and Thomas, A. C. The Phthalocyanines, Boca Raton, CRC Press, 1984; Kreimer-Birnbaum, M. Sem. Hematol. 26:157-193 (1989); and U.S. Pat. Nos. 5,120,649, 5,232,844 and 5,484,778, which are hereby incorporated by reference in their entirety. The photosensitizer is present in the composition in an amount effective to undergo a reaction and damage or destroy the hair follicles upon application of light to the skin area at an appropriate wavelength, energy and duration to penetrate the skin and activate the photosensitizer. The amount of photosensitizer present in the composition will depend upon the photosensitizer chosen, the duration, wavelength and energy of the light applied. When a phthalocyanine is used, the effective amount of the compound in the composition is preferably between about 50 and about 200 .mu.g phthalocyanine per ml composition, and more preferably between about 70 and about 140 .mu.g phthalocyanine per ml composition. Using these concentrations, the effective amount of the phthalocyanine applied is about 5 to about 20 .mu.g phthalocyanine per cm.sup.2 of skin area, and preferably about 7 to about 14 .mu.g phthalocyanine per cm.sup.2 of skin area. However, higher and lower concentrations may be used. Following application of the liposome composition, it is desirable to remove at least a portion of the composition, and preferably substantially all of the composition, which is present on the skin and which is not introduced into the hair follicle ducts, to prevent any damage or irritation to the skin upon application of the light. As used herein, "substantially all" means the amount of the composition which can be removed from the skin by conventional methods, i.e. by cleaning with an agent such as alcohol, without removing the composition from the hair follicle ducts. Finally, light is applied to the skin area at an appropriate wavelength, energy and duration to penetrate the skin and cause the photosensitizer to undergo a reaction to damage the hair follicles. Suitable sources of light include commercially available lasers, lamps, light emitting diodes and the like. Preferably, a 500 W xenon short arc lamp, Versa Light, Medic Lightech, Ltd., Haifa, Israel is employed. To achieve the desired wavelength of light, the lamp may be equipped with commercially available filters. The wavelength of light should be chosen so that it corresponds to or encompasses the absorption of the photosensitizer, and also penetrates deep into the region of the skin encompassing the hair follicles. Photosensitizers absorbing in the red light such as phthalocyanines are preferred since red light is able to penetrate deep into the region of the skin surrounding the hair follicles. The wavelength of light may be a broad range, a narrow range, or a specific wavelength corresponding to the maximum absorption of the photosensitizer used. The energy and duration of treatment will depend upon the wavelength of light applied, as well as the concentration of the photosensitizer in the composition. If a broad wavelength range is chosen, the energy and duration of treatment may be higher and longer, respectively, to achieve the desired effect. For example, the maximum absorption of phthalocyanines is typically between about 630 nm and about 730 nm. Therefore, in order to activate the phthalocyanine, light may be applied for about 5 minutes to about 6 hours at a broad wavelength range between about 500 nm and about 900 nm, and at an energy between about 200 and about 800 J/cm.sup.2 skin area. In another embodiment, light may be applied for about 5 minutes to about 2 hours at a wavelength range between about 600 nm and about 700 nm, and at an energy between about 400 and about 600 J/cm.sup.2 skin area. When light is applied at a specific wavelength which corresponds to the maximum absorption of the phthalocyanine or a narrow wavelength range which encompasses the maximum absorption (i.e. the maximum absorption of phthalocyanines is generally between about 630 and about 730 nm), the energy and duration of light applied may be lower (e.g. about 20-90 J/cm.sup.2 skin area for about 5 minutes to about 2 hours, or about 40-80 J/cm.sup.2 skin area for about 5-45 minutes). The method of the present invention results in hair removal which is more selective and permanent than conventional hair removal methods. In this regard, the use of the liposome composition permits an appropriate amount of the photosensitizer to be introduced in an efficient manner into all or substantially all of the hair follicle ducts of the skin area to which the composition is applied, as well as deep into the hair follicle ducts. Therefore, upon application of an appropriate wavelength, energy and duration of light, all or substantially all of the hair follicles in the treated skin area, as well as each entire hair follicle or a substantial portion of each hair follicle, can be destroyed. The method of the present invention thus results in the removal of hair which is more permanent than conventional laser/topical formulation hair removal methods which only result in the partial destruction of hair follicles. The present invention is described in the following Examples, which is set forth to aid in an understanding of the invention, and should not be construed to limit in any way the invention as defined in the claims which follow thereafter. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
|
Want more information ? Interested in the hidden information ? Click here and do your request. |