WO2007043721A1

WO2007043721A1 - Compositions for improving skin conditions comprising human growth hormones as an active ingredient

Info

Publication number: WO2007043721A1
Application number: PCT/KR2005/003402
Authority: WO
Inventors: Dahl Kyun Oh
Original assignee: Regeron, Inc.
Priority date: 2005-10-12
Filing date: 2005-10-12
Publication date: 2007-04-19
Also published as: CA2625806C; BRPI0520672A2; BRPI0520672B1; JP2009511574A; KR100962566B1; CA2625806A1; KR20090042871A; JP5649278B2

Abstract

Disclosed herein is a skin condition-improving composition for topical application to the skin, comprising human growth hormone as an active ingredient, and a method for improving skin conditions using the same. The disclosed composition exhibits various skin conditioning effects, such as acne treatment, wrinkle improvement, dark spot removal, skin elasticity improvement, hair growth stimulation, skin aging prevention, skin moisturization and the proliferation of skin epidermal stem cells.

Description

COMPOSITIONS FOR IMPROVING SKIN CONDITIONS COMPRISING HUMAN GROWTH HORMONE AS AN ACTIVE INGREDIENT

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to skin condition-improving compositions for topical application to the skin, which comprises human growth hormone as an active ingredient and a method for improving skin conditions of a human.

DESCRIPTION OF THE RELATED ART

It is a generally known in the art that macromolecules such as human growth hormone (molecular weight of about 22 kD), cannot pass through the skin stratum corneum. A molecular weight that can be delivered efficiently through the skin epidermis is generally recognized to be no more than about 500 daltons or at most 2 kD even with the help of skin penetration enhancers. Accordingly, applying macromolecules such as human growth hormone topically to the intact skin and expecting cosmetic or medical efficacies by the action of macromolecules have been considered unsuccessful.

Some attempts have been made to deliver proteins to the dermal layer of the skin by topical application of liposomes encapsulating the proteins. It has been reported that the proteins encapsulated into lipsomes are delivered via the dermis or the hair follicles. For delivery through hair follicles, either a delivery system in the form of liposomes or a lipid composite comprising lipids such as fatty acids has been reported to be favorable. In addition, although efficiencies turned out to be much lower, an aqueous solution containing an organic solvent such as ethanol or an aqueous solution containing a polymer such as polyethylene glycol, has also been tested as a facilitating medium for delivery through hair follicles. With respect to efficiencies of delivering proteins through the skin using liposomes carrying proteins, a general principle has not been established yet, because cases of liposomal protein deliveries have been scarce and even in those rare cases, the efficiencies of protein deliveries varied widely depending on the empirical choices of the target proteins and the nature of the liposomes used. One thing to note is that, although the idea of delivering proteins through hair follicles is gaining more acceptances, even when a protein is delivered in a liposome-encapsulated form, liposomes may not pass through the infundibular portion of the hair follicles intact, rather they may undergo different morphological transformations or phase transitions owing to, first, the characteristics of the phospholipids conferring inside and outside pH's and charge valences of the liposomes, second, those of the proteins attached to or encapsulated by the liposomes, and third, those of the constituting ingredients of the surrounding tissues making up the hair follicles. Thus as a whole, these three factors and their complex interactions seem to determine follicular delivery efficiencies of the liposomes containing the proteins in question through empirical formulations rather than by a general guiding principle at the moment. What is particularly noteworthy with regard to the present invention is the existence of a report stating human growth hormone receptors are located on the living cell layers of the epidermis and throughout the ancillary organs and tissues constituting and surrounding the hair follicles.

Human growth hormone is secreted from the anterior lobe of pituitary gland and circulates with blood while it influences each organ of the human body. In the growth stage of a human, it is particularly involved in the growth of skeleton, an increase in muscles, the decomposition of fat, the growth of the internal organs, sexual growth and the like. In addition, it was suggested that when human growth hormone was administered by injection to adults at a physiological range of blood concentration, it would show various effects, such as the strengthening of the heart circulatory system, the enhancement of exercise ability, the strengthening of muscles, the reduction in abdominal fatness, the increase in libido, the improvement of improvement of arteriosclerosis, and the improvement of geriatric depression. It is known that the effects of human growth hormone on the human body are not caused by the human growth hormone itself, but rather are caused by the action of insulin- like growth factor-1 (IGF-I), the expression of which is stimulated by human growth hormone and which is produced mainly in the liver and secreted into blood. This is because the blood half-time of human growth hormone is about 15 minutes, whereas the blood half-time of IGF-I is about 20 hours, indicating that IGF-I can be lasting much longer than human growth hormone. Concretely speaking, human growth hormone secreted from pituitary gland binds to human growth hormone-binding protein present in blood, migrates with blood circulation, and meets a human growth hormone receptor present in each tissue of the human. At this time, the human growth hormone is liberated from the human growth hormone-binding protein while it binds to the human growth hormone receptor, and the synthesis and secretion of IGF-I are stimulated as a result of signaling caused by the binding. The IGF-I secreted into blood then binds to an IGF-I binding protein, and circulates with blood flow while it binds to an IGF-I receptor present in each tissue of the human body, thus exhibiting various physiological effects caused by the secretion of human growth hormone. Accordingly, if the effect of the injection agent human growth hormone on the skin will be actually shown, it will be an effect caused by the action of IGF-I, and thus will necessarily depend on the presence or absence of the IGF-I receptor on the surface of dermal cells that can be brought into direct contact with blood. Even if the skin is considered to be influenced directly by human growth hormone, but not by IGF-I, the influence will necessarily be transferred by the human growth hormone receptor present at sites which are in contact with blood. Therefore, it is considered that expecting any effect on the skin by applying human growth hormone (having molecular size that cannot pass through the skin) together with cosmetics to the normal skin surface that is not brought into direct contact with blood is not common sense. The present invention is a first report that, through a method of applying human growth hormone in the form of a cosmetic preparation to the normal skin surface that is not in direct contact with blood, but not a method of transferring the effect of human growth hormone through blood, the human growth hormone can show cosmetic and medical effects on the skin, such as the improvement of acne, wrinkles, atopic skin, skin damage caused by UV light, dark spots, freckles, dry skin and oily skin, the reduction of hair follicles, and the stimulation of hair growth.

Skin tissue consists of the epidermis, the dermis and the hypodermis. The epidermis determines the properties of the skin, and is frequently susceptible to damage directly from the external environment, and thus the repair and regeneration of the epidermis are highly important. The epidermis consists of a layer of epidermal cells. The skin epidermal cells are also called "keratinocytes", because the skin epidermal cells synthesize intermediate filament protein keratin that strengthens the epidermis, during their differentiation. These cells are layered with differentiation while migrating toward the epidermis, and become flat while organs inside the cells gradually disappear and they become dead cells. A cell layer located at the innermost portion of the epidermis is contiguous to the basal lamina and called the "stratum basale", and the cells forming the layer are called "basal cells", among which epidermal stem cells are present. The cells of the stratum basale differentiate into the epidermis while they sequentially form the stratum spinosum, the stratum granulosum, the stratum lucidum and the stratum corneum, the stratums being divided into a living cell layer at the lower position with respect to the stratum granulosum, and a dead cell layer at the upper position. Flattened scale-like tissues outside the stratum corneum are also called "squames" where keratins are densely filled. Cells located from the outside of the stratum granulosum to the stratum corneum are reinforced with a layer of cross-linked protein whose plasma membrane is thin and tough. While the epidermal cells are proliferated from the epidermal stem cells and differentiated into the stratum corneum, they are internally reinforced by the cross-linking of keratins and are also linked by keratins with desmosomes firmly linked with other cells in the same layer so as to maintain the entire layer structure thereof. The epidermal cells are differentiated into the outer epidermis while they produce and secrete lipid so as to form double-layered tissue on a plasma membrane cornified with protein, thus preventing the skin surface from the external environment, like saran wrap. Since the human epidermis is replaced at two-week interval, the proliferation ability of skin stem cells forming the epidermis can be considered to be huge.

It was recently reported that the multipotent stem cells of the skin are located at the bulge region, which lies just below the sebaceous gland of hair follicles. These bulge stem cells serve as the basis for making epidermal stem cells, hair matrix stem cells, and sebaceous glands stem cells. The bulge stem cells are located only in the bulge region and express a special combination of protein while maintaining their property as stem cells. The epidermal stem cells maintain the epidermis while they proliferate and differentiate. When a hair falls out, the hair matrix stem cells will proliferate and differentiate to make a new hair. However, the epidermal stem cells, the hair matrix stem cells or the sebaceous glands stem cells have limitations in their proliferation ability or the ability to maintain the ability of stem cells, and thus, for example, most of the epidermal stem cells will differentiate after they proliferate 3-6 times. On the other hand, although the bulge stem cells proliferate slower than the other three stem cells, it seems that the bulge stem cells can indefinitely proliferate during the life of human beings while making the epidermal stem cells, the hair matrix stem cells and the sebaceous glands stem cells and, at the same time, maintaining their stem cell character. The fact that the expression and action of human growth hormone occurs at the location of the bulge stem cells has been disclosed for the first time through the present invention, and this novel finding is quite significant, considering that human growth hormone exhibits the effects of improving various skin conditions by the present invention. DETAILED DESCRIPTION OF THIS INVENTION

The present inventors have made intensive researches to develop a substance capable of improving skin conditions, and as a result, found that the topical application of human growth hormone to the skin can greatly improve skin conditions, thereby completing the present invention.

Accordingly, it is an object of the present invention to provide a skin condition-improving composition for topical application to the skin.

It is another object of the present invention to provide a method for improving skin conditions.

Other objects and advantages of the present invention will become apparent from the detailed description to follow taken in conjugation with the appended claims.

In one aspect of this invention, there is provided a composition formulated for topical administration to skin for improving skin conditions, which comprises human growth hormone as an active ingredient.

In another aspect of this invention, there is provided a method for improving skin conditions of a human, which comprises topically administering to the skin of human a composition comprising human growth hormone as an active ingredient. The present inventors have conducted studies and efforts to find a novel use of human growth hormone and, as a result, found that the topical application of human growth hormone to the skin can greatly improve skin conditions. Current therapy with human growth hormone is performed mainly to treat dwarfism and human growth hormone deficiency using an injection method. In the prior art, because of the high molecular weight of human growth hormone and a prejudice for the action pathway of human growth hormone, it was not noticed that the topical application of human growth hormone to the normal skin makes it possible to expect the effect thereof. The present invention greatly deviates from this conventional common sense or knowledge in the art and is characterized in that the effect of the topical application of human growth hormone to the normal skin has been found for the first time. The present invention is the first invention of applying human growth hormone to the skin through two routes, i.e., hair follicles and the epidermis. The present invention is the first report showing that, by a method of applying human growth hormone to the normal skin surface opposite to a region that is in contact with blood, but not by a method of transferring the effect of human growth hormone through blood, human growth hormone can show cosmetic and medical effects on the skin, such as the improvement of acne, wrinkles, atopic skin, skin damage caused by UV light, dark spots, freckles, dry skin and oily skin, the reduction of hair follicles, and the stimulation of hair growth.

Human growth hormone (hGH) which is used as an active ingredient in the present invention may be any polypeptide showing human growth hormone activity. For example, any one selected from the group consisting of mature hGH, Met-hGH, hGH variants, modified-hGH, hGH fragments and hGH analogues may be used. Preferred is mature hGH or Met-hGH. The mature hGH refers to a human growth hormone having the amino acid sequence of the major human growth hormone present in human blood, the Met-hGH refers to a human growth hormone having methionine added to the N-terminus of mature hGH, the hGH variants refer to human growth hormones having the amino acid sequences of human growth hormones other than the major human growth hormone present in the human body, the modified hGH refers to a human growth hormone modified by adhesion of an additive such as pegylation or glycation to at least one amino acid residue of human growth hormone, the hGH fragments indicate human growth hormones obtained by deleting a portion of the amino acid sequences of human growth hormones by a genetic engineering method or biochemical method, and the hGH analogue refers to a human growth hormone obtained by modifying the amino acid sequence of human growth hormone into another amino acid sequence having properties similar thereto by a genetic engineering method. As used herein, the phrase "having human growth hormone activity" can be specified according to one of the following two methods. In one method, it can be specified according to whether human growth hormone causes signaling by binding to a human growth hormone-binding protein or a human growth hormone receptor, and in another method, it can be specified according to whether biological effects caused by the action of human growth hormone are shown.

In the present invention, human growth hormone can be applied to the skin as an aqueous solution or with a carrier. One of the surprising characteristics of the present invention is that, as illustrated in Example XII and FIG. 10b, even when an aqueous solution of human growth hormone itself is applied directly to the skin, the desired effect of improving skin conditions can be somewhat achieved. Even when an aqueous solution of human growth hormone itself is topically applied to the skin, the human growth hormone will reach the location of bulge stem cells in hair follicles and can provide the effect of improving skin conditions. According to a preferred embodiment of the present invention, a composition according to the present invention has a phospholipid or liposome composition, and preferably a liposome composition. It is preferable that human growth hormone as an active ingredient be encapsulated in liposome and applied to the skin. According to a more preferred embodiment of the present invention, the present composition has a nanoliposome composition. As used herein, the term "nanoliposome" refers to a liposome having the form of conventional liposome and a mean particle diameter of 20-1000 nm. According to a preferred embodiment of the present invention, the mean particle diameter of the nanoliposome is 50-500 nm, more preferably 50-350 nm, and most preferably 50-250 nm. Liposome is defined as a spherical phospholipid vesicle of colloidal particles which are associated with themselves, and liposomes composed of amphiphilic molecules each having a water soluble head (hydrophilic group) and a water insoluble tail (hydrophobic group) show a structure aligned by spontaneous binding caused by the interaction therebetween, and are classified, according to the size and lamellarity thereof, into SUV (small unilamellar vesicle), LUV (large unilamellar vesicle) and MLV (multi lamellar vesicle). The liposomes showing various lamellarities as described above have a double membrane structure similar to the cell membrane. The (nano)liposome in the present invention can be prepared using phospholipid, polyol, a surfactant, fatty acid, salt and/or water.

Phospholipid which is a component used in the preparation of the present (nano)liposome is used as biphilic lipid, and examples thereof include natural phospholipids (e.g., egg yolk lecithin, soybean lecithin, and sphingomyelin) and synthetic phospholipids (e.g., dipalmitoylphosphatidylcholine or hydrogenated lecithin), the lecithin being preferred. More preferably, the lecithin is a naturally derived unsaturated or saturated lecithin extracted from soybean or egg yolk.

Polyols which can be used in the preparation of the present (nano)liposome are not specifically limited and preferably include propylene glycol, dipropylene glycol, 1,3-butylene glycol, glycerin, methylpropanediol, isoprene glycol, pentylene glycol, erythritol, xylitol and sorbitol.

The surfactant which can be used in the preparation of the present (nano)liposome may be any surfactant known in the art, and examples thereof include anionic surfactants (e.g., alkyl acyl glutamate, alkyl phosphate, alkyl lactate, dialkyl phosphate and trialkyl phosphate), cationic surfactants, amphoteric surfactants and nonionic surfactants (e.g., alkoxylated alkylether, alkoxylated alkylester, alkylpolyglycoside, polyglycerylester and sugar ester).

The fatty acids which can be used in the preparation of the present (nano)liposome are higher fatty acids, and preferably saturated or unsaturated fatty acid having a C₁₂.₂₂ alkyl chain, and examples thereof include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and linoleic acid.

The salt which is used in the preparation of the present (nano)liposome may be any salt known in the art, and examples thereof include phosphate salt, sulfate salt, nitrate salt, chloride salt, hydroxide salt, sodium salt, potassium salt, calcium salt, ammonium salt, amino acid salt, and amino acid.

Water which is used in the preparation of the present (nano)liposome is generally deionized distilled water. According to a preferred embodiment of the present invention, the present

(nano)liposome is prepared only with phospholipid, salt and water, as described in detail in Examples below.

According to a preferred embodiment of the present invention, the present hGH-containing nanoliposome is prepared through a process comprising the steps of: (a) dissolving a phospholipid capable of forming liposome (preferably, yellow yolk lecithin or soybean lecithin) in a buffered aqueous solution of salt containing human growth hormone; and (b) passing the aqueous solution containing human growth hormone and phospholipid through a high-pressure homogenizer while gradually increasing the content of the phospholipid and the pressure of the high-pressure homogenizer as the number of the passages increases, thus preparing a human growth hormone-containing nanoliposome.

The aqueous solution containing human growth hormone is preferably a buffer solution having a pH of 6-8, and more preferably about 7, for example, sodium phosphate buffer solution. If the sodium phosphate buffer solution is used, the concentration thereof will preferably be 5-100 mM, more preferably 5-60 mM, even more preferably 10-30 mM, and most preferably about 20 mM.

The most prominent feature of the present process is that the mixture of the phospholipid and the hGH-containing aqueous solution is passed through the high- pressure homogenizer several times, in which the amount of the phospholipid and the pressure of the homogenizer are increased in a stepwise manner as the number of the passages increases. According to a preferred embodiment of the present invention, the pressure of the homogenizer is stepwisely increased from 0 to 1000 bar, and preferably from 0 to 800 bar. The pressure may be increased by 50 bar or 100 bar, preferably 100 bar. According to a preferred embodiment of the present invention, the amount of the phospholipid is stepwisely increased from 5 to 40 w/v(%), and more preferably from 5 to 30 w/v(%).

Through the high-pressure homogenization process including these stepwise increases in phospholipid content and pressure, an hGH-containing nanoliposome is prepared and a liquid hGH-containing nanoliposome is preferably prepared.

The composition of the present invention is useful in the improvement in various skin conditions. Preferably, the present composition is effective in the improvement in skin conditions including acne, wrinkle, dark spots, skin elasticity, hair growth, skin aging, skin moisture and proliferation of dermal stem cell. More specifically, the improvements in skin conditions refer to the treatment of acne, improvement of wrinkle, removal of dark spots, improvement of skin elasticity, promotion of hair growth, prevention of skin aging, improvement of moisture- retaining property of skin or promotion of dermal stem cell proliferation. More preferably, the skin condition improved by the present invention is acne, wrinkle or hair growth.

The present composition may be provided as a cosmetic or pharmaceutical composition.

The cosmetic compositions of this invention for improving skin conditions may be formulated in a wide variety of forms, for example, including a solution, a suspension, an emulsion, a paste, an ointment, a gel, a cream, a lotion, a powder, a soap, a surfactant-containing cleanser, an oil, a powder foundation, an emulsion foundation, a wax foundation and a spray.

The cosmetically acceptable carrier contained in the present cosmetic composition, may be varied depending on the type of the formulation. For example, the formulation of ointment, pastes, creams or gels may comprise animal and vegetable fats, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silica, talc, zinc oxide or mixtures of these substances. In the formulation of powder or spray, it may comprise lactose, talc, silica, aluminum hydroxide, calcium silicate, polyamide powder and mixtures of these substances. Spray may additionally comprise the customary propellants, for example, chlorofluorohydrocarbons, propane/butane or dimethyl ether. The formulation of solution and emulsion may comprise solvent, solubilizer and emulsifier, for example water, ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylglycol, oils, in particular cottonseed oil, groundnut oil, maize germ oil, olive oil, castor oil and sesame seed oil, glycerol fatty esters, polyethylene glycol and fatty acid esters of sorbitan or mixtures of these substances. The formulation of suspension may comprise liquid diluents, for example water, ethanol or propylene glycol, suspending agents, for example ethoxylated isosteary alcohols, polyoxyethylene sorbitol esters and poly oxyethylene sorbitan esters, micocrystalline cellulose, aluminum metahydroxide, bentonite, agar and tragacanth or mixtures of these substances. The formulation of soap may comprise alkali metal salts of fatty acids, salts of fatty acid hemiesters, fatty acid protein hydrolyzates, isethionates, lanolin, fatty alcohol, vegetable oil, glycerol, sugars or mixtures of these substances.

Furthermore, the cosmetic compositions of this invention may contain auxiliaries as well as carrier. The non-limiting examples of auxiliaries include preservatives, antioxidants, stabilizers, solubilizers, vitamins, colorants, odor improvers or mixtures of these substances.

Where the present composition is formulated to provide a pharmaceutical composition, it may comprise a pharmaceutically acceptable carrier including carbohydrates (e.g., lactose, amylose, dextrose, sucrose, sorbitol, mannitol, starch, cellulose), gum acacia, calcium phosphate, alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, water, salt solutions, alcohols, gum arabic, syrup, vegetable oils (e.g., corn oil, cotton-seed oil, peanut oil, olive oil, coconut oil), polyethylene glycols, methyl cellulose, methylhydroxy benzoate, propylhydroxy benzoate, talc, magnesium stearate and mineral oil, but not limited to. The pharmaceutical compositions of this invention, further may contain wetting agent, sweetening agent, emulsifier, buffer, suspending agent, preservatives, flavors, perfumes, lubricant, stabilizer, or mixtures of these substances. Details of suitable pharmaceutically acceptable carriers and formulations can be found in Remington's Pharmaceutical Sciences (19th ed., 1995), which is incorporated herein by reference.

The pharmaceutical composition of this invention is formulated for topical application onto skin.

The correct dosage of the pharmaceutical compositions of this invention will be varied according to the particular formulation, the mode of application, age, body weight and sex of the patient, diet, time of administration, condition of the patient, drug combinations, reaction sensitivities and severity of the disease. It is understood that the ordinary skilled physician will readily be able to determine and prescribe a correct dosage of this pharmaceutical compositions. According to a preferred embodiment of this invention, the suitable dosage unit is to administer once a day with 0.001-100 ng/cm²(unit surface area of skin), most preferably, 0.1-2 ng/cm².

According to the conventional techniques known to those skilled in the art, the pharmaceutical compositions of this invention can be formulated with pharmaceutical acceptable carrier and/or vehicle as described above, finally providing several forms including a unit dosage form. Most preferably, the pharmaceutical composition is a solution comprising nanoliposomes.

The present composition acts on epidermal stem cell to increase the number of hair follicles so as to stimulate of hair growth, proliferates the keratinocytes of the epidermal layer to greatly inhibit skin aging, improves the skin damaged by UV light and wrinkles formed by UV light, remodels the connective tissue of the dermal layer to improve skin firmness and improve wrinkles, and shows the effects of treating acne and removing dark spots. Taken together, the composition of this invention can greatly improve skin conditions. In addition, the present composition is very safe to the human body, and has excellent stability when it is prepared in the form of a nanoliposome.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electron microscope photograph of a human growth hormone

(hGH)-containing liposome cream formulation (formulation A) prepared in Example I.

FIG. 2 is a gel permeation chromatogram of an hGH-containing liposome (Lipo-hGH) of formulation B prepared in Example I.

FIG. 3 shows the results of SDS-PAGE for hGH encapsulated with Lipo-hGH of formulation B prepared in Example I.

FIG. 4 is a reverse-phase HPLC chromatogram of hGH encapsulated in Lipo- hGH of formulation B prepared in Example I.

FIG. 5 is a reverse-phase HPLC chromatogram of phospholipid in Lipo-hGH of formulation B prepared in Example I. FIG. 6 is a graphic diagram showing safety test results for Lipo-hGH of formulation B prepared in Example I.

FIG. 7 is a graphic diagram showing safety test results for an hGH-containing liposome according to the present invention.

FIG. 8 shows test results for the wrinkle-reducing effect of the present hGH- encapsulated liposome on nude mice having UV-induced wrinkles.

FIG. 9 shows analysis results for the activity of human growth hormone encapsulated in an hGH-encapsulating liposome according to the present invention.

FIG. 10a is a photograph showing the localization of human growth hormone, which occurs when the present hGH-encapsulating nanoliposome is delivered to the skin through hair follicles in Sprague Dawley rats.

FIG. 10b is a photograph showing the effect of the present hGH- encapsulated nanoliposome on the dermal layer and hair follicles of the skin of Sprague Dawley rats. FIG. 11a is a photograph showing the effect of the present hGH- encapsulated nanoliposome on the epidermis and dermis of the skin of ICR mice.

FIG. lib is a photograph showing that the present hGH-encapsulated nanoliposome induces the remodeling of connective tissue in the dermal layer of ICR mice.

FIG. 12 is a photograph showing the effect of the present hGH-encapsulated nanoliposome on artificial human skin.

FIG. 13 shows analysis results for the particle size distribution of an hGH- encapsulated nanoliposome according to the present invention. FIG. 14 is a graphic diagram showing the wrinkle-reducing effect of the present hGH-encapsulated nanoliposome.

The following specific examples are intended to be illustrative of the invention and should not be construed as limiting the scope of the invention as defined by appended claims.

EXAMPLES

Example I: Preparation of various human growth hormone-containing liposome (Lipo-hGH) formulations Formulation A (cream formulation): human growth hormone-containing cream formulation

Phospholipid used in formulation A was lipoid SlOO (Lipoid GmbH, Germany) or lipoid S75 (Lipoid GmbH, Germany).

The heat exchanger of a high-pressure homogenizer (max. output 5 L/hr, highest pressure 1200 bar, Model HS-1002; manufactured by Hwasung Machinery Co.,

Ltd., South Korea) was placed in ice water such that the temperature of the outlet of the homogenizer did not exceed 30 ⁰C, and the inside of the homogenizer was then washed with distilled water so as to be ready to operate. Then, to 100 ml of a solution of human growth hormone (LG Life Sciences, Ltd) dissolved in a buffer solution (20 mM NaH₂PO₄ pH 6.5-7.5, 1 mM EDTA) at a concentration of 1 mg/ml, phospholipid was added at a ratio of 5 w/v% and sufficiently hydrated and stirred. The stirred solution was passed through the homogenizer three times or more at room temperature and a low pressure of 0 bar. To the solution passed through the homogenizer, phospholipid was added to a ratio of 6 w/v% and sufficiently hydrated and stirred. The stirred solution was passed through the homogenizer three times or more at 100 bar. Then, to the solution passed through the homogenizer in the condition of 100 bar, phospholipid was added to a ratio of 7 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 200 bar. Then, to the solution passed through the homogenizer in the condition of 200 bar, phospholipid was added to a ratio of 8 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 300 bar. To the solution passed through the homogenizer in the condition of 300 bar, phospholipid was added to a ratio of 9 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 400 bar. Then, to the solution passed through the homogenizer in the condition of 400 bar, phospholipid was added to a ratio of 10 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 500 bar. Then, to the solution passed through the homogenizer in the condition of 500 bar, phospholipid was added to a ratio of 11 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer thre times or more at 600 bar. Then, to the solution passed through the homogenizer in the condition of 600 bar, phospholipid was added to a ratio of 12 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 800 bar, thus preparing a human growth hormone-containing liposome (Lipo-hGH) cream formulation.

FIG. 1 shows an electron microscope photograph of the human growth hormone-containing liposome cream formulation prepared in this Example. The liposome cream formulation prepared in this Example was coated with gold and observed with a scanning electron microscope (HITACHI S 2500). In the observation result, the shape of the bent and connected background was presumed as gel, and small spherical grains were estimated as nanosize (0.02-0.3 μm) loposomes.

Formulation B (liposome formulation): Human growth hormone (hGH)- containing liposome formulation

Phospholipid used in the preparation of formulation B was soybean lecithin (ShinDongBang Corp., South Korea), Metarin P (Degussa Texturant Systems Deutschland GmbH & Co. KG), Nutripur S (Degussa Texturant Systems Deutschland GmbH & Co. KG) or Emultop (Degussa Texturant Systems Deutschland GmbH & Co. KG).

The heat exchanger of a high-pressure homogenizer (max. output 5 L/hr, highest pressure 1200 bar, Model HS-1002; manufactured by Hwasung Machinery Co., Ltd., South Korea) was placed in ice water such that the temperature of the outlet of the homogenizer did not exceed 30 ⁰C, and the inside of the homogenizer was then washed with distilled water so as to be ready to operate. Then, to 100 ml of a solution of human growth hormone (LG Life Sciences, Ltd.) dissolved in a buffer solution (20 mM NaH₂PO₄ pH 6.5-7.5, 1 mM EDTA) at a concentration of 1 mg/ml, phospholipid was added at a ratio of 10 w/v% and sufficiently hydrated and stirred. The stirred solution was passed through the homogenizer three times or more at room temperature and a low pressure of 0 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 14 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 100 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 18 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 200 bar. Then, to the solution passed through the homogneizer, phospholipid was added to a ratio of 20 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 300 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 22 w/v%, and sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 400 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 24 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 500 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 26 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 600 bar. Then, to the solution passed through the homogenizer, phospholipid was added to a ratio of 28 w/v%, sufficiently hydrated and stirred, and passed through the homogenizer three times or more at 700 bar. Then, the solution passed through the homogenizer at 700 bar was passed through the homogenizer three times or more at 800 bar and discharged from the homogenizer. The discharged solution was subjected to high-speed centrifugation at 15,000 x g for 30 minutes, and the supernatant was separated. At this time, human growth hormone which has not been encapsulated in liposome was removed by gel permeation chromatography (GE Healthcare, USA), thus obtaining liquid phase liposome (see FIG. 2).

Formulation B prepared using a solution of distilled water and buffer solution (20 mM NaH₂PO₄, 1 mM EDTA, pH 6.0-7.5) did not show a difference in the physical properties and stability of liposome. Also, the obtained formulation was stored in more than 10 w/v% of soybean lecithin at 15-30 ⁰C for a long period of time and, as a result, the phase separation into a lipid layer (lower) and an aqueous solution (upper) occurred. However, in less than 10 w/v% of soybean lecithin, it had excellent stability without phase separation.

Example II: FPLC separation and SDS-PAGE analysis For the analysis of the human growth hormone-containing liposome of formulation B prepared in Example I, FPLC (Acta explorer, Amersham Bioscience) was equipped with a superdex 200 HR/30 column at room temperature, and the column was equilibrated with two times the column volume of a buffer solution (20 imM NaH₂PO₄, 1 mM EDTA and 150 mM NaCI). Then, the human growth hormone- containing liposome was separated into fractions which were then collected and analyzed by SDS-PAGE. As shown in FIG. 3, the band of human growth hormone could be observed at about 22 kDa.

Example III: Quantification of human growth hormone in liposome

HPLC (Shimazu) was equipped with a C₁₈ Delta pack column (Waters, USA), and reverse phase-HPLC was performed by concentration gradient (B 60-10% : 0-25 min, B 60%: 25.01-30 min) at a flow rate of 1 ml/min using 0.1% TFA acetonitrile as solvent A and 0.1% TFA H₂O as solvent B. A standard sample (international standard human growth hormone NIBSC code 98/574) was quantified using a fluorescence detector (excitation: 295 nm, range: 270-300 nm; emission: 350 nm, range: 300-400 nm) in conditions of oven temperature of 55 ⁰C and run time of 30 min. Then, a sample was pretreated by disrupting the human growth hormone-containing liposome solution with a sonicator and adding a buffer solution (50 mM Tris-CI pH 8.0, 1 mM EDTA, 8 M urea, 2% Tween 20) thereto in the same volume as the sample and then pipetting the mixture, and was quantified by HPLC using the fluorescence detector (see FIG. 4).

From the quantification results, it can be seen that the Lipo-hGH of formulation B prepared in Example I contained about 3.69 μg/ml of human growth hormone.

Example IV: Analysis of phospholipid content HPLC (Shimazu) was equipped with a Spherisorb S5 NH₂ column (Waters), and HPLC was performed by isocratic gradient at a flow rate of 1 ml/min using a mixed solvent of 60% acetonitrile, 30% methanol and 5% H₂O. Phospholipid was completely dissolved in a mixed solvent of methanol: chloroform (90%: 10%) and quantified using a UV light detector (215 nm) in conditions of oven temperature of 35 ⁰C and run time of 20 min. In the same manner, the present human growth hormone-containing liposome solution was completely dissolved in a mixed solvent of methanol: chloroform (90%:10%) and then quantified by HPLC (see FIG. 5).

From the quantification results, it can be seen that the Lipo-hGH of formulation B prepared in Example I contained about 3.26 mg/ml of phospholipid.

Example V: Stability test

A stability test for the human growth hormone-containing liposome of formulation B prepared in Example I was performed in the following manner. The present Lipo-hGH containing 0.1% methyl paraben was analyzed for stability by placing it in brown color bottles, standing the bottles at 4 ⁰C and 15-30 ⁰C, respectively, and quantifying the content of hGH by HPLC at one-week intervals. As can be seen in FIG. 6, the present Lipo-hGH after 10 months of storing had initial hGH contents of 87.5% at 4 ⁰C and 75% at room temperature. This suggests that the present Lipo-hGH has excellent stability.

Example VI: Safety test

To test the safety of the present human growth hormone-containing liposome (formulation B prepared in Example I), cytotoxicities for human keratinocyte cell line HaCaT (DKFZ, Germany) and human embryonic fibroblast HEF (gift from Prof.

Lee, Jaeyong, Department of Biochemistry, School of Medicine, Hallym University) were examined. HaCaT and HEF were suspended in 10% FBS/DMEM (FD media at concentrations of 1 x 10⁵ cells/ml and 5 x 10⁴ cells/ml, respectively. 1 ml of each of the suspensions was added to a 24-well plate and then cultured in a 5% CO₂ incubator at 37 ⁰C for one day. After one day of the culture, the upper-layer medium was carefully removed, and a suitable amount of 10% FD medium and various concentrations of samples were added to the wells of the plate and allowed to react in a 5% CO₂ incubator at 37 °Cfor one day. The samples used were a buffer solution (containing 20 mM Na-Pi, pH 7.0, 1 mM EDTA and 0.1% methyl paraben), liposome, human growth hormone and the Lipo-hGH of formulation B prepared in Example I. After the reaction, the viability of the cells was measured using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT: Sigma, USA) (Shearman et al., Proc. Natl. Acad. ScL 91(4): 1470-4(1994), Shearman et al., J. Neurochem. 65(1):218-27(1995) and Kaneko et al., J. Neurochem. 65(6):2585-93(1995)). The MTT reaction products were measured for absorbance at 570 nm using an ELISA reader (Molecular Devices, USA). The cell viability by each of the samples was expressed as a value relative to the absorbance of a well not containing the samples, taken as 100 % (FIG. 7).

As can be seen in FIG. 7, the present hGH-containing nanoliposome had no effect the cell viability of HaCaT and HEF, indicating that it is a formulation very safe to a living body.

Example VII: Analysis for proliferation of nanoliposome formulation Lipo- hGH in Nb₂ cells

To the well of a 96-well plate containing 50 μl of the Nb₂ noble rat lymphoma cell line (NIBSC ECACC #97041101 ) at a concentration of 1 x 10⁵ cells/ml, S-hGH (standard human growth hormone, NIBSC code 98/574), a sample comprising a 1000-fold dilution of a pretreated solution (obtained by disrupting a liposome solution containing no human growth hormone with a sonicator and adding a solution (containing 50 mM Tris-CI pH 8.0, 1 mM EDTA, 8 M urea, 2% Tween 20) thereto in the same volume as the sample and then pipetting the mixture) added S-hGH, or a sample comprising a 1000-fold dilution of the Lipo-hGH (N-hGH; formulation B prepared in Example I) subjected to a sample pretreatment process (comprising disrupting a liposome solution containing no human growth hormone with a sonicator and adding a solution (containing 50 mM Tris-CI pH 8.0, 1 mM EDTA, 8 M urea, 2% Tween 20) thereto in the same volume as the sample and then pipetting the mixture), was added. Each of the samples was cultured in a 5% CO₂ incubator at 37 ^°Cfor 5 days, and the amount of the proliferated cells was measured using MTT. The mean absorbance of the group containing hGH was calculated as a value relative to the mean absorbance of the control group containing no hGH, taken as 100%.

As shown in FIG. 9, the human growth hormone encapsulated in the present Lipo-hGH maintained its original activity.

Example VIII: Analysis of particle size distribution The Lipo-hGH of formulation B separated by gel permeation chromatography in the above Example was analyzed for particle size distribution at a refractive index of 1.52 using a particle size analyzer (Mastersizer 2000/ Malvern Instruments Ltd.) (see FIG. 13). As represented in FIG. 13, the present Lipo-hGH showed the largest distribution at a particle size of 0.193 μrn, indicating that the Lipo-hGH of formulation B is present in the nanometer size.

Example IX: Analysis of wrinkle-improving effect

4-week-old nude mice (purchased from Korea Research Institute of Chemical Technology) were tested using the Lipo-hGH (N-hGH). An animal breeding chamber was kept at a temperature of 22 ± 2 ^°Cand a humidity of 55-60% in a 12-hr light/12- hr dark cycle, and the animals were permitted free access to solid feed (Central Lab. Animal Inc., Seoul, Korea) and water sterilized by irradiation and were acclimated for about 2 weeks. In order to induce wrinkles on the backside of these nude mice, 20 mJ of UVB was irradiated to the mice three times a week for 8 weeks. Then, to the UVB-irradiated back, each of a sample solution and a control solution were applied using a cosmetic brush for 8 weeks. Then, a wrinkle-improving effect was evaluated according to the Donald method (Hyun-Seok Kim et. al, Mech. Ageing Dev. (2005. 8.16 In press)).

The test results are shown in FIGS. 8 and 14. In FIG. 8, the control group (n=3) was not treated with anything, the UVB-control group (n=3) was treated with 20 mJ of UVB to induce only wrinkles, the liposome (n=3) was treated with 20 mJ of UVB to induce wrinkle and was treated with liposome, and the Lipo-hGH group (n=3) was treated with 20 mJ of UVB to induce wrinkles and treated with the present Lipo- hGH. As shown in FIGS. 8 and 14, the present Lipo-hGH had the effect of effectively removing the UV-induced wrinkles, which was clearly shown starting from 2 weeks after the topical application of the present Lipo-hGH.

Example X: Analysis of acne treatment effect

The acne treatment effect of the present human growth hormone-containing liposome was examined in the following manner.

Sixty 15-40-year-old women were randomly divided into three groups, and then allowed to use each of the hGH-containing liposome formulation B of Example I (formulation 1), a comparative solution containing only liposome (formulation 2) and a comparative buffer solution (formulation 3) first after face washing two times (morning and evening) a day for 3 weeks. In addition, there was no particular limitation on usually used cosmetics. Then, the improvement of acne was evaluated based on the user's opinion according to the following criteria. The rest results are shown in Table 1 below. Evaluation criteria: +++ (had a very good improvement effect); ++ (had a significant improvement effect); + (had a slight improvement effect); ± (had no improvement effect, but not became worse); and - (became worse). TABLE 1

As can be seen in Table 1, the present formulation had a very good effect on the improvement of acne, which started to be clearly shown 2 weeks after the application of the formulation. Furthermore, the present composition did not substantially cause irritation to the skin, for example, erythema or itching.

Example XI: Analysis of dark spot removal effect

The dark spot removal effect of the present human growth hormone- containing liposome was tested in the following manner. Sixty 40-60-year-old women were randomly divided into three groups, and then allowed to use each of the hGH-containing liposome formulation B of Example I (formulation 1), a comparative solution containing only liposome (formulation 2) and a comparative buffer solution (formulation 3) first after face washing two times (morning and evening) a day for 8 weeks. In addition, there was no particular limitation on usually used cosmetics. The improvement of dark spots was evaluated based on the user's opinion according to the following criteria. The test results are shown in Table 2 below. Evaluation criteria: +++ (had a very good improvement effect); ++ (had a significant improvement effect); + (had a slight improvement effect); ± (had no improvement effect, but not became worse); and - (became worse). TABLE 2

As indicated in Table 2, the present formulation had a significantly excellent effect on the improvement of dark spots, which started to be clearly shown from about 3-5 weeks after the application of the formulation. Furthermore, the present composition did not substantially cause irritation to the skin, for example, erythema or itching.

Example XII: Analysis of localization of nanoliposome formulation Lipo-hGH and effect thereof on skin

The abdominal region of a Sprague Dawley rat was divided into six zones (circles each having a radius of 1 cm) and treated with the following samples: 0.1% methyl-paraben buffer solution, 0.1% liposome, 0.001 U hGH, 0.0001 U hGH, 0.001 U Lipo-hGH, and 0.0001 U Lipo-hGH.

The animal was treated with each of the samples in an amount of 50 μl two times at 24-hour intervals seven times in total. At 24 hours after treatment with the last sample, tissue was extracted from the rat. The extracted tissue was sectioned to a thickness of 40 μm and treated with a polyclonal rabbit anti-human growth hormone primary antibody (DAKO, U.S.A.) and then with a biotin-conjugated anti- rabbit secondary antibody (VECTOR. VECTASTAIN ABC kit (RABBIT IgG), U.S.A.) at room temperature for 30 minutes. Next, the sectioned tissue was treated with a VECTASTAIN ABC reagent (VECTOR, U.S.A.) at room temperature for 30 minutes and subjected to a color development reaction with a DAB substrate (Diaminobenzidine, Sigma, USA). The sectioned tissue was dehydrated with 78% ethanol, 85% ethanol and 95% ethanol in order and then treated with xylene for 5 minutes. The tissue was fixed on a slide glass, and then the location of human growth hormone contained in Lipo-hGH was observed. As shown in FIG. 10a, the human growth hormone encapsulated in the present Lipo-hGH or the rat growth hormone originally contained in the rat was found at locations considered as the bulge stem cells of hair follicles.

Also, as shown in FIG. 10b, the dermal layer of the rat skin applied with the present Lipo-hGH (containing 0.0001 U hGH) widened, and the number of hair follicles on the dermal layer increased. Furthermore, it can be found in FIG. 12 that, even the hGH aqueous solution was applied to the skin, the hGH reached the location of bulge stem cells in hair follicles, and this finding was very surprising considering the technical level and common sense in the art. This result a possibility of achieving the improvement of skin conditions, even when not only hGH encapsulated in liposome, but also an hGH aqueous solution itself, are applied to the skin.

Example XIII: Analysis of effect of nanoliposome formulation Lipo-hGH on mouse skin The effect of the present nanoliposome formulation Lipo-hGH (prepared in

Example I) on the skin of ICR mice was analyzed by H&E (Hematoxylin & Eosin) staining. For this purpose, after removing the hairs of the back of ICR mice, the back regions divided with respect to the vertebra were treated with a control group and the present Lipo-hGH at 4-hr intervals for 2 weeks: group 1 (n=3); untreated group 2 (n=3); a group (n=3) treated with liposome/0.1 U of the present Lipo-hGH; group 3 (n=3) treated with liposome/0.01 U of the present Lipo-hGH; group 4 (n=3) treated with liposome/0.001 U of the present Lipo-hGH. After 2 weeks of the treatment, tissues were extracted from the mice. The extracted tissues were made into paraffin blocks and sectioned to a thickness of 4 μm, and the sectioned tissues were placed on a slide glass. Then, the sections were deparaffined and treated with a hematoxylene solution at room temperature for 10 minutes and then with an eosin solution at room temperature for 1 minute. Next, the sections were dehydrated with 78% ethanol, 85% ethanol, 95% ethanol and 100% ethanol in order and then treated with xylene for 5 minutes. The tissues were immobilized, and then the stained tissues were observed under a microscope.

As represented in FIG. 11a, the proliferation of cells in the epidermal layer of the skin treated with the present nanoliposome formulation Lipo-hGH was greatly increased, and the remodeling of connective tissues in the dermal layer occurred to form more compact connective tissues. FIG. lib is a photograph taken at 40Ox magnification and clearly shows that the remodeling of connective tissues in the dermal layer occurred.

Example XIV: Analysis of effect of nanoliposome formulation Lipo-hGH on artificial skin

Neoderm-ED™ (Tego Science, South Korea) was used to analyze the effect of the present nanoliposome formulation Lipo-hGH on artificial skin. Neoderm-ED™ is a human skin model for in vitro XesXs and consists of an epidermal and dermal matrix. Test groups were as follows: group 1 untreated; group 2 treated only with buffer solution; groups 3 and 4 treated with liposome; and groups 5 and 6 treated with 0.001 unit and 0.01 unit, respectively, of the present Lipo-hGH. Paraffin embedding and H&E staining were performed in the same manner as in the above Example. Finally, the stained tissues were observed under a microscope. As shown in FIG. 12, the proliferation of cells in the keratinocyte layer of

Neoderm-ED™ treated with the present nanoliposome formulation Lipo-hGH was actively made.

Having described specific examples of the present invention, it is to be understood that such examples are only preferred embodiments and should not be construed as limiting the scope of the invention. Therefore, the substantive scope of the invention may be determined by appended claims and their equivalents.

Claims

What is claimed is:

1. A composition formulated for topical administration to skin for improving skin conditions, which comprises human growth hormone as an active ingredient.

2. The composition according to claim 1, wherein the human growth hormone is encapsulated into a liposome.

3. The composition according to claim 2, wherein the liposome is a nanolipsome.

4. The composition according to claim 3, wherein the nanoliposome has a particle size of 50-250 nm.

5. The composition according to claim 1, wherein the skin condition is acne, wrinkle, dark spots, skin elasticity, hair growth, skin aging, skin moisture or dermal stem cell proliferation.

6. The composition according to claim 1, wherein the composition is a cosmetic or pharmaceutical composition.

7. A method for improving skin conditions of a human, which comprises topically administering to the skin of human the composition of any one of claims 1-6 comprising human growth hormone as an active ingredient.