KR20030048725A - Production of stabilized ascorbic acid capsules and its use for cosmetics - Google Patents

Abstract

PURPOSE: A method of preparing a stable vitamin C capsule, in particular, by using a conventional agitator during the manufacture of a cosmetic composition is provided, thereby easily and economically producing a cosmetic composition which is easily distributed. CONSTITUTION: In the manufacture of a cosmetic composition, L-ascorbic acid is firstly dispersed in one or two or more skin-compatible solvents. The dispersed solution is contained in a silicon capsule having a suitable size and the prepared capsule is then secondly dispersed in skin-compatible silicon oil, natural oil or a complex solvent mixture. The prepared capsule has a size of 1 to 1,000μm and the skin-compatible silicon oil and natural oil are dimethicone or cyclomethicone and olive oil, squalane, caster oil, borage oil, camomile oil, rose hip oil and soybean oil respectively.

Description

Preparation of Vitamin C Stabilized Capsules and Cosmetic Production Method Using Them {Production of stabilized ascorbic acid capsules and its use for cosmetics}

The present invention relates to a method of preparing a cosmetic composition by encapsulating vitamin C, which is difficult to be used in cosmetics due to instability of a substance, and a method for preparing a capsule for stabilization is a simple chemical in a homo mixer in which general cosmetic production is used. Relying on reactions is an economical method that does not require expensive equipment. It also interferes with the capsule-to-capsule binding produced in solution and allows it to be fully dispersed in the colloidal state by the addition of appropriate chemicals, such as air, high temperatures in the distribution, moisture in the air, light through the container, and ions in the formulation. Can be protected against vitamin disruptors. Therefore, in the present invention, the cosmetic composition does not require a special machine for encapsulation in the manufacturing process, even though the composition using a vitamin C stabilized capsule, it is possible to commercialize by filling in a general cosmetic container through which light and air pass through, and long-term distribution The present invention relates to a method for producing cosmetics having high commercial value, which can be stably maintained from temperature changes and various vitamin destruction factors.

Vitamin C is a white powder in the dry powder state that is widely present in nature. It is a common substance that most plants and animals are biosynthesized in the body. Unfortunately, primates, including fish and humans, can't synthesize vitamin C in the body, and organisms that don't have vitamin C biosynthesis mechanisms, such as humans, must supplement their vitamin C with food intake. In humans, lack of vitamin C does not heal the wound well and is susceptible to scurvy. In addition, since vitamin C performs an important function of removing peroxide, a product of metabolites in vivo, the risk of cardiovascular diseases is increased by lowering the body's content of vitamin C. In contrast, an increase in the body's content of vitamin C provides benefits throughout the biological mechanism by faithfully performing the function of removing peroxides.

Vitamin C is a representative water-soluble vitamin, and various functions are known in vivo. It is a potent antioxidant that has the ability to remove harsh oxygen and peroxides throughout the cardiovascular system (Colin Dollery, Teraputic drugs A213 pp. ~ A215pp, Churchill Livingstone, 1999). In particular, at the cellular level, it exhibits peroxide or toxic oxygen removal of metabolic pathways in the cytoplasm, the hydrophilic fraction (Bendich A et al. Advanced in Free Radical Biology and Medicine, 2: 419-444, 1986). For this reason, many pharmaceutical companies are adding vitamin C to general health supplements, and have recently been widely used in the food field.

The function of the skin is to compete with tyrosine for tyrosinase, a rate-limiting enzyme during melanin biosynthesis, as an inhibitor of the expression of tyrosinase gene itself, and to reduce oxidized melanin. By suppressing the above melanin biosynthesis, overall activity on the whitening-related biological processes (Postaire E et al., Biochem Mol Int, 42, 1023pp-1033pp, 1997). It is also involved in collagen biosynthesis, which is most often associated with skin wrinkles. In biosynthesis of collagen, proline and lysine substituted with hydroxyl groups are essential. For both amino acids, the origin of hydroxyl groups is vitamin C in cells. In other words, collagen synthesis can proceed smoothly only when the hydroxyl group of vitamin C is transferred to two amino acids. Therefore, the presence of vitamin C is essential for collagen biosynthesis (Padh H, Nutrition Reviews 49, 65pp-70pp, 1991). In fact, as the age of the vitamin C content in the skin is lowered accordingly, it is well known that wrinkles increase due to decreased elasticity of collagen and degradation of new collagen synthesis. Maintaining vitamin C content in skin cells has been reported as one of the most efficient ways to delay skin aging process (Kevin J Lenton et al., Am. J Clin Nutr 71, 1194pp-1200pp, 2000).

Recently, vitamin C is known to increase the production of glucosylceramide to inhibit skin aging and to strengthen the skin barrier.

As these points are noticed, the research and development of the industry to use vitamin C as a cosmetic has been continued, but it has been difficult to use due to the instability of the substance. When vitamin C is a dry powder, it can maintain stability to a certain extent, and there is almost no risk of deterioration during the commercialization period due to the addition of dried pharmaceutical capsules, pouches, and dry products, and thus there is no difficulty in commercialization. Cosmetics, however, are based on liquid formulations, such as skins, lotions, etchants, creams, etc. in most cases, except in special cases, and contain various substances such as various additives and weights in their formulations and have a shelf life of one to three years. It takes a long time. Therefore, in order to commercialize vitamin C as a cosmetic, a practical stabilization method is necessary to overcome the instability of the substance. In particular, deteriorated and destroyed vitamin C changes its color from yellow to brown to dark brown, almost black. This color change is accepted as a color change due to the deterioration of the entire contents of the cosmetics during the distribution period when used as a cosmetics, which is a requirement for consumer complaints, refunds, exchanges, etc., greatly reducing the merchandise as a product.

Vitamin C is slow but spontaneously destroyed by contact with air, even in dry powder, and the rate of destruction is accelerated when light or moisture is applied. The presence of metal ions in water or an acidity above 4 also accelerates the rate of destruction. Therefore, as a cosmetic composition by stabilizing vitamin C, a technique for blocking vitamin C from high temperature, moisture, oxygen, and light is essential, and as shown in an example of retinol, a stabilization method through proper encapsulation will be most suitable as a cosmetic composition.

Alternatively, a variety of derivatives may be used in combination with chemical reactions with various fats or other salts in the prone site of vitamin C. Most derivatives are relatively stable in the formulation. However, almost all vitamin C derivatives produced to date are lower than pure vitamin C in efficacy and can only function when the binding site is cleaved by an appropriate enzyme in vivo. However, the existence of such enzymes is very small. In addition, since derivatives include synthetic processes due to derivatization, they are expensive as raw materials, and there may be concerns such as skin irritation due to the presence of intermediates or harmful solvents used in the synthesis in terms of purity. Can not do it. Therefore, when vitamin C is used as a cosmetic, it is most economical and efficient to stabilize and commercialize pure form.

Therefore, various efforts have been made to stabilize this in order to prepare a cosmetic composition using L-ascorbic acid. Specifically, for example, US Pat. No. 5,140,043 discloses a method for dissolving L-ascorbic acid in an aqueous alcohol solution having a pH of 3.5 or less. Indeed, L-ascorbic acid is stable at low acidity and this patent completes the invention originating in the properties of such materials. However, such a composition is not suitable as a cosmetic composition because it contains a large amount of alcohol and irritation is a problem when using. The actual stabilization is considered to be almost a commercial product as a cosmetic, after which the product according to the invention has not been released at all.

U.S. Patent No. 5,843,411 completed the invention by dissolving L-ascorbic acid in a silicone solution and adjusting the viscosity with gelle for use as a cosmetic composition, and in the stability test, it was stable for at least 6 months at room temperature and 3 months at 40 degrees and 45 cities. It was. However, in the case of such a composition, only the vitamin C is dispersed in a solution that does not have any component that destroys vitamin C, and the vitamin is exposed in the solution. There is a risk of deterioration during distribution. In this case, special containers filled with air or filled with nitrogen must be used for the commercialization, and these methods always carry the risk of increasing the manufacturing cost and inadvertently degrading the stability of the product.

U.S. Patent No. 5,750,123 describes the use of Cetyl Dimethicone Copolyol and Dimethyl Isosorbid, which are used as water-in-oil emulsifiers, to dissolve L-ascorbic acid in polyols containing water. As a method of dispersing in volatile silicone oil, 97% of the composition containing 5% by weight of L-ascorbic acid remained after 2 weeks at room temperature. However, this is generally about 85% remaining after 2 weeks at room temperature and 10% by weight L-ascorbic acid when 5% by weight of L-ascorbic acid is dissolved in a cosmetic composition containing 80% by weight or more of water. It was analyzed that about 97% remained after 2 weeks at room temperature when it was dissolved. In particular, when cosmetics are commercialized, the temperature rises a lot depending on the storage location or distribution method in summer. Therefore, at least three weeks should be maintained in 40 cities. However, the patent does not mention data on harsh testing at high temperatures, leaving little potential for practical commercial value as a product. In this case, too, since discoloration and deodorization may occur during distribution, it cannot be regarded as having sufficient stability and usability as cosmetics.

On the other hand, U. S. Patent No. 6,103, 267 discloses a mixture of an aqueous solution in which an aqueous solution in which a water-soluble polymer is dissolved together with L-ascorbic acid and an aqueous solution in which an aqueous solution is mixed with an oil, emulsified at 55 DEG C, and then cooled to cool the water-soluble polymer and L-ascor. Disclosed is a method of solidifying a poor acid into particles having a thickness of 1 μm so as to be dispersed in oil in a particulate state. Here, exposure to air for 24 months at room temperature showed that 85% of the initial concentration remained, indicating that L-ascorbic acid could be stabilized if it was dispersed completely with water. In this case, not just capsules, vitamin C is evenly dispersed in oil-soluble oil. In this case, because vitamin C is present as particles, it precipitates and sinks over time. That is, vitamin C itself is stable, but if commercialized, there is a risk of layer separation. However, this invention suggests a good idea that stabilization of the actual substance is possible if vitamin C can be prevented from being exposed to moisture, air, high temperature and light in the formulation. Of course, a more improved method of the present invention would be a commercially available cosmetic composition if it is possible to maintain a uniformly dispersed colloidal state for a long time without precipitation of vitamin C in the formulation.

It is an object of the present invention to encapsulate vitamin C, which is difficult to be used in cosmetics due to the instability of the substance itself, and thus to maintain it in the formulation in a state of being blocked from factors such as high temperature, oxygen, moisture, and light, which accelerate the instability of vitamin C. It is trying to develop. In particular, the objective of the present invention is to develop an efficient and economical method for preparing capsules using only a stirrer that is generally used without special mechanical assistance in the manufacture of cosmetics.

1 is an electron micrograph of a microcapsule containing a high concentration of vitamin C completed by the present invention.

Vitamin C has a strong reducing power of the material itself and has the disadvantage of being easily oxidized because of its reactivity, stabilized vitamin C is essential for use as a cosmetic. As the stabilization method, the most appropriate method is to completely block vitamin C from inactivation by completely blocking it from air, moisture, light, high temperature, and ions, which destroy vitamins, and to prevent encapsulation of contact with other factors in the liquid phase. Would be the most appropriate way.

In order to achieve the above object, a method for producing a cosmetic composition containing a vitamin C stabilizing capsule according to the present invention, a vitamin C dry powder and a mixture of one or two or more solvents that do not induce the substance stability of vitamin C Dissolve completely by using a homo mixer to disperse the granules, and then encapsulate the dispersion into mixed silicone powder and disperse the prepared capsule in a stirrer by using a homo mixer in a solvent or a combination of skin-friendly silicone and natural oil. It is completed as a process for making a process characterized by using a binding blocker which can prevent the inter-capsule binding in this process to make the capsule floating in the colloidal state in the solvent used in the present invention.

That is, the method for preparing a pure vitamin C stabilized capsule-containing cosmetic composition according to the present invention is characterized by including the following steps:

(1) A step of selecting a solvent that does not decompose or destroy L-ascorbic acid, followed by complete stirring using a stirrer maintained at room temperature in one or two or more kinds of mixed liquids.

(2) adding a silicone polymer and an emulsifier to the stirred dispersion and vigorously stirring to form a viscous paste.

(3) preparing a micrometer-sized capsule by completely dispersing the resulting paste in a solvent containing an appropriate amount of silicone oil and a capsule binding barrier.

(4) dispersing and stirring the prepared capsule in skin-friendly silicone oil or natural oil or complex to complete the cosmetic composition.

The present invention will be described in more detail with reference to the following Examples. All weight percentages indicated are expressed as a percentage of the final volume of the final prepared cosmetic.

[Examples 1-3]

20% by weight of L-ascorbic acid 1 was dissolved in 30% by weight of ethyl alcohol 1, 20% by weight of 1,3-butylene glycol 5, and 30% by weight of polyethylene glycol 1, and then left at room temperature for 10 minutes. Using a stirrer adjusted to 25 degrees and rotated for 1 hour at 3000 Alm per minute to completely disperse. At this time, the granules should not be aggregated and there should be no graininess after dispersion. The stirrer may be used by using a stirrer, which is generally used for preparing cosmetics, but there is no particular note, but be careful not to increase the temperature above room temperature.

30% by weight of vinyldimethicone / methicone silsesquioxane crosspolymer 1 and 20% by weight of polymethyl silsesquioxane 1 and 30% by weight of silica in the dispersion Add% to stir under the same conditions as vitamin C dispersion to make a viscous paste.

30% by weight of fluoroalkyl silicone 1 in 30 wt% in cyclomethicone 1 and vigorous stirring at 80 ° C are completely dissolved to prepare a solvent necessary for encapsulation first, and includes pre-prepared vitamin C. The prepared paste was added and stirred for 1 hour at room temperature in a stirrer rotating at a high speed of 3000 ALPM again to prepare a capsule. The capsule is microscopic in size and can be observed with the eyes and better under an optical microscope. Under electron microscopy, the surface of the capsule is not smooth because the nanometer sized silicone polymer spans the surface of the capsule (see Figure 1).

The encapsulated agitated liquid is again dispersed in a mixed solution using 70% by weight of Cyclomethicone 10 and 5 to 30% by weight of borage oil in natural oil under the same conditions as described above. After stirring by adding and finally dissolved 20 to 1% by weight of the wax separately to adjust the viscosity to the cream to complete the cosmetic composition. At this time, jojoba wax is suitable as a wax. In this case the viscosity can be adjusted between the hardest creams in a commonly used lotion by the amount of wax used. In addition to waxes, gum thickeners such as xanthan gum can also be used.

In addition, because the manufactured capsule has its own weight, it will settle and settle over time. In order to prevent sedimentation, Cetyl dimethicone copolyol is used in an amount of 1 to 20% by weight, which prevents binding between capsules and increases the surface tension of the capsule in oil. The composition ratio is summarized in Table 1.

Number ingredient Content (weight%) Example 1 Example 2 Example 3 One Butylene Glycol 10 10 10 2 Ethyl alcohol 10 10 10 3 Polyethylene glycol 10 10 10 4 Vinyl dimethicone / methicone Schulsquioxane cross polymer 3 3 10 5 Polymethylsilsquioxane 5 5 10 6 Silica 10 10 5 7 Fluoro alkyl silicone 3 3 5 8 Cyclomethicone 20 20 10 9 Borage Oil 5 5 10 10 Jojoba wax 2 7 5 11 Cetyl Dimethicone Copolyol 2 2 2 12 water 0 0 3 13 incense Quantity Quantity Quantity

Comparative Example 1

10% of L-ascorbic acid is dissolved in ultrapure purified water and used immediately for analysis. The remaining sample is refrigerated and used within 3 days.

Comparative Example 2

The composition according to Korean Patent Application No. 10-1998-0041603 "Skin Protective Cosmetic Composition Containing Stabilized Vitamin C and Phytosphingosine" is shown in Table 2.

ingredient Content (weight%) Compound 10.0 Phytosphingosine 1.0 glycerin 10.0 1,3-butylene glycol 5.0 Fiji 1500 2.0 Allantoin 0.1 D, L-panthenol 0.3 E.T.A.-2Na 0.02 Hydroxyethyl cellulose 0.1 Sodium hyaluronate 8.0 Carboxy Vinyl Polymer 0.2 Triethanol amine 0.18 Octyldodeceth-16 0.4 ethanol 6.0 Incense, preservative, coloring Quantity Purified water Quantity Sum 100

Comparative Example 3

The composition used in "Stable water / oil / water emulsion and its use as a dermatological and / or dermatological composition" according to Korean Patent Application No. 10-1998-0058217 was used in the formulation.

Name content(%) 1st emulsion Phase A Abil WE90 2.5 Volatile Silicone Oil 17.5 Polydimethylsilonic acid 4 Phase B Glycerol 45 Ascorbic acid 10 antiseptic 0.8 Deionized water 20.2 Triple emulsion Phase A 1st emulsion 20 Silicone oil 10 Phase B Crosslinked poly (2-acrylamido-2-methylpropanesulfonic acid) neutralized with ammonia 0.5 Acrylate / C10-C30 Alkyl Acrylate 0.3 antiseptic One Deionized water 33.7 Phase C Triethanolamine 0.3 Deionized water 2 Phase D Crosslinked poly (2-acrylamido-2-methylpropanesulfonic acid) neutralized with ammonia 1.5 Deionized water 24.4

Example 4

Stabilization of the temperature between the composition prepared by the present invention and the composition exemplified in the comparative example was analyzed. Six samples were stored in a thermostat maintained at 75 ° C., 25 ° C. (at room temperature) and 45 ° C. and analyzed by high performance liquid chromatography at two week intervals. For vitamin C analysis by high-performance liquid chromatography, 0.1 grams of each sample was taken, dissolved in 10 milliliters of 100% pure methanol, pulverized and extracted three times for 10 seconds with an ultrasonic mill, and extracted for 12 hours, followed by centrifugation and 0.2 micrometer. Sample liquid was prepared by passing through a nylon filter for an organic solvent. The analysis method was carried out according to the analysis method of Korean Patent No. 2000-0038845.

The final comparative analysis is summarized in Table 4. Comparative Example 1 can be seen that the deterioration of more than 10% by storing for 4 weeks at 45 ° C, the color of the yellow color can be easily confirmed by the eye color change. The composition of Comparative Example 3 deteriorated faster than dissolved in water, presumably containing a substance that increases the instability of vitamin C, which is unknown to date. Comparative Example 2 is 2% more stable at 45 degrees C than Comparative Example 1, but was also able to visually confirm the yellow deterioration. On the other hand, as shown in Table 4, the cosmetic composition prepared according to the present invention can be seen that the degree of stabilization was excellent, remaining at least 95% even after 4 weeks at both room temperature and 45 degrees.

Time, temperature Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 0 weeks, room temperature / 45 degrees 100 100 100 100 100 100 2 weeks at room temperature 99.54 99.63 99.79 99.98 92.66 73.08 4 weeks at room temperature 98.62 98.71 98.87 97.49 91.74 55.53 45 degrees for two weeks 97.52 97.61 97.77 93.18 90.82 34.13 4 weeks 45 degrees 95.97 96.06 96.22 88.71 90.52 25.00

Unit: relative content (%) at 0 weeks

The technology based on the present invention stabilizes various substances including vitamin C, which are difficult to use as cosmetics due to the difficulty of formulation due to the instability of the substance, even though various effects on the skin are known. Cosmetic compositions can be made.

Claims (10)

L-ascorbic acid is dispersed in one kind or two or more kinds of skin-friendly solvents as a primary dispersion, and the dispersion is contained in a silicone capsule formed in an appropriate size, and the manufactured capsule is a secondary skin-friendly silicone oil. Cosmetic composition dispersed in natural oil or complex solvent Ethyl alcohol, polyethyleneglycol as skin-friendly solvents of claim 1 Polyethylene Glycol, 1,3 Butylene Glycol (1,3-Butylene Glycol) (Glycerin), Propylene Glycol, Dipropylene Glycol, Polypropylene Glycol, Diethylene Glycol, Sorbitol, Hydroxypropyl Sorbitol, Ethyl Characterized by Ethyl Carbitol, Methyl Carbitol According to claim 1, wherein the silicone used for the preparation of the silicone capsules are vinyl dimethicone / methicone silsesquioxane crosspolymer, polymethyl silsesquioxane, acrylate / dimethicone One or two or more polymers of copolymers (Acrylates / dimethicone copolymer), silica (Silica), cyclomethicone / dimethicone copolyol The method of claim 1 wherein the size of the capsule produced is between 1 micrometer and 1000 micrometers in size. The method of claim 1 wherein the skin-friendly silicone oil is Dimethicone, Cyclomethicone. The method of claim 1, wherein the skin-friendly natural oils are olive oil, squalane, castor oil, borage oil, prime rose oil, chamomile oil, rosehip oil, soybean oil. The method of claim 1, wherein the vitamin C stabilized capsule is made using a silicone polymer. 8. A method for preparing a vitamin C stabilized capsule according to claim 7, wherein the vitamin C is completely dispersed in one or two or more of the solvents of claim 2 so that no grains are visible, and the dispersion is one or two or more of the silicone polymers of claim 3. Method of producing a capsule by stirring thoroughly in a stirring tank using a homo mixer rotating at 3000 times per minute using a proper ratio at room temperature. 9. The capsule according to claim 8, wherein the capsule is dispersed in the skin-friendly silicone oil or the natural oil or the mixture of the two oils described in Claims 5 and 6, so that the relatively heavy capsules do not sink or mutually bind during dispersion. Method for preparing stable cosmetics in which the capsule is completely dispersed in the solution by adding a silicone bonding inhibitor 10. The method according to claim 9, wherein Fluoro alkyl silicone or Cetyl dimethicone copolyol is used as an intercapsule binding inhibitor.