Hyaluronic acid gel and manufacturing method thereof

Abstract

Provided is hyaluronic acid gel suitable for cosmetic and medical field. The hyaluronic acid gel contains hyaluronic acid, polycarboxylic acid or oxycarbonic acid, and polyhydric alcohol. The hyaluronic acid gel is produced by drying moisture of an aqueous solution in which the hyaluronic acid, the polycarboxylic acid, and the polyhydric alcohol are uniformly dissolved to be an intended form.

Claims

1. A hyaluronic acid gel sheet comprising hyaluronic acid alcogel containing 100 parts by weight of a hyaluronic acid having a molecular weight of from 510.sup.4 to 510.sup.6 daltons, 10 to 100 parts by weight of polycarboxylic acid or oxycarbonic acid, and 100 to 8000 parts by weight of polyhydric alcohol, wherein a thickness of the sheet is in a range of 30 m to 1 mm, wherein the polyhydric alcohol is selected from the group consisting of glycerin, propylene glycol, ethylene glycol, polyethylene glycol, 1,3-butylene glycol, dipropylene glycol and sorbitol, and wherein the hyaluronic acid alcogel is formed by drying an aqueous solution containing the hyaluronic acid, the polycarboxylic acid or oxycarbonic acid, and the polyhydric alcohol to remove water therefrom.

2. The hyaluronic acid gel sheet according to claim 1, wherein the hyaluronic acid alcogel further comprises: 10 parts by weight or more of a hyaluronic acid whose molecular weight is 210.sup.4 daltons or below in addition to the 100 parts by weight of said hyaluronic acid having a molecular weight of from 510.sup.4 to 510.sup.6 daltons.

3. The hyaluronic acid gel sheet according to claim 1, wherein the polycarboxylic acid or oxycarbonic acid is at least one or more carboxylic acids selected from a group consisting of citric acid, tartaric acid and lactic acid.

4. The hyaluronic acid gel sheet according to claim 1, wherein the polyhydric alcohol is glycerin.

5. The hyaluronic acid gel sheet according to claim 1, further containing at least one or more compounds selected from a group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, polyacrylic acid and polyethylene glycol.

6. The hyaluronic acid gel sheet according to claim 1, further containing active ingredients used for cosmetics and medicinal products.

7. A method for manufacturing a hyaluronic acid gel sheet, including a step of preparing an aqueous solution by uniformly dissolving 100 parts by weight of a hyaluronic acid, having a molecular weight of from 510.sup.4 to 510.sup.6 daltons, 10 to 100 parts by weight of a polycarboxylic acid or oxycarbonic acid and 100 to 8000 parts by weight of a polyhydric alcohol in water, and a step of producing the hyaluronic acid gel sheet by applying the aqueous solution on a film so that its thickness is uniform and drying it to remove water therefrom, wherein the polyhydric alcohol is selected from the group consisting of glycerin, propylene glycol, ethylene glycol, polyethylene glycol, 1,3-butylene glycol, dipropylene glycol and sorbitol.

8. The hyaluronic acid gel sheet according to claim 2, wherein the polycarboxylic acid or oxycarbonic acid is at least one or more carboxylic acids selected from a group consisting of citric acid, tartaric acid and lactic acid.

9. The hyaluronic acid gel sheet according to claim 2, wherein the polyhydric alcohol is glycerin.

10. The hyaluronic acid gel sheet according to claim 3, wherein the polyhydric alcohol is glycerin.

11. The hyaluronic acid gel sheet according to claim 2, further containing at least one or more compounds selected from a group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, polyacrylic acid and polyethylene glycol.

12. The hyaluronic acid gel sheet according to claim 3, further containing at least one or more compounds selected from a group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, polyacrylic acid and polyethylene glycol.

13. The hyaluronic acid gel sheet according to claim 4, further containing at least one or more compounds selected from a group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, polyacrylic acid and polyethylene glycol.

14. The hyaluronic acid gel sheet according to claim 2, further containing active ingredients used for cosmetics and medicinal products.

15. The hyaluronic acid gel sheet according to claim 3, further containing active ingredients used for cosmetics and medicinal products.

16. The hyaluronic acid gel sheet according to claim 4, further containing active ingredients used for cosmetics and medicinal products.

17. The hyaluronic acid gel sheet according to claim 5, further containing active ingredients used for cosmetics and medicinal products.

18. A hyaluronic acid gel sheet comprising hyaluronic acid alcogel containing 100 parts by weight of a hyaluronic acid having a molecular weight of from 510.sup.4 to 510.sup.6 daltons, 10 parts by weight or more of a hyaluronic acid having a molecular weight of 210.sup.4 daltons or below, 10 to 100 parts by weight of polycarboxylic acid or oxycarbonic acid, and 100 to 8000 parts by weight of polyhydric alcohol, wherein a thickness of the sheet is in a range of 30 m to 1 mm.

19. A method for manufacturing a hyaluronic acid gel sheet, including a step of preparing an aqueous solution uniformly dissolving 100 parts by weight of a hyaluronic acid having a molecular weight of from 510.sup.4 to 510.sup.6 daltons, 10 parts by weight or more of a hyaluronic acid having a molecular weight of 210.sup.4 daltons or below, 10 to 100 parts by weight of a polycarboxylic acid or oxycarbonic acid and 100 to 8000 parts by weight of a polyhydric alcohol in water, and a step of producing the hyaluronic acid gel sheet by applying the aqueous solution on a film so that its thickness is uniform and drying it.

20. The method for manufacturing a hyaluronic gel sheet according to claim 7, farther comprising: dissolving an active ingredient used for cosmetics and medicinal products in ethanol and then adding it to the prepared aqueous solution prior to producing the hyaluronic acid gel sheet.

21. The hyaluronic acid gel sheet according to claim 1, wherein the hyaluronic acid alcogel further comprises: 10 to 100 parts by weight of a hyaluronic acid whose molecular weight is 210.sup.4 daltons or below in addition to the 100 parts by weight of said hyaluronic acid having a molecular weight of from 510.sup.4 to 510.sup.6 daltons.

Description

DESCRIPTION OF EMBODIMENTS

(1) Hereinafter, the present invention will be explained with reference to Examples, but the present invention is not originally limited to Examples.

(2) (Manufacture of the Hyaluronic Acid Gel Sheet)

(3) The hyaluronic acid gel sheets in Examples 1 to 29 and Comparative Examples 1 to 9 were produced according to the compounding ratios (weight ratio) described in Table 1 and Table 2 below. In Table 1 and Table 2, the molecular weights of the used hyaluronic acid are described below the columns of the hyaluronic acid. All of these molecular weights are values indicated on the purchased products. H200 is a hyaluronic acid with molecular weight of about 2,000,000 (HA-LQH, Kewpie Corporation), H80 is a hyaluronic acid with molecular weight of about 800,000 (FCH-80, Kikkoman Biochemifa Company), H10 is a hyaluronic acid with molecular weight of about 5 to 100,000 (FCH-SU, Kikkoman Biochemifa Company), H1 is a hyaluronic acid with molecular weight of about 10,000 (Hyalo-Oligo, Kewpie Corporation), and H0.2 is a hyaluronic acid with molecular weight of about 2,000 (Micro Hyaluronic Acid, Kikkoman Biochemifa Company).

(4) In addition, glycerol (concentrated glycerin, MIYOSHI OIL & FAT CO., LTD.), citric acid (NACALAI TESQUE, INC.), vitamin C derivative (Apprecier, SHOWA DENKO K.K.), tocopherol (NACALAI TESQUE, INC.), adenosine (NACALAI TESQUE, INC.), polyethylene glycol (Polyethylene Glycol 400, Wako Pure Chemical Industries, Ltd.) were used. For all of other valuable components, grades described in Japanese Standards of Cosmetic Ingredients were used.

(5) TABLE-US-00001 TABLE 1 Acid Valuable Tar- Hydro- Component Hyaluronic acid Glyc- Citric Lactic taric chloric Acetic Tocoph- Aden- 2 million 800,000 100,000 10,000 2000 erin acid acid acid acid acid erol VC osine Water Exam- 1 1 1 0.2 197.8 ples 2 1 5 0.2 193.8 3 1 20 0.2 178.8 4 1 40 0.2 158.8 5 1 60 0.2 138.8 6 1 80 0.2 118.8 7 2 20 0.4 177.6 8 2 60 0.4 137.6 9 10 20 4 166 10 10 60 4 126 11 0.5 0.5 40 0.2 158.8 12 0.5 0.5 40 0.2 158.8 13 1 0.1 40 0.2 158.7 14 0.5 0.5 40 0.2 158.8 15 1 0.1 40 0.2 0.1 158.6 16 0.5 0.5 40 0.2 0.1 158.7 17 0.5 0.5 40 0.2 0.1 158.7 18 1 40 0.1 158.9 19 1 40 0.2 158.8 20 1 40 0.5 158.5 21 1 40 1 158 22 1 40 0.5 158.5 23 1 40 0.1 158.9 Compar- 1 1 0.5 0.2 198.3 ative 2 1 150 0.2 48.8 Exam- 3 20 20 8 152 ples 4 20 20 8 152 5 1 40 0.05 158.9 6 1 40 0.1 158.9 7 1 40 1 158 8 1 40 0.1 158.9 9 1 40 1 158.9 Note: VC: Vitamin C derivative

(6) TABLE-US-00002 TABLE 2 Hyaluronic acid Polyhydric alcohol Citric 2 million 800,000 100,000 10,000 2000 Glycerin Propylene Polyethylene Butylene acid Water Exam- 24 1 20 0.2 178.8 ples 25 1 40 0.2 158.8 26 1 10 0.2 188.8 27 1 20 0.2 178.8 28 1 10 0.2 188.8 29 1 20 0.2 178.8 Note: Propylene: propylene glycol, Polyethylene: polyethylene glycol 400, Butylene: butylene glycol

(7) Respective aqueous solutions, each of which contains the hyaluronic acid, the polyhydric alcohol, and the polycarboxylic acid or oxycarbonic acid, were stirred and homogenized by a propeller type rotary stirrer, for preparation. In Examples 15 and 16, the tocopherol and the adenosine were dissolved in a small amount of ethanol and then added. The prepared aqueous solution was applied on a polyethylene terephthalate film with a thickness of 26 m (DIAFOIL #130-26: Mitsubishi Plastics, Inc.) so that the thickness was uniform, and dried at 80 C. by a geer type oven for 30 minutes to obtain a hyaluronic acid gel sheet with a thickness of about 200 m or a non-gelatinized viscous material.

(8) (Comparison of Properties Among the Produced Hyaluronic Acid Gel Sheets)

(9) The produced hyaluronic acid gel sheets obtained in Examples 1 to 29 and Comparative Examples 1 to 9 were evaluated from the following three view points. The results of the evaluations are summarized in Table 3 below.

(10) 1. Results of Observation for the Properties

(11) Results of observation for flexibility, elasticity and tensile strength by naked eye and sense of touch are shown.

(12) 2. Results of Test for Adherence to the Skin

(13) Results of test for adherence to the skin in which hyaluronic acid gel sheets (2 cm2 cm) were applied on insides of forearms of human volunteers are shown.

(14) 3. Solubility Test

(15) Hyaluronic acid gel sheets (2 cm2 cm) were applied on forearms of human volunteers, on which 10 ml of water was dripped, and the skin was massaged over the sheet for 3 minutes, and the solubility of the hyaluronic acid gel was observed.

(16) TABLE-US-00003 TABLE 3 Property Adherence to skin Solubility Exam- 1 A A A ples 2 A A A 3 A A A 4 A A A 5 A A A 6 A A A 7 A A A 8 A A A 9 A A A 10 A A A 11 A A A 12 A A A 13 A A A 14 A A A 15 A A A* 16 A A A* 17 A A A* 18 A A A 19 A A A 20 A A A 21 A A A 22 A A A 23 A A A 24 A A A 25 A A A 26 A A A 27 A A A 28 A A A 29 A A A Compar- 1 B C B ative 2 D Insufficient sheet forming Unable to test Exam- 3 D Unable to form sheet Unable to test ples 4 D Unable to form sheet Unable to test 5 D Unable to form sheet Unable to test 6 D Unable to form sheet Unable to test 7 D Unable to form sheet Unable to test 8 D Unable to form sheet Unable to test 9 D Unable to form sheet Unable to test

(17) Respective symbols in Table 3 mean the following results.

(18) In the observation results for properties, A represents that all of flexibility, elasticity and tensile strength are sufficient, B represents that flexibility and elasticity are insufficient but tensile strength is sufficient, C represents that flexibility and elasticity are sufficient but tensile strength is insufficient, and D represents that it is a liquid, and all of flexibility, elasticity and tensile strength are insufficient.

(19) In the skin adherence test, A represents good adherence, B represents adherence with partial detachment, and C represents no adherence and moreover detachment. Basically, the products showing C and D in the observation results for the properties were not the subjects for this test.

(20) In the solubility test, A represents complete dissolution, and B represents partial dissolution. A* represents rapid dissolution within 30 seconds. Basically, the products showing C and D in the observation results for the properties were not the subjects for this test.

(21) (Evaluation of Moisturizing Effects by an Application Test for the Hyaluronic Acid Gel Sheet)

(22) The following four test samples were administered to the same sites of forearms of 5 human volunteers twice at morning and night for a total of 7 days, and one day after the completion of the administration (8 days after the start of the administration), their skin moisture contents were measured using Cutometer (MPA 580). The results of the measurement were indicated as electrostatic capacities (unit: a.u.). Also, their skin moisture contents before administration were measured as controls. The increment of electrostatic capacity (=increment of the moisture content) compared with that before administration were summarized in Table 4. The results are represented by an average and a standard deviation (SD) of the results of the 5 subjects.

(23) TABLE-US-00004 TABLE 4 Average and SD of increment of electrostatic Test Examples Target Samples capacity of skin (unit: a.u.) 1 Example 4 Gel sheet 42 6 2 Example 17 Gel sheet 47 5 3 Example 17 Solution 49 8 4 WO01/57093 Example 6 30 6

(24) The test samples and the administration method were as below.

(25) Test example 1: The hyaluronic acid gel sheet (2 cm2 cm) in Example 4 was applied on the forearm for 30 minutes, then the skin was massaged while the gel was dissolved by adding about 10 mL of purified water on the gel little by little for about 3 minutes, then it was rinsed with purified water, and naturally dried.

(26) Test example 2: The hyaluronic acid gel sheet (2 cm2 cm) in Example 17 was applied on the forearm for 30 minutes, then the skin was massaged while the gel was dissolved by adding about 10 mL of purified water on the gel little by little for about 3 minutes, then it was rinsed with purified water, and naturally dried.

(27) Test example 3: About 1 mL of the aqueous solution before preparation of the gel in Example 17 was applied on the forearm (about 2 cm2 cm), and 30 minutes later, the skin was massaged for about 3 minutes, then it was rinsed with purified water, and naturally dried.

(28) Test example 4: According to the method described in Example 6 of WO01/57093, the hyaluronic acid gel sheet (2 cm2 cm) prepared using an aqueous solution containing 0.5% of hyaluronic acid (HA-LQH: Kewpie Corporation) and 0.5% of hyaluronic acid (Hyalo-Oligo: Kewpie Corporation) was applied on the forearm for 30 minutes, then the skin was massaged while adding about 10 mL of purified water on the gel little by little for about 10 minutes, then it was rinsed with purified water, and naturally dried.

(29) The hyaluronic acid gel sheet showed significant increase of the skin moisture content compared to Example 6 in WO01/57093. In addition, the hyaluronic acid gel sheets in Examples 4 and 17 showed increment of the skin moisture content equal to that in the aqueous solution before preparation of the gel in Example 17. Furthermore, in sensory evaluation in all of 5 human volunteers, the hyaluronic acid gel sheets in Examples 4 and 17 showed handleability and sense of use in its administration to the skin superior to those of the hyaluronic acid aqueous solution in Example 17.

(30) (Evaluation for the Provision of Warm Sensation and CO.sub.2 Gas-generating Effects by Application Test of the Hyaluronic Acid Gel Sheet)

(31) The hyaluronic acid gel sheets in Examples 30 to 36 were produced according to the compounding ratios (weight ratio) described in Table 5 below. Aqueous solutions of each constituent were stirred and homogenized by a propeller type rotary stirrer, for preparation. The prepared aqueous solution was applied on a polyethylene terephthalate film with a thickness of 26 m (DIAFOIL #130-26: Mitsubishi Plastics, Inc.) so that the thickness was uniform, and dried at 80 C. by a geer type oven for 30 minutes to obtain a hyaluronic acid gel sheet with a thickness of about 200 m. This hyaluronic acid gel sheet was cut to obtain a circle hyaluronic acid gel sheet with a diameter of 20 cm, and a face mask having holes corresponding to eyes and mouth was produced.

(32) Also, the hyaluronic acid gel sheets in Comparative Examples 10 and 11 were similarly produced according to the compounding ratios (weight ratio) described in Table 5. Also, their face masks were similarly produced. The thicknesses of the films for the hyaluronic acid gel sheets were 15 m and 25 m respectively.

(33) TABLE-US-00005 TABLE 5 Acid Valuable Hyaluronic acid Polyhydric alcohol Lactic Citric Tartaric Component 2 million 2000 Glycerin Polyethylene acid acid acid Collagen Exam- 30 1 0.1 30 5 0.2 0.6 0.2 1 ples 31 1 0.1 40 0 0.2 0.8 0 2 32 1 0.1 60 0 0 1 0 0 33 1 0 50 0 0 0 1 0 34 1 0.1 40 0 0.2 0.6 0.2 1 35 1 0 40 2 0.2 0.8 0 2 36 1 0.1 50 0 0 0.2 0.8 0 Compar- 10 1 0 50 0 0.2 0.6 0.2 0 ative 11 1 0.05 50 2 0.2 0.6 0 0 Exam- ples Valuable Component Acetyl- Glycyrrhizin glucosamine Trehalose Niacinamide 2K Adenosine Scutellaria Hydroxy Water Exam- 30 0 0 0.02 0.01 0.05 0.02 0 150 ples 31 0 0 0.02 0.01 0.05 0.02 0 150 32 1 0 0.02 0.01 0.1 0.02 0.1 150 33 1 0 0.02 0.01 0.05 0.02 0.1 150 34 0 0 0.02 0.01 0.05 0.02 0 150 35 0 0 0.02 0.01 0.05 0.02 0 150 36 1 0 0.02 0.01 0.1 0.02 0 150 Compar- 10 1 0 0.02 0.01 0.05 0.02 0 150 ative 11 0 1 0.02 0.01 0.1 0.02 0 150 Exam- ples Note: Polyethylene: polyethylene glycol 400, Scutellaria: scutellaria baiealensis extract, Hydroxy: hydroxypropyl-cellulose

(34) The skin lotion for the test was produced according to the compounding ratios (weight ratio) for the components described in Table 6 below. Aqueous solutions of each constituent were mixed by a propeller type rotary stirrer, for preparation.

(35) TABLE-US-00006 TABLE 6 Scutellaria Skin Hyaluronic Acetyl- baicalensis Butylene Oleyl POE Methyl Sodium lotion acid 2000 glucosamine extract glycol Glycerin alcohol (25) paraben bicarbonate Water A 0.01 1 0.01 6 4 0.1 0.5 0.05 1 85 B 0.01 1 0.01 6 4 0.1 0.5 0.05 0 85

(36) Each of the obtained face masks was applied on the face of the volunteer lying face up, and presence of warm sensation at the application site on the skin was evaluated. The skin temperatures at the application site and the non-application site were measured to calculate the temperature difference between them. For measurement of the skin temperature, a digital thermometer (GT-07) was used.

(37) Subsequently, about 0.5 mL of skin lotion for the test was sprayed to the whole surface of the face mask by a spray, and the skin was massaged to evaluate foaming of CO.sub.2 gas. In this test, skin lotion A was used in Examples 30 to 35 and Comparative Examples 10 and 11, and skin lotion B was used in Example 36.

(38) The evaluation results were summarized in Table 7 below. The face mask was dissolved by massage for about 3 minutes, then it was rinsed with purified water, and naturally dried.

(39) TABLE-US-00007 TABLE 7 Test result Test result Handle- for warm for CO.sub.2 abiliy sensation of skin gas foaming Exam- 30 Good Skin temperature Intense ples increased by 0.5 C. foaming for more than 1 min 31 Skin temperature Intense increased by 0.5 C. foaming for more than 1 min 32 Skin temperature Intense increased by 0.5 C. foaming for more than 1 min 33 Skin temperature Intense increased by 0.5 C. foaming for more than 1 min 34 Skin temperature Intense increased by 0.5 C. foaming for more than 1 min 35 Skin temperature Intense increased by 0.5 C. foaming for more than 1 min 36 Skin temperature No foaming increased by 0.5 C. for more than 1 min Compar- 10 Insufficient Skin temperature Small amount ative sheet strength, increased by 0.3 C. of foam Exam- difficult or less generated ples to handle 11 Insufficient Skin temperature Small amount sheet strength, increased by 0.3 C. of foam difficult or less generated to handle