JP2008266261A - Ethanol-containing aqueous drug formulation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent aqueous drug formulation which has no precipitation or turbidness despite of the fact that hyaluronic acid and/or its salt is compounded with the aqueous drug formulation having high ethanol concentration. <P>SOLUTION: The transparent aqueous drug formulation having no precipitation or turbidness can be prepared by compounding hyaluronic acid and/or its salt with the aqueous drug formulation having high ethanol concentration, provided that the hyaluronic acid and/or its salt has an average molecular weight of ≤100,000 and does not form any precipitation when 9 pts. ethanol is added to 1 pt. 2% aqueous solution of the hyaluronic acid and/or its salt. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention is a transparent composition that does not cause precipitation or turbidity derived from hyaluronic acid and / or a salt thereof, even though hyaluronic acid and / or a salt thereof is blended in an aqueous preparation containing ethanol at a high concentration. It relates to an aqueous formulation.

Hyaluronic acid is a mucopolysaccharide present in living organisms, particularly subcutaneous tissues, and has been widely used as a raw material for cosmetics as hyaluronic acid or a salt thereof due to its high moisturizing function. On the other hand, since the solubility in an organic solvent is low and precipitation occurs in a high-concentration ethanol solution, blending into a composition having a high ethanol concentration is difficult. For example, as disclosed in Japanese Patent Application Laid-Open No. 2004-269410 (Patent Document 1) by the present applicant, in an alcohol sterilization preparation containing hyaluronic acid, particularly when the ethanol concentration exceeds 70%, hyaluronic acid or Depending on the salt content, precipitation may occur.

Therefore, attempts have been made to dissolve hyaluronic acid in a high-concentration ethanol aqueous solution. For example, in Japanese Patent No. 2873847 (Patent Document 2), ethanol coexisting with an acidic mucopolysaccharide and a quaternary ammonium salt allows ethanol to be dissolved. The content of increasing the solubility in is disclosed. JP-A-2006-89388 (Patent Document 3) discloses that acetylated sodium hyaluronate having high hydrophobicity is blended in a lower alcohol sterilizing preparation with respect to sodium hyaluronate that has been conventionally used. It is described that the alcohol concentration of the preparation can be increased. However, transparent addition of hyaluronic acid or a salt thereof in a high-concentration ethanol solution has not been achieved so far without adding additives to the formulation or modifying the molecular structure of hyaluronic acid.

JP 2004-269410 A Japanese Patent No. 2873847 JP 2006-89388 A

Accordingly, an object of the present invention is to cause precipitation or turbidity derived from hyaluronic acid and / or a salt thereof even though hyaluronic acid and / or a salt thereof is blended in an aqueous preparation containing ethanol at a high concentration. It provides a clear, water-based formulation.

As a result of intensive research on hyaluronic acid to achieve the above object, the present inventor has formulated hyaluronic acid and / or a salt thereof having an average molecular weight below a specific value in an aqueous preparation containing ethanol at a high concentration. Surprisingly, the inventors have found that a transparent aqueous preparation can be obtained without precipitation or turbidity derived from hyaluronic acid and / or a salt thereof, and the present invention has been completed.

That is, the present invention
(1) Hyaluronic acid and / or a salt thereof and an aqueous preparation containing 50% or more of ethanol with respect to the whole preparation, wherein the hyaluronic acid and / or a salt thereof satisfies the following requirements: Formulation,
(A) The average molecular weight is 100,000 or less.
(B) No precipitate is observed when 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or a salt thereof.
(2) The aqueous preparation of (1), wherein the hyaluronic acid and / or salt thereof has an average molecular weight of 50,000 or less,
(3) The aqueous preparation of (1) or (2), wherein the hyaluronic acid and / or salt thereof has an average molecular weight of 20,000 or less,
(4) The hyaluronic acid and / or salt thereof has a molecular weight distribution in which the proportion of components having a molecular weight of 10,000 or less is 40% or more and the proportion of components having a molecular weight of 50,000 or more is 5% or less (2) or (3 ) Any aqueous formulation,
(5) The aqueous preparation according to any one of (1) to (4), wherein the content of the hyaluronic acid and / or a salt thereof is 0.0001 to 2%,
(6) The hyaluronic acid and / or salt thereof has an absorbance (A ₆₆₀ ) of 0.1 or less when 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or salt thereof. An aqueous preparation of any one of (1) to (5),
(7) Cosmetics containing the aqueous preparations of (1) to (6),
(8) Bactericidal preparations containing the aqueous preparations of (1) to (6),
It is.

According to the present invention, even though hyaluronic acid and / or a salt thereof is blended in an aqueous preparation containing ethanol at a high concentration, it is transparent without precipitation or turbidity of hyaluronic acid and / or a salt thereof. An aqueous formulation can be provided. Therefore, further expansion of utilization of hyaluronic acid and / or its salt can be expected.

Hereinafter, the present invention will be described in detail. In the present invention, “%” means “mass%” and “part” means “part by mass”.

The aqueous preparation of the present invention refers to a preparation that is soluble in water. In the present invention, it refers to a preparation containing 50% or more of ethanol in particular. As other components, solvents such as polyhydric alcohols and lower alcohols that can be mixed with water, thickeners and preservatives that can be dissolved in aqueous preparations. , Oily components, surfactants, pigments, fragrances, and the like can be included as long as the effects of the present invention are not impaired.

An example of other components is as follows.
Examples of the polyhydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, dipropylene glycol, glycerin, diglycerin, polyglycerin, pentylene glycol, isoprene glycol, Glucose, maltose, sucrose, fructose, xylitol, sorbitol, maltotriose, erythritol and the like can be mentioned.

Examples of the lower alcohol include methanol, propyl alcohol, isopropyl alcohol, butyl alcohol, and isobutyl alcohol.

As the thickener, for example, carboxymethylcellulose, carboxyvinyl polymer, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, xanthan gum, carrageenan, alginate, pectin, gum arabic, caraya gum, tragacanth gum, tamarind gum, agate powder, polyethylene glycol Etc.

Examples of the preservative include parabens such as methylparaben, ethylparaben, propylparaben, and butylparaben, phenoxyethanol, and the like.

Examples of oil components include oil-soluble vitamins (vitamin A, vitamin D, vitamin E, vitamin F, vitamin K group vitamins, pyridoxine dicaprylate, pyridoxine dipalmitate, ascorbyl dipalmitate, ascorbyl monopalmitate, mono Vitamin derivatives such as ascorbyl stearate), oil-soluble hormones (estradiol, ethinylestradiol, estrone, diethylstilpestrol, etc.), oil-soluble pigments (sudan III, fluorescene, etc.), oil-soluble ultraviolet absorbers (oxybenzone, 2,5-diisopropyl cinnamate methyl), animal and vegetable oils (animal and vegetable oils such as avocado oil and olive oil, derivatives such as diglycerin fatty acid ester), higher aliphatic hydrocarbons (squalane, squalene, liquid paraffin, etc.), Grade fatty acids (stearic acid, isostearic acid, oleic acid, etc.), higher alcohols (stearyl alcohol, isostearyl alcohol, octyldodecanol, etc.), ester oils (isopropyl myristate, octyldodecyl myristate, etc.), sterols such as cholesterol And sphingolipids (ceramide, cerebroside, sphingomyelin, etc., and derivatives thereof).

Examples of the surfactant include polyoxyethylene [hereinafter abbreviated as POE-] alkyl ether (POE-oleyl ether, POE-cetyl ether, etc.), POE-branched alkyl ether (POE-octyldodecyl alcohol, POE-2-). Decyltetradecyl alcohol, etc.), sorbitan esters (sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, etc.), POE-sorbitan esters (POE-sorbitan monooleate, POE-sorbitan monoisostearate, POE-) Sorbitan monolaurate, etc.), glycerin fatty acid esters (glyceryl monooleate, glyceryl monostearate, glyceryl monomyristate, etc.), POE-glycerin fatty acid esters (POE-glycerin) Monooleate, POE-glyceryl monostearate, POE-glyceryl monomyristate, etc.), POE-dihydrocholesterol ether, POE-hardened castor oil fatty acid ester (POE-hardened castor oil, POE-hardened castor oil isostearate, etc.), POE -Alkyl aryl ether (POE-octylphenol ether, etc.), glycerol ether (glycerol monoisostearate, glycerol monomyristate, etc.), POE-glycerol ether (POE-glycerol monoisostearate, POE-glycerol monomyristate, etc.), Polyglycerin fatty acid ester (diglyceryl monostearate, decaglyceryl isostearate, decaglyceryl decaisostearate distearyl diisostearate Etc.), salts of higher fatty acids (myristic acid, stearic acid, palmitic acid, behenic acid, isostearic acid, oleic acid, etc.) (potassium, sodium, diethanolamine, triethanolamine, etc.), phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidine) Acid, phosphatidylinositol, phosphatidylserine, phosphatidylglycerol, and their lysates).

The aqueous preparation of the present invention has an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less, and 9 parts of ethanol with respect to 1 part of an aqueous solution of 2% hyaluronic acid and / or a salt thereof. It is characterized by containing hyaluronic acid and / or a salt thereof in which no precipitate is observed when added. By using the above hyaluronic acid and / or salt thereof, an ethanol-containing aqueous preparation that does not cause precipitation or turbidity derived from hyaluronic acid and / or salt thereof can be obtained. In the present invention, precipitation of hyaluronic acid and / or a salt thereof can be remarkably prevented in an aqueous preparation containing 50% or more, preferably 70% or more of ethanol with respect to the whole preparation, which is effective.

Here, “hyaluronic acid” refers to a polysaccharide having one or more repeating structural units composed of disaccharides of glucuronic acid and N-acetylglucosamine. The “hyaluronic acid salt” is not particularly limited, but is preferably a food or pharmaceutical acceptable salt, for example, sodium salt, potassium salt, calcium salt, zinc salt, magnesium salt, ammonium salt, etc. Is mentioned.

The average molecular weight of hyaluronic acid or a salt thereof used in the present invention is 100,000 or less, preferably 50,000 or less, and more preferably 20,000 or less. When the average molecular weight of hyaluronic acid or a salt thereof is larger than the above value, precipitation or turbidity of hyaluronic acid and / or a salt thereof occurs during storage when the hyaluronic acid and / or a salt thereof is formulated in an ethanol-containing aqueous preparation. Because. In the present invention, the lower limit of the average molecular weight is not limited, but an average molecular weight of 5,000 or more is preferable in consideration of industrial productivity of hyaluronic acid or a salt thereof having a high degree of purification.

The measurement method of the average molecular weight prescribed | regulated by this invention is demonstrated.

（式２）

The average molecular weight defined in the present invention is a molecular weight calculated from the intrinsic viscosity of hyaluronic acid and / or a salt thereof. In order to determine the intrinsic viscosity of hyaluronic acid and / or its salt, first, an aqueous solution of a plurality of hyaluronic acid and / or its salt is prepared, and hyaluronic acid and / or its The specific viscosity and the reduced viscosity are calculated based on the following formulas 1 and 2 from the flowing seconds of the aqueous salt solution and the flowing seconds of the solvent. At this time, an Ubbelohde viscometer having a coefficient such that the number of seconds of flow is 200 to 1000 seconds is used. The concentration of the aqueous solution of hyaluronic acid and / or a salt thereof is selected to be suitable for the measuring instrument. The measurement is performed in a constant temperature water bath at 30 ° C. so that there is no temperature change.
(Formula 1)

(Formula 2)

Next, for each aqueous solution of hyaluronic acid and / or salt thereof, a calibration curve was prepared by plotting the obtained reduced viscosity on the vertical axis and the hyaluronic acid and / or salt concentration in terms of dry matter on the horizontal axis, By extrapolating hyaluronic acid and / or its salt concentration to zero, the intrinsic viscosity of hyaluronic acid and / or its salt is obtained. Based on the following formula 3, the average molecular weight M can be determined from the intrinsic viscosity of hyaluronic acid and / or a salt thereof.
(Formula 3)
Intrinsic viscosity (dL / g) = K′M ^α
(In the above formula 3, K ′ = 0.036 and α = 0.78.)

The hyaluronic acid and / or salt thereof used in the present invention has an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less, It is preferable that the ratio is 40% or more and the ratio of components having a molecular weight of 50,000 or more is 5% or less. By using hyaluronic acid and / or a salt thereof having such a molecular weight distribution, precipitation of hyaluronic acid and / or a salt thereof is difficult to occur, especially when blended in a high concentration in an ethanol-containing aqueous preparation. is there.

The molecular weight distribution defined in the present invention can be obtained by liquid chromatography analysis of hyaluronic acid and / or a salt thereof using a gel filtration column. Hyaluronic acid and / or a salt thereof is a mixture of a plurality of components having different molecular weights depending on the number of repeating structural units (N-acetyl-D-glucosamine and D-glucuronic acid). Accordingly, by performing liquid chromatography analysis on an aqueous solution of hyaluronic acid and / or a salt thereof using a gel filtration column, the components constituting hyaluronic acid and / or the salt thereof can be separated by molecular size.

The molecular weight distribution of hyaluronic acid and / or a salt thereof in the present invention is determined by HPLC analysis device (trade name “Alliance PDA System”, manufactured by Nippon Waters Co., Ltd.) and gel filtration column (trade name “Diol-120”, manufactured by YMC Co., Ltd.). ) And a 0.1% (w / v) aqueous solution of hyaluronic acid and / or its salt as an analytical sample, and this analytical sample can be measured by liquid chromatography analysis.

The conditions for liquid chromatography analysis are as follows.
Column temperature: 40 ° C
Flow rate: 1 mL / min Injection volume of 0.1% (w / v) aqueous solution of hyaluronic acid and / or its salt: 20 μL
Mobile phase: 0.003 mol / L phosphate buffer (containing 0.15 mol / L NaCl, pH 7.0)
Ultraviolet detector: measured at λ = 210 nm In the liquid chromatography using the gel filtration column according to the present invention, the longer the retention time, the lower the molecular weight. In order of decreasing retention time, N-acetylglucosamine, D-glucuronic acid, hyaluronic acid (disaccharide: one repeating structural unit), hyaluronic acid (tetrasaccharide: two repeating structural units), hyaluronic acid (hexasaccharide: repeating structure) Peaks of 3 units), hyaluronic acid (octasaccharide: 4 repeating structural units)... Are obtained. The retention time and molecular weight at each peak are calculated, and a calibration curve of this retention time versus molecular weight is obtained (Formula 4).

In formula 4 described later, x represents a retention time, and y represents a molecular weight. Next, from the calibration curve shown in Equation 4, a retention time corresponding to a predetermined molecular weight (10,000 or 50,000) is calculated, and by dividing the peak by these retention times, the components in the predetermined molecular weight range are calculated. Find the percentage. The molecular weight indicated by each peak is referred to the peak in the chromatogram obtained by liquid chromatography analysis of the smallest structural unit (disaccharide) of hyaluronic acid and / or its salt with a known molecular weight in the same manner. To be identified.

For example, the ratio of components having a molecular weight of 10,000 or less is calculated by calculating a retention time corresponding to a molecular weight of 10,000 from the calibration curve shown in Equation 4, and dividing the absorption area of the component after this retention time by the total absorption area. Can be sought. Similarly, for the proportion of components having a molecular weight of 50,000 or more, the retention time corresponding to the molecular weight of 50,000 is calculated from the calibration curve shown in Equation 4, and the absorption area of the component is divided by the total absorption area before this retention time. It can ask for.

As an example, Table 1 shows the relationship between the number of repeating units of each molecular weight component obtained from the chromatogram shown in FIG.

(Formula 4)
y = -21.4x < ³ > + 1296.2x < ² > -267477.1x + 189427.1

A typical method for producing a low molecular weight hyaluronic acid and / or a salt thereof having an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less used in the present invention will be described below. In addition, the manufacturing method of the low molecular hyaluronic acid and / or its salt used by this invention is not limited to this.

Hyaluronic acid and / or a salt thereof (hereinafter also referred to as “raw hyaluronic acid and a salt thereof”), which is a raw material for the low molecular hyaluronic acid and / or salt thereof, is generally a living organism such as a chicken crown, umbilical cord, eyeball, skin, cartilage, It is obtained by extracting (and purifying as necessary) these raw materials from a culture solution obtained by culturing hyaluronic acid-producing microorganisms such as tissues or microorganisms belonging to the genus Streptococcus. For example, the molecular weight of the raw material hyaluronic acid and / or its salt extracted from a chicken crown is usually 2 million to 8 million.

The low molecular weight hyaluronic acid and / or salt thereof is produced by dispersing the raw material hyaluronic acid and / or salt thereof in an acidic water-containing medium and removing the acidic water-containing medium by heating and drying. be able to. Here, the degree of low molecular weight can be adjusted by adjusting the stirring speed and stirring time. Moreover, by performing the above-mentioned dispersion | distribution process on 30-70 degreeC on the heating conditions for less than 1 hour, it can be made low molecular weight stably to the target molecular weight. More specifically, the dispersion medium obtained by adding the powdered raw material hyaluronic acid and / or salt thereof to the acidic water-containing medium while stirring can be heated. Alternatively, the acidic water-containing medium may be heated in advance, and raw material hyaluronic acid and / or a salt thereof may be added thereto to maintain the temperature.

In the above production method, the water-containing medium refers to a dispersion medium of hyaluronic acid and / or a salt thereof containing water. The medium that can be used as the water-containing medium preferably has low solubility of hyaluronic acid and / or a salt thereof. The medium that can be used as the water-containing medium is not particularly limited, but for example, a liquid that has a property of being dissolved in water and that can be used in the production process of food or medicine is preferable. Examples of the medium that can be used as the water-containing medium include alcohol-based media (for example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol), ketone-based media (for example, acetone, methyl ethyl ketone), tetrahydrofuran, acetonitrile, and the like. These can be used alone or in combination. Among these, it is preferable that it is at least 1 sort (s) chosen from methanol, ethanol, and acetone at the point of the low boiling point and a price. The water content in the water-containing medium is not particularly specified, but if the water content is large, the hyaluronic acid and / or salt thereof cannot be maintained in a dispersed state and is dissolved in the water-containing medium, which may lead to a decrease in yield. Therefore, the ratio of water to the total amount of the water-containing medium is preferably 40% capacity or less, more preferably 30% capacity or less.

Moreover, in the said manufacturing method, as what is used in order to make a water-containing medium acidic, acids, such as hydrochloric acid and a sulfuric acid, and acidic cation exchange resin are mentioned, for example.

A method of converting a low molecular weight hyaluronic acid having an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less into a hyaluronic acid salt, and conversion from the low molecular hyaluronic acid salt to hyaluronic acid The method to do is not specifically limited. As a method for converting the low molecular weight hyaluronic acid into a hyaluronic acid salt, for example, an alkaline aqueous solution (for example, an aqueous solution of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, ammonium hydroxide, etc.) is used. And processing method. Examples of the method for converting the low molecular weight hyaluronic acid salt into hyaluronic acid include, for example, a method of treating with an acid aqueous solution (for example, an aqueous solution of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.), an acidic cation, and the like. A method using an exchange resin may be mentioned.

In the ethanol-containing aqueous preparation of the present invention, the blending amount of low molecular weight hyaluronic acid and / or a salt thereof having an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less obtained by the above-described production method is 0.0001 to 2% is preferable, and 0.001 to 0.5% is more preferable. If the blending amount of hyaluronic acid and / or salt thereof exceeds the above range, precipitation or turbidity of hyaluronic acid and / or salt thereof may occur, and the transparent aqueous preparation that is the object of the present invention cannot be obtained. It is not preferable. On the other hand, if the amount is less than the above range, the moisturizing effect of hyaluronic acid and / or a salt thereof hardly appears and the commercial value is lowered, which is not preferable.

The method for producing the aqueous preparation of the present invention comprises the above-mentioned low molecular weight hyaluronic acid and / or salt thereof having an average molecular weight of 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less, which is an essential ingredient of the present invention. If it is a method including the process of mix | blending with an ethanol containing aqueous formulation, it will not specifically limit. However, since hyaluronic acid and / or its salts are difficult to dissolve in high-concentration ethanol, the method of first dissolving in water or low-concentration ethanol and then diluting with high-concentration ethanol is not recommended. Turbidity is less likely to occur and is preferable.

The cosmetic containing the aqueous preparation of the present invention is not particularly limited, but the effect of the present invention is particularly effectively obtained by including the aqueous preparation of the present invention in a cosmetic containing a high concentration of ethanol. Can be used. Cosmetics containing high concentrations of ethanol, such as astringent lotions, cleaning lotions, pre-shave lotions, shaving lotions, after shave lotions, after sun lotions, body lotions, hair tonics, hair sprays, deodorant sprays, etc. Fragrance cosmetics such as perfume, mouthwash, insect repellent spray and the like.

The bactericidal preparation containing the aqueous preparation of the present invention refers to a bactericidal preparation for external use, a food disinfectant, a bacteriostatic agent, and the like that can be used at medical sites, food manufacturing sites, and the like. In addition to being able to use the aqueous preparation of the present invention as it is as a bactericidal preparation, other components such as substances having a bacteriostatic effect, thickeners, moisturizers, other excipients and the like can be used as long as the effects of the present invention are not impaired. It can also be contained.

The average molecular weight used in the present invention is 100,000 or less, preferably 50,000 or less, more preferably 20,000 or less, and 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or a salt thereof. An aqueous preparation using low molecular weight hyaluronic acid and / or a salt thereof, in which no precipitate is observed, will be specifically described based on examples and the like. The present invention is not limited to these.

[Preparation Example 1] Hyaluronic acid with an average molecular weight of 9000 In this preparation example, a sodium hyaluronate (hereinafter also referred to as “HANa”) fine powder extracted and purified from a chicken crown was prepared as a raw material. The raw material HANa had an average molecular weight of about 2.1 million and a purity of 97%.

First, a 300 L tank equipped with a stirrer and a jacket was filled with 110 L of 0.5% sulfuric acid-containing 80% water-containing acetone (acidic water-containing medium), and heated with stirring to a liquid temperature of 60 ° C. Here, 80% water-containing acetone contains 80 (w / w)% acetone and 20 (w / w)% water, and 80% acetone containing 0.5% sulfuric acid contains 0% sulfuric acid. 0.5 (w / w)% and 80% water-containing acetone is contained 99.5 (w / w)%. After reaching 60 ° C., 6 kg of the prepared raw material HANa fine powder was charged into the tank while stirring. While heating so as to maintain the temperature of the sulfuric acid-containing hydrous acetone at 60 ° C., the raw material HANa fine powder was stirred so as to be in a dispersed state.

Next, after stirring for 15 minutes and allowing to stand, the supernatant sulfuric acid-containing water-containing acetone was removed by decantation to obtain a precipitate. To the obtained precipitate, 110 L of 80% water-containing acetone containing 0.5% sulfuric acid previously heated to 60 ° C. was added, and similarly stirred for 15 minutes while heating to 60 ° C. This operation was repeated a total of 3 times.

Next, 110 L of 80% water-containing acetone was added to the precipitate obtained after removing sulfuric acid-containing water-containing acetone, and stirring was performed for 15 minutes for the purpose of removing sulfuric acid. This operation was repeated until no sulfuric acid remained.

Furthermore, water-containing acetone was removed by decantation to obtain a residue. The residue was further centrifuged to remove water-containing acetone and then heat-dried at 70 ° C. under reduced pressure for 12 hours using a vacuum dryer.

Through the above steps, 5.3 kg of hyaluronic acid (yield: about 88%) was obtained as white fine powder. This hyaluronic acid has an average molecular weight of 9,000 converted from intrinsic viscosity, and in the molecular weight distribution, the proportion of components having a molecular weight of 10,000 or less is 49% or more and the proportion of components having a molecular weight of 50,000 or more is 0.5%. there were.

[Preparation Example 2] Sodium hyaluronate having an average molecular weight of 35,000 In this preparation example, the HANa fine powder used in Preparation Example 1 was prepared as a raw material.

First, a 300 L tank equipped with a stirrer was filled with 110 L of 73% water-containing ethanol (acidic water-containing medium) containing 2% hydrochloric acid, and heated to 50 ° C. while stirring. Here, 73% hydrous ethanol contains 73 (w / w)% ethanol and 27 (w / w)% water, and 73% hydrous ethanol containing 2% hydrochloric acid contains 2 ( w / w)%, and it contains 98% (w / w)% of 73% water-containing ethanol. After the temperature reached 50 ° C., 6 kg of the prepared raw material HANa fine powder was charged into the tank while stirring. While heating to maintain the temperature of the hydrochloric acid-containing aqueous ethanol at 50 ° C., the raw material HA powder was stirred so as to be in a dispersed state.

Next, after stirring for 15 minutes and allowing to stand, the supernatant hydrochloric acid-containing aqueous ethanol was removed by decantation to obtain a precipitate. To the obtained precipitate, 110 L of 73% water-containing ethanol containing 2% hydrochloric acid previously heated to 50 ° C. was added, and similarly stirred for 15 minutes while heating to 50 ° C. This operation was repeated a total of 3 times.

Next, 110 L of 73% aqueous ethanol was added to the precipitate obtained after removing the hydrochloric acid-containing aqueous ethanol, and the mixture was stirred for 15 minutes for the purpose of removing hydrochloric acid. This operation was repeated until no hydrochloric acid remained.

Furthermore, the water-containing ethanol was removed by decantation to obtain a residue. The residue was further centrifuged to remove water-containing ethanol and then dissolved again in 100 L of water in the same tank to prepare an aqueous solution. While stirring the aqueous solution, a 20% sodium hydroxide solution was added to the aqueous solution to adjust the pH to 6.5. Subsequently, this aqueous solution was spray-dried with a spray dryer.

By the following steps, 5.1 kg (yield of about 85%) of low molecular weight sodium hyaluronate as a white fine powder was obtained. This hyaluronic acid has an average molecular weight converted to intrinsic viscosity of 35,000, and in the molecular weight distribution, the proportion of components having a molecular weight of 10,000 or less is less than 40% and the proportion of components having a molecular weight of 50,000 or more is more than 1%. Met.

[Example 1]
An aqueous preparation having the following composition was prepared. That is, the hyaluronic acid having an average molecular weight of 9,000 obtained in Preparation Example 1 was dissolved in fresh water to a concentration of 2%, 1 part of this hyaluronic acid aqueous solution was taken, ethanol and fresh water were added thereto, and hyaluronic acid was added. An aqueous preparation was prepared so that the acid concentration was 0.2% and the ethanol concentration was 70 to 90%.

<Combination ratio>
Ethanol 70% / 80% / 90%
Hyaluronic acid (Preparation Example 1) 0.2%
Shimizu Residues ――――――――――――――――――――――――――――――――――――
100%

[Example 2]
An aqueous preparation was prepared in the same manner as in Example 1 except that sodium hyaluronate having an average molecular weight of 35,000 obtained in Preparation Example 2 was used in place of the hyaluronic acid used in the aqueous preparation of Example 1. .

Example 3
Instead of the hyaluronic acid used in the aqueous preparation of Example 1, hyaluronic acid having an average molecular weight of 100,000 (trade name “Hyaluron Sun HA-L510”, manufactured by QP Corporation) was used in the same manner as in Example 1. An aqueous formulation was made.

[Comparative Example 1]
An aqueous preparation was prepared in the same manner as in Example 1 except that sodium hyaluronate having an average molecular weight of 400,000 was used instead of hyaluronic acid used in the aqueous preparation of Example 1.

[Comparative Example 2]
Instead of the hyaluronic acid used in the aqueous preparation of Example 1, hyaluronic acid having an average molecular weight of 800,000 (trade name “Hyaluron San HA-F”, manufactured by QP Corporation) was used in the same manner as in Example 1. An aqueous formulation was made.

[Comparative Example 3]
Instead of the hyaluronic acid used in the aqueous preparation of Example 1, hyaluronic acid having an average molecular weight of 1.3 million (trade name “Hyaluronic Sun HA-LQ”, manufactured by QP Corporation) was used in the same manner as in Example 1. An aqueous formulation was made.

[Comparative Example 4]
Instead of the hyaluronic acid used in the aqueous preparation of Example 1, hyaluronic acid having an average molecular weight of 9000 and hyaluronic acid having an average molecular weight of 400,000 (trade name “Hyaluronic Sun HA-LF”, manufactured by QP Corporation) of Preparation Example 1 ), And an aqueous preparation was prepared in the same manner as in Example 1 except that hyaluronic acid adjusted to have an average molecular weight of 100,000 was used.

[Test Example 1]
About the state of the aqueous formulation obtained in Examples 1-3 and Comparative Examples 1-4, the presence or absence of precipitation and turbidity was evaluated visually. The evaluation results are shown in Table 2.

From Table 2, the aqueous preparations of Examples 1 to 3 containing the hyaluronic acid and / or salt thereof having an average molecular weight of 100,000 or less according to the present invention are hyaluronic acid having an average molecular weight of more than 100,000 at any ethanol concentration. And / or the hyaluronic acid and / or its salt which were confirmed in Comparative Examples 1-3 which mix | blended the salt, and there was no precipitation, and it was favorable property. On the other hand, in Comparative Example 4, the average molecular weight of hyaluronic acid was 100,000, but when 9 parts of ethanol was added to 1 part of 2% hyaluronic acid aqueous solution, precipitates were observed. In this case, a transparent preparation was not obtained. Further, in the aqueous preparation of Example 1 or 2 in which hyaluronic acid having an average molecular weight of 50,000 or less and / or a salt thereof was blended, no precipitation was observed and no turbidity was observed even when the ethanol concentration was 90%. . From the above, in order to stably contain hyaluronic acid and / or a salt thereof without causing precipitation in an aqueous preparation containing a high concentration of ethanol, specifically, an aqueous preparation containing 50% or more of ethanol, And / or a salt thereof having an average molecular weight of 100,000 or less and a precipitate that is not observed when 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or a salt thereof. It is understood that an average molecular weight of 50,000 or less is particularly preferable.

[Test Example 2]
The absorbance (A ₆₆₀ ) of the aqueous preparations obtained in Examples 1 to 3 and Comparative Example 1 was measured. The results are shown in Table 3.

From Table 3, the aqueous formulations of Examples 1 to 3 was blended average molecular weight of 100,000 or less hyaluronic acid and / or salts thereof of the present invention, the absorbance _{(A 660)} was less than 0.1Abs. Further, the aqueous preparation of Example 1 or 2 containing hyaluronic acid having an average molecular weight of 50,000 or less and / or a salt thereof tended to have a low absorbance (A ₆₆₀ ) value even when the ethanol concentration was high. In particular, blending with hyaluronic acid having an average molecular weight of 20,000 or less, a molecular weight distribution in which the proportion of components with a molecular weight of 10,000 or less is 40% or more, and the proportion of components with a molecular weight of 50,000 or more is 5% or less The absorbance (A ₆₆₀ ) value of the aqueous preparation of Example 1 hardly increased even when the ethanol concentration was 90%.

Example 4
Using the aqueous preparation obtained in Example 1, a pre-shave lotion having the following composition was produced. The resulting pre-shave lotion was a clear lotion without precipitation and turbidity.
<Combination ratio>
Aqueous preparation (Example 1, ethanol concentration 90%) 83.5%
Zinc sulfocoborate 1.0%
Isopropyl myristate 7.0%
Isopropyl palmitate 8.0%
Fragrance 0.5%
――――――――――――――――――――――――――――――――
100%

Example 5
Using the aqueous preparation obtained in Example 2, a deodorant lotion having the following composition was prepared. The resulting deodorant lotion was a clear lotion without precipitation and turbidity.
<Combination ratio>
Aqueous preparation (Example 2, ethanol concentration 90%) 80.0%
Zinc paraphenol sulfonate 2.0%
Dimethylpolysiloxane 13.0%
Propylene glycol 3.0%
Triclosan 0.1%
Polyoxyethylene (40) hydrogenated castor oil 0.5%
Fragrance 0.5%
Shimizu Residue ――――――――――――――――――――――――――――――――
100%

Example 6
Using the aqueous preparation obtained in Example 3, an external bactericidal preparation having the following composition was prepared. The obtained bactericidal preparation was a transparent preparation without precipitation and turbidity.
<Combination ratio>
Aqueous preparation (Example 3, ethanol concentration 80%) 96.5%
Isopropyl alcohol 3.5%
――――――――――――――――――――――――――――――――
100%

FIG. 1 shows an example of a chromatogram of hyaluronic acid.

Claims (8)

An aqueous preparation containing 50% or more of hyaluronic acid and / or a salt thereof and ethanol with respect to the whole preparation, wherein the hyaluronic acid and / or a salt thereof satisfies the following requirements.
(A) The average molecular weight is 100,000 or less.
(B) No precipitate is observed when 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or a salt thereof. The aqueous preparation according to claim 1, wherein the hyaluronic acid and / or a salt thereof has an average molecular weight of 50,000 or less. The aqueous preparation according to claim 1 or 2, wherein the hyaluronic acid and / or salt thereof has an average molecular weight of 20,000 or less. The aqueous solution according to claim 2 or 3, wherein the hyaluronic acid and / or salt thereof has a molecular weight distribution in which the proportion of components having a molecular weight of 10,000 or less is 40% or more and the proportion of components having a molecular weight of 50,000 or more is 5% or less. Formulation. The aqueous preparation according to any one of claims 1 to 4, wherein a content of the hyaluronic acid and / or a salt thereof is 0.0001 to 2%. The hyaluronic acid and / or salt thereof has an absorbance (A ₆₆₀ ) of 0.1 Abs or less when 9 parts of ethanol is added to 1 part of an aqueous solution of 2% hyaluronic acid and / or salt thereof. The aqueous preparation according to any one of claims 1 to 5. A cosmetic comprising the aqueous preparation according to claim 1. A bactericidal preparation containing the aqueous preparation of claims 1 to 6.

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