CN110734506A

CN110734506A - Preparation method of sodium hyaluronate

Info

Publication number: CN110734506A
Application number: CN201911134874.5A
Authority: CN
Inventors: 刘守垒; 惠吉阳; 何斌; 秦会利; 王海泉; 张朋; 赵鹏; 解增朋; 李文源; 冯展谱; 苗为超; 万华伟; 郑成红; 卢滢滢; 王勇; 韩雪; 郭玲
Original assignee: SHANDONG TOPSCIENCE BIO-TECH CO LTD
Current assignee: SHANDONG TOPSCIENCE BIO-TECH CO LTD
Priority date: 2019-11-19
Filing date: 2019-11-19
Publication date: 2020-01-31

Abstract

The invention belongs to the field of biological macromolecule preparation, and relates to a preparation method of sodium hyaluronate, which comprises the steps of precipitating a solution containing hyaluronic acid or sodium hyaluronate with an ethanol solution with the pH value of 7.2-7.8, and drying after precipitation separation to obtain the sodium hyaluronate.

Description

Preparation method of sodium hyaluronate

Technical Field

The invention belongs to the field of preparation of biological macromolecules, and relates to a preparation method of stable sodium hyaluronate.

Background

The sodium hyaluronate is a natural biological molecule universally existing in skin and other tissues, has excellent moisturizing effect, is internationally called as an ideal natural moisturizing factor, and is a substance with the best moisturizing performance for cosmetics, which is found in nature at present.

Disclosure of Invention

Aiming at the problem of poor storage stability of the existing sodium hyaluronate, the invention provides a preparation method of kinds of stable sodium hyaluronate, which has good storage stability.

In order to achieve the purpose, the invention adopts the following technical scheme.

A preparation method of sodium hyaluronate comprises the following steps:

(1) precipitating the solution containing hyaluronic acid or sodium hyaluronate with ethanol solution with pH of 7.2-7.8;

(2) and (4) drying after separating precipitates to obtain the sodium hyaluronate.

The content of the solution containing hyaluronic acid or sodium hyaluronate is 3-5 g/L.

The concentration of ethanol in the ethanol solution is 85-98% v/v.

And the pH of the ethanol is adjusted by acid or alkali. Preferably, the pH of the ethanol solution is 7.4 to 7.8.

The step (1) can be repeated for a plurality of times, and the repetition times are determined according to the purity of the dried sodium hyaluronate. Preferably, the number of precipitations is 1 to 3.

In the step (2), the purity of the sodium hyaluronate is not less than 95 wt%.

Preferably, impurity removal steps such as ion replacement, protein removal, decoloration, small molecule removal and the like can be further included between the step (1) and the step (2).

sodium hyaluronate obtained by the above method, wherein the sodium hyaluronate is 0.1% water soluble and has a pH of 6.9-7.5.

The invention has the following advantages:

according to the preparation method of the sodium hyaluronate, provided by the invention, the pH value of the product is adjusted in the ethanol precipitation process, so that the final product can achieve a stable storage period, and the molecular weight is basically unchanged. The method of the invention has simple operation, no additional purification step, low cost and suitability for industrial production.

Detailed Description

The present invention is further illustrated at in the following examples, which should not be construed as limiting the invention.

Example 1 preparation of sodium hyaluronate

(1) Precipitating 0.4% sodium hyaluronate solution with 2 volume times of different 95% v/v ethanol solutions, and performing solid-liquid separation to obtain precipitate I;

(2) adding water into the precipitate I for redissolving, then precipitating by using 95% v/v ethanol solution with different pH values, and carrying out solid-liquid separation to obtain a precipitate II, wherein the volume of the ethanol solution is 2 times that of the precipitate I;

(3) precipitate II was dehydrated, dried and pulverized to obtain sodium hyaluronate samples 1-10.

The sodium hyaluronate sample prepared above was prepared into a 0.1% solution, and the pH of the solution was measured at room temperature using a pH meter. The results are shown in table 1:

TABLE 1 pH of ethanol solution and product solution during preparation

。

Example 2 stability assay of sodium hyaluronate

The product prepared in example 1 was formulated into a 1% solution, and the viscosity of the solution was measured initially after preparation, after 7 days of storage at 50 ℃ and after 14 days of storage at 50 ℃ using a Hill viscometer, respectively, as follows:

taking solution of different samples, taking 1 planimetric viscometer with capillary diameter of 2.0mm, accurately recording the outflow time of liquid level from the measuring line 1 to the measuring line 2 by using a stopwatch, repeatedly measuring for 3 times without reloading the sample, wherein the difference between the measured value and the average value does not exceed the average value +/-0.25%, additionally taking parts of test sample solution, and calculating the total average value obtained by sampling twice in sequence according to the following formula to obtain the dynamic viscosity of the test sample (the dynamic viscosity of the test sample is measured by using the viscosity of the test sample, wherein the viscosity of the test sample is obtained by using the following formulaη）：

η=Kt

In the formula (I), the compound is shown in the specification,

Kis a viscometer constant, mm²/s²(ii) a In this experiment, 1.340;

tfor measured average outflow time，s；

The degradation rate of sodium hyaluronate was calculated according to the following formula and the results are shown in table 2:

degradation rate (%) = (initial viscosity-viscosity after n days)/initial viscosity × 100%.

Table 2 viscosity of different sodium hyaluronate samples

。

As can be seen from the data in Table 2, the samples 5-8 showed less than 15% degradation after 7 days of storage and less than 30% degradation after 14 days of storage, showing better stability of the samples precipitated with alcohol at pH 7.2-7.8. In particular, samples 6-8, which had a degradation rate of less than 20% after 14 days of storage, demonstrated better stability of the samples precipitated with alcohol at pH 7.4-7.8.

Example 3 preparation of sodium hyaluronate

(1) Precipitating the hyaluronic acid fermentation liquor from which the thalli are removed by using a 95% v/v ethanol solution with the pH value of 7.7 which is 2 times of the volume of the hyaluronic acid fermentation liquor, and carrying out solid-liquid separation to obtain a precipitate I;

(2) dissolving the precipitate I in water, adding sodium chloride with the volume of 2% of the solution, adding active carbon with the volume of 0.5% of the solution to adsorb impurities, cooling, and performing pressure filtration to obtain a sodium hyaluronate solution;

(3) precipitating the sodium hyaluronate solution with 2 volume times of 95% v/v ethanol solution with pH of 7.7, and performing solid-liquid separation to obtain a precipitate II;

(4) precipitate II was dehydrated, dried and pulverized to obtain a sodium hyaluronate sample. The pH of its 0.1% solution was 7.25; the 1% solution had a degradation rate of 9.55% in 7 days and 17.02% in 14 days.

Claims

1, A preparation method of sodium hyaluronate, which is characterized by comprising the following steps:

2. The method according to claim 1, wherein the content of hyaluronic acid in the solution containing sodium hyaluronate is 3 to 5 g/L.

3. The method according to claim 1, wherein the concentration of ethanol in the ethanol solution is 85 to 98% v/v.

4. The method according to claim 1, wherein the step (1) is performed 1 to 3 times.

5. The method according to claim 1, wherein the purity of the sodium hyaluronate in step (2) is not less than 95 wt%.

6. The preparation method according to claim 1, characterized by further comprising ion replacement and impurity removal steps between the step (1) and the step (2).

7, sodium hyaluronate obtainable by the process of any of claims 1 to 6 to .