CN113018203A

CN113018203A - Aqueous retinol dispersion, method for preparing same and use thereof

Info

Publication number: CN113018203A
Application number: CN202011551117.0A
Authority: CN
Inventors: 祝文莉; 吕强
Original assignee: Suzhou Zhiming Zhixin Biotechnology Co ltd
Current assignee: Suzhou Zhiming Zhixin Biotechnology Co ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-06-25

Abstract

The invention provides a retinol water dispersion solution which is composed of retinol, high-crystal silk protein nano-fibers and water. The application also provides a preparation method of the retinol water dispersion solution. In the process of preparing the retinol water dispersion solution, the retinol is attached to the surface of the high-crystal silk protein nanofiber so as to be brought into a water solution system; the special stability and the dispersibility in a water phase of the high-crystal silk protein nanofiber enable the retinol to stably exist in a water-soluble system without precipitation or aggregation, the concentration of the retinol can reach more than 5%, the activity of the loaded retinol is kept well, the retinol is easy to be absorbed by cells and tissues, and the retinol can provide appropriate mother liquor for different fields of cosmetics, medicines and the like, so that the retinol has a wide market prospect.

Description

Aqueous retinol dispersion, method for preparing same and use thereof

Technical Field

The invention relates to the technical field of cosmetics and medical cosmetology, in particular to a retinol water dispersion solution, a preparation method and application thereof.

Background

Retinol has various biological properties such as cell behavior regulation, wrinkle resistance, oxidation resistance and hair follicle regeneration promotion, and is an important functional component in various fields such as cosmetics and medical cosmetology. However, retinol is insoluble in water, but soluble in organic solvents such as methanol and ethanol, which greatly limits its effective application in the fields of cosmetics and medicine.

In order to improve the practical application effect of retinol, the retinol with the highest concentration in the world is purified mainly through tween to obtain stock solution with the concentration of about 50 percent, but the retinol cannot be dispersed in a water phase, so that the application of the retinol is limited. In addition, various chemical modification methods have been used to modify retinol to improve its solubility in water, but this also results in a significant loss of retinol activity. At present, the wrapping body of the retinol is obtained by using an emulsion wrapping method in cosmetics and medical cosmetology, so that the dispersion of the retinol in water is realized, the concentration of the retinol can reach more than 10 percent, but the preparation process is complex and the price is high, and the retinol is wrapped in the wrapping body, so that the biological effect of the retinol is limited to a certain extent. Therefore, a new simple and effective way is developed to realize the stable dispersion of the retinol in the aqueous solution, and the method has huge application potential and economic value.

The high crystal silk protein nanofiber has special hydrophily and hydrophobicity. In recent years, the present group has succeeded in developing a simple active ingredient aqueous phase transfer technique by utilizing the characteristics of silk protein nanofibers, by attaching silk protein nanofibers to the surface of silk protein nanofibers from a good solvent for the active substance through good interaction between the silk protein nanofibers and different active substances, and then achieving aqueous dispersion of the active substance by utilizing the water dispersibility of the silk protein fibers. However, the above-mentioned technology mainly uses a centrifugal method to separate the good solvent of the active ingredient from water, resulting in a silk protein-active ingredient complex system in which more organic solvent remains after centrifugation, and multiple washing results in a great loss of the active ingredient and a decrease in the concentration of the active ingredient, and thus new improvements and developments of this technology are required.

Disclosure of Invention

The invention aims to provide a retinol water dispersion solution which has good stability and high concentration.

In view of the above, the present application provides a retinol aqueous dispersion solution, which is composed of retinol, high crystalline silk protein nanofibers and water.

Preferably, the concentration of the retinol in the aqueous retinol dispersion solution is more than or equal to 5 wt%.

The application also provides a preparation method of the retinol water dispersion solution, which comprises the following steps:

mixing the high-crystal silk protein nanofiber gel with a retinol organic solvent stock solution after stirring to obtain a mixed solution;

and dialyzing the mixed solution in water to obtain a retinol water dispersion solution.

Preferably, the crystallinity of the high-crystal silk protein nanofiber in the high-crystal silk protein nanofiber gel is more than 40%, the diameter of the high-crystal silk protein nanofiber gel is 10-30 nm, and the length of the high-crystal silk protein nanofiber gel is 100 nm-3 microns.

Preferably, the volume ratio of the retinol organic solvent stock solution to the high-crystal silk protein nanofiber gel is 1: 10-8: 1, the concentration of the high-crystal silk protein nanofiber gel is 0.3-5 wt%, the concentration of the retinol organic solvent stock solution is 2-55 wt%, and the organic solvent of the retinol organic solvent stock solution is tween, methanol or ethanol.

Preferably, the stirring speed of the high crystal silk protein nanofiber gel is 20-1000 rpm, and the stirring time is 10 min-48 h; the stirring speed for mixing with the retinol organic solution stock solution is 20-1000 rpm, and the time is 10 min-48 h.

Preferably, the dialysis device is a semipermeable membrane device with a molecular weight cut-off greater than 500.

Preferably, the dialysis temperature is 0-60 ℃, and the dialysis time is not less than 10 min.

Preferably, the water is deionized water, purified water or a PBS solution.

The application also provides a cosmetic which comprises the retinol water dispersion solution in the scheme or the retinol water dispersion solution prepared by the preparation method and auxiliary materials.

The application provides a retinol water dispersion solution, which takes high-crystal silk protein nano fibers as a carrier and a transfer agent, so that retinol is attached to the surfaces of the high-crystal silk protein nano fibers, and the retinol water dispersion solution with good stability and high concentration is obtained.

The application also provides a preparation method of the retinol water dispersion solution, which comprises the steps of firstly improving the viscosity of the high-crystal silk fibroin nanofiber gel through the adjustment of the concentration of silk fibroin nanofibers, then mixing the high-crystal silk fibroin nanofibers with a raw solution of a retinol organic solvent, taking water as a basic replacement solution in a dialysis mode after full action, discharging the organic solvent out of a system, utilizing the characteristic that retinol and silk fibroin cannot pass through a dialysis bag, keeping the retinol and silk fibroin in the dialysis bag, and realizing the separation of the retinol and the organic solvent on the premise of maintaining proper viscosity to obtain the high-concentration retinol water dispersion solution. The key point of the application lies in that the special hydrophilicity and hydrophobicity and the dispersibility in water of the silk fibroin nanofiber are utilized, the retinol is transferred on the surface of the silk fibroin nanofiber, the organic solvent is removed independently by a dialysis method, and finally the high-concentration retinol water dispersion solution is obtained.

Drawings

FIG. 1 is a macroscopic view of a highly concentrated aqueous retinol dispersion solution after being loaded with silk fibroin in example 4 of the present invention;

FIG. 2 is a photograph showing a comparison of the stability of an aqueous dispersion of retinol prepared in example 4 of the present invention when left at 25 ℃ for 4 weeks;

FIG. 3 is a graph showing the effect of different concentrations of retinol on cell survival, prepared in example 4 of the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In view of the problem that the solvent and water are separated in a centrifugal mode in the prior art, the method regulates the rheological property of silk protein nanofiber gel to a proper range by adjusting the concentration of high-crystal silk protein nanofibers, then mixes the silk protein nanofibers with a retinol stock solution, and after full action, uses water as a basic replacement solution in a dialysis mode, discharges tween or other retinol good solvents out of a system, and utilizes the characteristics that retinol is insoluble in water and silk protein cannot pass through a dialysis bag to realize full retention of loaded retinol silk protein and separation of the loaded retinol silk protein, tween and an organic solvent, so as to obtain a high-concentration retinol stock solution. The key point of the technology is that on the basis of deep understanding of silk protein nanofibers, firstly, the retinol is transferred from a good solvent of the retinol to the silk protein through the silk protein, then, the retinol-carrying silk protein is efficiently separated from a retinol original solvent through a dialysis method, and finally, a high-concentration retinol water dispersion solution is obtained. Specifically, the embodiment of the invention discloses a preparation method of a retinol water dispersion solution, which comprises the following steps:

In the preparation process of the retinol water dispersion solution, silk protein nanofiber is firstly adopted as a carrier and a transfer agent of the retinol, so that the method can be applied to water phase transfer of the retinol which is insoluble in water, and simultaneously, the irritation and the side effect of the retinol can be reduced. The crystallinity of the high-crystal silk protein nanofiber is more than 40%, the diameter of the high-crystal silk protein nanofiber is 10-30 nm, and the length of the high-crystal silk protein nanofiber is 100 nm-3 mu m. The concentration of the high crystalline silk fibroin nanofiber gel is 0.3-5 wt%, and more specifically, the concentration of the high crystalline silk fibroin nanofiber gel is 0.5 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2.2 wt%, 2.8 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.2 wt%, 4.8 wt%, or 5 wt%. The source of the high crystalline silk fibroin nanofiber gel is not particularly limited in this application. The stirring speed of the high-crystal silk protein nanofiber gel is 20-1000 rpm, more specifically 100-900 rpm, more specifically 300-800 rpm; the stirring time is 10 min-48 h, more specifically, the stirring time is 2-8 h, and more specifically, the stirring time is 4-8 h. The stirring can regulate and control the rheological property of the high crystal silk protein nanofiber gel.

The application then mixes the stirred high crystalline silk protein nanofiber gel with the retinol organic solvent stock solution to obtain a mixed solution. The retinol organic solvent stock solution is prepared by dissolving the retinol stock solution in an organic solvent of retinol, wherein the organic solvent is selected from Tween, methanol or ethanol. The concentration of the retinol organic solvent stock solution is 2-55 wt%, more specifically, the concentration of the retinol organic solvent stock solution is 10-50 wt%, more specifically, the concentration of the retinol organic solvent stock solution is 20-35 wt%; the good solvent can be one or more selected from ethanol, butanediol, propylene glycol, acetone and tween. The volume ratio of the retinol organic solvent stock solution to the high-crystal silk fibroin nanofiber gel is 1: 10-8: 1, and more specifically, the volume ratio of the retinol organic solvent stock solution to the high-crystal silk fibroin nanofiber gel is 1: 2-6: 1. Stirring the mixed solution at 0-50 ℃ in a dark place, wherein the stirring speed is 20-1000 rpm; more specifically, the stirring temperature is 20-40 ℃, and the stirring speed is 200-900 rpm. The stirring time is 10min to 48h, more specifically, the stirring time is 1h to 10 h. The mixing and stirring enable the retinol and the high-crystal silk protein nano-fiber to fully act, and the retinol and the high-crystal silk protein nano-fiber are transferred to the high-crystal silk protein nano-fiber from the organic solvent, so that the transfer and the carrier effect of the high-crystal silk protein nano-fiber are realized. In the above process, the volume ratio of the retinol organic solvent stock solution to the silk protein nanofiber gel and the stirring time and speed after mixing the two are the determining factors for determining the transfer efficiency.

The application then dialyses the above solution in water to obtain an aqueous retinol dispersion. The dialysis is carried out in a dialysis bag or a semi-dialysis device by putting the dialysis bag or the semi-dialysis device into water to remove the organic solvent in the mixed solution. The cut-off molecular weight of the dialysis is more than 500, the temperature of the dialysis is 0-60 ℃, the time is not less than 10min, more specifically, the cut-off molecular weight of the dialysis is 1000-5000, more specifically, the cut-off molecular weight of the dialysis is 2500-4000, and the temperature of the dialysis is 4-40 ℃; the dialysis time is 1-24 h, more specifically 3-12 h.

On the basis of the preparation method, the application also provides a retinol water dispersion solution which is prepared from retinol, high-crystal silk protein nanofiber and water.

In the present application, the concentration of retinol in the aqueous retinol dispersion solution is more than or equal to 5 wt%.

The application also provides a cosmetic which comprises the retinol water dispersion solution and auxiliary materials. The above-mentioned auxiliary materials are well known to those skilled in the art, and there is no particular limitation to this application, and the auxiliary materials may be selected from food preservatives or other novel preservatives, by way of example.

The invention aims to provide a method for preparing a high-concentration retinol water dispersion solution by taking silk protein nanofibers as a carrier and a transfer agent, loading retinol, realizing the separation of a retinol original solvent and a silk protein-retinol compound by combining a dialysis technology, obtaining the high-concentration retinol water dispersion solution and optimizing key parameters.

According to the application, through selection of the high-crystal silk protein nanofiber with a special structure, the hydrophobicity and the water dispersibility of the high-crystal silk protein nanofiber are fully utilized, so that the high-crystal silk protein nanofiber is fully combined with retinol, the retinol is transferred from an original organic phase, then the organic phase and a water phase are separated through a dialysis technology, and finally a high-concentration retinol water dispersion solution is obtained, wherein the concentration of the obtained retinol water dispersion solution is equivalent to that of a coating system, and the application requirements of cosmetics and medical cosmetology are completely met; the retinol dispersion liquid has good stability due to the interaction of silk protein and retinol, and silk protein can also reduce the side effect of retinol, reduce anaphylactic reaction caused by retinol and improve the efficacy of retinol in application; the aqueous dispersion solution of retinol can remove Tween and organic solvent, can be directly compounded with various other active ingredients, avoids the side effect of Tween and organic solvent, and is beneficial to the flexible design of cosmetic formula.

In addition, the method is realized in a water phase by adopting an easily-controlled physical mode, is simple and controllable, has good repeatability, is beneficial to keeping the activity of the active substance, is easy for large-scale production, and has wide application prospect.

For further understanding of the present invention, the aqueous retinol dispersion solution and the preparation method thereof provided by the present invention will be described in detail with reference to the following examples, and the scope of the present invention is not limited by the following examples.

In the present application, unless otherwise specified, the concentrations are mass percent concentrations.

Example 1

(1) Stirring silk protein nanofiber gel with the concentration of 2.5% at the rotating speed of 100rpm for 4 hours, adding retinol Tween stock solution with the concentration of 50% according to the volume ratio of 1:1 of the retinol Tween stock solution to the silk protein nanofiber gel, and stirring at the rotating speed of 200rpm for 6 hours at room temperature under the condition of keeping out of the sun;

(2) filling the mixed solution into a dialysis bag with the molecular weight cutoff of 3000, then putting the dialysis bag into purified water, and dialyzing for 12 hours at room temperature in a dark place;

(3) taking out the dialyzed solution from the dialysis bag, adding a preservative, and storing in dark place to obtain a retinol water dispersion solution with the concentration of 6.5%.

Example 2

(1) Stirring silk protein nano-fiber gel with the concentration of 1.2% at the rotating speed of 500rpm for 2h, adding retinol ethanol stock solution with the concentration of 25% according to the volume ratio of 2:1 of the retinol ethanol stock solution to the silk protein nano-fiber gel, and stirring at the rotating speed of 400rpm for 4h at room temperature under the condition of keeping out of the sun;

(2) filling the mixed solution into a dialysis bag with the molecular weight cutoff of 1000, then putting the dialysis bag into a PBS solution, and dialyzing for 16h at 4 ℃ in a dark place;

(3) taking out the dialyzed solution from the dialysis bag, adding a preservative, and storing in dark place to obtain a 5% retinol water dispersion.

Example 3

(1) Stirring silk protein nanofiber gel with the concentration of 2% for 6 hours at the rotating speed of 800rpm, adding retinol methanol stock solution with the concentration of 50% according to the volume ratio of 1:3 of the retinol methanol stock solution to the silk protein nanofiber gel, and stirring for 1 hour at the rotating speed of 800rpm at room temperature under the condition of keeping out of the sun;

(2) putting the mixed solution into a semipermeable membrane with the molecular weight cutoff of 5000, then adding deionized water, and dialyzing for 6 hours at 30 ℃ in a dark place;

(3) taking out the dialyzed solution from the dialysis bag, adding a preservative, and storing in dark place to obtain a 5.2% retinol water dispersion.

Example 4

(1) Stirring silk protein nano-fiber gel with the concentration of 3% for 8 hours at the rotation speed of 900rpm, adding retinol Tween stock solution with the concentration of 50% according to the volume ratio of 4:1 of the retinol Tween stock solution to the silk protein nano-fiber gel, and stirring for 2 hours at the rotation speed of 900rpm at 40 ℃ under the condition of keeping out of the sun;

(2) putting the mixed solution into a dialysis bag with the molecular weight cutoff of 1000, then putting purified water, and dialyzing for 6 hours at 4 ℃ in a dark place;

(3) taking out the dialyzed solution from the dialysis bag, adding a preservative, and storing in dark place to obtain a 7% retinol water dispersion.

Example 5

(1) Stirring silk protein nano-fiber gel with the concentration of 2% at the rotating speed of 300rpm for 3h, adding retinol ethanol stock solution with the concentration of 10% according to the volume ratio of 2:1 of the retinol ethanol stock solution to the silk protein nano-fiber gel, and stirring at the rotating speed of 100rpm for 8h at room temperature under the condition of keeping out of the sun;

(2) putting the mixed solution into a dialysis bag with the molecular weight cutoff of 2500, then putting purified water, and dialyzing for 3 hours at 40 ℃ in a dark place;

FIG. 1 is a macroscopic view of a highly concentrated aqueous retinol dispersion solution prepared in example 4 of the present invention, in which the concentration of retinol is 7%, and it can be seen that retinol is uniformly dispersed in the aqueous solution without precipitation.

FIG. 2 shows the results of stabilization of retinol prepared in example 4 at various times, and after 4 weeks at 25 ℃, there was no significant change in the color of the solution, indicating that retinol maintained activity well.

Fig. 3 is a result of the study of the cell activity by retinol of different concentrations in example 4, from which it can be seen that the side effect of retinol is significantly reduced after loading silk protein, and the survival rate of cells is improved at the same concentration, compared with retinol prepared in the conventional manner, demonstrating that the side effect of retinol can be significantly reduced after loading silk protein with retinol.

The high-concentration retinol water dispersion solution prepared by the method has good stability, does not precipitate in a water phase, keeps good bioactivity under the condition of light-shielding preservation, can obviously reduce the irritation of the retinol by the silk protein nanofiber, further improves the applicability of the retinol, can be conveniently and directly subjected to cosmetic formula design due to good water phase dispersion, and has good application prospect.

The core of the invention lies in the deep understanding of the special structure and performance of the high crystal silk protein nanofiber and the ingenious combined application of the traditional technology. According to the invention, after the silk fibroin nanofibers are used for transferring retinol from other organic phases, the characteristics that retinol is insoluble in water and silk fibroin cannot penetrate through a semipermeable membrane are fully utilized, and a dialysis method is adopted to remove organic phases such as methanol, ethanol and tween, so that retinol and silk fibroin are both kept in a dialysis bag, and the organic phases are separated by dialysis, so that the preparation problem of a high-concentration retinol water dispersion solution is successfully solved, and the application requirements of cosmetics and medical cosmetology are better met. On the basis of deep understanding of the silk protein, the breakthrough of performance is realized by combining the traditional mild physical method, the characteristics and advantages of the invention are realized, and the invention also has obvious advantages in the aspect of conversion.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The retinol water dispersion solution consists of retinol, high crystal silk protein nano fiber and water.

2. The aqueous retinol dispersion solution as defined in claim 1, wherein the concentration of retinol in the aqueous retinol dispersion solution is not less than 5 wt%.

3. A process for preparing an aqueous retinol dispersion solution as defined in claim 1, which comprises the steps of:

4. The preparation method according to claim 3, wherein the high-crystalline silk protein nanofiber gel has a crystallinity of > 40%, a diameter of 10 to 30nm, and a length of 100nm to 3 μm.

5. The preparation method according to claim 3, wherein the volume ratio of the retinol organic solvent stock solution to the high-crystalline silk protein nanofiber gel is 1: 10-8: 1, the concentration of the high-crystalline silk protein nanofiber gel is 0.3-5 wt%, the concentration of the retinol organic solvent stock solution is 2-55 wt%, and the organic solvent of the retinol organic solvent stock solution is Tween, methanol or ethanol.

6. The preparation method according to claim 3, wherein the stirring speed of the high crystal silk protein nanofiber gel is 20-1000 rpm, and the stirring time is 10 min-48 h; the stirring speed for mixing with the retinol organic solution stock solution is 20-1000 rpm, and the time is 10 min-48 h.

7. The method of claim 3, wherein the dialysis device is a semipermeable membrane device having a molecular weight cut-off of greater than 500.

8. The method according to claim 3, wherein the dialysis is carried out at a temperature of 0 to 60 ℃ for a period of not less than 10 min.

9. The method according to claim 3, wherein the water is deionized water, purified water or a PBS solution.

10. A cosmetic comprising the aqueous retinol dispersion solution as set forth in any one of claims 1 to 2 or the aqueous retinol dispersion solution prepared by the preparation method as set forth in any one of claims 3 to 9, and an auxiliary material.