Preparation method and application of retinol derivative

Abstract

The invention relates to a preparation method of a retinol derivative, which comprises the following steps: dissolving hydroxy propyl cellulose in water, heating, and introducing ozone to obtain a first solution; evaporating the first solution to dryness to obtain a first solid; dissolving the first solid in acetone, adding retinol, and stirring and mixing to obtain a retinol solution; and carrying out ultrasonic treatment on the retinol solution, dialyzing and / or carrying out ultrafiltration concentration, and drying to obtain the retinol derivative. According to the retinol derivative disclosed by the invention, the retinol derivative has relatively good acid stability, thermal stability and light stability through a large pi bond conjugation effect of hydroxy propyl cellulose, a winding effect of a macromolecular chain and steric hindrance influence.

Description

Technical Field

[0001] The present invention relates to the field of cosmetics, and in particular to a preparation method and application of a retinol derivative. Background Art

[0002] Retinol (also known as vitamin A) can be oxidized to retinal by alcohol dehydrogenase in the body, and then oxidized to retinoic acid by acetaldehyde dehydrogenase. After entering the skin, it is taken up from the extracellular matrix by retinoic acid-related binding protein (cytosolic RAbinding protein), transported to the cell nucleus, activating related target genes, causing gene expression or inhibition, and ultimately leading to changes in the structure and function of the epidermis and dermis. Retinoic acid has multiple alternating single and double bond configurations, which can bind to multiple RA receptors of cells, causing a wide range of physiological effects and may cause a variety of adverse reactions. Therefore, retinoic acid can only be used in medicine, not in the field of cosmetics.

[0003] In the cosmetics field, only retinol, retinal, and retinyl esters (common retinol ester compounds include retinol acetate, retinol palmitate, hydroxypinacolone retinoic acid ester, and retinol retinoic acid) can be used. Among them, retinal is less used, while retinol and retinyl esters are widely used, with significant effects in anti-aging, acne removal, whitening, and anti-oxidation. Since retinol and retinyl esters are a class of polyenol derivatives, they have multiple highly chemically reactive double bonds and are very sensitive to light, heat, and polar media; in addition, after retinol and retinyl esters enter the skin, they will be metabolized into retinoic acid within a certain period of time, causing a variety of adverse reactions.

[0004] Chinese patent 202410974419.0 discloses a method for preparing a retinol derivative, firstly oxidizing hydroxyethyl cellulose with potassium permanganate to form active groups such as carboxyl groups on cellulose, then mixing retinol powder and hydroxy silicone oil to coat the surface of retinol with hydroxy silicone oil, then mixing the oxidized cellulose, retinol coated with hydroxy silicone oil, catalyst and organic solvent, heating the reaction, and using the carboxyl groups on cellulose to react and bond with the hydroxyl groups on hydroxy silicone oil and retinol to obtain a retinol derivative. However, due to the high water solubility, low viscosity and low molecular weight of hydroxyethyl cellulose, it is not easy to separate from the oxidant in aqueous solution after oxidation with potassium permanganate, and the molecular weight of the oxidized hydroxyethyl cellulose is even lower, and it is not easy to form a molecular entanglement effect. The retinol derivatives obtained by this preparation method are of poor quality, difficult to purify, and difficult to meet the requirements of cosmetics. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a method for preparing a retinol derivative, thereby improving the preparation efficiency of retinol, while also improving the acid stability, thermal stability and light stability of retinol, and reducing allergic reactions during use.

[0006] First aspect:

[0007] A method for preparing a retinol derivative comprises the following steps:

[0008] Dissolving hydroxypropyl cellulose in water, heating, and introducing ozone to obtain a first solution;

[0009] Evaporating the first solution to dryness to obtain a first solid;

[0010] dissolving the first solid in acetone, adding retinol, and stirring to mix to obtain a retinol solution;

[0011] The retinol solution is sonicated, then dialyzed and / or ultrafiltered for concentration, and dried to obtain the retinol derivative.

[0012] The present invention moderately oxidizes hydroxypropyl cellulose by ozone to oxidize hydroxyl groups into aldehyde groups, so that hydroxypropyl cellulose can be better grafted with retinol. Moreover, ozone will not stay in the solution after oxidation is completed, and the obtained first solution is pure and does not need to be filtered and purified. In addition, ozone has stronger oxidizing ability, forms more new functional groups, and subsequently grafts more retinol. Acetone can better dissolve the oxidized hydroxypropyl cellulose and retinol, creating a better reaction environment. In subsequent dialysis and ultrafiltration concentration, acetone can be filtered and will not remain in the final product.

[0013] The retinol derivatives of the present invention have the following advantages.

[0014] 1. The sugar ring of hydroxypropyl cellulose has a large number of large π bonds, which can form a conjugated effect with the double bond of retinol, thereby improving the acid stability and thermal stability of retinoic acid.

[0015] 2. The entanglement of retinol with the hydroxypropyl cellulose polymer chain, that is, retinol is encapsulated in hydroxypropyl cellulose, can shield the effect of light on retinol and improve the photostability of retinol.

[0016] 3. Due to the influence of steric hindrance, the configuration of retinol is fixed on the long chain of cellulose, that is, retinol is grafted on hydroxypropyl cellulose. Even if retinoic acid is produced by biological enzymes, the types of configurations are reduced, the amount of metabolism is reduced, and thus allergic reactions are reduced.

[0017] 4. Due to the large π bond conjugation effect of hydroxypropyl cellulose, the entanglement of the polymer chain and the steric hindrance, hydroxypropyl cellulose can slowly release retinol, giving the skin time to build immune tolerance.

[0018] As a preferred solution, the hydroxypropyl cellulose reacts with the ozone at 50-220°C for 5-300 minutes to obtain the first solution. Controlling the reaction temperature and reaction time can further control the degree of oxidative degradation of hydroxypropyl cellulose. The pyrolysis temperature of hydroxypropyl cellulose is about 200°C. When the temperature is too high, hydroxypropyl cellulose will decompose violently, which is not conducive to the control of the reaction process. When the temperature is too low, the oxidative decomposition effect cannot be achieved.

[0019] As a preferred embodiment, the amount of ozone used relative to the hydroxypropyl cellulose is 480-960 ml·g -1 ·min -1 .

[0020] As a preferred embodiment, the hydroxypropyl cellulose is dried in an oven at 60 to 160° C. for 12 to 30 hours before the reaction. More preferably, the drying temperature before the reaction is 120° C. and the drying time is 24 hours. Drying before the reaction can remove organic gas in the hydroxypropyl cellulose and reduce the occurrence of side reactions.

[0021] As a preferred embodiment, the mass ratio of the first solid to the retinol is 1:1-5, and the stirring time of the first solid and the retinol is 4-10 hours. More preferably, the mass ratio of the first solid to the retinol is 1:3, and the stirring time is 6 hours. Under this mass ratio and reaction time, the retinol can be fully reacted and grafted onto the hydroxypropyl cellulose as much as possible.

[0022] As a preferred solution, the acetone is oxidatively distilled before the reaction, and a desiccant is added to the fraction. The oxidative distillation is used to remove reducing impurities such as methanol and acetaldehyde in the acetone, and the desiccant is used for dehydration and adsorption. Preferably, the oxidant can be potassium permanganate, and the use of potassium permanganate does not require additional preparation of reagents, and the desiccant can be a molecular sieve.

[0023] As a preferred embodiment, the retinol solution is ultrasonicated at -10 to 5°C, and the ultrasonic power is 100 to 500W. More preferably, the ultrasonication is performed in a water bath in an ice-water mixture, and the ultrasonic power is 300W. Ultrasound is used to make the grafting reaction of retinol more complete, and further promote the mixing, fixation and entanglement of retinol and hydroxypropyl cellulose. Too high ultrasonic power will decompose the macromolecules, and too low ultrasonic power is not conducive to the full reaction. The temperature of ultrasound increases over a long period of time, so it needs to be performed at a low temperature to avoid the decomposition of free retinol.

[0024] As a preferred embodiment, in the dialysis and / or ultrafiltration, the molecular weight cutoff of the dialysis bag and / or filter membrane used is 100-1000 Da, more preferably 300 Da, to filter out small molecules and free retinol and retain macromolecular products.

[0025] Second aspect:

[0026] A use of the retinol derivative prepared as described in the first aspect in cosmetics. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a Fourier infrared scanning image of the first solid prepared in Example 1 and Example 5;

[0028] Figure 2 This is a sustained-release curve of the retinol derivative prepared in Example 1. DETAILED DESCRIPTION

[0029] A method for preparing a retinol derivative comprises the following steps:

[0030] Hydroxypropyl cellulose is dissolved in water, heated to 50-220°C, and ozone is introduced for reaction for 5-300 minutes to obtain a first solution, wherein the amount of ozone introduced relative to the hydroxypropyl cellulose is 480-960 ml·g -1 ·min -1 ;

[0031] Evaporating the first solution to dryness to obtain a first solid;

[0032] Dissolving the first solid in acetone, adding retinol after it is completely dissolved, and stirring and mixing for 4 to 10 hours to obtain a retinol solution;

[0033] The retinol solution is ultrasonicated at -10 to 5°C with an ultrasonic power of 100 to 500W, then dialyzed using a dialysis bag with a molecular weight cutoff of 100 to 1000Da, and / or concentrated by ultrafiltration using a filter membrane to retain a high molecular weight product, which is then dried to obtain the retinol derivative.

[0034] The amount of ozone introduced to the hydroxypropyl cellulose is 480-960 ml·g -1 ·min -1 , hydroxypropyl cellulose is dried in an oven at 60-160° C. for 12-30 hours before the reaction; the mass ratio of the first solid to retinol is 1:1-5; acetone is distilled using potassium permanganate before the reaction, and the fraction is added with molecular sieves.

[0035] Example 1

[0036] A method for preparing a retinol derivative comprises the following steps:

[0037] The hydroxypropyl cellulose was dried in an oven at 120°C for 24 hours, then dissolved in water, heated to 100°C, and introduced with ozone for 5 minutes to obtain a first solution. The amount of ozone introduced relative to the hydroxypropyl cellulose was 960 ml·g -1 ·min -1 ;

[0038] Evaporating the first solution to dryness to obtain a first solid;

[0039] Acetone is distilled using potassium permanganate in a condensation reflux apparatus, and then molecular sieves are added to the distillate to obtain pure acetone;

[0040] The first solid was dissolved in pure acetone, and after it was completely dissolved, retinol was added, with the mass ratio of the precipitate to retinol being 1:3, and the mixture was stirred for 6 hours to obtain a retinol solution;

[0041] The retinol solution was placed in an ice-water mixture for ultrasonic treatment at an ultrasonic power of 300 W, and then dialyzed using a dialysis bag with a molecular weight cutoff of 300 Da to retain a high molecular weight product, which was freeze-dried to obtain the retinol derivative.

[0042] Example 2

[0043] A method for preparing a retinol derivative comprises the following steps:

[0044] The hydroxypropyl cellulose was dried in an oven at 60°C for 30 hours, then dissolved in water, heated to 150°C, and introduced with ozone for 20 minutes to obtain a first solution. The amount of ozone introduced relative to the hydroxypropyl cellulose was 600 ml·g -1 ·min -1 ;

[0045] Evaporating the first solution to dryness to obtain a first solid;

[0046] Acetone is distilled using potassium permanganate in a condensation reflux apparatus, and then molecular sieves are added to the distillate to obtain pure acetone;

[0047] The first solid was dissolved in pure acetone, and after it was completely dissolved, retinol was added, with the mass ratio of the precipitate to retinol being 1:5, and the mixture was stirred for 10 hours to obtain a retinol solution;

[0048] The retinol solution is placed in an ice-water mixture for ultrasonic treatment at an ultrasonic power of 300W, and then dialyzed using a dialysis bag with a molecular weight cutoff of 1000Da, and then ultrafiltered using a filter membrane with a molecular weight cutoff of 500Da to retain a high molecular weight product, which is freeze-dried to obtain the retinol derivative.

[0049] Example 3

[0050] A method for preparing a retinol derivative comprises the following steps:

[0051] The hydroxypropyl cellulose was dried in an oven at 160°C for 12 hours, then dissolved in water, heated to 220°C, and introduced with ozone for 60 minutes to obtain a first solution. The amount of ozone introduced relative to the hydroxypropyl cellulose was 480 ml·g -1 ·min -1 ;

[0052] Evaporating the first solution to dryness to obtain a first solid;

[0053] Acetone is distilled using potassium permanganate in a condensation reflux apparatus, and then molecular sieves are added to the distillate to obtain pure acetone;

[0054] The first solid was dissolved in pure acetone, and after it was completely dissolved, retinol was added, with the mass ratio of the precipitate to retinol being 1:1, and the mixture was stirred for 4 hours to obtain a retinol solution;

[0055] The retinol solution was sonicated at -10°C with an ultrasonic power of 500W, and then dialyzed using a dialysis bag with a molecular weight cutoff of 100Da to retain a high molecular weight product, which was lyophilized to obtain the retinol derivative.

[0056] Example 4

[0057] A method for preparing a retinol derivative comprises the following steps:

[0058] The hydroxypropyl cellulose was dried in an oven at 100°C for 18 hours, then dissolved in water, heated to 60°C, and introduced with ozone for 300 minutes to obtain a first solution. The amount of ozone introduced relative to the hydroxypropyl cellulose was 480 ml·g -1 ·min -1 ;

[0059] Wash the first solid with pure water, and when the outflowing aqueous solution is colorless, obtain a precipitate after filtering;

[0060] Acetone is distilled using potassium permanganate in a condensation reflux apparatus, and then molecular sieves are added to the distillate to obtain pure acetone;

[0061] The precipitate was freeze-dried and then dissolved in pure acetone. After it was completely dissolved, retinol was added in a mass ratio of precipitate to retinol of 1:4, and the mixture was stirred and mixed for 8 hours to obtain a retinol solution.

[0062] The retinol solution was ultrasonicated at a temperature of 5° C. with an ultrasonic power of 100 W, and then ultrafiltered with a filter membrane having a molecular weight cutoff of 800 Da to retain a high molecular weight product, which was freeze-dried to obtain the retinol derivative.

[0063] Example 5

[0064] Three parallel experiments were designed, with the ozone introduction time being 10 min, 15 min and 20 min respectively, and the rest was exactly the same as in Example 1.

[0065] Example 6

[0066] Fourier transform infrared scanning: Bruker EQUINOX-70 Fourier transform infrared spectrometer was used.

[0067] 10 mg of the first solid prepared in Example 1 and the first solid prepared in three parallel experiments in Example 5 were placed in an agate mortar, dried with a high-pressure mercury lamp, ground into uniform powder with an appropriate amount of potassium bromide, and pressed into tablets; the chemical structures of the three compounds were analyzed using a Fourier transform infrared spectrometer with a scanning range of 4000-400 cm -1 , scanned 64 times.

[0068] like Figure 1 As shown in the figure, the four curves from top to bottom are respectively for 5min, 10min, 15min and 20min of ozone introduction. It can be seen that as the oxidation time increases, the aldehyde peak gradually increases and the hydroxyl peak gradually weakens. This shows that the degree of oxidation can be controlled by controlling the oxidation time.

[0069] Example 7

[0070] Hemolysis rate test: According to the national standard GB / T16886.4-2003 and ISO10993-4, the hemolysis rate calculation formula is as follows, where the absorbance value of the positive control should be 0.8±0.3, and the absorbance value of the negative control group should not be greater than 0.03.

[0071]

[0072] Take 20 mg of the retinol derivative prepared in Example 1 and commercially available retinol and soak them in PBS buffer for 24 hours, then preheat at 37°C for 30 minutes and centrifuge to obtain the supernatant. Take fresh anticoagulated New Zealand white rabbit blood and incubate it with the sample in a silanized test tube at 37°C for 1 hour. Use distilled water as the positive control and physiological saline as the negative control. After the test tube is taken out, centrifuge at 2500r / min for 5 minutes, take the supernatant, use physiological saline as the reference solution, and use a UV-visible spectrophotometer to measure the absorbance value of the supernatant of each tube at 545nm.

[0073] After testing, it was found that the hemolysis rate of the retinol derivative prepared in Example 1 was 0.03%, which was much lower than 3.68% of commercially available retinol, indicating that the retinol derivative prepared in the present invention can delay the conversion of retinol into retinoic acid and reduce the adverse reactions after the accumulation of retinol concentration.

[0074] Example 8

[0075] Encapsulation efficiency test: 5 mg of the retinol solution prepared in Example 1 was added to 40 ml of PBS solution, 1 ml of which was taken out and the absorption wavelength of 325 nm was detected by ultraviolet spectrophotometer; 5 mg of the retinol solution after ultrasound in Example 1 was added to 40 ml of PBS solution, 1 ml of which was taken out and the absorption wavelength of 325 nm was detected by ultraviolet spectrophotometer; the absorbances of the two tests were compared, and it was found that the encapsulation efficiency of the retinol derivative prepared in Example 1 was 71.63±0.11%.

[0076] Example 9

[0077] Sustained release test: 5 mg of the retinol derivative prepared in Example 1 was added to 40 ml of PBS solution. The drug was released in a 37°C, 100 rad / min air-blast shaker. 1 ml of the release solution was taken out at 1, 3, 5, 7, 14, 21, and 28 days, and an equal volume of PBS solution was added. The absorption wavelength of 325 nm was detected by a UV spectrophotometer. The results are shown in Figure 2. Figure 2 As shown, the retinol derivative has a faster release rate within 1 week, enters a plateau phase after 2 weeks, and the cumulative release percentage after 4 weeks is 69.83%, indicating that the retinol derivative prepared by the present invention has a good sustained release effect.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing a retinol derivative, characterized in that: The steps include: Dissolving hydroxypropyl cellulose in water, heating, and introducing ozone to obtain a first solution; Evaporating the first solution to dryness to obtain a first solid; dissolving the first solid in acetone, adding retinol, and stirring to mix to obtain a retinol solution; The retinol solution is sonicated, then dialyzed and / or ultrafiltered for concentration, and dried to obtain the retinol derivative.

2. The method for preparing a retinol derivative according to claim 1, characterized in that: The hydroxypropyl cellulose and the ozone react at 50-220° C. for 5-300 minutes to obtain the first solution.

3. The method for preparing a retinol derivative according to claim 2, characterized in that: The amount of ozone used relative to the hydroxypropyl cellulose is 480-960 ml·g -1 ·min -1 .

4. The method for preparing a retinol derivative according to claim 3, characterized in that: The hydroxypropyl cellulose is dried in an oven at 60-160° C. for 12-30 hours before the reaction.

5. The method for preparing a retinol derivative according to claim 4, characterized in that: The mass ratio of the first solid to the retinol is 1:1-5, and the stirring time of the first solid and the retinol is 4-10 hours.

6. The method for preparing a retinol derivative according to claim 1, characterized in that: The acetone is oxidatively distilled before the reaction, and a desiccant is added to the distillate.

7. The method for preparing a retinol derivative according to claim 1, characterized in that: The retinol solution is ultrasonicated at -10 to 5°C, and the ultrasonic power is 100 to 500W.

8. The method for preparing a retinol derivative according to claim 1, characterized in that: In the dialysis and / or ultrafiltration, the dialysis bag and / or filter membrane used has a molecular weight cutoff of 100 to 1000 Da.

9. Use of the retinol derivative prepared as claimed in any one of claims 1 to 8 in cosmetics.

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