A barefaced cream containing biocompatible polylactic acid and a preparation method thereof

Abstract

The application belongs to the technical field of cosmetics, and particularly relates to a bare skin cream containing biocompatible polylactic acid and a preparation method thereof. The preparation method realizes emulsification and dissolution of polylactic acid in oil through an alkali modification process, avoids using organic solvents to dissolve polylactic acid, and maximally reduces the residue of organic solvents. The modified polylactic acid is added into the cream preparation, and there is no obvious particle scrubbing feeling, so that the application of polylactic acid in the ordinary water-oil emulsion system is realized. By replacing traditional titanium dioxide, silica and mineral powder raw materials, polylactic acid with better biocompatibility is added into the cream product, so that the filling of facial skin texture is realized, and the biocompatibility and safety of the powder particles are ensured.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, specifically relating to a BB cream containing biocompatible polylactic acid and its preparation method. Background Technology

[0002] Polylactic acid (PLA) is a biodegradable polymer made from lactic acid, also known as polylactide. Due to its safety and biocompatibility, it was among the first biodegradable materials approved by the U.S. Food and Drug Administration (FDA) for use in biomedicine. In the medical field, it is used to produce surgical sutures, tissue engineering scaffolds, and drug delivery systems. Its excellent biocompatibility and biodegradability allow for safe use and gradual absorption within the human body. Because its degradation is pollution-free, PLA is also widely used in the production of biodegradable plastic bags, food containers, and other packaging materials. Currently, PLA has been registered as a cosmetic ingredient, and its application in more cosmetic formulations is expected in the future.

[0003] For example, CN117883321A discloses a method for preparing L-polylactic acid (PLA) microspheres for cosmetic raw materials. The specific process involves using a cryogenic pulverizer to pulverize L-PLA particles into micron-sized powder, then sieving the powder to a predetermined size, and finally feeding the predetermined L-PLA powder into a self-developed dry spheroidizing and shaping device to prepare spherical powder. Finally, after freeze-drying and sterilization, L-PLA microspheres for cosmetic raw materials are obtained. However, this technical solution mainly uses physical methods for sieving, shaping, and then freeze-drying, making the overall process relatively complex.

[0004] CN117700696A discloses a polylactic acid (PLA) microsphere, its preparation method, and its application. Polyethylene glycol stearate, lactide, and a catalyst are placed in a reactor, melt-mixed uniformly, and then subjected to a ring-opening polymerization reaction to prepare a mixture of PLA microspheres and polyethylene glycol stearate. This mixture is then placed in water to completely dissolve the polyethylene glycol stearate, followed by separation and drying to obtain the PLA microspheres. However, this method involves a ring-opening polymerization reaction, which has complex reaction conditions. Post-processing requires eluting the polyethylene glycol stearate, which can easily lead to solvent residue.

[0005] CN117122580A discloses a hollow polylactic acid (PLA) microsphere, its preparation method, and its application. This method uses an emulsified solvent evaporation method to prepare sustained-release microspheres, specifically using biodegradable polymers, including PLA and cellulose nanocrystals, as drug-loaded microsphere carriers. The drug is curcumin or plant essential oil. However, in this technical solution, the use of organic solvents to dissolve PLA easily leads to residual organic solvents in the later stages, posing a risk of irritation in cosmetic applications.

[0006] CN118105312A discloses a fast-emulsifying makeup remover oil and its preparation process. This invention involves mixing modified polylactic acid, jojoba oil, emulsifier, phenoxyethanol, glycerin, and D-panthenol, heating the mixture, and then cooling it to room temperature to obtain the fast-emulsifying makeup remover oil. Specifically, the modified polylactic acid is prepared by dissolving polylactic acid in tetrahydrofuran solvent, adding a catalyst to obtain chlorinated polylactic acid; then reacting to obtain aminoated β-cyclodextrin; finally, precipitation, filtration, and washing yield the modified polylactic acid. However, this technical solution uses a large amount of organic solvents, many of which are highly toxic and easily cause solvent residue.

[0007] It is evident that when polylactic acid is currently used as a cosmetic ingredient, there are still various issues that need improvement, such as complex preparation processes and the potential for organic solvent residue.

[0008] As a newly emerging beauty product in recent years, BB cream has gained increasing popularity among consumers due to its natural, lightweight makeup effect and simple skincare and makeup steps, earning it the nickname "lazy person's face cream." BB cream combines the functions of a skincare cream and a base makeup product in one bottle, making it particularly appealing to urban white-collar workers. The base makeup ingredients in BB cream typically include titanium dioxide, silica, and mineral powders, which serve to modify and fill in imperfections. However, if not properly cleansed, these powdery ingredients can remain on the skin for extended periods, potentially causing damage. To address these issues, the inventors have researched and developed a BB cream product containing biocompatible polylactic acid (PLA) to replace conventional base makeup ingredients. Leveraging PLA's safe biocompatibility and biodegradability, the inventors have created a BB cream product containing PLA. Summary of the Invention

[0009] To address the deficiencies and shortcomings of existing technologies, this invention provides a BB cream containing biocompatible polylactic acid and its preparation method.

[0010] The objective of this invention can be achieved through the following technical solutions:

[0011] In a first aspect, the present invention provides a method for preparing a BB cream containing a biocompatible polymer, the method comprising the following steps:

[0012] Step 1: By weight, take 50-90 parts of water, first dissolve 0.5-1.5 parts of ammonium acryloyl dimethyl taurate / VP copolymer (AVC) or carbomer, then add 0.1-3 parts of glycerol, 0.1-3 parts of butylene glycol, 0.1-3 parts of propylene glycol, 0.1-3 parts of trehalose, and 1-5 parts of pentanediol until completely dissolved to form solution A;

[0013] Step 2: Dissolve 0.1-3 parts cetearyl glucoside in 1-5 parts jojoba seed oil, 0.1-3 parts white oil, and 0.1-3 parts hexadecanoic acid by weight, and disperse evenly at high temperature to form solution B;

[0014] Step 3: Add 0.3-0.8 parts by weight of alkali-modified polylactic acid to solution B and dissolve completely; and

[0015] Step 4: Add solution B to solution A, add the remaining water to make 100 parts by weight, then homogenize to obtain a BB cream containing biocompatible polymers.

[0016] Alternatively, in the above preparation method, the preparation method includes the following steps:

[0017] Step 1: Take 60-80 parts by weight of water, first dissolve 0.5-0.9 parts of AVC or carbomer, then add 0.5-2 parts of glycerol, 0.5-2 parts of butylene glycol, 0.5-2 parts of propylene glycol, 0.5-2 parts of trehalose, and 2-4 parts of pentanediol until completely dissolved to form solution A;

[0018] Step 2: Dissolve 0.5-2 parts cetearyl glucoside in 1-3 parts jojoba seed oil, 0.5-2 parts white oil, and 0.5-2 parts hexadecanoic acid by weight, and disperse evenly at high temperature to form solution B;

[0019] Step 3: Add 0.4-0.7 parts by weight of alkali-modified polylactic acid to solution B and dissolve completely; and

[0020] Step 4: Add solution B to solution A, add the remaining water to make 100 parts by weight, then homogenize to obtain a BB cream containing biocompatible polymers.

[0021] Alternatively, in the above preparation method, step 3 of the preparation method of alkali-modified polylactic acid includes the following steps:

[0022] Step 3.1: Dissolve 0.1-0.5 parts by weight of alkali in 0.1-3 parts by weight to form solution A;

[0023] Step 3.2: Add 0.1-2 parts by weight of polylactic acid to 1-5 parts of jojoba seed oil to form solution B;

[0024] Step 3.3: Under heating and stirring conditions, add solution A dropwise to solution B, and heat and stir to form solution C;

[0025] Step 3.4: Dissolve 0.5-2 parts by weight of citric acid in 0.1-3 parts by weight of water to form solution D;

[0026] Step 3.5: Under normal temperature conditions, homogenize and stir solution C, then add solution D dropwise to solution C to form a flocculent gel, thus obtaining alkali-modified polylactic acid.

[0027] Alternatively, in the above preparation method, in step 2, the high temperature is 80-85℃; in step 4, the homogenization conditions are centrifugation at 6000-8000 rpm for 20-30 seconds.

[0028] Alternatively, in the above preparation method, the alkali is selected from sodium hydroxide or potassium hydroxide.

[0029] Preferably, the alkali is selected from sodium hydroxide.

[0030] Alternatively, in the above preparation method, in step 3.3, the heating temperature is 85-95℃; the dropping rate is 0.01-0.1 g / min; and the stirring time is 2-5 hours.

[0031] Alternatively, in the above preparation method, in step 3.5, the homogenization conditions are centrifugation at 3000-5000 rpm for 20-30 seconds, and the solution is in a flocculent gel state when the solution temperature is close to room temperature.

[0032] Alternatively, in the above preparation method, the alkali-modified polylactic acid is emulsified and dissolved in oil, avoiding the use of organic solvents to dissolve the polylactic acid.

[0033] In a second aspect, the present invention provides a BB cream prepared using the preparation method described in the first aspect above.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] (1) Through the alkali modification process, polylactic acid is emulsified and dissolved in oils, avoiding the use of organic solvents to dissolve polylactic acid and minimizing the residue of organic solvents. This is especially beneficial in cosmetic formulations, reducing potential negative impacts from the source.

[0036] (2) When the modified polylactic acid is added to the face cream formulation, there is no obvious particle abrasive feeling, which realizes the application of polylactic acid in the ordinary water-oil emulsion system. In contrast, if the unmodified polylactic acid is added directly to the emulsion system, the particle feeling is obvious and cannot meet the skin feel requirements of cosmetics.

[0037] (3) Since polylactic acid is a green and natural source and has no risk of metabolism in the human body, it is a material with good biocompatibility and safety. By replacing traditional raw materials such as titanium dioxide, silica, and mineral powder, it can be added to face cream products to fill facial skin texture while ensuring the biocompatibility and safety of powder particles. Attached Figure Description

[0038] Figure 1 Infrared spectrum of unmodified polylactic acid.

[0039] Figure 2 Infrared spectrum of modified polylactic acid.

[0040] Figure 3 The results of microscopic observation of the prepared BB cream sample. Magnification: 200x. Detailed Implementation

[0041] The present invention will be further described below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0042] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0043] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available products.

[0044] Example 1: Sodium hydroxide-modified polylactic acid process

[0045] (1) Dissolve 0.2 g of sodium hydroxide in 1 g of water to form solution A;

[0046] (2) Add 0.5 g of polylactic acid to 4 g of jojoba seed oil to form solution B;

[0047] (3) Under the conditions of heating and stirring at 90℃, solution A is added dropwise to solution B at a rate of 0.05 g / min, and the mixture is heated and stirred for 4 hours to form solution C;

[0048] (4) Dissolve 0.1 g of citric acid in 0.5 g of water to form solution D;

[0049] (5) Under normal temperature conditions, solution C is homogenized and stirred at 4000 rpm for 20 seconds. Solution D is then added dropwise to solution C. When the solution temperature approaches room temperature, a flocculent gel is formed, and the preparation is complete.

[0050] like Figure 1 and Figure 2 As shown, 3500 cm -1 -3700 cm -1 The characteristic peak at 2722-3240 cm⁻¹ is the stretching vibration peak of -OH in polylactic acid, which is the main backbone peak of polylactic acid; -1The absorption peak at 1625-1920 cm⁻¹ is the stretching vibration peak of CH in non-aromatic PLA compounds; -1 The peak value at 400-850 cm represents the stretching vibration of C=O in PLA; -1 The absorption peak at 400-850 cm⁻¹ corresponds to the stretching vibration peak of aromatic CH groups. A comparison of the infrared spectra shows that the main difference between the modified and unmodified spectra lies in the 400-850 cm⁻¹ range. -1 The absorption peak at 557 cm⁻¹ is observed after modification. -1 and 697 cm -1 The peaks appearing at these locations are characteristic of the aromatic CH stretching vibration peaks that appear after modification.

[0051]

[0052] Based on the analysis of the polylactic acid (PLA) synthesis pathway and molecular structure, the first step involves the formation of a cyclic dimer, lactide, from lactic acid, followed by ring-opening and polycondensation into PLA. After modification with sodium hydroxide, the PLA undergoes partial ring-opening during the reaction, exposing more aromatic CH stretching peaks. Simultaneously, more carbonyl groups can be dissolved through emulsification with oils, thus enabling the addition of PLA to BB cream formulations.

[0053] Comparative Example 1: Sodium hydroxide-modified polylactic acid process - exploration of sodium hydroxide content

[0054] (1) Dissolve 0.1 g of sodium hydroxide in 1 g of water to form solution A;

[0055] (2) Add 0.5 g of polylactic acid to 4 g of jojoba seed oil to form solution B;

[0056] (3) Under the conditions of heating and stirring at 90℃, solution A is added dropwise to solution B at a rate of 0.05 g / min, and the mixture is heated and stirred for 4 hours to form solution C;

[0057] (4) Dissolve 0.1 g of citric acid in 0.5 g of water to form solution D;

[0058] (5) Under normal temperature conditions, solution C is homogenized and stirred at 4000 rpm for 20 seconds. Solution D is then added dropwise to solution C. When the solution temperature approaches room temperature, a flocculent gel is formed, and the preparation is complete.

[0059] Comparative Example 2: Sodium Hydroxide Modification Process for Polylactic Acid - Exploration of Polylactic Acid Content

[0060] (1) Dissolve 0.2 g of sodium hydroxide in 1 g of water to form solution A;

[0061] (2) Add 1 gram of polylactic acid to 4 grams of jojoba seed oil to form solution B;

[0062] (3) Under the conditions of heating and stirring at 90℃, solution A was added dropwise to solution B at a rate of 0.05 g / min, and the mixture was heated and stirred for 4 hours to form solution C;

[0063] (4) Dissolve 0.1 g of citric acid in 0.5 g of water to form solution D;

[0064] (5) Under normal temperature conditions, solution C is homogenized and stirred at 4000 rpm for 20 seconds. Solution D is then added dropwise to solution C. When the solution temperature approaches room temperature, a flocculent gel is formed, and the preparation is complete.

[0065] Comparative Example 3: Sodium Hydroxide Modified Polylactic Acid Process - Exploration of Reaction Conditions

[0066] (1) Dissolve 0.2 g of sodium hydroxide in 1 g of water to form solution A;

[0067] (2) Add 0.5 g of polylactic acid to 4 g of jojoba seed oil to form solution B;

[0068] (3) Under the condition of heating and stirring at 60℃, solution A is directly added to solution B, and the mixture is heated and stirred for 4 hours to form solution C;

[0069] (4) Dissolve 0.1 g of citric acid in 0.5 g of water to form solution D;

[0070] (5) Under normal temperature conditions, solution C is homogenized and stirred at 4000 rpm for 20 seconds. Solution D is then added dropwise to solution C. When the solution temperature approaches room temperature, a flocculent gel is formed, and the preparation is complete.

[0071] Comparative Example 4: Sodium Hydroxide Modified Polylactic Acid Process - Whether Citric Acid Was Added

[0072] (1) Dissolve 0.2 g of sodium hydroxide in 1 g of water to form solution A;

[0073] (2) Add 0.5 g of polylactic acid to 4 g of jojoba seed oil to form solution B;

[0074] (3) Under the conditions of heating and stirring at 90℃, solution A was added dropwise to solution B at a rate of 0.05 g / min, and the mixture was heated and stirred for 4 hours to form solution C;

[0075] (4) Under normal temperature conditions, solution C is homogenized and stirred at 4000 rpm for 20 seconds. When the solution temperature approaches room temperature and forms a flocculent gel, the preparation is complete.

[0076] Example 2: Preparation process of a face cream containing modified polylactic acid

[0077] The process of making a BB cream:

[0078] (1) Take 70g of water, first dissolve 0.8g of AVC, then add 1g of glycerol, 1g of butanediol, 1g of propylene glycol, 1g of trehalose and 3g of pentanediol until completely dissolved to form solution A;

[0079] (2) Dissolve 1 gram of cetearyl glucoside in 2 grams of jojoba seed oil, 1 gram of white oil, and 1 gram of hexadecanoic acid, and disperse evenly at 85°C to form solution B;

[0080] (3) Add 0.5 g of the modified polylactic acid prepared in Example 1 (Comparative Example 1, Comparative Example 2, Comparative Example 3 or Comparative Example 4) and conventional commercially available polylactic acid to solution B and dissolve completely;

[0081] (4) Add solution B to solution A, add the remaining water to 100g, and homogenize at 8000 rpm for 20 seconds to form a cream sample, which is a BB cream containing modified polylactic acid.

[0082] The prepared BB cream samples were subjected to skin feel tests and microscopic observations, and the results are shown in Table 1 and 2, respectively. Figure 3 As shown.

[0083] Table 1: Skin feel test results of BB cream samples containing polylactic acid

[0084]

[0085] The performance test results of the BB cream sample obtained in Example 2 are shown in Table 2 below.

[0086] Table 2: Performance test results of BB cream samples containing polylactic acid

[0087]

[0088] As can be seen from the data in Table 2 above, the polylactic acid-containing BB cream sample prepared in Example 2 has a uniform and stable appearance. It remains stable under high and low temperature conditions and does not exhibit any layering, emulsification, or other phenomena. The pH value is neutral, which meets the relevant standards of the cosmetics industry.

[0089] Example 3: Comparison of facial wrinkle radiance between polylactic acid-containing face cream and regular face cream.

[0090] Following the preparation process of the BB cream in Example 2, a regular face cream was prepared.

[0091] The preparation process of a regular face cream:

[0092] (1) Take 70g of aqueous solution, first dissolve 0.8g of AVC, then add 1g of glycerol, 1g of butanediol, 1g of propylene glycol, 1g of trehalose and 3g of pentanediol until completely dissolved to form solution A;

[0093] (2) Dissolve 1 g of cetearyl glucoside in 2 g of jojoba seed oil, 1 g of white oil, 1 g of hexadecanoic acid and 4 g of jojoba seed oil, and disperse evenly at 85°C to form solution B;

[0094] (3) Add solution B to solution A, add the remaining water to 100g, and homogenize at 8000 rpm for 20 seconds to form a cream sample, i.e., a regular face cream sample.

[0095] Individual typology angle (ITA) values ​​are based on L a b. Skin color measurement index established in color space. ITA value can quantify the examination of skin color and is an important indicator for objectively evaluating skin roughness. That is, the higher the ITA value, the brighter the skin color, the higher the skin gloss, and therefore the lower the roughness. The face cream samples prepared in Examples 2 and 3 above were used to conduct short-term wrinkle removal tests on 5 subjects.

[0096] After cleansing their faces with water and wiping them dry, the subjects sat quietly indoors for 20 minutes. Initial ITA values ​​were measured and recorded on the skin around the corners of each subject's eyes. Then, pea-sized amounts of Sample 2 and Sample 3 were applied to the left and right corners of the eyes of each of the five subjects, respectively. Sample 2 was applied to the left corner of the eye, and Sample 3 to the right corner. After 60 minutes of quiet rest following application, ITA values ​​were measured again on the skin around the corners of the eyes. The results of the trial are summarized in Table 3 below.

[0097] Table 3: Subject ITA Value Feedback Form

[0098]

[0099] The ITA value feedback table of the subjects shows that when the skin around the left corner of the eye was treated with the BB cream sample prepared in Example 2, polylactic acid filled the wrinkles around the eye, achieving an immediate wrinkle-reducing effect. At the same time, due to the effective filling of skin texture, the roughness was significantly reduced, and the skin radiance changed significantly, resulting in a significant increase in the ITA value. On the other hand, when the skin around the right corner of the eye was treated with the face cream sample prepared in Example 3, the ITA value only increased slightly. This is likely because the oils and moisturizing ingredients in the face cream temporarily improved the skin radiance. The addition of polylactic acid did not significantly affect the filling of skin wrinkles.

[0100] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a BB cream containing a biocompatible polymer, characterized in that: The preparation method includes the following steps: Step 1: By weight, take 50-90 parts of water, first dissolve 0.5-1.5 parts of ammonium acryloyl dimethyl taurate / VP copolymer (AVC) or carbomer, then add 0.1-3 parts of glycerol, 0.1-3 parts of butylene glycol, 0.1-3 parts of propylene glycol, 0.1-3 parts of trehalose, and 1-5 parts of pentanediol until completely dissolved to form solution A; Step 2: Dissolve 0.1-3 parts cetearyl glucoside in 1-5 parts jojoba seed oil, 0.1-3 parts white oil, and 0.1-3 parts hexadecanoic acid by weight, and disperse evenly at high temperature to form solution B, wherein the high temperature is 80-85℃; Step 3: Add 0.3-0.8 parts by weight of alkali-modified polylactic acid to solution B and dissolve completely; and Step 4: Add solution B to solution A, and add the remaining water until it reaches 100 parts by weight. Then homogenize to obtain a BB cream containing biocompatible polymers. In step 3, the preparation method of the alkali-modified polylactic acid includes the following steps: Step 3.1: Dissolve 0.1-0.5 parts by weight of alkali in 0.1-3 parts by weight to form solution A; Step 3.2: Add 0.1-2 parts by weight of polylactic acid to 1-5 parts of jojoba seed oil to form solution B; Step 3.3: Under heating and stirring conditions, add solution A dropwise to solution B, and heat and stir to form solution C; Step 3.4: Dissolve 0.5-2 parts by weight of citric acid in 0.1-3 parts by weight of water to form solution D; Step 3.5: Under normal temperature conditions, homogenize and stir solution C, then add solution D dropwise to solution C to form a flocculent gel, thus obtaining alkali-modified polylactic acid.

2. The method for preparing the BB cream according to claim 1, characterized in that: The preparation method includes the following steps: Step 1: Take 60-80 parts by weight of water, first dissolve 0.5-0.9 parts of AVC or carbomer, then add 0.5-2 parts of glycerol, 0.5-2 parts of butylene glycol, 0.5-2 parts of propylene glycol, 0.5-2 parts of trehalose, and 2-4 parts of pentanediol until completely dissolved to form solution A; Step 2: Dissolve 0.5-2 parts cetearyl glucoside in 1-3 parts jojoba seed oil, 0.5-2 parts white oil, and 0.5-2 parts hexadecanoic acid by weight, and disperse evenly at high temperature to form solution B, wherein the high temperature is 80-85℃; Step 3: Add 0.4-0.7 parts by weight of alkali-modified polylactic acid to solution B and dissolve completely; and Step 4: Add solution B to solution A, add the remaining water to make 100 parts by weight, then homogenize to obtain a BB cream containing biocompatible polymers.

3. The method for preparing the BB cream according to claim 1, characterized in that: In step 4, the homogenization conditions are centrifugation at 6000-8000 rpm for 20-30 seconds.

4. The method for preparing the BB cream according to claim 1, characterized in that: The alkali is selected from sodium hydroxide or potassium hydroxide.

5. The method for preparing the BB cream according to claim 1, characterized in that: In step 3.3, the heating temperature is 85-95℃; the dropping rate is 0.01-0.1 g / min; and the stirring time is 2-5 hours.

6. The method for preparing the BB cream according to claim 1, characterized in that: In step 3.5, the homogenization conditions are centrifugation at 3000-5000 rpm for 20-30 seconds, and the formation of flocculent gel at room temperature.

7. The method for preparing the BB cream according to claim 1, characterized in that: In the preparation method, the alkali-modified polylactic acid is emulsified and dissolved in oil, avoiding the use of organic solvents to dissolve the polylactic acid.

8. A BB cream prepared by any one of claims 1 to 7.

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