Mild and skin-injury-free compound preservative composition for cosmetics

Abstract

The invention designs a mild and skin-friendly compound preservative composition for cosmetics, and in the cosmetics containing the preservative composition, the growth of pathogenic microorganisms (such as staphylococcus aureus, pseudomonas aeruginosa and the like) in the cosmetics can be effectively inhibited; the skin care product is mild, does not cause harm to skin and is suitable for sensitive skin, and human healthy skin florae (such as staphylococcus epidermidis, staphylococcus capitis, propionibacterium acnes, micrococcus luteus, bacillus firmus, acinetobacter lwoffii and the like) are not inhibited, and the skin care product is mild, does not injure skin and is suitable for sensitive skin.

Description

Background Art

[0001] As daily necessities, cosmetics are suitable for a wide range of people, especially infants, the elderly, patients with chronic diseases, etc. However, there are also many adverse reactions to cosmetics during use, the most common of which are skin itching and skin allergies. Severe cases can also cause infection and cause serious harm. Preservatives are one of the main factors causing safety issues for cosmetics. In order to prevent cosmetics from spoiling, cosmetics manufacturers will add preservatives to cosmetics. The preservatives added may be one or a combination of multiple preservatives. At the same time, there are also a certain amount of preservatives in the raw materials of cosmetics. Therefore, the combined use of multiple preservatives can easily lead to an excess of the total amount of preservatives, thereby causing safety issues during use. The 2015 edition of the "Technical Specifications for Safety of Cosmetics" only limits the maximum allowable concentration of single-ingredient preservatives, and does not set any requirements for the combined use of multiple types of preservatives. Exceeding the total amount of multiple preservatives will bring corresponding safety risks: on the one hand, as the dosage of preservatives increases and the number of types increases, the risk of allergy will be greatly increased; on the other hand, long-term use of cosmetics containing multiple preservatives may cause the skin's resident bacterial microecology to be disturbed and damaged, affecting the balance of the skin's microecology, and may cause severe skin inflammation.

[0002] With the continuous deepening of skin microbiome research, the role of resident skin microbial flora in maintaining skin health has been recognized by the scientific community. Given that the purpose of cosmetics is to protect and beautify the skin, their short-term or long-term use should not kill or significantly inhibit the resident skin flora, which poses new challenges to the use of preservatives in cosmetics. The development of preservative systems in cosmetics needs to include the health of skin microbial flora in the scope of risk assessment research. Therefore, it is particularly important for cosmetics manufacturers to choose a suitable combination of mild, non-irritating and skin-health-protecting preservatives. Summary of the invention

[0003] The first aspect of the present invention provides a composite preservative combination for cosmetics, characterized in that it comprises: phenoxyethanol, propylparaben, and methylisothiazolinone, and the weight percentages of the three components in the cosmetics are as follows: 0.125-0.25% of phenoxyethanol, 0.0125-0.025% of propylparaben, and 0.000625-0.00125% of methylisothiazolinone.

[0004] In some embodiments, it is characterized in that the compound preservative combination consists of phenoxyethanol, propylparaben, and methylisothiazolinone, and the weight percentages of the three components in the cosmetics are as follows: phenoxyethanol is 0.125-0.25%, propylparaben is 0.0125-0.025%, and methylisothiazolinone is 0.000625-0.00125%.

[0005] In some embodiments, the weight percentages of the three components in the cosmetic are as follows: 0.125% of phenoxyethanol, 0.0125% of propylparaben, and 0.000625% of methylisothiazolinone.

[0006] In some embodiments, the cosmetic is selected from one or more of a facial cream, a lotion, a toner, a shower gel, a shampoo, a conditioner, a mask, a facial mask, an essence, and an eye cream.

[0007] The second aspect of the present invention provides a cosmetic composition comprising the compound preservative combination described in the first aspect of the present invention.

[0008] In some embodiments, the preservative in the cosmetic composition only includes the compound preservative combination described in the first aspect of the present invention.

[0009] In some embodiments, the cosmetic composition is selected from one or more of a facial cream, a lotion, a toner, a shower gel, a shampoo, a conditioner, a mask, a facial mask, an essence, and an eye cream.

[0010] The third aspect of the present invention provides use of the compound preservative combination described in the first aspect of the present invention in the preparation of a cosmetic preservative.

[0011] Beneficial Effects

[0012] The use of cosmetics containing the above-mentioned preservative combination can not only effectively inhibit the growth of pathogenic microorganisms in cosmetics (such as Staphylococcus aureus, Pseudomonas aeruginosa, etc.), but also does not inhibit the healthy skin flora of the human body (such as Staphylococcus epidermidis, Staphylococcus capitis, Propionibacterium acnes, Micrococcus luteus, Bacillus firmus, Acinetobacter lübe, etc.). It is gentle and does not harm the skin and is suitable for sensitive skin.

[0013] Specific implementation cases

[0014] The following embodiments can enable those skilled in the art to more fully understand the present invention, but the present invention is not limited to the scope of the embodiments.

[0015] Example 1: Inhibitory effect of the compound preservative BPM combination on the main resident bacteria on the face of healthy adults

[0016] 1 Materials and methods

[0017] 1.1 Materials

[0018] 1.1.1 Subject selection

[0019] Fifteen healthy Han adults aged 20-25 years with an average age of 21.4±1.3 years were recruited from Wuxi universities. They had no history of skin diseases. According to the test requirements, the subjects avoided washing their faces or using topical medications and moisturizers 24 hours before the collection of microbial samples. For facial microbial collection, two swabs moistened with a small amount of sterile 0.9% NaCl were used to wipe the 4×4cm area on the left and right halves of the face for 15-30 seconds, placed in a sampling tube, sealed and stored in a -80℃ refrigerator until further processing.

[0020] 1.1.2 Instruments

[0021] IN110plus incubator, Memmert, Germany; Microfiex LTMALDI-TOF microbial mass spectrometer, Bruker, Germany; BSC-1300IIA2 biological safety cabinet, Antai Company of Sujing Group; Densichekplus, BioMérieux, France; GR60DP vertical pressure steam sterilizer, Zealway, USA; JH2102 electronic balance, Shanghai Jingke Tianmei Scientific Instrument Co., Ltd.; GENbag anaerobic gas production bag, BioMérieux, France; Densichek turbidimeter, BioMérieux, France; GZX-9246MBZ oven, Shanghai Boxun Industrial Co., Ltd.; ZY-300IV automatic measurement and analyzer of inhibition zone, Beijing Pioneer Weifeng Technology Development Co., Ltd.

[0022] 1.1.3 Culture medium and reagents

[0023] Tryptic soy peptone agar medium (TSA), tryptic soy peptone liquid medium (TSB), Beijing Sanyao Technology Development Co., Ltd.; blood agar plate, 5% (mass concentration) triphenyltetrazolium chloride (TTC), Guangdong Huankai Microbiological Technology Co., Ltd.; Bengal red agar plate, Bengal red liquid medium, Beijing Luqiao Technology Co., Ltd.; nutrient broth medium, Beijing Luqiao Technology Co., Ltd.; sodium chloride, Tween 80, Sinopharm Chemical Reagent Co., Ltd.

[0024] 1.1.4 Test substances

[0025] Phenoxyethanol (hereinafter referred to as B, Beijing Bailingwei Technology Co., Ltd.); Propyl p-hydroxybenzoate (hereinafter referred to as P, Sigma); Methylisothiazolinone (hereinafter referred to as M, Sigma); Compound preservative combination (phenoxyethanol + propyl p-hydroxybenzoate + methylisothiazolinone) hereinafter referred to as BPM.

[0026] 1.2 Methods

[0027] 1.2.1 Bacterial culture, isolation and identification

[0028] Randomly take out a skin swab from each sample and rinse it with 3mL of sterile solution (0.9% NaCl and 0.1% Tween 80) for 5 seconds, then inoculate the rinse solution on the blood agar plate, and culture the inoculated blood agar plates aerobically and anaerobically, respectively. The anaerobic blood agar plates are placed in anaerobic culture bags, and culture after the oxygen in the anaerobic culture bags is exhausted and the indicator card changes color to form an anaerobic environment. All plates are incubated at 37°C, and bacterial growth is observed after 48 hours. After that, a single colony is picked for isolation, purification and culture for 24 hours. Each colony is inoculated on 3 plates, and the purified slant colonies are taken for identification using a MicrofiexLT MALDI-TOF microbial mass spectrometer.

[0029] 1.2.2 Cultivation, isolation and identification of molds and yeasts

[0030] Two skin swabs were randomly taken from each sample and rinsed with 3 mL of sterile solution (0.9% NaCl and 0.1% Tween 80) for 5 seconds, and then the rinse solution was inoculated on Bengal red agar plates. All plates were incubated at 28°C and the growth of molds and yeasts was observed after 48 hours. After that, a single colony was picked for isolation and purification and cultured for 24 hours. The purified slant colony was taken for identification using Microfiex LT MALDI-TOF microbial mass spectrometer.

[0031] 1.2.3 Minimum inhibitory concentration (MIC)

[0032] According to the requirements of the "Technical Specifications for Safety of Cosmetics" (2015 edition), the micro half-dilution method was used to determine the MIC of single preservatives and combined preservatives in cosmetics against 6 types of resident facial skin bacteria. The MIC of these test substances was defined as the lowest concentration at which no growth was observed (i.e., no turbidity in the wells of the 96-well plate).

[0033] Take fresh liquid culture of Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus, Propionibacterium acnes, Bacillus firmus, and Acinetobacter lwoffii, adjust the bacterial suspension to 0.5 McFarland turbidity using a turbidimeter, and dilute it 10 times with nutrient broth medium to make the final concentration of the bacterial suspension about 6×10 5 ~7×10 5 CFU / mL, for future use.

[0034] Take a 96-well sterile microplate, add 100 μL of nutrient broth medium to each well, then add 100 μL of various test substances at the initial concentration to the first well of each row, blow and evenly with a pipette, and then draw 100 μL to the second well of each row, and operate in sequence to dilute the drug solution to the 10th well of each row, and finally discard 100 μL after mixing the last well. Pipette 100 μL of the prepared bacterial suspension and add it to the test substance well and mix well. The 11th well with nutrient broth containing bacterial solution but not containing the test substance is used as a positive control, and the 12th well with nutrient broth containing no bacterial solution is used as a negative control. Add the prepared solution of the cosmetic compound preservative combination, cover the 96-well plate cover, seal with tape, and place in an incubator for 48 hours under appropriate temperature and oxygen conditions.

[0035] After 48 hours, observe the growth of colonies in each well. The colony growth in the positive control well is taken as the standard. Use the naked eye and a magnifying glass to observe the growth of colonies in each well, that is, the antibacterial effect of the test substance. The lowest drug concentration well position with no visible colony growth is taken as the MIC of the test.

[0036] 2 Results

[0037] 2.1 Cultivation, isolation and identification of resident bacteria on facial skin

[0038] By in vitro culture and microbial mass spectrometry, 11 species of bacteria were isolated from the facial samples of 15 healthy adults aged 20 to 25 years, including Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus, Propionibacterium acnes, Bacillus firmus, Acinetobacter lwoffii, Staphylococcus aureus, Pseudomonas songnensis, Rhodotorula colloidinum, Paenibacillus barcelonae, and Candida parapsilosis. The main detected species were Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus, Propionibacterium acnes, Bacillus firmus, Acinetobacter lwoffii, and Staphylococcus aureus. See Table 1.

[0039] Table 1 Resident bacterial flora on the face of healthy adults (n=15)

[0040]

[0041]

[0042] 2.2 Inhibitory effect of compound preservatives on facial resident bacteria

[0043] Table 2 Minimum inhibitory concentration of compound preservatives in cosmetics against resident bacteria on the face

[0044]

[0045] The minimum inhibitory concentration of phenoxyethanol, a preservative in cosmetics, against Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus, Propionibacterium acnes, Bacillus firmus, and Acinetobacter lwoffii is 1% (volume percentage), which is consistent with the limit requirements in the "Technical Specifications for Safety of Cosmetics" (2015 edition); the minimum inhibitory concentration of propyl paraben against Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus, and Bacillus firmus is 0.1% (mass percentage), and the minimum inhibitory concentration against Propionibacterium acnes and Acinetobacter lwoffii is 0.05% (mass percentage), and the limit requirement in the "Technical Specifications for Safety of Cosmetics" (2015 edition) is 0.4%; The minimum inhibitory concentration of isothiazolinone to Staphylococcus capitis and Bacillus firmus is 0.01% (mass percentage), the minimum inhibitory concentration to Staphylococcus epidermidis is 0.005% (mass percentage), and the minimum inhibitory concentration to Propionibacterium acnes, Micrococcus luteus and Acinetobacter lübe is 0.0025% (mass percentage); the minimum inhibitory concentration of the composite preservative BPM combination to Staphylococcus epidermidis, Staphylococcus capitis, Micrococcus luteus and Bacillus firmus is (0.5+0.05+0.0025)%, and the minimum inhibitory concentration to Propionibacterium acnes and Acinetobacter lübe is (0.25+0.025+0.00125)%. Compared with single preservatives, the compound preservative combination (BPM) has a lower MIC. When the concentration is lower than (0.25+0.025+0.00125)%, it will have no inhibitory effect on the main resident bacteria on the skin and can be safely used in cosmetics.

[0046] Example 2: Test of the antiseptic performance of the composite preservative combination against pathogenic microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Aspergillus niger)

[0047] 1 Materials and methods

[0048] 1.1 Materials

[0049] 1.1.1 Instruments

[0050] IN110plus incubator, Memmert, Germany; IMP180 low-temperature incubator, Thermo, USA; GR60DP vertical pressure steam sterilizer, Zealway, USA; JH2102 electronic balance, Shanghai Jingke Tianmei Scientific Instrument Co., Ltd.; BSC-1000IIA2 biological safety cabinet, Suzhou Antai Air Technology Co., Ltd. of Sujing Group.

[0051] 1.1.2 Culture medium and reagents

[0052] Tryptic soy peptone agar medium (TSA), tryptic soy peptone broth medium (TSB), Beijing Sanyao Technology Development Co., Ltd.; potato dextrose agar medium (PDA), potato dextrose water (PDB), Guangdong Huankai Microbiological Technology Co., Ltd.; nutrient broth medium, Beijing Luqiao Technology Co., Ltd.; sodium chloride, Tween 80, Sinopharm Chemical Reagent Co., Ltd.

[0053] 1.1.3 Test substances

[0054] Phenoxyethanol (hereinafter referred to as B, Beijing Bailingwei Technology Co., Ltd.); Propyl p-hydroxybenzoate (hereinafter referred to as P, Sigma); Methylisothiazolinone (hereinafter referred to as M, Sigma); Compound preservative combination (phenoxyethanol + propyl p-hydroxybenzoate + methylisothiazolinone) hereinafter referred to as BPM.

[0055] 1.1.4 Bacterial strains

[0056] Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC8739), Pseudomonas aeruginosa (ATCC9027), Candida albicans (ATCC10231), and Aspergillus niger (ATCC16404) were all from Guangdong Provincial Microbiological Culture Collection Center.

[0057] 1.1.5 Testing cosmetic emulsion samples

[0058] Different concentrations of compound preservative combinations (0.25+0.025+0.00125)% (hereinafter referred to as compound 1), (0.125+0.0125+0.000625)% (hereinafter referred to as compound 2), and (0.0625+0.00625+0.0003125)% (hereinafter referred to as compound 3) were added to the cosmetic emulsion formula, and a blank control group (without preservatives) was set up. The emulsion formula is shown in the table below.

[0059] Table 3 Emulsion formula ingredients

[0060]

[0061]

[0062] 1.2 Methods

[0063] 1.2.1 Anticorrosion test

[0064] Each different bacterial species was inoculated on the corresponding appropriate culture medium slant, and the bacteria were cultured in a 37°C incubator for 24 hours, and the fungi were cultured in a 25°C incubator for 72 hours. The test sample (50g sample) was placed in a sterile container and mixed with the bacterial and fungal suspensions to make the final bacterial concentration of 10 6 cfu / g, the final fungal concentration was 10 5 cfu / g. The samples were gently mixed and sampled at 0h, 1d, 3d, 7d, 14d, 21d, and 28d. After dilution with sterile saline, TSA and PDA plate counts were performed to test the bacterial content of the samples, which were converted into logarithmic values ​​for evaluation. The judgment criteria are shown in Table 4 (reference to the cosmetic preservative efficacy test methods provided by the United States Pharmacopoeia, the European Pharmacopoeia, the American Personal Care Products Association (PCPC), and ISO11930).

[0065] Table 4 Anticorrosion performance criteria

[0066]

[0067] Note: NI: Not increased

[0068] 2 Results

[0069] 2.1 Anticorrosion test results

[0070] From the results, we can see that compound 1 and compound 2 have inhibitory effects on bacteria and fungi and passed the antiseptic performance test; compound 3 does not meet the requirements for the inhibitory effect on bacteria and fungi and failed to pass the antiseptic performance test.

[0071] Table 5. Anticorrosion performance test results of different compound prescriptions

[0072]

[0073]

[0074] 3 Conclusion

[0075] Both Compound 1 and Compound 2 passed the antiseptic performance test. Compound 2 can still maintain a considerable inhibitory effect on fungi or bacteria when the concentration is only half of Compound 1, and it is lower than the minimum inhibitory concentration of healthy skin flora. Compound 3 has a weaker inhibitory effect on bacteria, and the 7-day R X The value is 1.35, which is less than 3, and cannot pass the antiseptic performance test; the 7-day R X The value is 1.55 which is greater than 1, but at 28 days R X The value has increased, so it cannot pass the anti-corrosion performance test.

[0076] Therefore, the concentration of the compound preservative (phenoxyethanol + propyl paraben + methylisothiazolinone) in cosmetics is (0.125 + 0.0125 + 0.000625)% which is the safe and effective concentration of the compound preservative, which can pass the preservative performance test and inhibit bacteria and fungi in the sample without inhibiting the healthy skin flora of the human body and destroying the human skin microecology.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite preservative combination for cosmetics, characterized in that include: Phenoxyethanol, propyl paraben, methylisothiazolinone, the weight percentages of the three components in the cosmetics are as follows: phenoxyethanol is 0.125-0.25%, propyl paraben is 0.0125-0.025%, and methylisothiazolinone is 0.000625-0.00125%.

2. The composite preservative combination for cosmetics according to claim 1, characterized in that The compound preservative combination consists of phenoxyethanol, propyl parahydroxybenzoate and methylisothiazolinone, and the weight percentages of the three components in the cosmetics are as follows: 0.125-0.25% of phenoxyethanol, 0.0125-0.025% of propyl parahydroxybenzoate, and 0.000625-0.00125% of methylisothiazolinone.

3. The composite preservative combination for cosmetics according to claim 1 or claim 2, wherein the weight percentages of the three components in the cosmetics are as follows: 0.125% of phenoxyethanol, 0.0125% of propyl paraben, and 0.000625% of methylisothiazolinone.

4. The composite preservative combination for cosmetics according to any one of claims 1 to 3, wherein the cosmetics are selected from one or more of facial cream, lotion, toner, shower gel, shampoo, conditioner, mask, facial mask, essence, and eye cream.

5. A cosmetic composition comprising the compound preservative combination according to any one of claims 1 to 3.

6. The cosmetic composition according to claim 5, wherein the preservative in the cosmetic composition comprises only the compound preservative combination according to any one of claims 1 to 3.

7. The cosmetic composition according to any one of claims 5 to 6, wherein the cosmetic composition is selected from one or more of a facial cream, an emulsion, a toner, a shower gel, a shampoo, a conditioner, a mask, a smear mask, an essence, and an eye cream.

8. Use of the compound preservative combination according to any one of claims 1 to 3 in the preparation of a cosmetic preservative.

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