An antibacterial hand sanitizer and its preparation method

Abstract

This invention belongs to the field of handwashing technology, specifically relating to an antibacterial hand sanitizer and its preparation method. The hand sanitizer comprises the following raw materials in parts by weight: 4-9 parts modified nano-attapulgite clay, 1-5 parts *Hydrocotyle vulgaris* polysaccharide, 1-5 parts plant essential oil, 15-22 parts surfactant, 10-17 parts moisturizer, 0.1-0.3 parts pH adjuster, 1-3 parts thickener, and 90-100 parts deionized water. The preparation process of the modified nano-attapulgite clay is as follows: S1. Add the pretreated nano-attapulgite clay to an ethanol-water solution, then add γ-aminopropyltriethoxysilane, and stir to obtain aminated nano-attapulgite clay; S2. Add the aminated attapulgite clay to a solvent, then add gallic acid and triethylamine, and heat and stir to obtain modified nano-attapulgite clay. Modified attapulgite clay can improve the stability of gallic acid in the product, reduce skin irritation, and, when used in combination with *Hydrocotyle vulgaris* polysaccharide, exhibits good antibacterial properties.

Description

Technical Field

[0001] This invention belongs to the field of hand care technology, specifically relating to an antibacterial hand sanitizer and its preparation method. Background Technology

[0002] In daily life and medical settings, hand hygiene and disinfection are crucial measures to prevent cross-infection and disease transmission. Antibacterial hand sanitizers, due to their convenience and effectiveness, have become indispensable personal care products. However, the antibacterial properties of many commercially available antibacterial hand sanitizers gradually decline during prolonged storage or use, affecting their effectiveness. Therefore, developing an antibacterial hand sanitizer with long-lasting antibacterial properties, high safety, and stability has become a current research hotspot.

[0003] Currently, there are many types of antibacterial hand sanitizers on the market, with main ingredients including surfactants, antibacterial agents, moisturizers, and fragrances. Among these, antibacterial agents are the key factor determining the antibacterial effect. However, these antibacterial agents have the following problems during use: the antibacterial components in hand sanitizers may degrade under the influence of environmental factors such as temperature, leading to a decrease in antibacterial performance. In addition, some antibacterial agents are highly irritating to the skin, and long-term use may cause skin problems.

[0004] Gallic acid is a natural antibacterial agent with a broad antibacterial spectrum, exhibiting good inhibitory effects against a variety of bacteria, fungi, and viruses. However, gallic acid itself is somewhat irritating and may cause skin discomfort.

[0005] Attapulgite, primarily composed of magnesium aluminum silicate, is a natural inorganic mineral. It possesses a unique chain-like layered structure and extremely high specific surface area (9.6~36 m² / g) and porosity, allowing it to adsorb large amounts of water and other molecules. It also exhibits excellent adsorption properties for heavy metal ions and organic pollutants. However, when attapulgite is prepared into nanoscale particles, the increased surface area and energy lead to an unstable state, making particle aggregation more likely. This can affect its dispersibility and uniformity in other media.

[0006] Based on the above background technology, the present invention provides an antibacterial hand sanitizer and its preparation method to solve the above-mentioned problems. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, the primary objective of this invention is to provide an antibacterial hand sanitizer.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] An antibacterial hand sanitizer comprises the following raw materials in parts by weight: 4-9 parts modified nano-attapulgite clay, 1-5 parts seaweed polysaccharide, 1-5 parts plant essential oil, 15-22 parts surfactant, 10-17 parts moisturizer, 0.1-0.3 parts pH adjuster, 1-3 parts thickener, and 90-100 parts deionized water.

[0010] The preparation process of the modified nano-attapulgite is as follows:

[0011] S1. Add the pretreated nano-attapulgite to an aqueous ethanol solution, then add γ-aminopropyltriethoxysilane and stir to react, to obtain aminated nano-attapulgite.

[0012] S2. Add the aminated nano-attapulgite to the solvent, then add gallic acid and triethylamine, heat and stir to react, and obtain the modified nano-attapulgite.

[0013] Furthermore, the mass ratio of the pretreated nano-attapulgite clay, γ-aminopropyltriethoxysilane, and ethanol aqueous solution in S1 is 1g:(0.1-0.2)g:(10-15)mL.

[0014] Furthermore, the mass ratio of the aminated nano-attapulgite, gallic acid, and triethylamine in S2 is 1:(0.2-0.4):(0.5-0.9).

[0015] Furthermore, the heating and stirring temperature in S2 is 80-90℃, and the time is 1-2 hours.

[0016] Further, the ethanol-water solution in S1 is obtained by mixing ethanol and water in a volume ratio of (3-5):1; the solvent in S2 is DMF.

[0017] Furthermore, the pretreatment process of the nano-attapulgite in S1 is as follows: calcining the nano-attapulgite at 150-230℃ for 30-90 minutes.

[0018] Furthermore, the plant essential oil is lavender essential oil or orange essential oil; the moisturizer is any one of glycerin, propylene glycol, and polyethylene glycol; the thickener is xanthan gum or carbomer; the surfactant is cocamidopropyl betaine or dodecyl glucoside; and the pH adjuster is sodium citrate.

[0019] Another object of the present invention is to provide a method for preparing an antibacterial hand sanitizer.

[0020] The purpose of the present invention is achieved through the following technical solutions:

[0021] A method for preparing an antibacterial hand sanitizer includes the following steps: according to the stated weight ratio, a surfactant and a humectant are added to water, heated and stirred, and then modified nano-attapulgite clay, seaweed polysaccharide, plant essential oil, thickener, and pH adjuster are added and stirred evenly.

[0022] The present invention has the following advantages over the prior art:

[0023] 1. In this invention, nano-attapulgite is calcined to increase its internal pore size, then γ-aminopropyltriethoxysilane is added for amination, and then it is reacted with gallic acid. Through the reaction between the amino groups on the attapulgite and the carboxyl groups of gallic acid, gallic acid is attached to the amination nano-attapulgite, thereby improving the stability of gallic acid and improving the dispersion uniformity of the nano-attapulgite.

[0024] 2. This invention demonstrates through experiments that the combined use of modified attapulgite clay and sea hazel polysaccharide not only improves the stability of gallic acid and reduces its irritation, but also enhances the antibacterial stability of hand sanitizer, providing consumers with a safer, more effective, and environmentally friendly hand cleaning product.

[0025] 3. This invention provides a method for preparing an antibacterial hand sanitizer, which is simple to operate and suitable for industrial production. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Test methods in the following embodiments that do not specify specific experimental conditions are generally performed according to conventional experimental conditions or experimental conditions recommended by the manufacturer. Unless otherwise specified, the reagents and raw materials used in the present invention are commercially available.

[0027] Example 1

[0028] An antibacterial hand sanitizer comprises the following raw materials in parts by weight: 6 parts modified nano-attapulgite clay, 3 parts seaweed polysaccharide, 3 parts orange essential oil, 18 parts cocamidopropyl betaine, 15 parts glycerin, 2 parts xanthan gum, 0.2 parts sodium citrate, and 95 parts deionized water.

[0029] The preparation process of the modified nano-attapulgite is as follows:

[0030] S1. Calcine nano-attapulgite at 200℃ for 60 min to obtain pretreated nano-attapulgite; add the pretreated nano-attapulgite to an ethanol-water solution (ethanol and water are mixed in a volume ratio of 4:1), and then add γ-aminopropyltriethoxysilane, wherein the ratio of pretreated nano-attapulgite, γ-aminopropyltriethoxysilane, and ethanol-water solution is 1 g:0.15 g:12 mL; stir the reaction at room temperature for 2 h to obtain aminated nano-attapulgite;

[0031] S2. The aminated nano-attapulgite is added to DMF, followed by gallic acid and triethylamine, wherein the mass ratio of aminated nano-attapulgite, gallic acid and triethylamine is 1:0.2:0.8. The mixture is stirred at 85°C for 1.5 h, and then filtered, washed and dried to obtain modified nano-attapulgite.

[0032] The preparation process of sea hareweed polysaccharide is as follows:

[0033] After drying, *Hydrocotyle vulgaris* was pulverized and passed through a 50-mesh sieve to obtain *Hydrocotyle vulgaris* powder. The powder was then placed in a steam explosion apparatus and subjected to pressure treatment at 2 MPa for 1 min to obtain the treated powder. Ten times the volume of pure water was added to the treated powder, and the mixture was refluxed at 100°C for 50 min. After filtration, five times the volume of pure water was added to the residue, and the mixture was refluxed at 100°C for 50 min. The residue was filtered again, and the two filtrates were combined. The filtrates were then concentrated using a rotary evaporator. Ethanol was added to the concentrate until the ethanol concentration reached 85%, and the mixture was subjected to alcohol precipitation for 24 h. The precipitate was then centrifuged at 5000 rpm for 20 min, and the precipitate was crude *Hydrocotyle vulgaris* polysaccharide. Sevage reagent was added to the crude polysaccharide to remove proteins, and the mixture was centrifuged at 5500 rpm for 15 min. This process was repeated twice. The resulting product was then concentrated and freeze-dried to obtain the final product.

[0034] A method for preparing an antibacterial hand sanitizer includes the following steps:

[0035] According to the above weight ratio, cocamidopropyl betaine and glycerin are added to water, heated to 50°C and stirred. Modified nano-attapulgite clay, seaweed polysaccharide, orange essential oil, xanthan gum and sodium citrate are added under the heating condition of 50°C. After mixing evenly, the antibacterial hand sanitizer is obtained.

[0036] Example 2

[0037] An antibacterial hand sanitizer comprises the following raw materials in parts by weight: 4 parts modified nano-attapulgite clay, 1 part seaweed polysaccharide, 1 part lavender essential oil, 15 parts dodecyl glucoside, 10 parts propylene glycol, 1 part carbomer, 0.1 parts sodium citrate, and 90 parts deionized water.

[0038] The preparation process of the modified nano-attapulgite is as follows:

[0039] S1. Calcine nano-attapulgite at 150℃ for 90 min to obtain pretreated nano-attapulgite; add the pretreated nano-attapulgite to an ethanol-water solution (ethanol and water are mixed in a volume ratio of 4:1), and then add γ-aminopropyltriethoxysilane, wherein the amounts of pretreated nano-attapulgite, γ-aminopropyltriethoxysilane, and ethanol-water solution are 1 g: 0.1 g: 10 mL; stir the reaction at room temperature for 2 h to obtain aminated nano-attapulgite;

[0040] S2. The aminated nano-attapulgite is added to DMF, followed by gallic acid and triethylamine, wherein the mass ratio of aminated nano-attapulgite, gallic acid and triethylamine is 1:0.3:0.5; the mixture is stirred at 80°C for 2 hours, and then filtered, washed and dried to obtain modified nano-attapulgite.

[0041] The preparation process of the polysaccharide from *Hydrocotyle vulgaris* is the same as in Example 1.

[0042] A method for preparing an antibacterial hand sanitizer includes the following steps:

[0043] According to the above weight ratio, dodecyl glucoside and propylene glycol are added to water, heated to 50°C and stirred. Modified nano-attapulgite clay, seaweed polysaccharide, lavender essential oil, carbomer and sodium citrate are added under the heating condition of 50°C. After mixing evenly, the antibacterial hand sanitizer is obtained.

[0044] Example 3

[0045] An antibacterial hand sanitizer comprises the following raw materials in parts by weight: 9 parts modified nano-attapulgite clay, 5 parts seaweed polysaccharide, 5 parts orange essential oil, 22 parts cocamidopropyl betaine, 17 parts polyethylene glycol, 3 parts xanthan gum, 0.3 parts sodium citrate, and 100 parts deionized water.

[0046] The preparation process of the modified nano-attapulgite is as follows:

[0047] S1. Calcine nano-attapulgite at 230℃ for 30 min to obtain pretreated nano-attapulgite; add the pretreated nano-attapulgite to an ethanol-water solution (ethanol and water are mixed in a volume ratio of 4:1), and then add γ-aminopropyltriethoxysilane, wherein the ratio of pretreated nano-attapulgite, γ-aminopropyltriethoxysilane, and ethanol-water solution is 1 g:0.2 g:15 mL; stir the reaction at room temperature for 2 h to obtain aminated nano-attapulgite;

[0048] S2. The aminated nano-attapulgite is added to DMF, followed by gallic acid and triethylamine, wherein the mass ratio of aminated nano-attapulgite, gallic acid and triethylamine is 1:0.4:0.9; the mixture is stirred at 90°C for 1 hour, and then filtered, washed and dried to obtain modified nano-attapulgite.

[0049] The preparation process of sea hail polysaccharide is the same as in Example 1.

[0050] A method for preparing an antibacterial hand sanitizer includes the following steps:

[0051] According to the above weight ratio, cocamidopropyl betaine and polyethylene glycol are added to water, heated to 50°C and stirred. Modified nano-attapulgite clay, seaweed polysaccharide, orange essential oil, xanthan gum and sodium citrate are added under the heating condition of 50°C. After mixing evenly, the antibacterial hand sanitizer is obtained.

[0052] Comparative Example 1

[0053] A hand sanitizer comprises the following raw materials in parts by weight: 6 parts nano-attapulgite clay, 3 parts seaweed polysaccharide, 3 parts orange essential oil, 18 parts cocamidopropyl betaine, 15 parts glycerin, 2 parts xanthan gum, 0.1 parts sodium citrate, and 95 parts deionized water; the other components are consistent with those in Example 1.

[0054] Comparative Example 2

[0055] A hand sanitizer comprises the following raw materials in parts by weight: 5 parts nano-attapulgite clay, 1 part gallic acid, 3 parts seaweed polysaccharide, 3 parts orange essential oil, 18 parts cocamidopropyl betaine, 15 parts glycerin, 2 parts xanthan gum, 0.1 parts sodium citrate, and 95 parts deionized water; the other components are consistent with those in Example 1.

[0056] Comparative Example 3

[0057] A hand sanitizer comprises the following raw materials in parts by weight: 6 parts modified nano-attapulgite clay, 3 parts orange essential oil, 18 parts cocamidopropyl betaine, 15 parts glycerin, 2 parts xanthan gum, 0.1 parts sodium citrate, and 95 parts deionized water; the other components are consistent with those in Example 1.

[0058] Test case

[0059] Experimental Example 1

[0060] 1. Antibacterial test:

[0061] The test strains were *Escherichia coli* and *Staphylococcus aureus*, and the concentrations of both *E. coli* and *S. aureus* suspensions were adjusted to 3.0 × 10⁻⁶. 6CFU / mL. Take 10 mL of the hand sanitizer prepared in Examples 1-3 and Comparative Examples 1-3, sterilize it, and add it to a sterile test tube. Add 100 µL of Escherichia coli suspension and 100 µL of Staphylococcus aureus suspension to the sterile test tube respectively, and incubate for 2 min. Use a sterile pipette to take 0.5 mL of the liquid in the above sterile test tube and add it to 4.5 mL of neutralizing agent (1 g of sodium thiosulfate added to 100 mL of 0.03 mol / L phosphate buffer, steam sterilized at 121 °C for 20 min) and mix well. After 10 min, take 200 µL of each and inoculate it onto the culture medium. Spread it evenly with a spreader, and then incubate it upside down at 37 °C for 48 h. Count the number of viable colonies and calculate the antibacterial rate. Replace the hand sanitizer with double-distilled water and perform the same treatment as a blank control group.

[0062] Antibacterial rate = (average colony count in blank control group - average colony count in experimental group) / average colony count in blank control group × 100%; each group was tested in 3 parallel experiments, and the antibacterial rate was the average of the 3 parallel experiments. The results are shown in Table 1.

[0063] Table 1

[0064]

[0065] As shown by the experimental data in Table 1, the hand sanitizers of Examples 1-3 of the present invention have good antibacterial properties. Compared with Example 1, the antibacterial rates of Comparative Examples 1 and 3 decreased, indicating that the combined use of modified attapulgite clay and seaweed polysaccharide can improve the antibacterial properties of the hand sanitizer.

[0066] 2. Antibacterial stability test:

[0067] Take 10 mL of the hand sanitizers from Examples 1-3 and Comparative Examples 1-3 above and place them at 54℃ and 75% relative humidity for 14 days. Following the above antibacterial test procedure, test the antibacterial rate of each group of hand sanitizers. The results are shown in Table 2.

[0068] Table 2

[0069]

[0070] As shown in Table 2, the hand sanitizers of Examples 1-3 still have a good antibacterial rate after being placed at 54°C and 75% relative humidity for two weeks.

[0071] Compared to Example 1, Comparative Example 2 directly mixed nano-attapulgite and gallic acid, Comparative Example 1 replaced modified nano-attapulgite with nano-attapulgite, and Comparative Example 3 omitted *Hydrocotyle vulgaris* polysaccharide. All three groups showed varying degrees of decrease in antibacterial rates. Analysis shows that grafting gallic acid onto amination-treated attapulgite enhances the stability of gallic acid in hand sanitizer, allowing it to distribute stably and achieve a long-lasting antibacterial effect while reducing skin irritation. Furthermore, modified attapulgite can be used in combination with *Hydrocotyle vulgaris* polysaccharide to jointly enhance the antibacterial activity and stability of the hand sanitizer.

[0072] Experimental Example 2

[0073] The stability of the hand sanitizers obtained in Examples 1-3 and Comparative Examples 1-3 was tested according to the testing standards of "Special Hand Sanitizers GB19877.1—2005". The specific steps are as follows:

[0074] Take 10 mL of the hand sanitizers from Examples 1-3 and Comparative Examples 1-3 above, and place them at -5℃ and 40℃ for 24 hours respectively. Then take them out and wait for them to return to room temperature. Observe whether they show phenomena such as layering. The results are shown in Table 3.

[0075] Table 3

[0076]

[0077] As shown in Table 3, the antibacterial hand sanitizer of the present invention exhibits good stability, showing no stratification or turbidity after being placed at 40℃ and -5℃ for 24 hours. Compared with Example 1, Comparative Example 3 omitted the sea haystack polysaccharide, and the hand sanitizer showed varying degrees of stratification under both hot and cold environments. These phenomena indicate that the antibacterial hand sanitizer has poor stability. The sea haystack polysaccharide can be used in combination with modified attapulgite clay to jointly improve the stability of the hand sanitizer.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. An antibacterial hand sanitizer, characterized in that, The raw materials include the following parts by weight: 4-9 parts modified nano-attapulgite, 1-5 parts seaweed polysaccharide, 1-5 parts plant essential oil, 15-22 parts surfactant, 10-17 parts humectant, 0.1-0.3 parts pH adjuster, 1-3 parts thickener, and 90-100 parts deionized water. The preparation process of the modified nano-attapulgite is as follows: S1. Add the pretreated nano-attapulgite to an aqueous ethanol solution, then add γ-aminopropyltriethoxysilane and stir to react, to obtain aminated nano-attapulgite. S2. The aminated nano-attapulgite is added to a solvent, then gallic acid and triethylamine are added, and the mixture is heated and stirred to react, thereby obtaining modified nano-attapulgite. The preparation process of sea hareweed polysaccharide is as follows: After drying, *Hydrocotyle vulgaris* was pulverized and passed through a 50-mesh sieve to obtain *Hydrocotyle vulgaris* powder. The powder was then placed in a steam explosion apparatus and subjected to pressure treatment at 2 MPa for 1 min to obtain the treated powder. Ten times the volume of pure water was added to the treated powder, and the mixture was refluxed at 100°C for 50 min. After filtration, five times the volume of pure water was added to the residue, and the mixture was refluxed at 100°C for 50 min. The residue was filtered again, and the two filtrates were combined. The filtrates were then concentrated using a rotary evaporator. Ethanol was added to the concentrate until the ethanol concentration reached 85%, and the mixture was subjected to alcohol precipitation for 24 h. The precipitate was then centrifuged at 5000 rpm for 20 min, and the precipitate was crude *Hydrocotyle vulgaris* polysaccharide. Sevage reagent was added to the crude polysaccharide to remove proteins, and the mixture was centrifuged at 5500 rpm for 15 min. This process was repeated twice. The resulting product was then concentrated and freeze-dried to obtain the final product.

2. The antibacterial hand sanitizer according to claim 1, characterized in that, The mass ratio of the pretreated nano-attapulgite clay, γ-aminopropyltriethoxysilane, and ethanol aqueous solution in S1 is 1 g:(0.1-0.2) g:(10-15) mL.

3. The antibacterial hand sanitizer according to claim 1, characterized in that, The mass ratio of the aminated nano-attapulgite, gallic acid, and triethylamine in S2 is 1:(0.2-0.4):(0.5-0.9).

4. The antibacterial hand sanitizer according to claim 1, characterized in that, The heating and stirring temperature in S2 is 80-90℃, and the time is 1-2 hours.

5. The antibacterial hand sanitizer according to claim 1, characterized in that, The ethanol-water solution in S1 is obtained by mixing ethanol and water in a volume ratio of (3-5):1; the solvent in S2 is DMF.

6. The antibacterial hand sanitizer according to claim 1, characterized in that, The pretreatment process of the nano-attapulgite clay described in S1 is as follows: calcining the nano-attapulgite clay at 150-230℃ for 30-90 minutes.

7. The antibacterial hand sanitizer according to claim 1, characterized in that, The plant essential oil is lavender essential oil or orange essential oil; the moisturizer is any one of glycerin, propylene glycol, and polyethylene glycol; the thickener is xanthan gum or carbomer; the surfactant is cocamidopropyl betaine or dodecyl glucoside; and the pH adjuster is sodium citrate.

8. A method for preparing an antibacterial hand sanitizer according to any one of claims 1-7, characterized in that, Includes the following steps: According to the stated weight ratio, the surfactant and humectant are added to deionized water, heated and stirred, and then modified nano-attapulgite clay, seaweed polysaccharide, plant essential oil, thickener, and pH adjuster are added and stirred evenly to obtain the final product.

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