CN117815456A - Water-based lubricant and preparation method thereof - Google Patents

Abstract

The invention provides an aqueous lubricant and a preparation method thereof, wherein the aqueous lubricant comprises the following components: polyol mixture, gelatin, lecithin, sodium alginate, polyvinylpyrrolidone, thickener, dipotassium glycyrrhizinate, methyl benzoate and deionized water; gelatin is dissolved in water to form gel as a primary network, sodium alginate, polyalcohol and the like are connected to the primary network formed by the gelatin through hydrogen bond action, so that a uniform and stable hydrogel network structure is obtained, and sorbitol with more moisture retention and lecithin with amphipathy are added, so that the gel has good film forming performance and high lubrication degree, and meanwhile, the functions of water locking and moisture retention can be fully achieved, and the action time of the lubricant is prolonged.

Description

Water-based lubricant and preparation method thereof

Technical field:

the invention relates to a lubricant, in particular to an aqueous lubricant and a preparation method thereof.

The background technology is as follows:

the female vaginal secretion is a viscous white or transparent liquid flowing out from vagina, and has the functions of lubricating and protecting vagina. 0.22% protein, 0.55% sodium chloride, 0.059% calcium and 0.31% inorganic salt; the pH is slightly acidic, generally 4.2 to 7. Insufficient vaginal secretion in women can lead to insufficient vaginal lubrication during sexual life, which is medically known as sexual arousal disorder, which can lead to female's inability to achieve sexual satisfaction in sexual life, and can also induce various diseases.

The human body lubricant sold in the market at present is a silicone oil lubricant which is mainly applied to sexual life, especially used as a lubricating liquid of condoms, plays a role in lubrication in the sexual intercourse process, and can increase vaginal lubrication, add sexual pleasure and reduce discomfort; meanwhile, the utility model is also widely used for the lubrication of the gynecological surgical instruments in hospitals and the daily vaginal nursing, and plays a role in preventing vaginal dryness, keratosclerosis and the like.

Due to technological developments and advances in physical life, silicone oil lubricants used in conventional condoms have been gradually replaced by aqueous lubricants. The reason for this is mainly: the silicone oil lubricant has relatively high price, high friction coefficient, poor lubrication degree, insufficient film forming property and difficult cleaning. The water-based lubricant can just fill the trouble and the defect brought by the silicone oil lubricant. In addition, the aqueous lubricant is similar to the vaginal secretion of women, does not cause allergy to human body, and improves the safety to a higher level compared with the silicone oil lubricant.

However, in the using process, particularly in the preservation process, the water content is easy to evaporate, so that the water-based lubricant has the problems of premature failure, insufficient acting time, insufficient lubricating performance, influence on sexual life experience and the like.

The invention comprises the following steps:

the invention aims to provide an aqueous lubricant and a preparation method thereof, and aims to solve the problems of premature failure, insufficient action time, insufficient lubricating performance, influence on sexual life experience and the like of the aqueous lubricant.

In order to achieve the technical purpose of the invention, the invention provides the aqueous lubricant which reduces the viscosity and the PH value environment of female vaginal secretion and improves the action time and the effect of lubrication on the basis.

The aqueous lubricant of the present invention comprises the following components: polyol mixture, gelatin, lecithin, sodium alginate, polyvinylpyrrolidone, thickener, dipotassium glycyrrhizinate, methyl benzoate and deionized water.

The aqueous lubricant also comprises a PH regulator, wherein the PH regulator has the function of simulating the PH environment of human vaginal secretion, so that the PH value of the aqueous lubricant is maintained in a weak acidic environment of 5-7, and the PH regulator is lactic acid or acetic acid.

In the aqueous lubricant of the present invention, the polyol mixture is a mixture of propylene glycol, glycerol and sorbitol. The polyol mixture has the functions of absorbing moisture, delaying volatilization and reducing the solidifying point, and the propylene glycol has low overall viscosity and good lubrication; glycerol has higher viscosity and poorer lubrication feeling, but has low price; sorbitol is a carbohydrate derivative containing only hydroxyl functional groups, is readily soluble in propylene glycol, glycerol, and has excellent moisture retention properties.

Gelatin is used as a macromolecular polypeptide polymer of collagen through partial hydrolysis, can form a gel film with fluidity and moisture retention in water at 35-40 ℃, and can improve the lubricity and the moisture retention of the lubricant. At a low temperature, the gel formed by gelatin and water is solid as a whole, and is difficult to flow. However, when the temperature is high, gelatin is dissolved in water, and it is difficult to form a gel.

Sodium alginate is polysaccharide salt extracted from natural plants, is a linear macromolecule, and hydroxyl and carboxyl in the molecular structure of the sodium alginate can form hydrogen bonds with water molecules to form viscous colloid through adsorption; meanwhile, the hydrogel can be linked on a primary gel network of gelatin by utilizing hydrogen bonds, so that the stability of the hydrogel network structure is maintained; meanwhile, the anti-inflammatory agent can also play an anti-inflammatory role by inhibiting the generation and release of inflammatory mediators.

Lecithin is also called phosphatidylcholine, has hydrophilic groups and lipophilic groups, the hydrophobic group fatty acid chain has good physical adsorption effect with the surface of latex, and the hydrophilic groups such as phosphoric acid, choline and the like have good affinity with mucous membrane tissues; when the hydrogel formed by the lubricant slides on the surface, lecithin can gather on the surface of the hydrogel, thereby keeping moisture and reducing the dynamic friction coefficient of the lubricant.

Polyvinylpyrrolidone has excellent biocompatibility and can be matched with other chemicals by means of hydrogen bonds, and is usually used as a cosolvent in lubricants.

The thickener comprises one or two of carboxymethyl cellulose and carboxyethyl cellulose. After the water-soluble thickening agent is dissolved in water, a viscous solution can be formed, and a thickening effect is achieved.

Dipotassium glycyrrhizinate is used as a desensitizer, methyl hydroxybenzoate is used as a bacteriostatic agent, and when the substances are added into the lubricant, the bacterial growth and allergy of the lubricant can be effectively reduced.

In the invention, gelatin is dissolved in water to form gel as a primary network, sodium alginate and the like are connected to the primary network formed by gelatin through the action of hydrogen bond formed by water molecules, so that a uniform and stable hydrogel network structure is obtained, and sorbitol with more moisture retention and lecithin with amphipathy are added, so that the gel has good film forming performance and high lubrication degree, and meanwhile, the functions of water locking and moisture retention can be fully achieved, and the action time of the lubricant is prolonged.

Specifically, in the aqueous lubricant of the present invention, the components thereof are, by mass fraction,

wherein, polyol mixture: 27-41 parts;

gelatin: 4-6 parts;

lecithin: 0.5-1 part;

sodium alginate: 1-3 parts;

polyvinylpyrrolidone: 0.2-0.5 part;

and (3) a thickening agent: 0.2-0.5 part;

dipotassium glycyrrhizinate: 0.01-0.05 part;

methyl paraben: 0.01-0.05 part;

deionized water: 50-60 parts.

Further, the polyol mixture includes: propylene glycol, glycerol and sorbitol in the mass ratio of (2-7): (20-26): (5-8).

The aqueous lubricant of the invention finally achieves a viscosity of 500-1500mpa.s; the dynamic friction coefficient is 0.2-0.5.

In order to further improve the water locking and moisturizing effects and prolong the acting time of the lubricant, 0.05-0.1 part of calcium chloride can be further added in the invention, so that the sodium alginate further forms a crosslinked hydrogel network structure.

The invention also provides a preparation method of the water-based lubricant, which comprises the following steps: the method comprises the following specific steps:

step (1): adding 4-6 parts of gelatin into 20-30 parts of deionized water, and stirring for 10-30min at 35-40 ℃ to form a primary crosslinked network;

step (2): adding 0.5-1 part of lecithin, 1-3 parts of sodium alginate, 0.2-0.5 part of thickener and the balance of deionized water into the mixture in the step (1), and stirring for 10-30min;

step (3): adding 27-41 parts of polyol mixture, and stirring for 10-30min; adding 0.2-0.5 polyvinylpyrrolidone, stirring for 5-10min, and regulating solution viscosity; finally, adding a PH regulator to regulate the PH of the solution to 5-7.

Further, 0.05 to 0.1 part of calcium chloride may be added in the step (2).

The viscosity and PH value of the invention are similar to those of the vaginal secretion of human body.

The aqueous lubricant can form a uniform and stable hydrogel network structure; the lubricant has good film forming performance and high lubrication degree, can fully play a role in water locking and moisture retention, and prolongs the action time of the lubricant. During actual use of the aqueous lubricant, lecithin may accumulate on the surface of the hydrogel, thereby reducing the dynamic friction coefficient of the lubricant.

The lubricant of the present invention can be used as a condom external lubricant or a medical instrument lubricant or a human body lubricant.

The specific embodiment is as follows:

in order to make the purposes, technical solutions and advantages of the implementation of the present invention more clear, the technical solutions of the present invention are further described below by means of specific embodiments. Those skilled in the art should appreciate that the examples are only for aiding in understanding the technical contents and effects of the present invention and should not be construed as limiting the present invention.

The present invention was carried out in total for 3 examples and 3 comparative examples.

Example 1:

step (1): adding 4 parts of gelatin into 20 parts of deionized water, and stirring for 30min at 40 ℃ to form a primary crosslinked network;

step (2): adding 1 part of lecithin, 1.5 parts of sodium alginate, 0.2 part of carboxymethyl cellulose, 0.02 part of dipotassium glycyrrhizinate, 0.02 part of methyl benzoate and 30 parts of deionized water into the mixture in the step (1), and stirring for 30min;

step (3): adding 4 parts of propylene glycol, 20 parts of glycerol and 6 parts of sorbitol, and stirring for 20min; adding 0.5 part of polyvinylpyrrolidone, stirring for 10min, and regulating the viscosity of the solution; lactic acid was added to adjust the pH of the solution to 6.

Example 2:

step (1): adding 6 parts of gelatin into 30 parts of deionized water, and stirring for 30min at 35 ℃ to form a primary crosslinked network;

step (2): adding 0.7 part of lecithin, 3 parts of sodium alginate, 0.5 part of carboxyethyl cellulose, 0.02 part of dipotassium glycyrrhizinate, 0.02 part of methyl benzoate and 30 parts of deionized water into the mixture in the step (1), and stirring for 20min;

step (3): adding 6 parts of propylene glycol, 24 parts of glycerol and 8 parts of sorbitol, and stirring for 30min; adding 0.2 part of polyvinylpyrrolidone, stirring for 5min, and regulating the viscosity of the solution; acetic acid was added to adjust the pH of the solution to 7.

Example 3:

the procedure was substantially the same as in example 2, except that 0.1 part more of calcium chloride was added in step (2).

Comparative example 1:

step (1): mixing 1 part of lecithin, 1.5 parts of sodium alginate, 0.2 part of carboxymethyl cellulose, 0.02 part of dipotassium glycyrrhizinate, 0.02 part of methyl benzoate and 50 parts of deionized water under stirring for 30min;

step (2): adding 4 parts of propylene glycol, 20 parts of glycerol and 6 parts of sorbitol, and stirring for 20min; adding 0.5 part of polyvinylpyrrolidone, stirring for 10min, and regulating the viscosity of the solution; lactic acid was added to adjust the pH of the solution to 6.

Comparative example 2:

step (1): adding 6 parts of gelatin into 30 parts of deionized water, and stirring for 30min to form a primary crosslinked network;

step (2): adding 3 parts of sodium alginate, 0.5 part of carboxyethyl cellulose, 0.02 part of dipotassium glycyrrhizinate, 0.02 part of methyl benzoate and 30 parts of deionized water into the mixture in the step (1), and stirring for 20min;

step (3): adding 6 parts of propylene glycol, 24 parts of glycerol and 8 parts of sorbitol, and stirring for 30min; adding 0.2 part of polyvinylpyrrolidone, stirring for 5min, and regulating the viscosity of the solution; acetic acid was added to adjust the pH of the solution to 7.

Comparative example 3:

step (1): adding 6 parts of gelatin into 30 parts of deionized water, and stirring for 30min to form a primary crosslinked network;

step (2): adding 0.7 part of lecithin, 3 parts of sodium alginate, 0.5 part of carboxyethyl cellulose, 0.02 part of dipotassium glycyrrhizinate, 0.02 part of methyl benzoate and 30 parts of deionized water into the mixture in the step (1), and stirring for 20min;

step (3): adding 8 parts of propylene glycol and 30 parts of glycerol, and stirring for 30min; adding 0.2 part of polyvinylpyrrolidone, stirring for 5min, and regulating the viscosity of the solution; acetic acid was added to adjust the pH of the solution to 7.

The following performance tests were conducted on the aqueous lubricants prepared in examples 1 to 3 and comparative examples 1 to 3.

1. Viscosity.

The viscosity was measured with an NDJ-5S type digital viscosimeter at 40℃using a rotor No. 2, 12 rpm.

2. Moisture retention.

5g of each of the samples of examples 1 to 3 and comparative examples 1 to 3 was weighed, placed in a weighing bottle without covering, placed in a constant temperature and humidity box at 40℃and 30% Relative Humidity (RH) at 24h intervals, taken out and weighed, and the quality difference was calculated. The smaller the quality difference, the better the moisturizing performance.

Mass difference = (G1-G2)/(G1-G) 100;

g1: initially the weight of the sample along with the weighing flask, G2: after a defined time interval the sample is taken together with the weight of the weighing flask. And G, weighing the weight of the bottle.

3. Lubricity.

The dynamic coefficient of friction μ of the lubricants of each example and comparative example was measured as in the determination of the coefficient of friction of plastic films and sheets of GB 10006-1988. In addition, the surface of the latex condom wetted by the lubricant is used as a test surface, the friction pair surface is pigskin, the test surface is placed in a constant temperature and humidity box with the Relative Humidity (RH) of 30% at 40 ℃, the linear repeated friction speed is 60 times per minute, and the dynamic friction coefficient of the friction surface of the condom is tested after three minutes, so that the lubrication aging of the lubricant of each embodiment and comparative example of the surface of the latex condom is evaluated.

4. Vaginal irritation test.

The test is carried out by referring to the method specified in GB/T168880-2017, the rabbit vaginal stimulation test is divided into sesame oil extraction and 0.9% sodium chloride injection extraction, the extremely light stimulation is judged according to the specified vaginal stimulation integral less than or equal to 4, and the integral 0 is no stimulation.

5. Sensitization test.

Skin sensitization test was performed with reference to the method specified in ISO10993-10:2010, guinea pig maximum method, 0.9% sodium chloride injection leaching, grade 0 no sensitization reaction, and grades 1-3 correspond to mild to severe sensitization levels, respectively.

6. Pinhole and blast experiments.

According to the guiding method in GB/T7544-2019, after the lubricant in the embodiment of the application is applied to a male condom, pinhole and explosion tests are passed, so that the lubricant does not adversely affect the quality of the condom.

	Viscosity (Pa/s)	Moisture retention	Coefficient of dynamic friction	Vaginal irritation test	Sensitization test
						Example 1	535	73.6	0.30	0	0
Example 2	781	75.9	0.21	0	0
						Example 3	1164	83.2	0.37	0	0
Comparative example 1	337	54.8	0.64	0	0
						Comparative example 2	768	69.1	0.71	0	0
Comparative example 3	694	61.8	0.27	0	0

From a comparison of example and comparative example 1, the lubricant failed to form a hydrogel structure having fluidity in the absence of the primary crosslinked network of gelatin, and thus failed to meet the use requirements in terms of viscosity, moisture retention, and dynamic friction coefficient.

From a comparison of example and comparative example 2, when lecithin is not added, lecithin cannot form a hydrophilic structure on the surface, and thus has adverse effects on both the moisture retention and the coefficient of dynamic friction.

From a comparison of example and comparative example 3, when sorbitol is not contained in the mixed alcohol, but only propylene glycol and glycerol are used as the mixed alcohol, the moisture retention is significantly reduced, resulting in a reduction of the overall lubrication time, affecting the user experience.

In addition, from a comparison of examples 2 and 3, sodium alginate and calcium ions form a further crosslinked network when calcium chloride is further added, and the generation of the crosslinked network makes the moisture retention of the lubricant more excellent, thereby increasing the action time thereof, and the influence on the lubrication effect thereof is negligible as can be seen from the dynamic friction coefficient.

The present application is not limited to the above embodiment. The above embodiments are merely examples, and embodiments having substantially the same configuration and the same effects as those of the technical idea within the scope of the present application are included in the technical scope of the present application. Further, various modifications that can be made to the embodiments and other modes of combining some of the constituent elements in the embodiments, which are conceivable to those skilled in the art, are also included in the scope of the present application within the scope not departing from the gist of the present application.

Claims (9)

1. An aqueous lubricant comprising the following components: polyol mixture, gelatin, lecithin, sodium alginate, polyvinylpyrrolidone, thickener, dipotassium glycyrrhizinate, methyl benzoate and deionized water;

the components of the composition are calculated according to mass fraction,

wherein, polyol mixture: 27-41 parts;

gelatin: 4-6 parts;

lecithin: 0.5-1 part;

sodium alginate: 1-3 parts;

polyvinylpyrrolidone: 0.2-0.5 part;

and (3) a thickening agent: 0.2-0.5 part;

dipotassium glycyrrhizinate: 0.01-0.05 part;

methyl paraben: 0.01-0.05 part;

deionized water: 50-60 parts;

the thickener comprises one or two of carboxymethyl cellulose and carboxyethyl cellulose.

2. The aqueous lubricant of claim 1, wherein the polyol mixture is a combination of propylene glycol, glycerol, and sorbitol.

3. The aqueous lubricant according to claim 2, wherein the mass ratio of propylene glycol, glycerol and sorbitol is (2-7): (20-26): (5-8).

4. The aqueous lubricant of claim 1, wherein the composition further comprises a PH adjuster to maintain a PH of 5 to 7.

5. The aqueous lubricant according to claim 4, wherein the pH adjustor is lactic acid or acetic acid.

6. The aqueous lubricant according to claim 1, characterized in that the viscosity is 500-1500mpa.s; the dynamic friction coefficient is 0.2-0.5.

7. The aqueous lubricant according to claim 6, wherein 0.05 to 0.1 parts of calcium chloride is further added.

8. A process for preparing an aqueous lubricant according to claim 1 to 6, comprising the steps of,

step (1): adding 4-6 parts of gelatin into 20-30 parts of deionized water, and stirring for 10-30min at 35-40 ℃ to form a primary crosslinked network;

step (2): adding 0.5-1 part of lecithin, 1-3 parts of sodium alginate, 0.2-0.5 part of cosolvent and the rest of deionized water into the mixture in the step (1), and stirring for 10-30min;

step (3): adding 27-41 parts of polyol mixture, and stirring for 10-30min; adding 0.2-0.5 polyvinylpyrrolidone, stirring for 5-10min, and regulating solution viscosity; finally, adding a PH regulator to regulate the PH of the solution to 5-7.

9. The method according to claim 8, wherein 0.05 to 0.1 parts of calcium chloride is further added in step (2).