A microneedle semi-embedded gel mask and its preparation method

Abstract

This invention discloses a microneedle semi-embedded gel mask and its preparation method. The preparation method involves mixing nanocellulose, sodium alginate, and an essence, then pouring the mixture into a mold. A layer of microneedles is then evenly sprinkled onto the mold surface, followed by immersion in a salt solution for complete gelation, resulting in the microneedle semi-embedded gel mask. The microneedle semi-embedded gel mask obtained by this invention can form numerous micropores on the skin surface to promote transdermal absorption of the essence. Furthermore, because the microneedles are tightly encapsulated by the gel, no microneedles remain on the face after the mask is applied, allowing for rapid healing of skin wounds.

Description

Technical Field

[0001] This invention belongs to the field of cosmetics, specifically relating to a microneedle semi-embedded gel mask and its preparation method. Background Technology

[0002] Human skin protects the body from external damage and prevents the loss of nutrients, moisture, and electrolytes, playing a crucial role in maintaining the stability of the body's internal environment. The skin consists of three parts: the epidermis, dermis, and subcutaneous tissue. The outermost layer of the epidermis, the stratum corneum, is approximately 10-20 micrometers thick and has a strong barrier function. The stratum corneum is mainly composed of keratinized cells and lipids in the intercellular spaces, resembling a "cement mortar" structure. This structure effectively protects the skin from the invasion of harmful external substances. The stratum corneum is the main site for the skin to absorb external substances. Because the intercellular spaces of the stratum corneum are mainly composed of lipids, it can absorb relatively small, fat-soluble substances, but it has difficulty absorbing water-soluble substances. However, many key functional components of human skin tissue, such as hyaluronic acid, collagen, and ceramides, are all water-soluble substances. Therefore, the transdermal absorption of active ingredients in skincare products has always been a key research topic in this field.

[0003] Microneedles are spindle-shaped, hard needle-like materials extracted from marine sponges. Due to their small size, high hardness, and environmentally friendly nature, they have been widely used in cosmetics in recent years to improve the permeability of active ingredients and promote skin self-repair. These microneedles have a diameter of 10–30 micrometers and a length of 100–1000 micrometers, resulting in extremely minor skin trauma and no scarring. However, current products containing microneedles are usually formulated as creams with various functional ingredients and applied to the skin surface. After a certain period of application, they need to be washed off. However, because these microneedles have already penetrated the skin, they remain embedded in the epidermis even after washing, causing a noticeable stinging sensation after use. This stinging sensation can last for 3–5 days until the skin naturally expels the microneedles. Therefore, developing a microneedle skincare product that can improve the permeability of active ingredients, promote skin self-repair, and is easy or requires no rinsing after use without harming the skin is a pressing problem with significant practical value. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a method for preparing a microneedle semi-embedded gel mask.

[0005] This invention uses nanocellulose, sodium alginate, essence, and microneedles as raw materials to create a gel mask. Because nanocellulose has a shear-thinning effect, the gel mask preparation process is unaffected by viscosity. Furthermore, nanocellulose's excellent thickening effect in this system gives the gel mask the property of solidification, allowing the microneedles, added in a special way, to be semi-embedded on the surface of the mask solution without sinking. In addition, the shrinkage properties during gelation ensure that the microneedles are tightly bound within the gel, preventing them from falling off. This results in a microneedle-embedded gel mask. This microneedle-embedded gel mask can partially disrupt the stratum corneum of the skin during application, forming numerous microchannels to promote transdermal absorption of the active ingredients in the mask. After use, the microneedles can be removed directly by removing the gel mask, leaving no residue on the skin surface and preventing continuous irritation and pain. The wounds heal within 2-3 hours after use, greatly reducing user discomfort.

[0006] Another object of the present invention is to provide a microneedle semi-embedded gel mask prepared by the above preparation method.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing a microneedle semi-embedded gel mask includes the following steps:

[0009] (1) Dissolve the essence components in water, add sodium alginate and nanocellulose, mix evenly and pour into a mold, then evenly sprinkle microneedles through filter cloth to obtain precursor gel solution;

[0010] (2) The precursor gel solution is immersed in the salt solution and after molding, a microneedle semi-embedded gel mask is obtained and stored in the essence environment.

[0011] Preferably, the essence in step (1) consists of at least one of hyaluronic acid, niacinamide, collagen, ceramide, ascorbyl glucoside AA2G and bisabolol.

[0012] Preferably, in step (1), before sprinkling the microneedles, the product contains, by weight percentage, 0.1-8.0% essence, 0.3-1.0% sodium alginate, 0.5-1.0% nanocellulose, and the remainder is water.

[0013] Preferably, the microneedles in step (1) are at least one of plant microneedles and sponge microneedles.

[0014] Preferably, the microneedles in step (1) have a diameter of 10 to 30 micrometers, a length of 100 to 1000 micrometers, and a purity of 70% or higher.

[0015] Preferably, the mass of the microneedles in step (1) is 10–120 g / m² of the area of ​​the precursor gel solution in the mold. 2 .

[0016] Preferably, before adding the microneedles in step (1), the mass of the solution is 1550 g / m² of the bottom area of ​​the mold. 2 .

[0017] Preferably, the filter cloth in step (1) has a pore size of 80 to 200 mesh.

[0018] Preferably, the salt solution in step (2) is at least one of 0.1-2 wt% calcium chloride solution, 0.1-2 wt% copper chloride solution and 0.1-2 wt% ferric chloride solution; the solidification time in the salt solution is 10-40 min.

[0019] Preferably, the essence environment in step (2) refers to an aqueous solution of 0.1 to 8 wt% essence; the mass ratio of the microneedle semi-embedded gel mask to the aqueous essence solution is 1:1 to 1:3.

[0020] The microneedle semi-embedded gel mask prepared by the above method.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] (1) This invention utilizes the solidification and shaping properties of gel masks, embedding microneedles semi-embedded in the surface of the mask. The contraction properties during gelation ensure the microneedles are tightly bound within the gel, preventing them from falling off. During application, the microneedles partially disrupt the stratum corneum, creating numerous microchannels that promote transdermal absorption of the mask's active ingredients. Furthermore, because the microneedles are tightly bound by the gel mask, they are directly carried away by the mask after piercing the stratum corneum, preventing residue on the skin surface and avoiding continuous skin irritation and pain. The wounds heal within 2-3 hours after application, significantly reducing user discomfort.

[0023] (2) This invention creatively uses nanocellulose filaments as a viscosity modifier added to the formula. While increasing the solution viscosity, its shear-thinning characteristics do not affect the mask-making process. In fact, due to the difference in density, microneedles will quickly sink to the bottom when added to the sodium alginate and essence solution, and cannot form a microneedle layer on the surface. Simply increasing the sodium alginate concentration to increase the solution viscosity in order to delay the sinking of microneedles will, on the one hand, greatly reduce the fluidity of the solution and make it impossible to form a mask; on the other hand, it will make the formed mask too hard and unusable. Nanocellulose has special thixotropic and shear-thinning properties. After being added, the static solution viscosity is very high, which can prevent the sponge microneedles from sinking quickly and thus solidifying on the mask surface; when flowing, due to the shearing effect of the solution flow, the solution viscosity will quickly decrease, so that the mask can be formed normally; after forming, due to the high aspect ratio of nanocellulose, it can form a support network in the mask, making the mask more flexible.

[0024] (3) This invention effectively combines microneedles and mask substrate, making it more convenient to use compared to traditional cream-based products containing sponge microneedles. The gel mask has a high water content and can be used after being refrigerated. The lower temperature can constrict capillaries, reduce the stimulation of nerve endings after the microneedles pierce the skin, and reduce pain during application. Attached Figure Description

[0025] Figure 1 This is a microscope image of the sponge microneedle mask from Example 2.

[0026] Figure 2 This is a scanning electron microscope image of the sponge microneedle mask from Example 2.

[0027] Figure 3 This is a microscopic image of the sponge microneedle mask for comparison example 2.

[0028] Figure 4 This is a microscopic image of the sponge microneedle mask for comparison example 3.

[0029] Figure 5 The rheological properties of the mask solutions in Example 2, Comparative Example 2, and Comparative Example 3 are shown in the diagram.

[0030] Figure 6 The pigskin surface after being cleaned following application of the mask without sponge microneedles from Comparative Example 1.

[0031] Figure 7 The pigskin surface that was not cleaned after the sponge microneedle mask of Example 1 was applied.

[0032] Figure 8 The pigskin surface after being cleaned following application of the sponge microneedle mask of Example 1.

[0033] Figure 9 Three-dimensional fluorescence image of pig skin with fluorescently stained Comparative Example 1 (without sponge microneedles).

[0034] Figure 10 Three-dimensional fluorescence image of pigskin of the sponge microneedle mask of Example 1, which was treated with fluorescent staining.

[0035] Figure 11 Three-dimensional fluorescence image of pigskin of the sponge microneedle mask of Example 2, which was treated with fluorescent staining.

[0036] Figure 12 Three-dimensional fluorescence image of pigskin of the sponge microneedle mask of Example 3, which was treated with fluorescent staining.

[0037] Figure 13 Fluorescence image of a cross-section of pigskin from Comparative Example 1, which was treated with a fluorescently stained mask without sponge microneedles.

[0038] Figure 14 Fluorescence image of a cross-section of pigskin from Example 1, which was treated with fluorescently stained sponge microneedle mask.

[0039] Figure 15 Fluorescence image of a cross-section of pigskin from Example 2, which was treated with fluorescently stained sponge microneedle mask.

[0040] Figure 16 Fluorescence image of a cross-section of pigskin from Example 3, which was treated with fluorescently stained sponge microneedle mask. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0042] The nanocellulose used in this embodiment of the invention was prepared in-house using a laboratory mechanical method. Specifically, the nanocellulose was obtained by grinding bleached softwood pulp at a concentration of 1.0 wt% using a nanomill at a gap of -10 micrometers 20 times. The sponge microneedles were purchased from Shaanxi Sain Biotechnology Co., Ltd., and their parameters met the following requirements: diameter 10–30 micrometers, length 100–1000 micrometers, and purity of 70% or higher. Other pharmaceuticals could be purchased directly from the market.

[0043] Comparative Example 1

[0044] The preparation method of the gel mask without sponge microneedles in this embodiment is as follows:

[0045] (1) Dissolve hyaluronic acid in water and add sodium alginate and nanocellulose to it. The mass percentages are 0.1% hyaluronic acid, 1.0% sodium alginate, 0.8% nanocellulose and the remainder water.

[0046] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0047] (3) Immerse the solution in the mold into a 0.5wt% calcium chloride solution and solidify for 20 minutes to obtain a gel mask without sponge microneedles.

[0048] (4) The obtained gel mask is stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0049] Example 1

[0050] The preparation method of the sponge microneedle gel mask in this embodiment includes the following specific preparation steps:

[0051] (1) Dissolve hyaluronic acid in water and add sodium alginate and nanocellulose to it. The mass percentages are 0.1% hyaluronic acid, 1.0% sodium alginate, 0.8% nanocellulose and the remainder water.

[0052] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0053] (3) Sprinkle sponge microneedles evenly through a 120-mesh filter cloth into the solution, with a quantitative amount of 30 g / m 2 ;

[0054] (4) After immersing the solution in the mold in a 0.5wt% calcium chloride solution and solidifying for 20 minutes, a sponge microneedle semi-depression gel mask is obtained.

[0055] (5) The obtained microneedle semi-depression gel mask was stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0056] Example 2

[0057] The preparation method of the sponge microneedle gel mask in this embodiment includes the following specific preparation steps:

[0058] (1) Dissolve hyaluronic acid in water and add sodium alginate and nanocellulose to it. The mass percentages are 0.1% hyaluronic acid, 1.0% sodium alginate, 0.8% nanocellulose and the remainder water.

[0059] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0060] (3) Sprinkle sponge microneedles evenly through a 120-mesh filter cloth into the solution, with a quantitative amount of 60 g / m 2 ;

[0061] (4) Immerse the solution in the mold into a 0.5wt% calcium chloride solution and solidify for 20 minutes to obtain a sponge microneedle semi-depression gel mask.

[0062] (5) The obtained microneedle semi-depression gel mask was stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0063] Example 3

[0064] The preparation method of the sponge microneedle gel mask in this embodiment includes the following specific preparation steps:

[0065] (1) Dissolve hyaluronic acid in water and add sodium alginate and nanocellulose to it. The mass percentages are 0.1% hyaluronic acid, 1.0% sodium alginate, 0.8% nanocellulose and the remainder water.

[0066] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0067] (3) Sprinkle sponge microneedles evenly through a 120-mesh filter cloth into the solution, with a quantitative amount of 90 g / m 2 ;

[0068] (4) Immerse the solution in the mold into a 0.5wt% calcium chloride solution and solidify for 20 minutes to obtain a sponge microneedle semi-depression gel mask.

[0069] (5) The obtained microneedle semi-depression gel mask was stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0070] Comparative Example 2

[0071] The preparation method of the sponge microneedle gel mask in this embodiment includes the following specific preparation steps:

[0072] (1) Dissolve hyaluronic acid in water and add sodium alginate to it, according to the mass percentage: 0.1% hyaluronic acid, 1.0% sodium alginate and the remainder water;

[0073] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0074] (3) Sprinkle sponge microneedles evenly through a 120-mesh filter cloth into the solution, with a quantitative amount of 60 g / m 2 ;

[0075] (4) Immerse the solution in the mold into a 0.5wt% calcium chloride solution and solidify for 20 minutes to obtain a sponge microneedle gel mask.

[0076] (5) The obtained microneedle gel mask was stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0077] Comparative Example 3

[0078] The preparation method of the sponge microneedle gel mask in this embodiment includes the following specific preparation steps:

[0079] (1) Dissolve hyaluronic acid in water and add sodium alginate and nanocellulose to it. The mass percentages are 0.1% hyaluronic acid, 1.0% sodium alginate, 1.6% nanocellulose and the remainder water.

[0080] (2) Pour the obtained solution into a mold, with a solution quantity of 1550 g / m³. 2 ;

[0081] (3) Sprinkle sponge microneedles evenly through a 120-mesh filter cloth into the solution, with a quantitative amount of 60 g / m 2 ;

[0082] (4) Immerse the solution in the mold into a 0.5wt% calcium chloride solution and solidify for 20 minutes to obtain a sponge microneedle gel mask.

[0083] (5) The obtained gel mask is stored in a 0.1wt% hyaluronic acid essence aqueous solution at a mass ratio of 1:2 with the mask mass.

[0084] The gel mask prepared in Example 2 was observed under an optical microscope and a scanning electron microscope, respectively, and its morphology is shown in the figure below. Figures 1-2 As shown, a dense layer of sponge microneedles has formed on its surface. (As...) Figures 3-4 As shown, after observing the gel masks prepared in Comparative Examples 2 and 3 under an optical microscope, it can be found that in Comparative Example 2, due to the low solution viscosity, the sponge microneedles had sunk to the bottom of the solution, with few microneedles remaining on the surface; in Comparative Example 3, due to the high solution viscosity, the sponge microneedles had not yet formed a semi-submerged state in the solution, and after forming, the adhesion of the gel to the microneedles was insufficient, resulting in a large number of microneedles detaching when immersed in the preservation solution. The rheological properties of the mask solutions of Examples 2, Comparative Examples 2 and 3 before solidification are as follows: Figure 5 As shown, the addition of nanocellulose resulted in significantly higher viscosities in Examples 2 and 3 at low shear rates compared to Comparative Example 2. Due to the thixotropic and shear-thinning properties of nanocellulose, the viscosities of Examples 2 and 3 decreased rapidly at high shear rates, which is of great significance for the mask preparation process.

[0085] The gel masks prepared using Examples 1-3 and Comparative Example 1 were applied to the surface of fresh pigskin and massaged continuously for 20 minutes. The pigskin was then rinsed with water and its surface was observed under a microscope. The results are as follows: Figures 6-8 As shown. In preparing the gel mask, hyaluronic acid was fluorescently stained with 50 ppm Rhodamine B beforehand. After applying the mask to pigskin, the pigskin was placed under a laser confocal microscope to observe the penetration of hyaluronic acid into the pigskin. The XYZ axis three-view fluorescence images of the pigskin, and the XY plane fluorescence superimposed bright-field images at different depths are shown below. Figures 9-12 As shown. The pigskin was cut open, and fluorescently stained hyaluronic acid was observed permeating the cut surface through the cut surface. Figures 13-16 As shown.

[0086] like Figure 1 and Figure 2 The sponge microneedles shown are attached to the surface of the gel mask and tightly wrapped by the gel, ensuring that the sponge microneedles can be removed from the face by the mask during subsequent application. Figure 6 The image shows the surface of pigskin after 20 minutes of application without sponge microneedles, and no obvious trauma was observed. Figure 7 The pig skin that was not rinsed with water after applying the sponge microneedle gel mask in Example 1 shows that a large number of micron-sized wounds (circled) were formed on its surface, with only a very small number of sponge microneedles remaining (arrow). Figure 8 The pigskin in the experiment was washed with water after applying the sponge microneedle gel mask described in Example 1. It was difficult to find any residual sponge microneedles, and the surface had numerous micron-sized wounds. After fluorescently staining hyaluronic acid with Rhodamine B, the pigskin mask was used to characterize the penetration of hyaluronic acid into the skin. Figure 9 and Figure 13 This is a fluorescence image of pig skin treated with the mask that did not contain the microneedles (as in Comparative Example 1). It can be seen that, without the microneedles, hyaluronic acid remained only on the surface of the pig skin. However... Figure 10 and Figure 14 In the process, the product containing 30g / m² from Example 1 was applied. 2 The pigskin mask with microneedles showed a relatively strong fluorescent effect, and it can be seen that hyaluronic acid has penetrated into the epidermal layer of the pigskin. Figure 11 , Figure 12 as well as Figure 15 , Figure 16 The sponge microneedle content of Examples 2 and 3 was 60 g / m². 2 and 90g / m 2The mask was made from pig skin. It can be seen that the pig skin exhibits extremely strong fluorescence, and hyaluronic acid has penetrated extensively into the sublayer of the pig skin to a depth greater than 400 micrometers. In contrast, the thickness of the human stratum corneum is only 10-20 micrometers. This indicates that the semi-deep-set gel mask with sponge microneedles of this invention can assist the effective ingredients of skincare products in penetrating deep into the skin.

[0087] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a microneedle semi-embedded gel mask, characterized in that, Includes the following steps: (1) Dissolve the essence components in water, add sodium alginate and nanocellulose, mix evenly and pour into a mold, then evenly sprinkle microneedles through filter cloth to obtain precursor gel solution; (2) The precursor gel solution was immersed in the salt solution and after molding, a microneedle semi-embedded gel mask was obtained and stored in the essence environment. In step (1), before the microneedles are sprinkled in, the following components are added by weight percentage: 0.1-8.0% essence, 0.3-1.0% sodium alginate, 0.5-1.0% nanocellulose and the remainder is water. The mass of the microneedles in step (1) is 10-120 g / m² of the surface area of ​​the precursor gel solution in the mold. 2 ; The microneedles mentioned in step (1) are sponge microneedles.

2. The method for preparing a microneedle semi-embedded gel mask according to claim 1, characterized in that, The microneedles in step (1) have a diameter of 10 to 30 micrometers, a length of 100 to 1000 micrometers, and a purity of 70% or higher.

3. The method for preparing a microneedle semi-embedded gel mask according to claim 1, characterized in that, The essence in step (1) consists of at least one of hyaluronic acid, niacinamide, collagen, ceramide, ascorbyl glucoside and bisabolol.

4. The method for preparing a microneedle semi-embedded gel mask according to claim 1, characterized in that, The salt solution in step (2) is at least one of 0.1-2 wt% calcium chloride solution, 0.1-2 wt% copper chloride solution and 0.1-2 wt% ferric chloride solution; the solidification time in the salt solution is 10-40 min.

5. The method for preparing a microneedle semi-embedded gel mask according to claim 1, characterized in that, The filter cloth in step (1) has a pore size of 80 to 200 mesh.

6. The method for preparing a microneedle semi-embedded gel mask according to claim 1, characterized in that, Before adding the microneedles in step (1), the solution mass is 1550 g / m² of the bottom area of ​​the mold. 2 The essence environment in step (2) refers to an aqueous solution of 0.1 to 8 wt% essence; the mass ratio of the microneedle semi-embedded gel mask to the aqueous essence solution is 1:1 to 1:

3.

7. The microneedle semi-embedded gel mask prepared by the preparation method according to any one of claims 1 to 6.

Images