Local high-efficiency Pickering emulsion with nano-microparticle structure and preparation method of modified mesoporous silicon of local high-efficiency Pickering emulsion

Abstract

The invention provides a local high-efficiency Pickering emulsion with a nano-microparticle structure and a preparation method of modified meso-porous silicon of the Pickering emulsion, and the Pickering emulsion is mainly prepared from the following raw materials in percentage by mass: 5-60% of a hydrophilic phase, 5-60% of a nano-microparticle structure, 5-60% of a nano-microparticle structure, 5-60% of a nano-microparticle structure and the balance of a 40%-95% of an oleophylic phase; the hydrophilic phase is mainly composed of modified mesoporous silicon, a hydrophilic reagent and an active component; the modified meso-porous silicon is obtained by modifying meso-porous silicon by triethylamine and methylsilane. Compared with a traditional emulsifiable paste stabilized by an emulsifier and unmodified mesoporous silicon, the Pickering emulsion has better stability, viscoelasticity and smearing performance, meanwhile, efficient transdermal drug delivery can be achieved, a mesoporous structure can rapidly and continuously release drugs, interaction with skin can be improved through lipophilicity of an external phase of the emulsifiable paste, and the effect of the Pickering emulsion on the skin is achieved. The skin permeability and retention of active drugs are enhanced, and better pharmacological activity is shown.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and in particular to a local high-efficiency Pickering emulsion with a nano-micro particle structure and a method for preparing the modified mesoporous silica. Background Art

[0002] Skin drug delivery has the characteristics of exerting drug efficacy at the target site, avoiding the first-pass effect of the liver and gastrointestinal irritation, and having good compliance. However, skin delivery has the problems of narrow drug selection, poor safety of conventional penetration enhancement methods, low drug utilization in preparations, and poor physicochemical stability.

[0003] Pickering emulsion is an emulsion stabilized by solid particles instead of traditional emulsifiers. Due to the dual wettability of solid particles, the particles are irreversibly adsorbed at the oil-water interface, reducing the interfacial energy between oil and water and preventing the coalescence of the two phases, so the emulsion system can be stabilized. Different types of Pickering emulsions can be formed according to the wettability of solid particles in different phases. If the hydrophilic phase is first wetted, that is, the wetting angle θ with the water phase is less than 90°, an O / W type Pickering emulsion is formed, and vice versa, a W / O type Pickering emulsion is formed. If θ is too large or too small, the injected energy required for the particles to desorb from the surface is small, and the formed Pickering emulsion is unstable and has poor hydrophobicity, making it difficult to achieve transdermal delivery.

[0004] Mesoporous silica (MS) and silica both contain a large number of hydroxyl groups on their surfaces, making them easy to chemically modify, biocompatible, and degradable. Unlike silica, mesoporous silica has a pore structure with a pore size range of 2-50nm. The high specific surface area provides more attachment sites for drugs and can be used to improve the solubility of drugs. Chinese patent CN112823788A discloses a topical skin external preparation for encapsulating drugs based on solid particle emulsification technology, its preparation method, and application, which enhances the skin permeability and retention of drugs. However, the surface hydroxyl content of commercially available silica is high and hydrophilic, making it difficult to form a W / O type Pickering cream.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The first object of the present invention is to provide a local high-efficiency Pickering emulsion with a nano-particle structure. The Pickering emulsion has a lipophilic external phase and has the advantages of higher drug penetration and intradermal retention than traditional emulsifiers and unmodified mesoporous silica. At the same time, it reduces the greasiness of traditional emulsifier-stabilized creams and improves application comfort.

[0007] The second purpose of the present invention is to provide a method for preparing mesoporous silica used in the above-mentioned local high-efficiency Pickering emulsion with nano-micro particle structure. The preparation method changes the pore structure inside the mesoporous silica by screening modification reagents and modifying the mesoporous silica, making it easier for drugs to dissolve. At the same time, the preparation method is simple and easier to promote.

[0008] The third object of the present invention is to provide a method for preparing the local high-efficiency Pickering emulsion with the nano-micro particle structure. The preparation method is simple and effectively solves the problem of difficult transdermal delivery of Pickering emulsion, and has great application prospects.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The present invention provides a local high-efficiency Pickering emulsion with a nano-micro particle structure, which is mainly prepared from the following raw materials in terms of mass percentage: Hydrophilic phase 5%-60%; Lipophilic phase 40%-95%; The hydrophilic phase is mainly composed of modified mesoporous silica, a hydrophilic agent and an active ingredient; The modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane.

[0010] In traditional Pickering emulsion, macromolecular starch, cellulose, chitosan, and inorganic granular clay, metal, silicon dioxide, etc. are selected as emulsifiers, which are easy to be chemically modified, have good biocompatibility, and are degradable, but at the same time they have high hydrophilicity, and the modification process is relatively cumbersome and costly. Therefore, in the present invention, modified mesoporous silica is introduced into the hydrophilic phase as an emulsifier, wherein the modified mesoporous silica is modified using triethylamine and methylsilane. Methylsilane can introduce silicon-containing alkyl groups into mesoporous silica, increase the hydrophobicity of mesoporous silica, and convert the original hydrophilicity of mesoporous silica into lipophilicity, while not destroying the original structure of the mesopores, and maintaining the original particle morphology. In addition, the modified surface of the modified mesoporous silica provides more attachment sites for active ingredients or drugs, can adsorb more active ingredients, improve the penetration of active ingredients and the advantages of intradermal retention, and improve the solubility of drugs; thereby, the coating comfort of Pickering emulsion can be improved, greasyness can be reduced, and the patient's experience of use can be improved.

[0011] At the same time, the present invention adjusts the amount of the hydrophilic phase and the lipophilic phase to achieve lipophilicity of the outer phase of the Pickering cream, making it easier to form a W / O type Pickering cream, making it more stable and easier to achieve transdermal delivery. When the ratio of a component of the hydrophilic phase or the lipophilic phase is too large or too small, it is easy to make the wetting angle θ with the water phase too large or too small, causing the Pickering emulsion to aggregate, thereby making it unstable.

[0012] Preferably, as a further specific embodiment, the modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane in a molar ratio of (2:1) to (1:2); Preferably, the modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane in a molar ratio of 1:1.

[0013] In the present invention, the dosage of triethylamine and methylsilane is limited, and the reaction process can be accelerated to the maximum extent within the limited range, while ensuring the morphology of the mesoporous structure in the mesoporous silicon. Triethylamine, as a coupling agent for the reaction, can make the functional groups introduced on the modified mesoporous silicon more evenly distributed and have a higher loading amount; when the dosage of triethylamine is too low, it is difficult to achieve the modification effect on the mesoporous silicon; and when the dosage of triethylamine is too high, triethylamine may damage the mesoporous structure on the surface of the mesoporous silicon / or delay the progress of the reaction, resulting in a decrease in reaction efficiency. Preferably, as a further specific embodiment, the methylsilane is one or more of methyldimethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, chlorotrimethylsilane, and dichlorodimethylsilane; Preferably, the methylsilane is methyltrimethoxysilane.

[0014] In the actual selection of methylsilanes, the difficulty of introducing alkyl groups into mesoporous silicon varies due to the different difficulty of chemical bond breaking and steric hindrance of different methylsilanes. Through a large number of screenings, it was found that methyldimethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, chlorotrimethylsilane, and dichlorodimethylsilane can more easily introduce alkyl groups into mesoporous silicon; methyltrimethoxysilane can better graft alkyl groups into mesoporous silicon, and at the same time, the reaction efficiency is higher, making the surface area of ​​the modified mesoporous silicon larger, which is more conducive to the adsorption of drugs by the modified mesoporous silicon.

[0015] Preferably, as a further specific embodiment, the hydrophilic agent is one or more of PEG400, propylene glycol or glycerol; Preferably, the hydrophilic agent is PEG400 and propylene glycol mixed in a mass ratio of (10-50): (3-25); Preferably, the PEG400 and propylene glycol are mixed in a mass ratio of (15-25):(5-10).

[0016] In the present invention, PEG400 and propylene glycol are selected to be mixed in a mass ratio of 19:7.

[0017] In the present invention, the modified mesoporous silica is more hydrophobic after modification. During interfacial adsorption, the modified mesoporous silica will bend toward the hydrophilic phase to form a W / O emulsion. Therefore, it is necessary to select an appropriate hydrophilic agent to assist the modified mesoporous silica in increasing the angle of the wetting angle θ with the water phase. Through creative experiments, it is found that PEG400, propylene glycol or glycerol have a better auxiliary effect on the modified mesoporous silica; preferably, PEG400 and propylene glycol are mixed in a mass ratio of (10-50): (3-25) to better improve the stability of the formed Pickering emulsion; more preferably, PEG400 and propylene glycol are mixed in a mass ratio of (15-25): (5-10), which can increase the angle θ formed, enhance the hydrophobic properties of the Pickering emulsion, and form a more stable oil-in-water system.

[0018] Preferably, as a further specific embodiment, the active ingredient is any one of arctiin compounds, PDE4 inhibitor compounds or corticosteroid compounds.

[0019] Psoriasis occurs on the skin. Local treatment can act directly on the affected area, avoiding gastrointestinal irritation and first-pass effect of the liver. It has a rapid onset of action, good compliance, and few systemic adverse reactions. However, the thickened stratum corneum structure in the psoriasis area hinders the diffusion of drugs in topical preparations. Traditional ointments, creams and other preparations are difficult to pass through the stratum corneum to reach the dermis for treatment. Traditional local treatments for psoriasis also have problems such as local atrophy and skin irritation. Therefore, there is an urgent need for new preparations that can be used for the local treatment of psoriasis.

[0020] In recent years, targeted treatment of psoriasis has developed rapidly. Among them, biological agents have shown significant efficacy in some moderate and severe patients, but their drug resistance and potential adverse reactions have limited their application. Small molecule inhibitors have become a hot area for new drug research and development due to their advantages such as high efficiency, safety, low cost, and convenient administration routes (oral and topical). Arctigenin (AG, hereinafter referred to as AG) is a dibenzylbutyrolactone lignan active compound extracted from burdock seeds. AG has good anti-inflammatory, anti-tumor, antioxidant, and antiviral pharmacological activities, especially its outstanding anti-inflammatory activity, which makes it have great therapeutic potential for inflammatory-related diseases. Experiments have confirmed that AG is a small molecule targeted drug that can selectively inhibit the activity of phosphodiesterase-4 (PDE-4), but there are no literature reports on marketed drugs and topical preparations related to AG.

[0021] Other phosphodiesterase-4 (PDE-4) drugs currently on the market include roflumilast, apremilast and other compounds. Apremilast is an oral, selective phosphodiesterase 4 (PDE4) inhibitor used to treat adult patients with moderate to severe plaque psoriasis who are suitable for phototherapy and systemic therapy. Since oral apremilast causes severe gastrointestinal reactions, the patient's compliance and compliance are reduced. Therefore, changing the original oral route of apremilast to local delivery through the skin can significantly improve the symptoms of the disease in the target skin area and greatly improve the local treatment effect.

[0022] Topical delivery of psoriasis treatment drugs can improve drug bioavailability and patient compliance. Silica-stabilized creams can improve the storage stability and skin feel of traditional emulsifiers. The hydroxyl groups on the surface of mesoporous silica are hydrophilic and easy to modify. The mesoporous structure can provide more attachment sites for drugs. Therefore, this project uses the solid particle mesoporous silica and the negatively charged and lipophilic characteristics of the skin surface to synthesize modified mesoporous silica, and topically delivers the new psoriasis treatment drug AG in the form of Pickering emulsion. The mechanism of mesoporous silica promoting drug retention in the skin is also explained, which provides ideas for the application of mesoporous silica in transdermal drug delivery.

[0023] Preferably, as a further specific embodiment, the lipophilic phase is one or more of monoglyceride, dimethicone, liquid paraffin, glyceryl monostearate or isopropyl myristate; Preferably, the lipophilic phase is a mixture of monoglyceride: dimethicone: isopropyl myristate in a mass ratio of (7-12): (17-23): (4-9).

[0024] In the scheme of the present invention, monoglyceride: dimethicone: isopropyl myristate are selected and mixed in a mass ratio of 9:19:6.

[0025] In the present invention, the lipophilic phase is screened, and the screened lipophilic phase can make the formed oil-in-water structure more stable, and utilize the negatively charged and lipophilic characteristics of the skin surface to assist in the release of the drug in the modified mesoporous silica grafted with the active ingredient. When monoglyceride: dimethyl silicone oil: isopropyl myristate is mixed in a mass ratio of (7-12): (17-23): (4-9), the cumulative drug penetration and cumulative drug retention of the active ingredient within 24 hours can be more effectively improved, which greatly improves the permeability and retention of the skin and increases the use efficiency of the active ingredient. In addition, under this ratio, the solubility of some poorly soluble active ingredients can also be improved, effectively improving the stability of the active ingredients.

[0026] The present invention also provides a method for preparing modified mesoporous silicon, comprising the following steps: The vacuum-dried mesoporous silicon is uniformly dispersed in toluene to prepare a dispersion; adding triethylamine and methylsilane to the dispersion to obtain a mixed solution, and refluxing the mixed solution in a water bath; After reflux, centrifugation is performed, and the supernatant is discarded to obtain a precipitate, which is then washed with anhydrous ethanol and dried in vacuum.

[0027] Preferably, as a further specific embodiment, the reflux time is 4h-12h; Preferably, the reflux time is 4-8h.

[0028] In the above-mentioned process of modifying mesoporous silicon, the modification efficiency can be effectively improved, the reaction process can be simplified, the reaction efficiency can be improved, the production cost can be reduced, and it is easier to promote.

[0029] The present invention also provides a method for preparing Pickering milk, comprising the following steps: Ultrasonic dispersion of the active ingredient, the hydrophilic agent and the modified mesoporous silica 1 until they are completely dissolved to obtain a mixed solution; Heat the lipophilic phase to dissolve; The mixed solution and the modified mesoporous silica 2 are alternately added to the lipophilic phase to form a reaction system, and stirred and emulsified to obtain; The modified mesoporous silica 1 accounts for 1%-6% of the mass of the reaction system; The modified mesoporous silica 2 accounts for 5%-8% of the mass of the reaction system.

[0030] Preferably, the emulsification temperature is 70°C-80°C; The stirring time is 30 min-60 min.

[0031] In the present invention, the amount of mesoporous silica added for the first time is different from the amount of mesoporous silica added for the second time. The purpose of this design is to better increase the adsorption state of modified mesoporous silica at the water / oil interface, so that the formed W / O type Pickering emulsion has better lipophilicity; it can also facilitate the stepwise grafting of active ingredients and increase the solubility of poorly soluble active ingredients.

[0032] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method of the present invention can obtain hydrophobic mesoporous silica and a stable Pickering emulsion based on hydrophobic mesoporous silica. Compared with the cream stabilized by traditional emulsifiers and unmodified mesoporous silica, the Pickering emulsion of the present invention has better stability, viscoelasticity and spreadability, and can achieve efficient transdermal drug delivery. The mesoporous structure can release drugs quickly and continuously, and the lipophilicity of the outer phase of the cream can increase the interaction with the skin, enhance the permeability and retention of active drugs in the skin, and show better pharmacological activity.

[0033] (2) This method can increase the solubility of poorly soluble drugs at room temperature by adding some mesoporous silica, thereby improving the stability of the drugs.

[0034] (3) The invention of synthesizing mesoporous silicon has low cost and simple process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 : Scanning electron micrograph of the modified mesoporous silicon prepared in Example 1; Figure 2 : BET gas adsorption curve and particle size distribution diagram of the modified mesoporous silicon prepared in Example 1; Figure 3 : Wetting angle measurement diagram of the modified mesoporous silicon prepared in Example 1; Figure 4 : Statistical graph of in vitro retention of arctigenin external preparation in Comparative Example 1; Figure 5 : Statistical graph of the in vivo retention of arctigenin external preparation in Comparative Example 1. DETAILED DESCRIPTION

[0036] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premises, all belong to the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or conditions recommended by the manufacturer. Those who do not specify manufacturers for reagents used or instruments are conventional products that can be purchased commercially, and the reagent list used in the embodiments of the present invention and the comparative examples is as shown in Table A.

[0037] Table A: List of reagents used

[0038] Example 1 In the following examples, all the raw materials used are commercially available raw materials, among which arctigenin is selected as the active ingredient.

[0039] 1. Preparation of modified mesoporous silica In this example, AEROPERL ® 300 Pharma mesoporous silica was modified. 1.5 g of dried mesoporous silica (dried at 120 °C for 4 h) was weighed, 8 mL of toluene was added for ultrasonic dispersion, 3 mmol of triethylamine (0.45 g) was added and stirred evenly, and then 3 mmol of methyltrioxysilane (0.61 g) was added. At this time, the molar ratio of methyltrioxysilane to triethylamine was 1:1 to obtain a mixed solution. The mixture was stirred and refluxed in an oil bath at 110° C. for 4 h. After the reaction was completed, the white precipitate obtained by centrifugation was washed 4 times with anhydrous ethanol and vacuum dried to finally obtain methyl-modified hydrophobic modified mesoporous silica.

[0040] 2. Preparation of Pickering Milk Weigh 0.010 g of the prepared modified mesoporous silica, 0.336 g of PEG 400, 0.124 g of propylene glycol (mass ratio of PEG 400:propylene glycol = 19:7) and 0.050 g of arctigenin and disperse them in sterile water by ultrasonic for 1 h until they are completely dissolved to obtain a mixed solution; Weigh 0.105 g monoglyceride, 0.223 g dimethicone, and 0.072 g isopropyl myristate (mass ratio of monoglyceride: dimethicone: isopropyl myristate = 9:19:6), mix and heat until the three are dissolved in each other to form a lipophilic phase; Weigh 0.080 g of modified mesoporous silica; 0.080g of modified mesoporous silica and the mixed solution were alternately added to the lipophilic phase and emulsified at 75°C. After the addition was complete, the mixture was heated for 10 minutes, and then the heating was stopped and stirred for 30-60 minutes until the temperature reached 25°C. The experimental results are as follows: Figure 1-3 As shown, Figure 1 The scanning electron micrograph of the modified mesoporous silica is shown in ; Figure 2 The BET gas adsorption curve and particle size distribution of the modified mesoporous silica are shown. The results in the figure show that the prepared Pickering emulsion has a suitable and uniform specific surface area and particle size distribution, and has stable performance. Figure 3 The wetting angle of modified mesoporous silica is 139.18°, which is an oil-in-water system. Figure 1-3 It can be seen that the Pickering milk prepared in this example is a stable W / O system.

[0041] Example 2 The specific implementation method is consistent with Example 1, only the molar ratio of triethylamine to methyltrioxysilane is changed, and the specific changes are shown in Table 1.

[0042] Table 1: Molar ratio of triethylamine to methyltrioxysilane

[0043] Example 3 The process of preparing modified mesoporous silica was consistent with that in Example 1, except that the amount of modified mesoporous silica was changed: Weigh 0.060 g of the prepared modified mesoporous silica, 0.322 g of PEG 400, 0.118 g of propylene glycol (mass ratio of PEG 400:propylene glycol = 19:7) and 0.05 g of arctigenin and disperse them in sterile water by ultrasonic for 1 h until they are completely dissolved to obtain a mixed solution; Weigh 0.105 g monoglyceride, 0.223 g methyl silicone oil and 0.072 g isopropyl myristate (mass ratio of monoglyceride: dimethyl silicone oil: isopropyl myristate = 9:19:6), mix and heat until the three are dissolved in each other to form a lipophilic phase; Weigh 0.050 g of modified mesoporous silica; 0.050 g of modified mesoporous silica and the mixed solution were alternately added to the lipophilic phase, emulsified at 75°C, heated for 10 min after complete addition, then stopped heating, and stirred for 30 min-60 min until the temperature reached 25°C.

[0044] Example 4 The specific implementation method is consistent with Example 1, only the ratio of the hydrophilic phase to the lipophilic phase is changed, as follows: The proportion of the hydrophilic phase was changed to 50% (0.5 g), and the proportion of the lipophilic phase was changed to 50% (0.5 g); The amounts of modified mesoporous silica added for the first time were 0.010 g, 0.263 g PEG 400, 0.097 g propylene glycol (mass ratio of PEG400:propylene glycol = 19:7), and 0.050 g arctigenin.

[0045] The second time, 0.080 g of modified mesoporous silica, 0.132 g of monoglyceride, 0.280 g of dimethyl silicone oil, and 0.088 g of isopropyl myristate (mass ratio of monoglyceride: dimethyl silicone oil: isopropyl myristate = 9:19:6) were added.

[0046] Example 5 The specific implementation method is consistent with Example 1, only the ratio of the hydrophilic phase to the lipophilic phase is changed, as follows: The proportion of hydrophilic phase was changed to 5% (0.05g), and the proportion of lipophilic phase was changed to 95% (0.95g); The mass of the modified mesoporous silica added for the first time was 0.010 g, 0.015 g PEG 400, 0.005 g propylene glycol (mass ratio of PEG 400:propylene glycol = 19:7), and 0.010 g arctigenin.

[0047] The second time, 0.010 g of modified mesoporous silica, 0.252 g of monoglyceride, 0.530 g of dimethyl silicone oil, and 0.168 g of isopropyl myristate (mass ratio of monoglyceride: dimethyl silicone oil: isopropyl myristate = 9:19:6) were added.

[0048] Example 6 The mass ratio of the hydrophilic reagent to PEG 400 and propylene glycol was changed, and the specific changes are shown in Table 2: Table 2: Changes in the mass ratio of PEG 400 and propylene glycol

[0049] Example 7 The specific implementation method is consistent with Example 1, only the mass ratio of monoglyceride: dimethicone: isopropyl myristate is changed, and the specific changes are shown in Table 3.

[0050] Table 3: Changes in the mass ratio of monoglyceride: dimethicone: isopropyl myristate

[0051] Comparative Example 1 The preparation of traditional emulsifiers is as follows: Weigh 6 g of monoglyceride, 0.99 g of Tefose 63, 2.25 g of liquid paraffin, 0.75 g of CC497, 13.5 g of PEG400, 3.51 g of Transcutol P, 1.5 g of S630, and 1.5 g of arctigenin.

[0052] The weighed monoglyceride, Tefose 63, liquid paraffin, and CC497 are heated to 75°C to form the lipophilic phase, and PEG400, Transcutol P, S-630, and AG are heated and mixed to 75°C; the lipophilic phase is added to the hydrophilic phase, homogenized at 7000 rpm for 10 min to emulsify, and then cooled to condense at room temperature.

[0053] Comparative Example 2 The Pickering emulsion was prepared using unmodified mesoporous silica. The specific steps are as follows: Weigh 2.7 g monoglyceride, 5.7 g methyl silicone oil, 1.8 g isopropyl myristate, 2.7 g mesoporous silica, 11.4 g PEG400, 4.2 g propylene glycol and 1.5 g arctigenin.

[0054] The weighed PEG400, propylene glycol, arctigenin, and 0.4 g mesoporous silica were ultrasonically treated for 30 min to form a hydrophilic phase; monoglyceride, methyl silicone oil, and isopropyl myristate were heated in a 75°C water bath until dissolved to form an oil phase; 2.3 g mesoporous silica and the hydrophilic phase were alternately added to the oil phase and stirred. After complete addition, stirring was continued for 10 min and the temperature was lowered to condense.

[0055] Experimental Example 1 The external preparations of arctigenin provided in Example 1 and Comparative Examples 1 and 2 were subjected to in vitro skin permeation assay: 1. In vitro skin treatment Take pig ear skin, carefully remove the hair on the skin surface with a shaver, clean it with saline, absorb the water on the skin surface with non-woven fabric, and set aside.

[0056] 2. Transdermal test In vitro permeation tests were performed using a vertical permeation diffusion test cell (permeation area 3.14 cm 2 , receiving pool volume 8.0mL). The water bath temperature of the transdermal instrument was set to 32°C, and the speed of the magnetic stirrer was 200 r / min. The pig skin was fixed in the diffusion pool with the stratum corneum facing up, and an appropriate amount of the prescription sample (control the amount of the drug in the preparations given in different embodiments to be consistent) was placed in the supply pool, in close contact with the skin, and fixed on the receiving pool, and the skin surface was in contact with the receiving medium. The receiving medium was 50% PEG400. 0.3 mL was sampled from the receiving pool at 1h, 2h, 4h, 8h, and 24h, respectively. After each sampling, the same volume of fresh receiving solution was added and the bubbles in the receiving chamber were removed. The sample was centrifuged at 13000 r / min for 5 min, and the supernatant was taken and its concentration was determined by high performance liquid chromatography, which was the total drug permeation in 24 hours.

[0057] After 4 hours, the skin was removed and the effective transdermal area (3.14 cm 2 ), wipe the residual test sample with non-woven cloth, rinse repeatedly with pure water, dry with non-woven cloth, weigh, cut into pieces, add 1 mL of extraction solvent, and homogenize for 3 minutes. After the sample is taken out and centrifuged at 13000 r / min for 5 minutes, the supernatant is taken and its concentration is determined by high performance liquid chromatography, which is the total amount of drug skin retention for 24 hours.

[0058] The evaluation was conducted using the 24-hour cumulative drug permeation per unit area and the 24-hour drug skin retention rate as indicators.

[0059] The calculation formula is as follows: Cumulative drug permeation per unit area in 24 hours = total drug permeation in 24 hours / 3.14; 24h drug skin retention rate = 24h drug skin retention total amount / skin weight * 100%; 3. Analytical methods The chromatographic column was Ultimate AQ-C18 column (4.6 mm × 150 mm, 5 μm); the mobile phase was acetonitrile-water (40:60); the flow rate was 1.0 mL / min; the detection wavelength was 200 nm; the column temperature was 40 °C; the injection volume was 10 μL, and the external standard method was used for quantification. The experimental results are shown in Table 4.

[0060] Table 4: Cumulative permeation and skin retention of arctigenin in pig skin in Example 1 and Comparative Examples 1 and 2 (n=3)

[0061] The above experimental method was used to test all the groups in Examples 2-6. The specific experimental results are shown in Table 5.

[0062] Table 5: Cumulative permeation and skin retention of arctigenin in pig skin in all groups of Examples 2-6 (n=3)

[0063] From the experimental data in Table 4, it can be seen that the present invention uses triethylamine and methylsilane to modify mesoporous silica, which can introduce functional groups on the surface of mesoporous silica and adjust the wettability of the particle surface. The mesoporous silica particles obtained by this method have more uniform functional group distribution and higher loading capacity, thereby further improving the penetration and retention of drugs. ® The Pickering cream modified by 244FP has better 24h cumulative drug permeation and 24h cumulative drug retention, improves the drug administration performance, and shows better pharmacological activity.

[0064] By comparing Example 1, Example 2-1 and Example 2-2, the specific dosage of triethylamine and methylsilane was adjusted. It can be seen from the experimental results that when the ratio of triethylamine to methylsilane is 1:1, the functional groups introduced on the modified mesoporous silica are more evenly distributed and the loading amount is higher, so that its drug delivery performance is the best.

[0065] Comparing Example 1 and Example 3, it can be seen that when the amount of mesoporous silica is changed, the drug delivery performance of the prepared Pickering emulsion will be affected. When the amount of modified mesoporous silica added in batches changes, the adsorption state of the oil / water interface will change; at the same time, due to the particularity of the mesoporous silica added in batches, the grafting ability of the modified mesoporous silica for drugs will also change. When the sum of the masses of mesoporous silica added in batches is small, the adsorption capacity for the oil / water interface is weakened, and the grafting ability for drugs is weakened; and if the sum of the masses of mesoporous silica added in batches is too large, the grafting ability for drugs will also be reduced, and ultimately the formed Pickering emulsion will be unstable. Therefore, the amount of modified mesoporous silica added in batches should be appropriate to ensure that the performance of the prepared Pickering emulsion is more stable.

[0066] By comparing Example 1 with Examples 4-5, it can be seen that changing the content between the hydrophilic phase and the lipophilic phase, when the content of one of the hydrophilic phase or the lipophilic phase is excessive, will cause the θ angle of the formed Pickering emulsion to be too large or too small, thereby reducing the stability of the Pickering emulsion and further affecting the cumulative permeation and retention of the drug within 24 hours.

[0067] Comparing all the schemes in Example 1 and Example 6, it can be seen that changing the mass ratio of PEG400:propylene glycol will affect the drug delivery performance of the Pickering emulsion. It can be seen from the experimental data that although the drug delivery performance of the scheme in Example 6 can meet the needs of the present invention, its actual use effect has decreased to varying degrees. The reason is that the angle θ formed when PEG400 and propylene glycol are mixed at a mass ratio of 19:7 is larger than that of the scheme in Example 6, the formed W / O system is more stable, and the lipophilic property is effectively improved, thereby greatly improving the stability of the Pickering emulsifier and the efficiency of the drug delivery system.

[0068] It can be seen from the experimental data of Example 6 and Example 7 that when the mass ratio of PEG 400 to propylene glycol in the hydrophilic phase and the mass ratio of monoglyceride: dimethicone: isopropyl myristate are within the range designed by the present invention, the cumulative drug permeation and cumulative drug retention in 24 hours are not greatly affected, and the drug administration and system efficiency are good. When the dosage of a component is too large or too small, it will lead to an imbalance in the ratio, thereby affecting the performance of the emulsifier, thereby reducing its stability or efficiency.

[0069] Experimental Example 2 The external preparations of arctigenin provided in the above-mentioned example and comparative examples 1 and 2 were subjected to in vivo pharmacokinetic tests.

[0070] 1. Experimental animals: SD rats, female, weighing (200±20) g, purchased from Bikewing Biotechnology Co., Ltd.

[0071] 2. Experimental Methods Rats (≥36) were randomly divided into three groups, namely (1) traditional emulsifier group (12 rats), (2) mesoporous silica group and (3) methylated mesoporous silica group (12 rats). Rats were allowed to drink water and eat freely before and after administration. The hair on the back was removed with an electric scalpel, and the depilatory cream was applied. After about 2 minutes, the rats were washed with water. After depilation, the rats were observed for 24 hours, and the rats with skin erythema and damage were removed. The local administration dose for rats was set at 70 mg / kg. The rats were administered in the area marked by the mold once a day. The rats were applied with a cotton swab, and the actual dosage was calculated by calculating the weight loss of the cream and the weight of the cotton swab before and after administration. After application, the rats were fixed with breathable tape to prevent licking. The blood was collected at 3 h, 9 h, and 24 h after administration on the first day (Day 1) and at 3 h, 9 h, and 24 h on the sixth day (Day 6) of continuous administration (once a day). After blood was collected from each group of rats at each blood collection point, the plasma samples were separated by centrifugation (4000 rPm, 15 min), 3000 rPm, 4°C, centrifugation for 15 min, 100 μL of the upper plasma was taken and added with 200 μL of internal standard solution and 100 μL of methanol solution, protein precipitation was performed to extract AG in the plasma, vortexed for 1 min, 14000 rPm, 4°C, centrifuged for 10 min, and 200 μL of the supernatant was taken for sampling and analysis.

[0072] Among them, the animals were killed by dislocation after blood collection at the 3-hour and 24-hour blood collection points on Day 1 and Day 6, and the skin for drug administration was cut, washed with pure water, and the residual drugs on the surface were removed by tape, rinsed with pure water, dried with non-woven fabric, weighed, cut into pieces, and 1 mL of extraction solvent was added. The tissue was homogenized for 3 minutes. After the sample was centrifuged at 13000 r / min for 5 minutes, the supernatant was taken and its concentration was determined by high-performance liquid chromatography, which was the drug skin retention.

[0073] 3. Analytical methods (1) Plasma samples: Chromatographic conditions: Phase A: 10% methanol water (containing 0.2% formic acid) solution; Phase B: methanol; A:B = 80:20 (v / v) isocratic elution. Chromatographic column: Inertsil ODS-3 (5 µm, 4.6*150 mm, SN: OD185252); Column temperature: 40°C; Flow rate: 0.5 mL / min; Injection volume: 10 µL; Single needle running time: 10 min; Mass spectrometry conditions: electrospray ion source (ESI), positive ion mode, multiple reaction monitoring (MRM Positive), DL tube temperature: 250°C; Heating module temperature 400°C; Drying gas flow rate: 15.0 L / min; Nebulizer flow rate 3 L / min. Other parameters are shown in Table 6 below.

[0074] Table 6: Mass spectrometry parameter settings for arctigenin and internal standard (IS)

[0075] (2) Skin samples: Liquid phase method was used for content determination, and the analysis method was the same as that of pig ear skin. Figure 4 and Figure 5 shown.

[0076] from Figure 4-Figure 5 It can be seen from the experimental results that the intradermal retention of arctiin in the Pickering emulsion stabilized by methylated mesoporous silica (modified mesoporous silica) is the highest, followed by mesoporous silica, and the lowest in the traditional emulsifier group. In addition, the drug amounts in the plasma of the three groups are all below the quantitative lower limit or near the quantitative lower limit. It can be seen that the Pickering emulsion prepared by the present invention is highly safe.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A local high-efficiency Pickering emulsion with nano-micro particle structure, characterized in that: In terms of mass percentage, it is mainly made from the following raw materials: Hydrophilic phase 5%-60%; Lipophilic phase 40%-95%; The hydrophilic phase is mainly composed of modified mesoporous silica, a hydrophilic agent and an active ingredient; The modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane.

2. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 1, characterized in that: The modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane in a molar ratio of (2:1)-(1:2); Preferably, the modified mesoporous silica is obtained by modifying mesoporous silica with triethylamine and methylsilane in a molar ratio of 1:

1.

3. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 2, characterized in that: The methylsilane is one or more of methyldimethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, chlorotrimethylsilane, and dichlorodimethylsilane; Preferably, the methylsilane is methyltrimethoxysilane.

4. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 1, characterized in that: The hydrophilic agent is one or more of PEG400, propylene glycol or glycerol; Preferably, the hydrophilic agent is PEG400 and propylene glycol mixed in a mass ratio of (10-50): (3-25); Preferably, the PEG400 and propylene glycol are mixed in a mass ratio of (15-25):(5-10).

5. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 1, characterized in that: The active ingredient is any one of arctiin compounds, PDE4 inhibitor compounds or corticosteroid compounds.

6. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 1, characterized in that: The lipophilic phase is one or more of monoglyceride, dimethyl silicone oil, liquid paraffin, glyceryl monostearate or isopropyl myristate; Preferably, the lipophilic phase is a mixture of monoglyceride: dimethicone: isopropyl myristate in a mass ratio of (7-12): (17-23): (4-9).

7. A method for preparing the modified mesoporous silica used in the local high-efficiency Pickering emulsion of nano-micro particle structure according to any one of claims 1 to 6, characterized in that: The steps include: The vacuum-dried mesoporous silicon is uniformly dispersed in toluene to prepare a dispersion; adding triethylamine and methylsilane to the dispersion to obtain a mixed solution, and refluxing the mixed solution in a water bath; After reflux, centrifugation is performed, and the supernatant is discarded to obtain a precipitate, which is then washed with anhydrous ethanol and dried in vacuum.

8. The method for preparing modified mesoporous silicon according to claim 7, characterized in that: The reflux time is 4h-12h; Preferably, the reflux time is 4-8h.

9. A method for preparing a Pickering emulsion with a local high-efficiency nanoparticle structure according to any one of claims 1 to 6 and a method for preparing the modified mesoporous silica according to claim 8, characterized in that: The steps include: Ultrasonic dispersion of the active ingredient, the hydrophilic agent and the modified mesoporous silica 1 until they are completely dissolved to obtain a mixed solution; Heat the lipophilic phase to dissolve; The mixed solution and the modified mesoporous silica 2 are alternately added to the lipophilic phase to form a reaction system, and stirred and emulsified to obtain; The modified mesoporous silica 1 accounts for 1%-6% of the mass of the reaction system; The modified mesoporous silica 2 accounts for 5%-8% of the mass of the reaction system.

10. The local high-efficiency Pickering emulsion with nano-micro particle structure according to claim 9, characterized in that: The emulsification temperature is 70°C-80°C; The stirring time is 30 min-60 min.

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