A preparation process of antibacterial essential oil sustained-release capsules

Abstract

The present invention relates to the field of microcapsules, and specifically to a preparation process of an antibacterial essential oil sustained-release capsule. The process comprises the following steps: modification of lecithin; preparation of an antibacterial nano-essential oil emulsion; and cross-linking and coating of antibacterial essential oil with rutin-silk fibroin. The present invention generates a rutin-silk fibroin wall material by making rutin nanoparticles and silk fibroin generate a rutin-silk fibroin wall material under the action of an epichlorohydrin cross-linking agent. The obtained composite wall material not only has good mechanical strength, but also has a dense grid-like cross-linked structure, thereby prolonging the release time of the active substance, and rutin can further enhance the antibacterial ability of the antibacterial sustained-release capsule, and then liquid paraffin and the antibacterial nano-essential oil emulsion are added for homogenization, so that each component is evenly dispersed, the effect of subsequent cross-linking and coating is improved, and sustained-release capsule particles with uniform plasmids are formed, which can release the antibacterial essential oil components more stably and uniformly.

Description

Technical Field

[0001] The invention relates to the field of microcapsules, in particular to a preparation process of antibacterial essential oil sustained-release capsules. Background Art

[0002] Antibacterial essential oil is a natural antibacterial agent derived from plants and is widely used in food preservation, drug delivery, cosmetics and health care products. Essential oil has strong antibacterial and antioxidant properties, can effectively inhibit the growth of bacteria and fungi, and as a natural ingredient, has good biocompatibility. However, essential oil has poor volatility and stability and is easily affected by light, heat and oxygen, causing the active ingredients to lose effectiveness quickly. Therefore, the development of a stable sustained-release capsule system can prolong the activity time of essential oils and slowly release their active ingredients, thereby improving the stability and application breadth of antibacterial essential oils.

[0003] Sustained-release capsules refer to essential oils wrapped in porous or multi-layer materials, which prolong the duration of the antibacterial effect by slowly releasing the active substances inside. Commonly used sustained-release wall materials are divided into polymer materials and inorganic materials. Polymer materials include natural polymer materials, such as chitosan and gelatin, and synthetic polymer materials, such as polylactic acid and polycaprolactone. These polymer materials have poor mechanical stability and are easily broken due to extrusion deformation during fiber molding and textile processing, resulting in rapid loss of active ingredients in sustained-release capsules. Although inorganic materials have good mechanical properties, they have poor processability and are difficult to form dense wall materials, which affects the sustained-release effect of essential oils. Summary of the invention

[0004] In order to solve the above technical defects, the present invention has developed a preparation process of an antibacterial essential oil sustained-release capsule, so that the prepared antibacterial essential oil sustained-release capsule has excellent mechanical properties and stable essential oil sustained-release ability, and the essential oil combined with the wall material inside it has excellent antibacterial properties, which greatly improves the antibacterial performance of the sustained-release capsule.

[0005] A preparation process of an antibacterial essential oil sustained-release capsule comprises the following steps:

[0006] S1: Modification of lecithin

[0007] Mixing lecithin and anhydrous ethanol and fully stirring to obtain a lecithin suspension, maintaining the temperature and continuously stirring, mixing citric acid and distilled water in a container, adding phospholipase A2, stirring until the citric acid is completely dissolved to obtain a citric acid solution, slowly adding the lecithin suspension to the citric acid solution under stirring to obtain a cross-linked mixed solution, subjecting the cross-linked mixed solution to ultrasonic treatment and then allowing it to stand, and then subjecting the cross-linked mixed solution to centrifugal filtration to obtain a solid product, and washing and drying to obtain a modified lecithin;

[0008] S2: Preparation of antibacterial nano-essential oil emulsion

[0009] Mix luteolin and carvacrol in a container, add anhydrous ethanol and stir to obtain a premixed solution, place distilled water in a container, add modified lecithin after heating, and continue stirring until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution, add clove essential oil to the lecithin aqueous phase solution, increase the temperature and perform magnetic stirring to obtain a crude emulsion, add the premixed solution to the crude emulsion, and then perform high-speed shear treatment to obtain an antibacterial nano essential oil emulsion;

[0010] S3: Rutin-Silk Fibroin Cross-linked Coated Antibacterial Essential Oil

[0011] A sodium hydroxide solution is placed in a container, rutin powder is added, and the solution is heated and stirred before filtering to obtain a rutin solution. A hydrochloric acid solution is slowly added to the rutin solution under stirring to control the pH drop rate of the rutin solution, and then centrifugal filtration is performed to obtain a rutin precipitate. The rutin precipitate is washed and dried to obtain rutin nanoparticles. The rutin nanoparticles and silk fibroin are uniformly dispersed in deionized water to obtain a rutin nanoparticle dispersion. The rutin nanoparticle dispersion is placed in a container, a cross-linking agent is added and pre-stirred, and liquid paraffin and antibacterial nano essential oil emulsion are added, and then the solution is placed in a homogenizer for homogenization, and then heated and stirred to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled, centrifugal filtration is performed, and the nanocapsule precipitate is collected for vacuum freeze drying to obtain an antibacterial essential oil sustained-release capsule.

[0012] Furthermore, step S1, the modification treatment of lecithin, comprises the following steps:

[0013] S1.1: 1-2 parts by weight of lecithin is placed in a container, and then 10-15 parts by weight of anhydrous ethanol is added, and the mixture is stirred at 45-50° C. to obtain a lecithin suspension, and the temperature of the lecithin suspension is maintained at 40-45° C. and stirred continuously, 3-5 parts by weight of citric acid and 50-60 parts by weight of distilled water are mixed in a container, and then 0.01-0.02wt% of phospholipase A2 is added, and the mixture is stirred until the citric acid is completely dissolved to obtain a citric acid solution;

[0014] S1.2: 8-10 parts by weight of lecithin suspension are slowly added to 45-50 parts by weight of citric acid solution, and stirred at a stirring speed of 500-600rpm. When the lecithin suspension is completely added, a cross-linked mixed solution is obtained. The cross-linked mixed solution is placed in an ultrasonic cleaner for ultrasonic treatment for 15-20 minutes. After standing for 25-30 minutes, it is centrifuged at a speed of 4000-6000rpm for 10-15 minutes, and a solid product is obtained by suction filtration. After washing with deionized water, it is placed in a vacuum drying oven and dried at a temperature of 30-40°C for 2-3 hours to obtain modified lecithin.

[0015] Further, step S2 prepares the antibacterial nano essential oil emulsion, comprising the following steps:

[0016] S2.1: 0.8-1 parts by weight of luteolin and 1-2 parts by weight of carvacrol are mixed and placed in a container, 15-20 parts by weight of anhydrous ethanol is added and stirred for 20-30 minutes to obtain a premixed solution, 50-60 parts by weight of distilled water are placed in a container, heated to 40-45° C., and then 5-6 parts by weight of modified lecithin are added, and stirring is continued until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution;

[0017] S2.2: Add 3-5 parts by weight of clove essential oil to the lecithin aqueous solution obtained in step S2.1, heat the temperature to 40-45°C, and then use a magnetic stirrer to stir at a stirring speed of 300-500 rpm for 10-15 minutes to obtain a crude emulsion, add the premix obtained in step S2.1 to the crude emulsion, and then use a high-speed shearing machine to perform shearing treatment for 5-10 minutes to obtain an antibacterial nano essential oil emulsion.

[0018] Furthermore, step S3 of cross-linking and coating the antibacterial essential oil with rutin-silk fibroin comprises the following steps:

[0019] S3.1: 18-20 parts by weight of sodium hydroxide solution is placed in a container, 1-2 parts by weight of rutin powder is added, the mixture is heated to 40-45°C and stirred for 45-50 minutes, and then filtered through a microporous filter to remove insoluble impurities to obtain a rutin solution, a hydrochloric acid solution with a concentration of 0.06-0.08 mol / L is slowly added to the rutin solution while stirring, and the pH of the rutin solution is controlled to drop to 3-4 within 25-30 minutes, and then the mixture is transferred to a centrifuge and centrifuged at a speed of 8000-10000 rpm for 10-15 minutes, and a rutin precipitate is obtained by suction filtration, and the rutin precipitate is washed with deionized water for 2-3 times, and then dried in a vacuum drying oven to obtain rutin nanoparticles;

[0020] S3.2: Evenly disperse rutin nanoparticles and silk fibroin in deionized water at a mass ratio of 1:(0.6-0.8) to obtain a rutin nanoparticle dispersion, control the concentration of the rutin nanoparticle dispersion to be 1-2wt%, take 10-12 parts by weight of the rutin nanoparticle dispersion into a container, add 0.08-0.1 parts by weight of a cross-linking agent and pre-stir for 12-15 minutes, then add 2-3 parts by weight of liquid paraffin and 4-5 parts by weight of an antibacterial nano essential oil emulsion, The mixture is then placed in a homogenizer and homogenized at a homogenization speed of 16000-18000 rpm for 6-8 minutes, and then stirred at a stirring speed of 300-350 rpm for 2-3 hours at 45-50° C. to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled to room temperature, it is placed in a centrifuge and centrifuged at a speed of 10000-12000 rpm for 15-20 minutes. The nanocapsule precipitate is collected by suction filtration and then vacuum freeze-dried to obtain antibacterial essential oil sustained-release capsules.

[0021] Furthermore, the lecithin in step S1.1 is soybean lecithin.

[0022] Furthermore, in step S1.2, the frequency of the ultrasonic treatment performed by the ultrasonic cleaning machine is 40-45 kHz.

[0023] Furthermore, in step S2.2, the rotation speed of the high-speed shearing machine for shearing treatment is 10000-12000 rpm.

[0024] Furthermore, the concentration of the sodium hydroxide solution in step S3.1 is 0.1-0.15 mol / L.

[0025] Furthermore, the filtration pore size of the microporous filter in step S3.1 is 0.45-0.5 μm.

[0026] Furthermore, the cross-linking agent in step S3.2 is epichlorohydrin.

[0027] The beneficial effects are as follows: 1. The present invention dissolves rutin powder in an alkaline solution, then adds hydrochloric acid to adjust the pH value of the solution, so that the dissolved rutin is precipitated in the form of nanoparticles to obtain rutin nanoparticles, then mixes the rutin nanoparticles and silk fibroin to prepare a rutin nanoparticle dispersion, adds an epichlorohydrin crosslinking agent for pre-stirring, so that the rutin nanoparticles and silk fibroin undergo a pre-crosslinking reaction, so that a subsequent crosslinking and coating reaction can better generate a rutin-silk fibroin wall material, and the obtained composite wall material not only has good mechanical strength, but also forms a dense grid-like crosslinking structure under the action of the epichlorohydrin crosslinking agent, which limits the release speed of the active substance, thereby prolonging the release time of the active substance, and the antibacterial property of rutin can further enhance the antibacterial ability of the antibacterial sustained-release capsule, and then adds liquid paraffin and antibacterial nano essential oil emulsion for homogenization, so that each component is evenly dispersed, and the effect of subsequent crosslinking and coating is improved, so that the formed sustained-release capsule particle plasmid is more uniform, and the antibacterial essential oil component can be released more stably and at a uniform rate.

[0028] 2. The present invention uses modified lecithin as an emulsifier to prepare a lecithin aqueous phase solution, then adds clove essential oil as an oil phase thereto, and simultaneously adds a premix prepared by mixing luteolin and carvacrol, and then performs high-speed shearing to prepare an antibacterial nano essential oil emulsion. In this process, the modified lecithin uniformly disperses the clove essential oil into the aqueous phase to form an O / W type nanoemulsion. This structure can encapsulate the active ingredients of the clove essential oil and make them uniformly distributed in the aqueous phase, thereby achieving better stability in the sustained-release system. The addition of the premix can not only synergistically enhance the antioxidant capacity of the modified lecithin through luteolin and carvacrol, prolong the life of the active ingredients of the subsequently prepared antibacterial sustained-release capsules, and improve the sustained-release stability, but also synergistically enhance the antibacterial ability of the clove essential oil, and further enhance the antibacterial ability of the entire capsule system.

[0029] 3. The present invention prepares a citric acid solution by using citric acid, phospholipase A2 and distilled water, and then slowly adds a lecithin suspension thereto and stirs simultaneously. In this process, the phospholipase A2 firstly undergoes a hydrolysis reaction with the lecithin, selectively cuts off the fatty acid chain at position 2, generates lysophospholipids, and improves the hydrophilicity and emulsification properties of the lecithin. At the same time, the carboxyl groups in the citric acid can react with the polar groups in the lysophospholipids, thereby introducing more polar groups, further improving the emulsification ability and water solubility of the modified lecithin, enhancing its stability in the aqueous phase, and being able to improve the stability of the subsequent sustained-release system, so as to form antibacterial sustained-release capsule particles with better sustained-release ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flow chart of the preparation process of the antibacterial essential oil sustained-release capsules used in the embodiments of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0032] A preparation process of an antibacterial essential oil sustained-release capsule, such as Figure 1 As shown, the following steps are included:

[0033] S1: Modification of lecithin

[0034] S1.1: 1 part by weight of soybean lecithin is placed in a container, and then 10 parts by weight of anhydrous ethanol is added, and the mixture is stirred at 45°C to obtain a lecithin suspension, the temperature of the lecithin suspension is maintained at 40°C and stirred continuously, 3 parts by weight of citric acid and 50 parts by weight of distilled water are mixed in a container, and then 0.01wt% of phospholipase A2 is added, and the mixture is stirred until the citric acid is completely dissolved to obtain a citric acid solution;

[0035] S1.2: 8 parts by weight of lecithin suspension are slowly added to 45 parts by weight of citric acid solution, while stirring at a stirring speed of 500 rpm. When the lecithin suspension is completely added, a cross-linked mixed solution is obtained. The cross-linked mixed solution is placed in an ultrasonic cleaner and ultrasonically treated at a frequency of 40 kHz for 15 minutes. After standing for 25 minutes, it is centrifuged at a speed of 4000 rpm for 10 minutes. The solid product is filtered out, washed with deionized water, placed in a vacuum drying oven, and dried at a temperature of 30°C for 2 hours to obtain modified lecithin.

[0036] S2: Preparation of antibacterial nano-essential oil emulsion

[0037] S2.1: 0.8 parts by weight of luteolin and 1 part by weight of carvacrol are mixed and placed in a container, 15 parts by weight of anhydrous ethanol is added and stirred for 20 minutes to obtain a premixed solution, 50 parts by weight of distilled water are placed in a container, heated to 40° C., and then 5 parts by weight of modified lecithin are added, and stirring is continued until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution;

[0038] S2.2: Add 3 parts by weight of clove essential oil to the lecithin aqueous solution obtained in step S2.1, heat the temperature to 40°C, and then use a magnetic stirrer to stir at a stirring speed of 300 rpm for 10 minutes to obtain a crude emulsion, add the premix obtained in step S2.1 to the crude emulsion, and then use a high-speed shearing machine to perform shearing treatment at a rotation speed of 10,000 rpm for 10 minutes to obtain an antibacterial nano essential oil emulsion.

[0039] S3: Rutin-Silk Fibroin Cross-linked Coated Antibacterial Essential Oil

[0040] S3.1: 18 parts by weight of a 0.1 mol / L sodium hydroxide solution is placed in a container, 1 part by weight of rutin powder is added, the solution is heated to 40°C and stirred for 45 minutes, and then insoluble impurities are removed by filtering through a microporous filter with a pore size of 0.45 μm to obtain a rutin solution, a 0.06 mol / L hydrochloric acid solution is slowly added to the rutin solution while stirring, and the pH of the rutin solution is controlled to drop to 3 within 25 minutes, and then the solution is transferred to a centrifuge and centrifuged at 8000 rpm for 10 minutes, and a rutin precipitate is obtained by suction filtration, the rutin precipitate is washed twice with deionized water, and then dried in a vacuum drying oven to obtain rutin nanoparticles;

[0041] S3.2: Rutin nanoparticles and silk fibroin are uniformly dispersed in deionized water at a mass ratio of 1:0.6 to obtain a rutin nanoparticle dispersion. The concentration of the rutin nanoparticle dispersion is controlled to be 1wt%. 10 parts by weight of the rutin nanoparticle dispersion is placed in a container, 0.08 parts by weight of epichlorohydrin is added and pre-stirred for 12 minutes, and then 2 parts by weight of liquid paraffin and 4 parts by weight of antibacterial nano essential oil emulsion are added. The mixture is then placed in a homogenizer and homogenized at a homogenization speed of 16000 rpm for 6 minutes, and then stirred at a stirring speed of 300 rpm at 45°C for 2 hours to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled to room temperature, it is placed in a centrifuge and centrifuged at a speed of 10000 rpm for 15 minutes. The nanocapsule precipitate is collected by suction and then vacuum freeze-dried to obtain antibacterial essential oil sustained-release capsules. Example 2

[0042] A preparation process of an antibacterial essential oil sustained-release capsule, such as Figure 1 As shown, the following steps are included:

[0043] S1: Modification of lecithin

[0044] S1.1: 2 parts by weight of soybean lecithin are placed in a container, and then 15 parts by weight of anhydrous ethanol are added, and the mixture is stirred at 45° C. to obtain a lecithin suspension. The temperature of the lecithin suspension is maintained at 40° C. and stirred continuously. 5 parts by weight of citric acid and 60 parts by weight of distilled water are mixed in a container, and then 0.01 wt% of phospholipase A2 is added, and the mixture is stirred until the citric acid is completely dissolved to obtain a citric acid solution.

[0045] S1.2: Slowly add 10 parts by weight of lecithin suspension into 50 parts by weight of citric acid solution, stirring at a stirring speed of 500 rpm. When the lecithin suspension is completely added, a cross-linked mixed solution is obtained. The cross-linked mixed solution is placed in an ultrasonic cleaner and ultrasonically treated at a frequency of 40 kHz for 15 minutes. After standing for 25 minutes, it is centrifuged at a speed of 4000 rpm for 10 minutes. The solid product is filtered out, washed with deionized water, placed in a vacuum drying oven, and dried at a temperature of 30°C for 2 hours to obtain modified lecithin.

[0046] S2: Preparation of antibacterial nano-essential oil emulsion

[0047] S2.1: 1 part by weight of luteolin and 2 parts by weight of carvacrol are mixed and placed in a container, 20 parts by weight of anhydrous ethanol are added and stirred for 20 minutes to obtain a premixed solution, 60 parts by weight of distilled water are placed in a container, heated to 40° C., and then 6 parts by weight of modified lecithin are added, and stirring is continued until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution;

[0048] S2.2: Add 5 parts by weight of clove essential oil to the lecithin aqueous solution obtained in step S2.1, heat the temperature to 40°C, and then use a magnetic stirrer to stir at a stirring speed of 300 rpm for 10 minutes to obtain a crude emulsion, add the premix obtained in step S2.1 to the crude emulsion, and then use a high-speed shearing machine to perform shearing treatment at a rotation speed of 10,000 rpm for 5 minutes to obtain an antibacterial nano essential oil emulsion.

[0049] S3: Rutin-Silk Fibroin Cross-linked Coated Antibacterial Essential Oil

[0050] S3.1: 20 parts by weight of a 0.1 mol / L sodium hydroxide solution is placed in a container, 2 parts by weight of rutin powder is added, the solution is heated to 40°C and stirred for 45 minutes, and then insoluble impurities are removed by filtering through a microporous filter with a pore size of 0.45 μm to obtain a rutin solution, a 0.06 mol / L hydrochloric acid solution is slowly added to the rutin solution while stirring, and the pH of the rutin solution is controlled to drop to 3 within 25 minutes, and then the solution is transferred to a centrifuge and centrifuged at 8000 rpm for 10 minutes, and a rutin precipitate is obtained by suction filtration, the rutin precipitate is washed twice with deionized water, and then dried in a vacuum drying oven to obtain rutin nanoparticles;

[0051] S3.2: Rutin nanoparticles and silk fibroin are uniformly dispersed in deionized water at a mass ratio of 1:0.8 to obtain a rutin nanoparticle dispersion. The concentration of the rutin nanoparticle dispersion is controlled to be 1wt%. 12 parts by weight of the rutin nanoparticle dispersion is placed in a container, 0.1 parts by weight of epichlorohydrin is added and pre-stirred for 12 minutes, and then 3 parts by weight of liquid paraffin and 5 parts by weight of antibacterial nano essential oil emulsion are added. The mixture is then placed in a homogenizer and homogenized at a homogenization speed of 16000 rpm for 6 minutes, and then stirred at a stirring speed of 300 rpm at 45°C for 2 hours to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled to room temperature, it is placed in a centrifuge and centrifuged at a speed of 10000 rpm for 15 minutes. The nanocapsule precipitate is collected by suction and then vacuum freeze-dried to obtain antibacterial essential oil sustained-release capsules. Example 3

[0052] A preparation process of an antibacterial essential oil sustained-release capsule, such as Figure 1 As shown, the following steps are included:

[0053] S1: Modification of lecithin

[0054] S1.1: 1 part by weight of soybean lecithin is placed in a container, and then 10 parts by weight of anhydrous ethanol is added, and the mixture is stirred at 50° C. to obtain a lecithin suspension, and the temperature of the lecithin suspension is maintained at 45° C. and stirred continuously, 3 parts by weight of citric acid and 50 parts by weight of distilled water are mixed in a container, and then 0.02 wt% of phospholipase A2 is added, and the mixture is stirred until the citric acid is completely dissolved to obtain a citric acid solution;

[0055] S1.2: 8 parts by weight of lecithin suspension are slowly added to 45 parts by weight of citric acid solution, while stirring at a stirring speed of 600 rpm. When the lecithin suspension is completely added, a cross-linked mixed solution is obtained. The cross-linked mixed solution is placed in an ultrasonic cleaner and ultrasonically treated at a frequency of 45 kHz for 20 minutes. After standing for 30 minutes, it is centrifuged at a speed of 6000 rpm for 15 minutes. The solid product is filtered out, washed with deionized water, placed in a vacuum drying oven, and dried at a temperature of 40°C for 3 hours to obtain modified lecithin.

[0056] S2: Preparation of antibacterial nano-essential oil emulsion

[0057] S2.1: 0.8 parts by weight of luteolin and 1 part by weight of carvacrol are mixed in a container, 15 parts by weight of anhydrous ethanol is added and stirred for 30 minutes to obtain a premixed solution, 50 parts by weight of distilled water are placed in a container, heated to 45° C., and then 5 parts by weight of modified lecithin are added, and stirring is continued until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution;

[0058] S2.2: Add 3 parts by weight of clove essential oil to the lecithin aqueous solution obtained in step S2.1, heat the temperature to 45°C, and then use a magnetic stirrer to stir at a stirring speed of 500 rpm for 15 minutes to obtain a crude emulsion, add the premix obtained in step S2.1 to the crude emulsion, and then use a high-speed shearing machine to perform shearing treatment at a rotation speed of 12000 rpm for 5 minutes to obtain an antibacterial nano essential oil emulsion.

[0059] S3: Rutin-Silk Fibroin Cross-linked Coated Antibacterial Essential Oil

[0060] S3.1: 18 parts by weight of a 0.15 mol / L sodium hydroxide solution is placed in a container, 1 part by weight of rutin powder is added, the solution is heated to 45°C and stirred for 50 minutes, and then filtered through a microporous filter with a pore size of 0.5 μm to remove insoluble impurities to obtain a rutin solution, a 0.08 mol / L hydrochloric acid solution is slowly added to the rutin solution while stirring, and the pH of the rutin solution is controlled to drop to 4 within 30 minutes, and then the solution is transferred to a centrifuge and centrifuged at a speed of 10,000 rpm for 15 minutes, and a rutin precipitate is obtained by suction filtration, and the rutin precipitate is washed 3 times with deionized water, and then dried in a vacuum drying oven to obtain rutin nanoparticles;

[0061] S3.2: Rutin nanoparticles and silk fibroin are uniformly dispersed in deionized water at a mass ratio of 1:0.6 to obtain a rutin nanoparticle dispersion. The concentration of the rutin nanoparticle dispersion is controlled to be 2wt%. 10 parts by weight of the rutin nanoparticle dispersion is placed in a container, 0.08 parts by weight of epichlorohydrin is added and pre-stirred for 15 minutes, 2 parts by weight of liquid paraffin and 4 parts by weight of antibacterial nano essential oil emulsion are added, and then the mixture is placed in a homogenizer and homogenized at a homogenization speed of 18000 rpm for 8 minutes, and then stirred at a stirring speed of 350 rpm for 3 hours at 50°C to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled to room temperature, it is placed in a centrifuge and centrifuged at a speed of 12000 rpm for 20 minutes. The nanocapsule precipitate is collected by suction and then vacuum freeze-dried to obtain antibacterial essential oil sustained-release capsules.

[0062] Comparative Example 1

[0063] Compared with Example 1, the difference of Comparative Example 1 is that step S3.1 is removed in Comparative Example 1, and the rutin nanoparticle dispersion in step S3.2 is replaced by a mixed solution of chitosan with a concentration of 1wt% and sodium alginate with a concentration of 0.1wt%, and the remaining steps are the same as those in Example 1. The prepared antibacterial essential oil sustained-release capsules are recorded as Comparative Example 1.

[0064] Comparative Example 2

[0065] Compared with Example 1, the difference of Comparative Example 2 is that no premixed liquid is added in step S2.2 of Comparative Example 2, and the remaining steps are the same as those of Example 1. The prepared antibacterial essential oil sustained-release capsules are recorded as Comparative Example 2.

[0066] Comparative Example 3

[0067] Compared with Example 1, the difference of Comparative Example 3 is that carvacrol is not added to the premixed solution in step S2.1, and the remaining steps are the same as those in Example 1. The prepared antibacterial essential oil sustained-release capsules are recorded as Comparative Example 3.

[0068] Comparative Example 4

[0069] Compared with Example 1, the difference of Comparative Example 4 is that no luteolin is added to the premixed solution in step S2.1 in Comparative Example 4, and the remaining steps are the same as those in Example 1. The prepared antibacterial essential oil sustained-release capsule is recorded as Comparative Example 4.

[0070] Comparative Example 5

[0071] Compared with Example 1, the difference of Comparative Example 5 is that step S1 is removed in Comparative Example 5, and the subsequent modified lecithin is replaced with soybean lecithin. The remaining steps are the same as those in Example 1. The prepared antibacterial essential oil sustained-release capsule is recorded as Comparative Example 5.

[0072] Experiment 1: Take the same mass of the antibacterial essential oil sustained-release capsules prepared in Examples 1-3 and Comparative Examples 1-5, weigh them to obtain a mass M, place them in conical bottles, and then put them in an electric constant temperature drying oven, adjust the temperature to 30°C, weigh them every 60 days, and record the mass M t , and then use the formula R = (MM t ) / M×100%, calculate the loss ratio R of the active ingredient of the antibacterial essential oil, record the data and make a table, as shown in Table 1. The smaller the value of the active ingredient loss ratio, the more stable the sustained-release effect and the better the sustained-release performance.

[0073] It can be seen from Table 1 that the effective ingredient loss ratios of the antibacterial essential oil sustained-release capsules prepared in the embodiment are less than those of Comparative Examples 1 and 5 in the same period of time, which proves that the composite wall material formed by rutin-silk fibroin under the cross-linking agent can limit the release rate of the active substance, thereby prolonging the release time of the active substance and improving the sustained-release performance of the antibacterial essential oil sustained-release capsules. It can also be proved that the lecithin is modified and used as an emulsifier to evenly disperse the clove essential oil in the aqueous phase to form an O / W type nanoemulsion, which can effectively encapsulate the active ingredients of the clove essential oil and make them evenly distributed in the aqueous phase, thereby achieving better stability in the sustained-release system;

[0074] It can also be seen that the effective ingredient loss ratios of the antibacterial essential oil sustained-release capsules prepared in the examples are all smaller than those of comparative examples 2-4, and the sum of the increases in the effective ingredient loss ratios of comparative examples 3-4 relative to example 1 is greater than the increase in the effective ingredient loss ratios of comparative example 2, which can prove that the introduction of luteolin and carvacrol into the essential oil components can synergistically improve the sustained-release stability.

[0075] Experiment 2: 1 g of the antibacterial essential oil sustained-release capsules prepared in Example 1 and Comparative Examples 1-4 were placed in culture plates, and then 10 μL of Staphylococcus aureus suspension (1×10 8 CFU / mL) and 10 μL of E. coli suspension (1×10 8 CFU / mL) was applied on the top surface of the traditional Chinese medicine compound moisturizing, repairing and antibacterial cream and incubated at 37°C for 1 hour so that the relative humidity in the plate was not less than 90%. After 1 hour, 1 mL of sterile saline was added to each well to resuspend the bacteria. The bacterial suspension was gradiently diluted and then dripped onto the agar plate. After incubation at 37°C overnight, the bacterial reduction rate was calculated, which was the antibacterial rate and was tabulated as shown in Table 2.

[0076] It can be seen from Table 2 that the antibacterial essential oil sustained-release capsules prepared in Example 1 have a higher antibacterial rate against Staphylococcus aureus and Escherichia coli than that in Comparative Example 1, which proves that the composite wall material formed by rutin-silk fibroin under the crosslinking agent has good antibacterial properties;

[0077] It can also be seen that the sum of the reduction in the inhibition rate of Comparative Examples 3-4 against Staphylococcus aureus and Escherichia coli is greater than the reduction in the inhibition rate of Comparative Example 2, which can prove that the introduction of luteolin and carvacrol into the essential oil components can synergistically improve the antibacterial performance of the antibacterial sustained-release capsules.

[0078] Table 1: Sustained-release properties of antibacterial essential oil sustained-release capsules

[0079] Sustained release performance / % 30 days 90 days 150 days Example 1 3.9 11.5 28.4 Example 2 4.1 12.4 29.8 Example 3 3.5 11.2 26.9 Comparative Example 1 12.7 29.4 52.3 Comparative Example 2 4.8 12.7 36.3 Comparative Example 3 4.5 12.2 33.5 Comparative Example 4 4.6 12.3 33.9 Comparative Example 5 7.9 23.6 45.9

[0080] Table 2: Antibacterial properties of antibacterial essential oil sustained-release capsules

[0081] Antibacterial rate / % Staphylococcus aureus Escherichia coli Example 1 98.9 99.2 Example 2 98.7 99.5 Example 3 98.4 99.6 Comparative Example 1 96.1 97.3 Comparative Example 2 95.3 95.7 Comparative Example 3 96.2 96.1 Comparative Example 4 97.1 97.4

[0082] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A preparation process for an antibacterial essential oil sustained-release capsule, characterized in that: The following steps are involved: S1: Modification of lecithin Mixing lecithin and anhydrous ethanol and fully stirring to obtain a lecithin suspension, maintaining the temperature and continuously stirring, mixing citric acid and distilled water in a container, adding phospholipase A2, stirring until the citric acid is completely dissolved to obtain a citric acid solution, slowly adding the lecithin suspension to the citric acid solution under stirring to obtain a cross-linked mixed solution, subjecting the cross-linked mixed solution to ultrasonic treatment and then allowing it to stand, and then subjecting the cross-linked mixed solution to centrifugal filtration to obtain a solid product, and washing and drying to obtain a modified lecithin; S2: Preparation of antibacterial nano-essential oil emulsion Mix luteolin and carvacrol in a container, add anhydrous ethanol and stir to obtain a premixed solution, place distilled water in a container, add modified lecithin after heating, and continue stirring until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution, add clove essential oil to the lecithin aqueous phase solution, increase the temperature and perform magnetic stirring to obtain a crude emulsion, add the premixed solution to the crude emulsion, and then perform high-speed shear treatment to obtain an antibacterial nano essential oil emulsion; S3: Rutin-Silk Fibroin Cross-linked Coated Antibacterial Essential Oil A sodium hydroxide solution is placed in a container, rutin powder is added, and the mixture is heated and stirred before filtering to obtain a rutin solution. A hydrochloric acid solution is slowly added to the rutin solution under stirring, and the pH drop rate of the rutin solution is controlled, and then centrifugal filtration is performed to obtain a rutin precipitate. The rutin precipitate is washed and dried to obtain rutin nanoparticles. The rutin nanoparticles and silk fibroin are uniformly dispersed in deionized water to obtain a rutin nanoparticle dispersion. The rutin nanoparticle dispersion is placed in a container, a cross-linking agent is added and pre-stirred, and liquid paraffin and an antibacterial nano-essential oil emulsion are added, and then the mixture is placed in a homogenizer for homogenization, and then heated and stirred to obtain a nanocapsule suspension. After the nanocapsule suspension is cooled, centrifugal filtration is performed, and the nanocapsule precipitate is collected for vacuum freeze drying to obtain an antibacterial essential oil sustained-release capsule. Step S1 specifically includes the following steps: S1.1: 1-2 parts by weight of soybean lecithin is placed in a container, and then 10-15 parts by weight of anhydrous ethanol is added, and the mixture is stirred at 45-50° C. to obtain a lecithin suspension, and the temperature of the lecithin suspension is maintained at 40-45° C. and stirred continuously, 3-5 parts by weight of citric acid and 50-60 parts by weight of distilled water are mixed in a container, and then 0.01-0.02wt% of phospholipase A2 is added, and the mixture is stirred until the citric acid is completely dissolved to obtain a citric acid solution; S1.2: 8-10 parts by weight of lecithin suspension is slowly added to 45-50 parts by weight of citric acid solution, and stirred at a stirring speed of 500-600 rpm. When the lecithin suspension is completely added, a cross-linked mixed solution is obtained. The cross-linked mixed solution is placed in an ultrasonic cleaning machine for 15-20 minutes of ultrasonic treatment. The frequency of the ultrasonic treatment is 40-45 kHz. After standing for 25-30 minutes, the mixture is centrifuged at a speed of 4000-6000 rpm for 10-15 minutes. A solid product is obtained by suction filtration. After washing with deionized water, the solid product is placed in a vacuum drying oven and dried at a temperature of 30-40°C for 2-3 hours to obtain modified lecithin. Step S2 specifically includes the following steps: S2.1: 0.8-1 parts by weight of luteolin and 1-2 parts by weight of carvacrol are mixed and placed in a container, 15-20 parts by weight of anhydrous ethanol is added and stirred for 20-30 minutes to obtain a premixed solution, 50-60 parts by weight of distilled water are placed in a container, heated to 40-45° C., and then 5-6 parts by weight of modified lecithin are added, and stirring is continued until the modified lecithin is evenly dispersed to obtain a uniform lecithin aqueous phase solution; S2.2: 3-5 parts by weight of clove essential oil is added to the lecithin aqueous solution obtained in step S2.1, heated to 40-45°C, and then stirred at a stirring speed of 300-500 rpm using a magnetic stirrer for 10-15 minutes to obtain a crude emulsion, the premix obtained in step S2.1 is added to the crude emulsion, and then sheared for 5-10 minutes using a high-speed shearing machine at a shearing speed of 10000-12000 rpm to obtain an antibacterial nano essential oil emulsion; Step S3 specifically includes the following steps: S3.1: 18-20 parts by weight of a sodium hydroxide solution with a concentration of 0.1-0.15 mol / L is placed in a container, 1-2 parts by weight of rutin powder is added, the solution is heated to 40-45°C and stirred for 45-50 minutes, and then insoluble impurities are removed by filtering using a microporous filter with a pore size of 0.45-0.5 μm to obtain a rutin solution, a hydrochloric acid solution with a concentration of 0.06-0.08 mol / L is slowly added to the rutin solution while stirring, and the pH of the rutin solution is controlled to drop to 3-4 within 25-30 minutes, and then the solution is transferred to a centrifuge and centrifuged at a speed of 8000-10000 rpm for 10-15 minutes, and a rutin precipitate is obtained by suction filtration, and the rutin precipitate is washed 2-3 times with deionized water, and then placed in a vacuum drying oven for drying to obtain rutin nanoparticles; S3.2: Evenly disperse rutin nanoparticles and silk fibroin in deionized water at a mass ratio of 1:(0.6-0.8) to obtain a rutin nanoparticle dispersion, control the concentration of the rutin nanoparticle dispersion to be 1-2wt%, take 10-12 parts by weight of the rutin nanoparticle dispersion and place it in a container, add 0.08-0.1 parts by weight of epichlorohydrin and pre-stir for 12-15 minutes, then add 2-3 parts by weight of liquid paraffin and 4-5 parts by weight of antibacterial nano essential oil emulsion , then placed in a homogenizer, homogenized at a homogenization speed of 16000-18000rpm for 6-8 minutes, and then stirred at a stirring speed of 300-350rpm at 45-50°C for 2-3 hours to obtain a nanocapsule suspension, and after the nanocapsule suspension is cooled to room temperature, placed in a centrifuge, centrifuged at a speed of 10000-12000rpm for 15-20 minutes, the nanocapsule precipitate was collected by suction filtration, and then vacuum freeze-dried to obtain antibacterial essential oil sustained-release capsules.

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