Soluble microneedle containing cannabidiol suspension and preparation method therefor

Abstract

To provide a nanonization method for cannabidiol, a nanosized cannabidiol suspension prepared by the same, and applications therefor.SOLUTION: A nanonization method for cannabidiol includes following steps: the cannabidiol is dissolved in a good solvent to obtain a cannabidiol-good solvent solution; and the cannabidiol-good solvent solution is added to an aqueous solution of a stabilizer, followed by ultrasonic treatment and then rotary evaporation to remove the good solvent, resulting in a nanosized cannabidiol suspension. The stabilizer includes one or more selected from the group consisting of poloxamer, polysorbate, polyoxyethylene alkyl ether, polyvinyl pyrrolidone, hydroxypropyl methyl cellulose and chitosan. Nanonization technology for poorly soluble drugs reduces the particle size of the cannabidiol to produce the nanosized cannabidiol suspension. In the nanosized cannabidiol suspension, nanosized cannabidiol has a high solid content. The method achieves the solubilization of the cannabidiol.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of nano-ization of cannabidiol. More specifically, the present invention relates to a method for nano-izing cannabidiol, a nano-ized cannabidiol suspension prepared thereby, and its application. [Background technology]

[0002] Cannabidiol is the most abundant cannabinoid in industrial hemp, it is non-psychoactive and essentially free of toxicity and side effects. Cannabidiol has attracted great attention from the scientific community due to its therapeutic beneficial potential. Research has shown that cannabidiol has anti-inflammatory, anti-necrotic and antioxidant properties, and has significant therapeutic applications for patients with multiple sclerosis, Alzheimer's disease, epilepsy and Parkinson's disease. Currently, there are two US FDA approved cannabidiol products on the market, including Epidiolex® (pure CBD oral solution) and Sativex® (CBD and Δ-9THC oral mucosal spray). However, due to the low water solubility of cannabidiol, the instability of absorption in the gastrointestinal system and the first-pass effect, its bioavailability when administered orally is about 6%. In addition, the extreme lipophilicity of cannabidiol (logP: 5.79) makes it more likely to remain in the stratum corneum of the skin, and transporting cannabidiol to deeper skin poses certain challenges. Therefore, the passive diffusion transdermal system makes it difficult to achieve circulation of cannabidiol in the body.

[0003] Nanoization is defined as a pharmaceutical process that involves reducing the particle size of active drug ingredients to the nano-size range. This means that a particle size in the submicron range, i.e., a particle size of <1 μm, is achieved. According to the Noible-Wheaton equation, the smaller the particle size of a drug, the larger its surface area, which proportionally increases the dissolution rate and improves the absorption rate of poorly soluble drugs. In recent years, in order to improve the solubility and bioavailability of asahiniphenol, researchers have developed various nanoization methods for asahiniphenol, such as oral self-emulsifying systems, nanoliposomes, and nanomicelles, but these methods tend to have limited solubilization of asahiniphenol, and the system may be unstable.

[0004] Microneedles are an active skin penetration enhancement technology, in which microneedles exhibit needle-like structures, usually hundreds of microns in length, which form micron-sized pores in the skin and enhance drug delivery, which do not stimulate pain-related nerves, thus increasing patient compliance and reducing pain.

[0005] Due to the poor water solubility of cannabidiol, low oral bioavailability, and limited and unstable solubilization amount of the conventional technology, it is necessary to develop high-dose cannabidiol nano-technology, and combine it with a micro-injection dosage form to improve the storage stability and skin penetration rate of cannabidiol, reduce the administration frequency, and improve bioavailability and patient convenience. Summary of the Invention [Problem to be solved by the invention]

[0006] Based on the above problems, the object of the present invention is to provide a method for nanoparticle-forming cannabidiol, a nanoparticle-formed cannabidiol suspension prepared thereby, and its application. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: In one aspect, the method for nanoparticleization of cannabidiol provided by the present invention comprises: dissolving cannabidiol in a good solvent to obtain a cannabidiol-good solvent solution; adding the cannabidiol-good solvent solution into the aqueous solution of the stabilizer, and removing the good solvent by rotary evaporation after ultrasonic treatment to obtain a nano-sized cannabidiol suspension; Wherein, the stabilizer is one or more selected from poloxamer, polysorbate, polyoxyethylene alkyl ether, polyvinylpyrrolidone, polyoxyethylene alkyl ether and chitosan, in which the concentration of nano-sized cannabidiol in the obtained nano-sized cannabidiol suspension is high, the drug loading rate is high and the particle size of nano-sized cannabidiol in the suspension can be well controlled.

[0008] Further, the polyoxyethylene alkyl ether is selected from polyoxyethylene (20) cetyl ether (Brij 58) or polyoxyethylene (20) oleyl ether (Brij 98).

[0009] Furthermore, when the stabilizer is a mixture of several selected from poloxamer, polysorbate, polyoxyethylene alkyl ether, polyvinylpyrrolidone, hydroxypropyl methylcellulose and chitosan, the mixing ratio is not required and can be mixed at any ratio. For example, the stabilizer is selected from a mixture of polysorbate and hydroxypropyl methylcellulose, the mixing ratio of the two is 1:0.5, the stabilizer is selected from a mixture of polysorbate and polyvinylpyrrolidone, the mixing ratio of the two is 1:0.5 to 1:0.7, the stabilizer is selected from a mixture of polysorbate and carboxymethylchitosan, the mixing ratio of the two is 1:0.7 to 1:0.8, the stabilizer is selected from a mixture of poloxamer and polyvinylpyrrolidone, the mixing ratio of the two is 1:0.4, etc.

[0010] Further, the mass ratio of the cannabidiol to the stabilizer is 1:0.1 to 1:10. In some more specific examples, the mass ratio of the cannabidiol to the stabilizer is 1:0.1 to 1:5, 1:0.1 to 1:3, 1:0.1 to 1:2, 1:0.1 to 1:1.2, 1:0.1 to 1:0.8, 1:0.1 to 1:0.6, 1:0.1 to 1:0.5, 1:0.3 to 1:5, 1:0.3 to 1:3, 1:0.3 to 1:2, 1:0.3 to 1: The range includes, but is not limited to, 1:0.2, 1:0.3-1:0.8, 1:0.3-1:0.6, 1:0.3-1:0.5, 1:0.5-1:5, 1:0.5-1:3, 1:0.5-1:2, 1:0.5-1:1.2, 1:0.5-1:0.8, 1:0.5-1:0.6, 1:0.3, 1:0.5:1:0.6, 1:0.8, 1:1.2, etc. In this case, the concentration of nano-sized cannabidiol in the obtained nano-suspension of nano-sized cannabidiol is high, the drug loading rate is high, and the particle size of nano-sized cannabidiol in the suspension can be well controlled.

[0011] Further, the cannabidiol concentration in the cannabidiol-good solvent solution is 20 to 500 mg / mL. In some more specific examples, the cannabidiol concentration in the cannabidiol-good solvent solution is 25 to 500 mg / mL, 25 to 400 mg / mL, 25 to 300 mg / mL, 25 to 200 mg / mL, 25 to 150 mg / mL, 25 to 100 mg / mL, 100 to 500 mg / mL, 100 to 400 mg / mL, 100 to 300 mg / mL, 100 to 200 mg / mL, 100 to 150 mg / mL, 150 to Including, but not limited to, 500mg / mL, 150-400mg / mL, 150-300mg / mL, 150-200mg / mL, 200-500mg / mL, 200-400mg / mL, 200-300mg / mL, 300-500mg / mL, 300-400mg / mL, 25mg / mL, 100mg / mL, 150mg / mL, 200mg / mL300mg / mL, 400mg / mL, 500mg / mL, etc.

[0012] Furthermore, the good solvent is one or more selected from ethanol, isopropanol, propylene glycol, ethyl acetate, dimethylsulfoxide, dichloroethane, and polyethylene glycol.

[0013] Further, in the aqueous solution of the stabilizer, the concentration of the stabilizer is 10 to 100 mg / mL. In some more specific examples, the concentration of the stabilizer in the aqueous solution of the stabilizer includes, but is not limited to, 20 to 50 mg / mL, 20 to 30 mg / mL, 30 to 50 mg / mL, 20 mg / mL, 30 mg / mL, etc.

[0014] Further, the volume ratio of the good solvent to water is 1:1 to 1:10. In some more specific examples, the volume ratio of the good solvent to water includes, but is not limited to, 1:1 to 1:7, 1:1 to 1:5, 1:1 to 1:5, 1:1 to 1:3, 1:1 to 1:2, 1:2 to 1:7, 1:2 to 1:5, 1:2 to 1:5, 1:2 to 1:3, 1:3 to 1:7, 1:3 to 1:5, 1:3 to 1:5, 1:1, 1:2, 1:3, 1:4:1.5, 1:7, 1:10, etc.

[0015] Furthermore, the power of the ultrasonic waves is 25 to 75 W, and the ultrasonic wave duration is 5 to 30 minutes.

[0016] Furthermore, in the nanoized cannabidiol suspension, the concentration of the nanoized cannabidiol is 10 to 100 mg / mL, and the particle size is 50 to 1000 nm.

[0017] In a further aspect, the present invention provides a nanoized cannabidiol suspension, which is prepared by the above method.

[0018] In a further aspect, the present invention provides a soluble microneedle prepared from a raw material containing the drug component and excipients of the nanoized cannabidiol suspension.

[0019] Furthermore, in the soluble microneedles, the content of nano-sized cannabidiol is 1.5 to 25 wt %.

[0020] Furthermore, the excipient is one or more selected from polyvinyl alcohol, polyvinylpyrrolidone, hyaluronic acid, sodium carboxymethyl cellulose, and hydroxyethyl cellulose.

[0021] Furthermore, the raw material further includes a porogen, the function of which is to promote dissolution of the needle tip.

[0022] In addition, the porogen helps the water molecules in the fur to enter the needle matrix and regulate the drug release rate. The porogen includes, but is not limited to, one or more selected from trehalose, maltose, sucrose, and magnesium chloride.

[0023] Furthermore, the soluble microneedle is a monolithic needle or a layered needle. When the soluble microneedle is a layered needle, the drug component of the nano-sized cannabidiol suspension is located at the needle tip.

[0024] Further, the soluble microneedles are coated microneedles.

[0025] In a further aspect, the method for preparing the soluble microneedle provided by the present invention comprises: mixing the nano-sized cannabidiol-containing drug component and excipients to obtain an aqueous solution; placing the aqueous solution in a microneedle mould or a microneedle tip mould and drying to obtain the microneedles or soluble microneedle tips.

[0026] Furthermore, when the soluble material is an integral needle, the preparation method thereof includes the steps of: mixing the nano-sized cannabidiol-containing drug component and excipients to obtain an aqueous solution; placing the aqueous solution in a microneedle mold and drying to obtain the microneedle; When the soluble microneedles are layered needles, the preparation method thereof includes the steps of: Mixing the nano-sized cannabidiol suspension-containing drug ingredients and excipients to obtain a needle tip aqueous solution; placing the needle tip aqueous solution in a microneedle mold and drying; The method further includes the steps of dropping a base liquid, evacuating the mold under negative pressure, and drying to obtain the microneedle.

[0027] Furthermore, in the aqueous solution, the solid content of the excipient is 10 to 25%, and the solid content of the porogen is 0.03 to 1%. Effect of the Invention

[0028] In the nano-cannabidiol method provided by the present invention, the particle size of the poorly soluble drug cannabidiol is reduced by using poorly soluble drug nano-technology to obtain a cannabidiol nano-suspension, and the suspension has a high solid content of nano-cannabidiol, and the method realizes the solubilization effect of cannabidiol.In the preparation method of soluble microneedles provided by the present invention, an excipient is added to the cannabidiol nano-suspension, and then the microneedles are prepared, eliminating the traditional method of solidifying the nano-sized poorly soluble drug suspension, improving the stability of the nano-sized drug, and utilizing the drug targeting property of the microneedle to complete the transdermal administration of poorly soluble drugs, improving the skin penetration rate of cannabidiol, reducing the administration frequency compared with oral drugs, and improving the bioavailability. [Brief description of the drawings]

[0029] Hereinafter, specific embodiments of the present invention will be described in more detail with reference to the drawings. [Figure 1] FIG. 1 shows the particle size distribution diagram of the cannabidiol nanosuspension prepared in Example 10 of the present invention. [Diagram 2] 1 shows an optical microscope photograph of a microneedle prepared in Example 30 of the present invention. [Diagram 3]1 shows the results of trypan blue staining after the microneedles prepared in Example 30 of the present invention are pierced into ex vivo pigskin. [Figure 4] FIG. 2 shows a graph of the change in dissolution height after the microneedles prepared in Example 39 of the present invention are pierced into ex vivo pigskin. [Diagram 5] FIG. 2 shows the in vitro drug release curve of the microneedle prepared in Example 39 of the present invention. [Figure 6] FIG. 2 shows a curve diagram of the cumulative transdermal permeation amount of the microneedle prepared in Example 39 of the present invention. [Figure 7] 1 shows the experimental results of drug metabolism kinetics in rats using microneedles prepared in Example 39 of the present invention. [Figure 8] FIG. 2 shows a topographical view of a split-layer microneedle prepared in Example 47 of the present invention under a fluorescent microscope. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] In order to more clearly explain the present application, the present invention will be further described below in conjunction with preferred embodiments and drawings. In the drawings, similar components are designated by the same reference numerals. It will be understood by those skilled in the art that the contents specifically described below are illustrative and not limiting, and thus should not limit the scope of protection of the present invention.

[0031] Example 1 Preparation and Evaluation of Cannabidiol Nanosuspensions: Prepare the cannabidiol suspension according to the following steps: Preparation of cannabidiol nanosuspension: 0.20g of cannabidiol was dissolved in 1mL of absolute ethanol to form the organic phase, and 2% (w / w) polysorbate aqueous solution was used as the aqueous phase. The volume ratio of the two mixtures was controlled to 1:5, the organic phase was gradually added dropwise to the aqueous phase, and ultrasonicated at a power of 45W for 10min. The resulting mixture was spin-evaporated to remove the organic solvent, and polysorbate-cannabidiol nanosuspension was obtained. Content test: The solution of Example 1 was diluted 100-fold with a mobile phase of acetonitrile:water=75:25, and a content test was carried out by high performance liquid chromatography to calculate the drug loading rate. Drug loading rate = actual measured cannabidiol concentration / theoretical obtained cannabidiol concentration × 100%; Theoretical obtained cannabidiol concentration = cannabidiol added / aqueous phase volume. Particle size test: The sample prepared in Example 1 was diluted 100 times with ultrapure water, and then the nanoparticle size was measured using a nanoparticle size analyzer (Mastersizer2000). Through testing, the measured concentration of cannabidiol in the nanosuspension was 24.7mg / mL, the drug loading rate was 61.8%, and the particle size of the nano-sized cannabidiol was approximately 284nm.

[0032] Comparative Example 1 Prepare the cannabidiol nanosuspension by stirring: 0.20 g of cannabidiol was dissolved in 1 mL of absolute ethanol to serve as the organic phase, and 2% (w / w) aqueous polysorbate solution was used as the aqueous phase. The mixing volume ratio of the two was controlled to 1:5, and the organic phase was gradually added dropwise to the aqueous phase under magnetic stirring. The resulting mixed solution was spin-evaporated to remove the organic solvent, and a polysorbate-cannabidiol nanosuspension was obtained. The test measured a cannabidiol concentration of 17.0 mg / mL and a drug loading rate of 42.5%. The particle size was approximately 93 nm.

[0033] Comparative Example 2 Prepare the cannabidiol nanoemulsion by stirring: 0.20 g of cannabidiol was added directly to 5 mL of 2% (w / w) aqueous polysorbate solution and after 24 h of magnetic stirring, an emulsion containing cannabidiol was finally obtained. The tests showed that the concentration of cannabidiol was measured to be 10.1 mg / mL, the drug loading rate was 25.2%, and the particle size of cannabidiol was approximately 55 nm.

[0034] (Examples 2 to 9) The preparation method is the same as in Example 1, and the parameters of each component in Examples 2 to 9 are as shown in Table 1.

[0035] [Table 1]

[0036] As is clear from the above results, the ultrasonic anti-solvent precipitation method in the examples has a better solubilizing effect on cannabidiol than the methods used in Comparative Examples 1 and 2.

[0037] Example 10 The preparation of cannabidiol nanosuspension comprises the following steps: 0.30g of cannabidiol was dissolved in 1mL of absolute ethanol to form the organic phase, and 3% (w / w) aqueous polysorbate solution was used as the aqueous phase. The volume ratio of the two mixtures was controlled to 1:5, and the organic phase was gradually added dropwise to the aqueous phase, and ultrasonicated at a power of 45W for 10min. The resulting mixture was spin-evaporated to remove the organic solvent, and a cannabidiol nanosuspension was obtained. Through testing, the concentration of cannabidiol in the final suspension was 46.4mg / mL, and the drug loading rate was 77.33%.As shown in Figure 1, the particle size of cannabidiol in the suspension obtained in Example 10 was about 128nm.

[0038] (Examples 11 to 24, Comparative Examples 3 to 6) Different stabilizers were selected to prepare cannabidiol nanosuspension, the method is the same as in Example 1, and the formulation is as shown in Table 2 below.

[0039] [Table 2]

[0040] As is clear from the above results, the stabilizers used in Comparative Examples 3 to 6 cannot prepare cannabidiol nanosuspensions well, and cannot perform ideal solubilizing and stabilizing functions. The particle size of the cannabidiol nanosuspensions prepared with the stabilizer formulations in Examples 12 to 24 was between 50 and 1000 nm, and the concentration was 10 to 60 mg / mL.

[0041] (Examples 25 to 29) Referring to Example 10, cannabidiol nanosuspensions were prepared using different ultrasonic powers and times, and the formulations and results are shown in Table 3 below.

[0042] [Table 3]

[0043] As is clear from the above results, in Examples 26 to 29, the target concentration and nano-ization requirements can be met when the ultrasonic power is in the range of 25 to 75 W and the ultrasonic time is in the range of 5 to 30 minutes.

[0044] (Example 30) A method for preparing an integrated microneedle carrying nano-sized cannabis biphenols includes the following steps: (1) Preparation of microneedle solution: 4.0 g of the cannabidiol nanosuspension prepared in Example 10 above was taken, and 1.0 g of the excipient polyvinylpyrrolidone was added thereto, and the two were mixed uniformly, and then centrifuged to remove air bubbles. (2) Preparation of microneedles: 60 μL of the microneedle solution was added to the PDMS mold, and the mold was subjected to vacuum pulling for 5 minutes and dried at room temperature to obtain the microneedle. (3) Inspection of each parameter of the microneedle Microneedle Integrity: Observe the entire morphology of the microneedle under a stereomicroscope to see whether it can be completely released and whether the needle tip morphology is complete. The topography of the microneedle in Example 30 under an optical microscope is shown in Figure 2, and the microneedle array is composed of 144 (12 x 12) cone-shaped arrays, with an area of ​​0.56 cm2 and a needle height of 500 μm. Puncture ability of microneedle: Use the ear skin of a young animal, cut out an appropriate area, flatten the needle tip of the microneedle downward, press the needle feed pressure of 20N from the back of the microneedle, continue to press for 10s, and after the pressing is completed, take out the microneedle from the skin, drip trypan blue dyeing solution on the skin of the needle application site, stain for 5 minutes, wash the skin, and if an orderly colored pinhole array is observed, it has puncture ability. The puncture result of Example 30 is as shown in Figure 3, and the pinholes observed by the naked eye are obvious, and when a piece of the skin is removed, the pinhole array becomes orderly and more complete.

[0045] (Examples 31 to 34 and Comparative Examples 7 to 11) Comparative Examples 7 to 11 and Examples 31 to 34 list integrated dissolving microneedles prepared using excipients that the inventors have tried. The excipients in the Comparative Examples include polyglutamic acid (γ-PGA), chondroitin sulfate (CS), dextran (DEX), hypromellose (HPMC), and hydroxypropyl cellulose (HHPC), and the excipients in the Examples include polyvinyl alcohol (PVA), hyaluronic acid (HA), hydroxyethyl cellulose (EC), and sodium carboxymethyl cellulose (CMC), all of which were prepared based on the method of Example 30 and the weight percentages of the materials shown in Table 1.

[0046] The integrity, puncture ability and needle body color of the microneedle were detected in the same manner as in Example 30, and the detection results are shown in Table 4.

[0047] [Table 4]

[0048] As can be seen from Table 4, Comparative Examples 7 to 11 use different microneedle substrate materials, of which γ-PGA, CS and HPMC cause yellowing when needles are formed, and the DEX microneedles become brittle and are easily cut when the needle tip is peeled off, all of which do not meet the appearance requirements of the formulation. When HHPC is used as the microneedle material, the microneedles have no puncture ability and do not meet the usage requirements of the microneedle formulation. When PVA, PVP, CMC, HA and EC are used as the microneedle material, the appearance and puncture ability can all meet the appearance and usage requirements of the formulation.

[0049] (Examples 35 to 36 and Comparative Example 12) Cannabidiol percentage ranges in soluble microneedles: The concentration range of the prepared nano-sized cannabidiol is 10-100mg / mL, which requires the upper and lower limits of the drug loading rate prepared in the microneedle. The concentration of cannabidiol was selected to be 10mg / mL to consider the lower limit of the drug loading rate of the microneedle, and the concentration of cannabidiol was selected to be 100mg / mL to consider the upper limit of the drug loading rate. According to the preparation method of Example 30, microneedles were prepared with the weight percentages of materials shown in Table 5, and the needle properties and drug loading rate of the microneedles were considered. Microneedle content test: One microneedle sample was placed in a centrifuge tube, 3 mL of mobile phase (acetonitrile:water = 75:25) was added, and the tube was shaken with a vortex meter for 120 minutes to extract cannabidiol, which was then filtered into a liquid phase vial with a 0.22 μm filter membrane and subjected to HPLC testing. Percentage of cannabidiol in microneedles = cannabidiol content / total solid content in microneedles x 100%.

[0050] [Table 5]

[0051] The drug loading rate of the microneedle is related to the amount of cannabidiol added and the mass ratio of excipients, and when considering the lower limit of the drug loading rate, the ratio of excipients should be as high as possible.Example 35 selects an excipient with a mass fraction of 70%, and the obtained microneedle has good needle formability and a drug loading rate of 1.5%, and when preparing an excipient with a higher mass ratio, the drug loading rate of the microneedle for cannabidiol should be lower, and the microneedle prepared in Example 36 has a perfect needle tip and excellent toughness, but for Comparative Example 12, when the proportion of PVA is reduced, the toughness of the microneedle is insufficient and the needle tip is broken, so it is preferable to limit the drug loading rate of the microneedle cannabidiol to within 25%.

[0052] (Examples 37 to 42 and Comparative Example 13) Different porogens are added to prepare integral microneedles carrying nanoized cannabidiol: (1) Preparation of microneedle solution: Take 5.0g of the cannabidiol nanosuspension prepared in Example 10 above, add 0.70g of hyaluronic acid and 0.30g of PVP as excipients, then add porogen according to the formula shown in Table 6, mix uniformly, and then centrifuge to remove air bubbles. (2) Preparation of microneedles: 60 μL of the microneedle solution was added to the PDMS mold, and the mold was subjected to vacuum pulling for 5 minutes and dried at room temperature to obtain the microneedle. (3) Microneedle solubility experiment: The microneedles were attached to the in vitro pigskin for 30 s, and the pressure-sensitive adhesive was attached to the base layer and maintained for a certain period of time. To characterize the transdermal dissolution of the microneedles, the remaining microneedles were placed under a fluorescent microscope to study the change in microneedle height.

[0053] Figure 4 shows the results of the solubility experiment of the microneedle prepared in Example 39. As can be seen, the dissolution rate of the microneedle is fast, and the needle tip is almost completely dissolved within 10 minutes, so that the microneedle can quickly enter the skin and release the drug.

[0054] [Table 6]

[0055] As can be seen from the above results, the addition of porogen improves the dissolution rate of the microneedles in the skin, which is helpful in releasing the drug.

[0056] (Example 43) Accelerated Stability Content Testing of Cannabidiol Microneedles: The microneedle patch in Example 39 was packaged in a blister and an aluminum plastic bag, and was left to stand in a 50°C environment for 3 months. The cannabidiol content of the integrated microneedle on day 0 and month 3 was measured using high performance liquid chromatography. The microneedle content measured after liquid phase test can be maintained at 99.3%, and after cannabidiol is prepared into the microneedle, the drug can be maintained at a good stability, and the microneedle dosage form is easy to store and transport.

[0057] (Example 44) Measurement of in vitro drug release of cannabidiol microneedles: The microneedles prepared in the examples were collected. One microneedle was taken, placed in a dialysis bag, and dispersed in 200 μL of receptor solution, and then the dialysis bag was precisely sealed and suspended in a stoppered Erlenmeyer flask containing 5 mL of receptor solution. The receptor solution was a 1% polysorbate 80-PBS solution. A magnet was attached to the Erlenmeyer flask, the magnetic stirring speed was 280 rpm, and the flask was placed in a thermostatic water bath at 37 ± 0.2 ° C., and the entire sample in the Erlenmeyer flask was taken out at the appropriate time and the same volume of release medium was replenished. The liquid taken out was filtered through a 0.45 μm filter membrane, then transferred to a liquid phase vial, and the concentration of cannabidiol in the sample was obtained by high performance liquid chromatography test.

[0058] Figure 5 shows the in vitro drug release rate curve of the microneedle obtained in Example 39. It can be seen that the microneedle of Example 39 can achieve a rapid release rate of 71.25±1.19% from 2 hours before the drug release, and the cumulative release curve after 8 hours becomes smooth, and finally the drug is released completely.

[0059] (Example 45) In vivo skin kinetics of cannabidiol microneedles in rats A male adult SD rat (weight approximately 250g) was fixed, its abdominal skin was depilated using a hair removal cream, and the obtained microneedles were inserted vertically into the skin and pressed for 2, 4, 8, 12, and 24 hours. After that, the microneedle array was removed, the skin was washed twice with a cotton ball dipped in medical alcohol, and the removed patch was placed in a 5mL centrifuge tube and stored. The remaining microneedle content was extracted and analyzed by high performance liquid chromatography.

[0060] 6 shows the cumulative permeation curve of the microneedle after the rat skin dynamics experiment on the microneedle obtained in Example 39. It can be seen that the permeation rate of the microneedle can reach 1246.90±404.07 μg / cm2 before 2 h, and the permeation slows down in the following time. (Example 46)

[0061] Drug metabolism and kinetics in rats using cannabidiol microneedles A male adult SD rat (weight about 250g) was fixed, its abdominal skin was depilated using a depilatory cream, and the obtained microneedle was inserted vertically into the skin, and the microneedle was removed 24 hours after administration. Blood was collected from the rat's tail vein at a predetermined time before and after administration, placed in a heparin tube, centrifuged at 5000 rpm at 4°C for 10 minutes, and the upper layer plasma was collected and stored at 80°C. After plasma processing, a content test was performed.

[0062] Figure 7 shows the experimental results of drug metabolism kinetics in rats using microneedles obtained in Example 39. Microneedle administration can maintain the blood drug concentration for 3 days, while the intragastric administration group can only maintain it for 2 days, and the area under the curve is 12 times that of the intragastric administration group. The cannabidiol microneedle dosage form designed in the present invention can not only improve the bioavailability of cannabidiol, but also achieve a certain sustained release effect, reduce the administration frequency, and improve patient compliance.

[0063] Comparative Example 14 Preparation of cannabidiol-integrated microneedles dissolved in organic solvent, heat resistance evaluation and in vitro release evaluation: A cannabidiol base solution containing 10% (w / w) polylactic acid-co-glycolic acid (PLGA), 10% (w / w) PVP, and 4% (w / w) cannabidiol was prepared using N,N-dimethylacetamide (DMA) as a solvent, and after uniform mixing, it was used as the needle tip injection molding liquid. 50 μL of the microneedle solution was placed in a PDMS mold, vacuumed for 5 min, and heated at 50°C for 3 h. Heat resistance evaluation: The microneedles obtained in Comparative Example 14 were sealed and packaged, then placed in an incubator at 60°C for 10 days, and after 10 days, they were taken out and the side view of the microneedles was observed under an optical microscope to observe the completeness and color of the microneedles' topography. Measurement of in vitro drug release: The procedure was the same as in Example 44.

[0064] (Comparative Examples 15 to 18) The preparation method was based on Comparative Example 14, using polylactic acid (PLA), PVA, PVP and HPMC materials, dissolving organic solvents DMA, N,N-dimethylformamide (DMF) and N-methylpyrrolidone (NMP), heating and natural drying, and finally in vitro release evaluation. The components and experimental results in Comparative Examples 15 to 18 are shown in Table 7.

[0065] [Table 7]

[0066] When using PLGA, PLA, PVA, PVP and HPMC materials, the cannabidiol integrated microneedle system dissolved in an organic solvent has problems such as difficulty in in vitro release and easy discoloration under high temperature conditions, so it is inappropriate to directly dissolve cannabidiol in an organic solvent to prepare an integrated microneedle.

[0067] (Example 47) Nano-sized cannabidiol hierarchical dissolving microneedles Prepare nanoized cannabidiol hierarchical dissolving microneedles according to the following steps: (1) Preparation of layered microneedle substrate solution: Preparation of needle tip solution: Take 1.0 g of the cannabidiol nanosuspension (containing the fluorescent substance coumarin 6) in Example 10, add 0.14 g of HA, 0.06 g of PVP, and 0.01 g of trehalose in that order. Stir evenly and centrifuge to prepare for use. Preparation of the base solution: 10.0 g of ultrapure water was weighed into a centrifuge tube, 10.0 g of PVA weighed into the centrifuge tube was added, and the tube was heated in an oven at 80°C to cause swelling. The tube was stirred every half hour until completely dissolved, and centrifuged to remove air bubbles, to obtain a base solution with a PVA solid content of 50%. (2) Preparation of microneedles: 5 μL of each solution was transferred from the liquid addition gun and dropped onto the PDMS microneedle. After vacuuming for 5 minutes, the tip of the microneedle was allowed to dry naturally at room temperature for 30 minutes. Next, 50 μL of the base liquid was dropped onto the mold, and the mold was depressurized and vacuumed for 10 minutes. The microneedle was then allowed to dry naturally at room temperature and released from the mold. (3) Observation of microneedle topography: As shown in FIG. 8, the tip height of the prepared fractionation microneedle was observed with a fluorescence microscope and was found to be approximately 300 μm. (4) Microneedle solubility experiment: (According to the steps of Example 37, it was observed under a microscope that the drug-loaded needle tip was completely dissolved when placed on the layered needle within 5 minutes. (5) In vitro drug release measurement: (According to the steps of Example 44, the layered needle release rate measurement was carried out. The layered needle can reach a cumulative release rate of more than 50% within the first 30 minutes.

[0068] (Example 48) Nano-sized cannabidiol coated microneedles Prepare coated microneedles of nanoized cannabidiol according to the following steps: (1) An appropriate amount of PLGA was placed into a microneedle-integrated matrix mold, a vacuum was drawn below the mold, and the mold was heated to a high temperature of 190°C for 5 minutes. The polymer material was pressed to be flattened, and then cooled and demolded to obtain a polylactic acid-integrated microneedle base. (2) Drug solution: (Take 1.0 g of the cannabidiol nanosuspension in Example 10, add 0.1 g of PVP, 0.1 g of 50% (w / w) PVA solution, and 0.02 g of trehalose in that order. Stir evenly and centrifuge to prepare for use. (3) The drug solution prepared above was placed in a drug-loaded pool with a height of 300 μm. The microneedle base with PLGA mounted was taken, and the needle tip was dropped downward into the drug-loaded pool to immerse it in the drug solution. The microneedle was then left to stand for 3 minutes to dry the coating layer. This dip drying process was repeated four times. Finally, a coated microneedle carrying nano-sized cannabidiol was obtained. (4) Microneedle solubility experiment: According to the steps of Example 37, when observed under a microscope, it was observed that the drug-carrying needle tip of the coated needle was almost completely dissolved when placed for 30 minutes. (5) In vitro drug release measurement: The release rate of the coated needle was measured according to the steps of Example 44. The coated needle can reach a cumulative release rate of more than 50% within the previous 8 hours.

[0069] The above examples of the present invention are merely illustrative to clearly explain the present invention, and are not intended to limit the embodiments of the present invention. In addition to the above description, those skilled in the art may make other different forms of changes or variations. It is not possible to cover all embodiments here, and obvious changes or variations due to the technical solutions of the present invention are included in the protection scope of the present invention.

Claims

1. A soluble microneedle, prepared from a raw material containing a drug component and an excipient of a nano-sized cannabidiol suspension, the preparation of the nano-sized cannabidiol suspension comprising: dissolving cannabidiol in a good solvent to obtain a cannabidiol-good solvent solution, the good solvent being one or more selected from ethanol, isopropanol, propylene glycol, ethyl acetate, dimethylsulfoxide, dichloroethane and polyethylene glycol; adding the cannabidiol-good solvent solution into the aqueous solution of the stabilizer, and removing the good solvent by rotary evaporation after ultrasonic treatment to obtain a nano-sized cannabidiol suspension, wherein the ultrasonic power is 25-75W and the ultrasonic time is 5-30min; wherein the stabilizer is one or more selected from the group consisting of poloxamer, polysorbate, polyoxyethylene alkyl ether, polyvinylpyrrolidone, hydroxypropyl methylcellulose, and carboxymethyl chitosan; The mass ratio of the cannabidiol to the stabilizer is 1:0.3 to 1:5; The excipient is one selected from polyvinylpyrrolidone, polyvinyl alcohol, sodium carboxymethyl cellulose, hyaluronic acid, and hydroxyethyl cellulose; The soluble microneedle, characterized in that the content of nano-sized cannabidiol in the soluble microneedle is 1.5 to 25 wt %.

2. The soluble microneedle according to claim 1, characterized in that the cannabidiol concentration in the cannabidiol-good solvent solution is 20 to 500 mg / mL.

3. The soluble microneedle according to claim 1, characterized in that the concentration of the stabilizer in the aqueous solution of the stabilizer is 10 to 100 mg / mL.

4. The soluble microneedle according to claim 1, characterized in that the volume ratio of the good solvent to water is 1:1 to 1:

10.

5. The soluble microneedle according to claim 1, characterized in that in the nano-sized cannabidiol suspension, the concentration of nano-sized cannabidiol is 10 to 100 mg / mL and the particle size is 50 to 1000 nm.

6. mixing the nano-sized cannabidiol-containing drug component and excipients to obtain an aqueous solution; A method for preparing a soluble microneedle according to any one of claims 1 to 5, further comprising the steps of: placing the aqueous solution in a microneedle mould or a microneedle tip mould and drying to obtain the microneedle or the tip of the soluble microneedle.

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