Chicoric acid self-microemulsion, chicoric acid self-microemulsion pellet and preparation method of chicoric acid self-microemulsion pellet

Abstract

The invention relates to the technical field of medicines, in particular to a chicoric acid self-microemulsion, a chicoric acid self-microemulsion preparation and a preparation method of the chicoric acid self-microemulsion preparation. According to the chicoric acid self-microemulsion under the optimal formula, the average drug loading capacity is 69.50 + / -0.31 mg / g, the average particle size is 15.01 + / -0.25 nm, and the average PDI is 0.251 + / -0.01. The chicoric acid self-microemulsion has good stability. The chicoric acid self-microemulsion pellet prepared from the chicoric acid self-microemulsion pellet also has good stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medicine, in particular to a chicoric acid self-microemulsion, a chicoric acid self-microemulsion preparation and a preparation method thereof. BACKGROUND

[0002] Chicoric acid is an important active ingredient in traditional medicinal plants such as dandelion, Echinacea and chicory. Studies have shown that chicoric acid helps plants protect themselves from insect infestation and infection by viruses, bacteria, fungi and nematodes, and helps wound healing after mechanical damage; at the same time, chicoric acid also has a wide range of biological activities such as anti-inflammatory, antioxidant, immune regulation, glycolipid metabolism regulation, antibacterial, antiviral and antitumor activities. However, chicoric acid is a phenolic acid component with high polarity, which is not conducive to transmembrane absorption, resulting in low oral bioavailability, limiting its preparation research and clinical application. Therefore, it is extremely urgent to improve the bioavailability of chicoric acid through appropriate pharmaceutical technology to exert its potential medicinal value.

[0003] The self-microemulsion drug delivery system is a uniform transparent solution composed of oil, surfactant and co-surfactant or a small amount of water. The drug is dissolved and dispersed in the oil phase medium, and after oral administration, the self-microemulsion system containing the drug spontaneously disperses to form an O / W type microemulsion under the peristalsis of the gastrointestinal tract; this technology can effectively increase the solubility and bioavailability of the drug. However, there are problems such as low drug loading capacity, large particle size and poor physical and chemical stability in the preparation of chicoric acid self-microemulsion. SUMMARY

[0004] In order to overcome the above problems, the present application provides a chicoric acid self-microemulsion, a chicoric acid self-microemulsion preparation and a preparation method thereof.

[0005] To achieve the above technical purposes, the present application adopts the following technical solutions: In a first aspect of the present application, a chicoric acid self-microemulsion is provided, comprising chicoric acid and a self-microemulsion drug delivery system carrier; wherein the self-microemulsion drug delivery system carrier comprises an oil phase and a mixed emulsifier composed of an emulsifier and a co-emulsifier; the concentration of chicoric acid is 68-73 mg / g, the mass fraction of the oil phase is 17-18%, and the mass ratio (Km) of the emulsifier to the co-emulsifier in the mixed emulsifier is 2.35-2.45.

[0006] In one or more embodiments, the concentration of chicoric acid is 70 mg / g, the mass fraction of the oil phase is 18%, and the mass ratio (Km) of the emulsifier to the co-emulsifier in the mixed emulsifier is 2.4.

[0007] In one or more embodiments, the oil phase is Capryol 90.

[0008] In one or more embodiments, the emulsifier is polyoxyethylene castor oil EL-35.

[0009] In one or more embodiments, the co-emulsifier is 1,2-propanediol.

[0010] In one or more embodiments, the particle size of the chrysin self-microemulsion is 14-16 nm.

[0011] In a second aspect of the present application, a chrysin self-microemulsion pellet is provided, comprising the chrysin self-microemulsion of the first aspect and a solid adsorbent.

[0012] In one or more embodiments, the solid adsorbent is composed of lactose and microcrystalline cellulose.

[0013] Preferably, the mass ratio of lactose and microcrystalline cellulose is 1: (1-2), preferably 1:2.

[0014] In one or more embodiments, the mass ratio of the chrysin self-microemulsion and the solid adsorbent is 1: (3.5-5.5), preferably 1:4.

[0015] In one or more embodiments, the chrysin self-microemulsion pellet further comprises a binder and a humectant. Preferably, the binder is hypromellose. Further preferably, the amount of hypromellose is 2.5-3.5 wt% of the chrysin self-microemulsion pellet, preferably 3 wt%. Preferably, the humectant is water; further preferably, the amount of water is 45-50 wt% of the chrysin self-microemulsion pellet, preferably 50 wt%.

[0016] In a third aspect of the present application, a preparation method of the chrysin self-microemulsion pellet of the second aspect is provided, comprising: Preparation of the chrysin self-microemulsion pellet by extrusion-spheronization.

[0017] In one or more embodiments, the extrusion speed is 8-12 Hz, the spheronization speed is 45-55 Hz, and the spheronization time is 7.5-8.5 min. Preferably, the extrusion speed is 10 Hz, the spheronization speed is 50 Hz, and the spheronization time is 8 min.

[0018] The present application has the following beneficial effects: (1) In the present application, the oil phase, emulsifier and co-emulsifier with larger solubility of chicoric acid are screened out through solubility experiment, and they are matched to preliminarily investigate the physical and chemical compatibility between the excipients; subsequently, the types of the oil phase, emulsifier and co-emulsifier are determined through pseudo-ternary phase diagram screening; with the oil phase ratio and Km value as dependent variables, and the drug loading capacity, average particle size and polydispersity coefficient (PDI) as evaluation indexes, the response surface graph and contour graph are drawn according to the response equation to determine the optimal formula of the chicoric acid self-microemulsion. The average drug loading capacity of the chicoric acid self-microemulsion under the optimal formula is 69.50±0.31 mg / g, the average particle size is 15.01±0.25 nm, and the average PDI is 0.251±0.01. The chicoric acid self-microemulsion prepared by the present application has good stability in high temperature (60 ℃±2 ℃), high humidity (relative humidity is 90%±5%) or strong light irradiation environment (4500±500lx), the average particle size and PDI have no obvious change, and the drug loading capacity slightly decreases, but still can reach more than 55 mg / g. The chicoric acid self-microemulsion can still maintain good stability under the condition of 40 ℃±2 ℃ and relative humidity of 75%±5% for 3 months, the average particle size and PDI have no obvious change, and the drug loading capacity slightly decreases, but still can reach more than 55 mg / g. Meanwhile, the chicoric acid self-microemulsion has good centrifugal stability, and can still maintain good stability under the condition of pH being 1.2 and 6.8.

[0019] (2) The chicoric acid self-microemulsion as a liquid preparation has the disadvantages of inconvenience in carrying, storage and taking, therefore, the chicoric acid self-microemulsion is solidified into pellets, the yield of pellets, roundness and bulk density are used as indexes, the proportion of the filler, binder and wetting agent is adjusted through single factor test to optimize the prescription, and then the extrusion-spheronization parameters are adjusted to determine the optimal conditions of the chicoric acid self-microemulsion pellets. The emulsion formed after the chicoric acid self-microemulsion pellets are redissolved is still an O / W type emulsion, which indicates that the emulsion type of the chicoric acid self-microemulsion is not affected in the solidification process. After the chicoric acid self-microemulsion is solidified, the particle size, PDI and absolute value of Zeta potential all increase to different degrees, which may be caused by the dissolution of the pellet excipients, but still meets the requirements of the self-microemulsion emulsion; the increase of the absolute value of Zeta potential indicates that the solidification technology can improve the stability of the self-microemulsion. The chicoric acid self-microemulsion pellets have good stability in high temperature (60 ℃±2 ℃), high humidity (relative humidity is 90%±5%) or strong light irradiation environment (4500±500lx), and the average particle size and PDI have no obvious change. Moreover, the appearance of the chicoric acid self-microemulsion pellets is still white spherical after being placed for 6 months, and the average particle size has no obvious change, indicating good stability. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated herein by reference. The illustrations are of exemplary embodiments of the application and explain the principles of the application, but do not limit the application.

[0021] Figure 1 Pseudo-ternary phase diagrams, wherein A is Capryol 90-EL35-Transcutol HP; B is Capryol 90-EL35-PEG 400; C is Capryol 90-EL35-1,2-propanediol; D is Capryol 90-Tween 80-Transcutol HP; E is Capryol 90-Tween 80-PEG 400; F is Capryol 90-Tween 80-1,2-propanediol Figure 2 Response analysis results, wherein A is the drug loading response surface plot, B is the particle size response surface plot, and C is the PDI response surface plot; Figure 3 Appearance of the chrysophanic acid self-microemulsion, wherein A is the appearance of the blank self-microemulsion at room temperature, B is the appearance of the chrysophanic acid self-microemulsion at room temperature, and C is the appearance after dilution with ultrapure water (Dial test); Figure 4 A and B are both transmission electron microscopy images of the chrysophanic acid self-microemulsion; Figure 5 Identification results of the chrysophanic acid self-microemulsion, wherein A is water-soluble dye methyl blue, and B is oil-soluble dye Sudan red; Figure 6 Particle size and Zeta potential distribution of the chrysophanic acid self-microemulsion; wherein A is the particle size, and B is the Zeta potential; Figure 7 Adsorption capacity test results of different solid adsorbents; Figure 8 Chrysophanic acid self-microemulsion pellet properties, wherein A is a direct view, B is 32x, and C is 56x. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed description is merely exemplary, and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0025] Example 1 (1) Determination of the solubility of chicoric acid in various excipients: Weigh out excess chicoric acid raw material and add it to a 10mL beaker. Then, add 2g of the oil phase (medium-chain triglycerides (MCT), propylene glycol monocaprylate (Capryol 90), oleoyl polyoxyethylene glycerol (Labrafil M 1944 CS), glyceryl monolinoleate (Maisine CC), isopropyl myristate (IPM)), emulsifiers (Tween 80, Tween 20, polyoxyethylene castor oil (EL-35), polyoxyethylene 40 hydrogenated castor oil (RH-40), PEG-40 caprylic / capric glycerol (LabrasolALF)) and co-emulsifiers (1,2-propanediol, polyethylene glycol 400 (PEG 400), diethylene glycol monoethyl ether (TranscutolHP), anhydrous ethanol, glycerol) to the oil phase. Vortex mix for 5 min, sonicate at 40 kHz for 30 min, and magnetically stir at 37 ℃ and 120 r / min for 1 minute. After being left at room temperature for 24 hours, the solution was transferred to a stoppered centrifuge tube and centrifuged at 3500 r / min for 15 min. The supernatant was then diluted with methanol to a suitable concentration, filtered through a 0.22 μm filter membrane, and injected according to the chromatographic conditions. The peak area was recorded, and the solubility was calculated. The results are shown in Table 1.

[0026] Table 1. Solubility of chicoric acid in various excipients

[0027] The solubility of chicoric acid in each oil phase ranked as: Labrafil M 1944 CS > Capryol 90 > monolinolein. There was little difference in the solubility of chicoric acid in Labrafil M 1944 CS, Capryol 90 and monolinolein as oil phase, while chicoric acid was almost insoluble in IPM and MCT. Among the emulsifiers screened, the solubility of chicoric acid ranked as: Labrasol ALF > EL-35 > Tween 80 > RH-40 > Tween 20. The solubility of chicoric acid in Labrasol ALF was the highest (4.24 mg / mL), and Labrasol ALF, EL-35 and Tween 80 had better solubility of chicoric acid than RH-40 and Tween 20. Among the co-emulsifiers, the solubility of chicoric acid ranked as: HP > absolute ethanol > 1.2 propylene glycol > PEG400 > glycerol, and the solubility of chicoric acid in HP, absolute ethanol, 1.2 propylene glycol and PEG400 was 130.01 mg / mL, 123.64 mg / mL, 95.39 mg / mL and 87.47 mg / mL respectively, which was much higher than that in glycerol.

[0028] According to the results of the solubility experiment, oil phase, emulsifier and co-emulsifier with higher solubility of chicoric acid were screened, and they were combined to preliminarily investigate the physical and chemical compatibility between the excipients. The selected oil phase was: capryol 90, Labrafil M 1944 CS, Maisine CC, the emulsifier was: Labrasol ALF, EL-35, Tween 80, and the co-emulsifier was: 1,2-propylene glycol, PEG400, absolute ethanol, Transcutol HP.

[0029] (2) According to the solubility experiment results, the oil phase (Capryol 90, Labrafil M 1944 CS, Maisine CC), emulsifier (Labrasol ALF, polyoxyethylene castor oil EL-35, Tween 80) and co-emulsifier (1,2-propanediol, PEG400, anhydrous ethanol, Transcutol HP) with larger solubility of chicoric acid were screened out, and they were compounded to preliminarily investigate the compatibility between the excipients. The mixed solution with a total amount of 1 g, the mass ratio of oil phase, emulsifier and co-emulsifier was 4:3:3 was fully mixed and then placed for 30 min, whether the liquid was clear and transparent, and whether the components could be mutually soluble were observed to investigate the mutual solubility of the excipients, and the results were shown in Table 2. The results showed that when Labrafil M 1944 CS was used as the oil phase, it was not mutually soluble with the co-emulsifiers 1,2-propanediol and PEG400, and the reason might be that the polarity difference between the components was too large, so Labrafil M 1944 CS was excluded as the oil phase. In addition, it was found in the experiment that anhydrous ethanol was volatile and would affect the stability of the self-microemulsion, so the use of anhydrous ethanol as a co-emulsifier was excluded in the subsequent screening.

[0030] Table 2 Investigation results of mutual solubility

[0031] (3) According to the results of the excipient mutual solubility experiment, the oil phase was Capryol 90 and Maisine CC, the emulsifier was Labrasol ALF, EL-35 and Tween 80, and Transcutol HP, 1,2-propanediol and PEG400 were used as the co-emulsifier. The oil phase and the emulsifier were vortexed and mixed in the mass ratio of 1:9, 2:8, 3:7, 4:6 and 5:5, respectively, and then 100 times of ultrapure water at 37℃ was added, and the mixture was fully mixed at a constant speed of 300 r / min. The emulsification was observed, and the compatibility between the oil phase and the emulsifier was judged by referring to the self-microemulsification standard rating table (Table 3), and the excipients without phase separation were selected for the next experiment, and the results were shown in Table 4.

[0032] Table 3 Self-microemulsification standard rating table

[0033] Table 4 Compatibility investigation of different oil phases and emulsifiers

[0034] Labrasol ALF as the highest solubility of chicoric acid emulsifier, its emulsifying effect is poor, it is difficult to form a uniform and stable microemulsion with various oils, the emulsion state score after self-emulsification has no A (clear and transparent or slightly blue), B (blue white or slightly turbid) level, even D (dark gray, slightly oily liquid), E (liquid surface with a large number of oil droplets) cannot be compatible phenomenon, the effect is obviously not as good as EL-35 and Tween 80. Maisine CC as the oil phase, the emulsion state score after self-emulsification is significantly lower than Capryol 90, the effect is obviously not as good as Capryol 90. According to the compatibility experiment results, the excipients that can be mutually soluble and form stable emulsion system are preliminarily selected: Capryol 90 as the oil phase, EL-35 and Tween 80 as the emulsifier, Transcutol HP, 1,2-propanediol, PEG400 as the co-emulsifier for further prescription screening.

[0035] (4) Compatibility between emulsifier and co-emulsifier: Respectively, take 1 g of the corresponding emulsifier (Labrasol ALF, EL-35, Tween 80) and co-emulsifier (anhydrous ethanol, Transcutol HP, 1,2-propanediol, PEG400) in an ep tube, continuously vortex mixing for 5 min, 8000 rpm high speed centrifugation for 5 min, take out, observe whether it is layered. If there is no layering, it indicates that the emulsifier and the co-emulsifier are compatible; otherwise, they are not compatible. The specific results are shown in Table 5.

[0036] Table 5 Compatibility of emulsifier and co-emulsifier (n=3)

[0037] From Table 5, it can be seen that the above three co-emulsifiers can be mutually soluble with the emulsifiers EL-35 and Tween 80, and have good compatibility. Therefore, the four kinds of co-emulsifiers and the two previously determined phases are further selected to construct the pseudo-ternary phase diagram.

[0038] (5) Pseudo-ternary phase diagram method to screen excipients: According to the compatibility of excipients, the oil phase Capryol 90 with the best compatibility was selected, and the emulsifiers (EL-35, Tween 80) and co-emulsifiers (Transcutol HP, 1,2-propanediol, PEG400) were screened. The total mass of the fixed oil phase, emulsifier and co-emulsifier was 1 g, and the emulsifier and co-emulsifier were mixed uniformly according to different mass ratios (Km=1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1) to obtain mixed emulsifiers. Then the oil phase and the mixed emulsifiers were mixed in different mass ratios (1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1). 0.1 g was taken and added into 100 times of pure water, and the microemulsion morphology formed was observed. According to the evaluation standard, the three-phase ratio of the points reaching A, B state was recorded, and the pseudo-ternary phase diagram was drawn. The size of the self-microemulsion existing area in the phase diagram was used as an index to screen the best emulsifier and co-emulsifier.

[0039] The results are shown in Table 7. Figure 1 As shown in Table 7, under the condition of fixed oil phase Capryol 90, emulsifier EL-35 and co-emulsifier Transcutol HP formed the largest microemulsion area, but the pre-experiment showed that after adding the raw material drug chicoric acid, the self-microemulsion particle size became large, so it was excluded; EL-35, PEG400 appeared stratification after adding the raw material drug chicoric acid, which was also excluded. Through solubility determination and pseudo-ternary phase diagram, the oil phase was determined to be Capryol 90, the emulsifier was EL-35, and the co-emulsifier was 1,2-propanediol. By changing the proportion of excipients, the pseudo-ternary phase diagram was drawn, and the area that could form microemulsion was determined to judge the dosage range of three phases. The results showed that within the range of 10%~30% of the oil phase, a good uniform and clear microemulsion solution could be obtained. Considering that the content of emulsifier should not be too much, the value of Km was set to 0.67~4, which laid a foundation for subsequent star point design and response surface optimization.

[0040] (6) Self-microemulsion formula optimization: The oil phase ratio (X1), the mass ratio of emulsifier and co-emulsifier Km (X2) were used as the observation factors, and the drug loading (Y1), the average particle size (Y2) and PDI (Y3) were used as the evaluation indexes. Central Composite Design was used to design and optimize the self-microemulsion formula, and the specific factor level setting was as follows Table 6.

[0041] Table 6 Star point design factors and levels

[0042] The self-microemulsion formulations with different ratios were obtained according to the experimental design. 0.1 mL of the microemulsion sample with different ratios was taken into a vial containing 10 mL of pure water, and was slowly added at 200 rpm and 37 ℃ until a uniform and stable microemulsion with blue opalescence was formed. The particle size of the microemulsion was determined by a laser particle size analyzer. After being appropriately diluted with the mobile phase, the sample was determined by HPLC through a 0.22 μm microporous filter membrane, and the equilibrium solubility was calculated. The results are shown in Table 7.

[0043] Table 7 Results of the star point design-response surface optimization

[0044] The data were analyzed and processed, the oil phase ratio (X1) and the Km value (X2) were taken as the dependent variables, the drug loading (Y1), the average particle size (Y2) and the PDI (Y3) were taken as the evaluation indexes, the response surface graph was drawn according to the response equation, the influence trend of the independent variables on the indexes was objectively described, three batches of self-microemulsion of chicoric acid were prepared according to the optimal formula, the particle size, the PDI and the drug loading were determined, and the results were compared with the predicted values to verify the optimal formula. The results are shown in Figure 2 According to the contour graph and the effect surface graph, it can be seen that when the Km remains unchanged, increasing the oil phase ratio will increase the particle size and the PDI, and the drug loading will first increase and then decrease; when the oil content is constant, with the increase of the Km, the particle size will decrease, the PDI will first decrease and then increase, and the drug loading will first increase and then decrease. Therefore, the optimal formula is that the oil phase ratio is 17.93% and the Km value is 2.424.

[0045] (7) Model fitting and variance analysis: the results in Table 7 were fitted by a quadratic polynomial, and the equations are as follows: drug loading: Y1=+72.51-1.54A+1.94B+0.4825AB-8.42A 2 -6.08B 2 (R 2 =0.9712, P<0.0001); particle size: Y2=+15.93+1.09A-1.26B-1.04AB+1.74A 2 +2.42B 2 (R 2 =0.9764, P<0.0001); PDI: Y3=+0.2530+0.0287A+0.0087B+0.0033AB+0.0189A 2 +0.0266B 2 (R 2 =0.9124, P=0.0014). The R 20.9712, 0.9764, 0.9124, indicating that the model adopted has a good fitting effect and can accurately predict the evaluation index according to the independent variable. The significance level P value of the Y1, Y2, and Y3 response equation is less than 0.01, indicating that the regression equation reaches a significant level, and the results are statistically significant. The lack-of-fit P values are 0.0607, 0.8682, and 0.4012, respectively, indicating that the lack-of-fit has no statistical significance to the pure error level, and the model fitting is successful. The variance analysis is shown in Tables 8, 9, and 10.

[0046] Table 8 Variance analysis of drug loading

[0047] Table 9 Variance analysis of particle size

[0048] Table 10 Variance analysis of PDI

[0049] (8) Optimal self-microemulsion formula Taking the maximum drug loading, the minimum particle size and PDI as the indicators, the optimal solution of the model is obtained according to the response surface results: the mass fraction of the oil phase is 17.93%, and the Km value of the mixed emulsifier is 2.424. To simplify the formula, the mass fraction of the oil phase is 18%, the Km value of the mixed emulsifier is 2.4, and the chicoric acid is 70 mg / g.

[0050] (9) Verification of the optimal self-microemulsion formula: To verify the credibility of the model, three batches of chicoric acid self-microemulsion were prepared according to the optimal formula, and the verification experiment was carried out. The difference between the measured value and the predicted value was compared, and the results are shown in Table 11. The difference between the predicted value and the measured value is not large, and the relative error is within 5%, indicating that the prediction of the constructed mathematical model is good.

[0051] Table 11 Verification of the optimal formula (n=3)

[0052] Example 2 Quality evaluation of chicoric acid self-microemulsion: (1) The appearance of the blank self-microemulsion and the chicoric acid self-microemulsion at room temperature (25°C) was observed, and the appearance of the obtained emulsion after diluting the chicoric acid self-microemulsion with ultrapure water by 100 times was observed. The results are shown in Table 11. Figure 3 As shown in Table 11, the chicoric acid self-microemulsion is an orange yellow clear transparent liquid at room temperature, with good uniformity; the chicoric acid self-microemulsion can be uniformly dispersed and emulsified to form a clear and transparent emulsion after dilution with ultrapure water, with good dilution stability and Dandling phenomenon.

[0053] (2) Micro-morphology: Take the appropriate amount of chicoric acid self-microemulsion diluted with ultrapure water to a certain multiple, take a small amount of emulsified microemulsion on the copper mesh, dry naturally, then negative stain with 2% phosphotungstic acid for 10 min, and then observe the micro-morphology of the chicoric acid self-microemulsion under a transmission electron microscope after the film is formed. The results are shown in Figure 4 The microemulsion formed by the chicoric acid self-microemulsion is spherical or spherical under the transmission electron microscope, uniformly dispersed, and the particles are dispersed without aggregation. The particle size is small, which meets the requirements of microemulsion.

[0054] (3) Two samples of chicoric acid self-microemulsion were prepared in parallel and placed in transparent vials, then diluted with pure water to a certain multiple, stirred to obtain completely uniform microemulsion samples, and then water-soluble dye methyl blue and oil-soluble dye Sudan red were added respectively. The diffusion of the two dyes was observed to determine the type of microemulsion. If the blue color diffuses quickly, it indicates that the formed microemulsion is O / W type, otherwise it indicates that the formed microemulsion is W / O type. The staining conditions are shown in Figure 5 It can be seen that the diffusion speed of blue color is faster than that of red color in the solution, so the chicoric acid self-microemulsion forms O / W type microemulsion after being dispersed in water.

[0055] (4) Particle size, Zeta potential and PDI determination: Take an appropriate amount of self-microemulsion, dilute with 100 times purified water to prepare a clear and transparent chicoric acid microemulsion solution. Take an appropriate amount of microemulsion for particle size, polydispersity index and potential determination. The results are shown in Figure 6 The average particle size of the chicoric acid self-microemulsion is 15.08±0.55 nm, the polydispersity index PDI is 0.251±0.004, and the Zeta potential is -19.5±0.44 mV.

[0056] (5) Stability investigation: Take the chicoric acid self-microemulsion and place it in an appropriate container, and then store it in a high temperature (60℃±2℃), high humidity (relative humidity 90%±5%) or strong light irradiation environment (4500±500lx) for 10 days. Observe the appearance and take samples for detection on the 0th, 5th and 10th days. The results are shown in Table 12. The chicoric acid self-microemulsion has good stability under high temperature, high humidity and strong light conditions, and the average particle size and PDI do not change significantly, and the drug loading capacity decreases slightly, but it can still reach more than 55 mg / g.

[0057] Table 12 Stability test results under high temperature, high humidity and strong light conditions

[0058] The chrysophanic acid self-microemulsion was taken from a flask, sealed with a film, and stored at 40℃±2℃ and 75%±5% relative humidity. The appearance was observed and samples were taken for testing at 0, 1, 2, 3, and 6 months. The results are shown in Table 13. The chrysophanic acid self-microemulsion remained an orange-yellow clear transparent liquid after 6 months of storage. The average particle size and PDI did not change significantly, but the drug loading tended to decrease. The drug loading decreased slightly after 3 months of storage, but was still above 55 mg / g.

[0059] Table 13 Results of accelerated stability test

[0060] An appropriate amount of chrysophanic acid self-microemulsion was taken in a centrifuge tube and centrifuged at 10,000 r / min for 15 min. The chrysophanic acid self-microemulsion remained an orange-yellow clear transparent liquid without precipitation, stratification, or turbidity, indicating that the chrysophanic acid self-microemulsion had good centrifugal stability.

[0061] (6) Determination of encapsulation efficiency and drug loading: Chrysophanic acid self-microemulsion 100 mg (W) was precisely weighed, placed in a 25 mL volumetric flask, and dissolved with methanol. After filtration, the chrysophanic acid content (W1) was determined. Chrysophanic acid self-microemulsion 100 mg was precisely weighed, diluted 100 times with ultrapure water to prepare a microemulsion, and centrifuged at 4,000 r / min for 30 min. The supernatant 5 mL was precisely measured, dissolved with methanol to a 25 mL volumetric flask, and filtered. The chrysophanic acid content (W2) was determined. The encapsulation efficiency and drug loading were calculated according to the following formula. The results (Tables 14 and 15) showed that the drug loading of chrysophanic acid self-microemulsion was 68.91±0.67 mg / g, and the relative standard deviation (RSD) was 0.97%. The encapsulation efficiency was 98.57±1.00%, and the RSD was 1.01%.

[0062] Encapsulation efficiency (%) = W2 / W1 × 100%; Drug loading (mg / g) = W1 / W.

[0063] Table 14 Results of determination of encapsulation efficiency of chrysophanic acid self-microemulsion

[0064] Table 15 Results of determination of drug loading of chrysophanic acid self-microemulsion

[0065] Example 3 (1) Preparation method of micro-pellets: The self-microemulsion and excipients were mixed according to the prescription amount, and water was added to knead into a soft material. The soft material was placed in an extruder, and the extrusion speed was set. The extruded strips were poured into a rounder, and the speed and rounder time were adjusted. The micro-pellets were taken out after the time was reached. Drying and sieving were performed to obtain the micro-pellets.

[0066] (2) Evaluation index and determination method of micro-pellets: The yield was calculated by particle size screening method. The prepared micro-pellets were weighed, and then passed through 20-mesh sieve (diameter 0.9 mm) and 40-mesh sieve (diameter 0.45 mm). The weight of the micro-pellets between 20-mesh and 40-mesh sieves was recorded as M1, and the total weight of the micro-pellets was recorded as M2. The percentage of the micro-pellets between 20-mesh and 40-mesh sieves was calculated.

[0067] Calculation method: yield (%) = M1 / M2 x 100%.

[0068] The sphericity was calculated by the method of planar critical stability (OPCS). A fixed amount of micro-pellets was placed on a smooth flat plate. The plate was slowly lifted on one side, and the angle between the plate and the horizontal plane when the micro-pellets started to roll was measured (θ). The smaller the angle value, the better the sphericity of the micro-pellets.

[0069] The bulk density was determined according to the method of bulk density and determination in Chinese Pharmacopoeia (2020) 0993 fixed mass method. 10 g of micro-pellets was weighed and slowly and smoothly poured into a 25 mL glass graduated cylinder using a funnel. The cylinder should not be tapped, and the top was carefully scraped flat. The apparent volume was recorded with the nearest scale line, and the bulk density was calculated according to the following formula.

[0070] = M / V In the formula: bulk density, g / mL; M, mass of the micro-pellets to be tested, g; V, apparent volume of the micro-pellets to be tested, mL.

[0071] Subjective weighting G1 method: G1 method is a subjective weighting method that can reflect the importance of indexes according to subjective ranking. The priority order of the three evaluation indexes was micro-pellet yield > sphericity > bulk density, and the weight evaluation scales were r2=1.4, r3=1.2, respectively. The weight coefficients of yield, sphericity and bulk density were obtained by the formula. i s .

[0072]

[0073] In the formula: k = n, n-1, …, 2; n is the number of evaluation indexes, n = 3.

[0074] Objective weighting entropy weight method: entropy weight method is an objective weighting method based on information entropy, which determines the weight by the degree of change of a certain index. According to the formula, the weight of each index W i o .

[0075] Standardization of data: the data were standardized by minimization method. The yield and bulk density were standardized by high priority index, and the sphericity was standardized by low priority index.

[0076] Standardization of high priority index:

[0077] Standardization of low priority index:

[0078] In the formula: X ij is the jth value under the ith evaluation index.

[0079] Calculation of information entropy:

[0080] In the formula: m is the number of data in each index.

[0081] Calculation of index weight:

[0082] The comprehensive consideration of G1 and entropy weight method is more reasonable than single weight calculation. α and β represent the relative importance of subjective weight and objective weight, and the coefficients of α and β are calculated by matrix idea. The combination weight coefficient of G1-EWM is calculated according to the formula, that is, the comprehensive weight of evaluation index of chrysanthemum acid self-microemulsion pellets, and the results are shown in Table 16. i i

[0083]

[0084] Table 16 Comprehensive weight of evaluation index

[0085] G1-entropy weight method for calculating comprehensive score Comprehensive score = 100 × [(0.5388 × yield / yieldmax) + (0.2562 × sphericitymin / sphericity) + (0.2050 × bulk density / bulk densitymax)] (3) Prescription composition screening: ​​Investigation of solid adsorbent adsorption capacity: according to the preparation method of self-microemulsion in Example 1, a blank liquid self-microemulsion preparation is prepared. The adsorption capacity of the solid adsorbent for the liquid self-microemulsion is used as the investigation index, and the adsorption capacity of the adsorbent: PEG4000, PEG6000, mannitol, soluble starch, poloxamer, microcrystalline cellulose, lactose is tested. The specific method is: take 1.0 g of liquid self-microemulsion in a mortar, continuously add solid adsorbent, and continuously grind until the oily substance is completely absorbed, the solid powder is dry, record the amount of solid adsorbent added, repeat 3 times for each adsorbent, the results are shown in Table 17. It is found in the experiment that only lactose is used as an excipient to prepare pellets, the extrusion and rounding machine cannot extrude, and the pellet size is uneven and easy to break during rounding, affecting the uniformity of the product. Lactose has good water solubility and can adjust the hardness of the pellets, but has poor plasticity, and separate use can lead to poor roundness after rounding. Considering the adsorption capacity, lactose and microcrystalline cellulose are finally selected as the solid adsorbent, and the mass adsorption ratio of self-microemulsion to lactose is 1:4, and the results are shown in Table 18. Figure 8

[0086] Table 17 Adsorption capacity test results of different solid adsorbents

[0087] Filler ratio screening: the filler is the basis of the prescription, which directly affects the uniformity of the extrudate and the roundness after rounding. The MCC proportion in the filler usually needs to be ≥30%. The process parameters are fixed, other prescription factors are unchanged, the lactose:MCC ratio is changed, the roundness, bulk density and yield of the pellets under different ratios are measured, and the best filler ratio is determined.

[0088] The results show (Table 18) that when the microcrystalline cellulose proportion in the pellet excipient increases, the pellet roundness improves, and the bulk density and yield increase. When the ratio of lactose to microcrystalline cellulose is 2:1, the flowability of the excipient increases, but the plasticity decreases, the extrusion is difficult, and the strip-shaped material is easy to break during extrusion, and the yield is the lowest. The plasticity and flowability of the 1:1 and 1:2 groups are balanced, the extrusion is smooth, and the roundness and bulk density results are not much different, but the yield of the 1:2 group is obviously better than that of the 1:1 group, so the ratio of the filler lactose and microcrystalline cellulose is determined as 1:2.

[0089] Table 18 Effect of filler ratio on pellet properties

[0090] ​The amount of the binder: The binder directly affects the continuity of the extrudate and the formability during the rounding by adjusting the viscosity and cohesion of the soft material. In pharmaceutical preparations, hydroxypropyl methyl cellulose (HPMC) as a binder can ensure the stability of the forming of the pellets, and the addition ratio is 2%-10% relative to the total mass of the drug and excipients. The amount of the binder HPMC is investigated, and the roundness, bulk density and yield of the pellets at different proportions are determined to determine the optimal proportion of the binder.

[0091] The results show (Table 19) that when HPMC is used as the binder, high concentration of HPMC leads to over-viscosity of the soft material, large extrusion pressure, easy adhesion of the pellets during rounding, poor roundness, and low yield. The soft material prepared with 3% HPMC can be uniformly extruded into continuous strips without caking or drying, and the pellets have high quality and are easy to form during the preparation process, so 3% HPMC is used as the binder.

[0092] Table 19 Effect of the amount of HPMC on the properties of the pellets

[0093] The amount of the wetting agent: The role of the wetting agent is to fully wet the excipients to form a soft material with plasticity, and its amount is the key to the extrusion performance. With the target of "smooth surface of the extruded strip without bubbles", the amount of the wetting agent is usually 20%-40% of the total mass of the excipients. The amount of water as the wetting agent is investigated, and the effects of the amount of water on the roundness, bulk density and yield of the pellets are determined to determine the optimal amount of the wetting agent.

[0094] The results show (Table 20) that when water is used as the wetting agent, when the amount is 455, the soft material will dry during the basic process, and "powder-like fracture" will occur during extrusion, and the particle size of the pellets after rounding is uneven; when the amount is 55%, the viscosity of the soft material is too large, and the extruded strip is easy to stick together, and "large agglomeration" is formed during rounding, and the roundness is poor. Therefore, the amount of the wetting agent water is 50% of the total mass of the excipients.

[0095] Table 20 Effect of the amount of the wetting agent on the properties of the pellets

[0096] (4) Preparation process research: There is an interaction between the prescription and the process parameters (such as extrusion speed, rounding speed, rounding time), and the core process parameters need to be fixed when screening the prescription. After the prescription is preliminarily determined, the process parameters are optimized to further improve the quality of the pellets.

[0097] Extrusion speed investigation: The extrusion speed of the instrument was fixed at 50 Hz, the roundness time was 10 min, the extrusion speed was changed, and the effects of five different extrusion speeds (10 Hz, 20 Hz, 30 Hz, 40 Hz and 50 Hz) on the roundness, bulk density and yield of the pellets were compared to select the best extrusion speed range. The results are shown in Table 21.

[0098] Table 21 Effects of different extrusion speeds on the properties of the pellets

[0099] The results show that when the extrusion speed is 10-30 Hz, the extrusion mass is high, the yield and roundness of the pellets after rolling are good; when the extrusion speed is 40 Hz and 50 Hz, the extrusion speed is too fast, the extrusion mass is too much per unit time, the strip is uneven in thickness, the material is loose, the pellets are easy to break during rolling, and the yield is low. Therefore, the extrusion speeds of 10 Hz, 20 Hz and 30 Hz are selected for orthogonal test investigation.

[0100] Rolling speed investigation: The rolling speed of the instrument was fixed at 15 Hz, the rolling time was 10 min, the rolling speed was changed, and the effects of five different rolling speeds (10 Hz, 20 Hz, 30 Hz, 40 Hz and 50 Hz) on the roundness, bulk density and yield of the pellets were investigated to select the best rolling speed range. The results are shown in Table 22.

[0101] Table 22 Effects of different rolling speeds on the properties of the pellets

[0102] The results show that when the rolling speed is 10 Hz, the rotation speed is too low, the centrifugal force is small, and the soft material is difficult to cut off, so that the pellets cannot be prepared; when the rolling speed is 20-30 Hz, the centrifugal force is small, the strip breaks slowly, the kneading force is not enough, the pellets are mostly short rod-shaped or large in particle size, the roundness is poor, and the yield is relatively low; when the speed is increased to 40-50 Hz, the yield of the pellets is significantly improved. Therefore, the rolling speeds of 40-50 Hz are selected for orthogonal test investigation.

[0103] Rolling time investigation: The rolling speed of the instrument was fixed at 50 Hz, the extrusion speed was 15 Hz, the rolling time was changed, and the effects of different rolling times (2 min, 4 min, 6 min, 8 min and 10 min) on the properties of the pellets were investigated to select the best rolling time range. The results are shown in Table 23.

[0104] Table 23 Effects of different rolling times on the properties of the pellets

[0105] The results show that when the rounding time is 2 min, the shaping is insufficient, the strip is not completely broken, or the particles after breaking are not fully twisted, and the pellets are mostly short rod-shaped, olive-shaped, and low in roundness; when the time increases to 8 min, the pellet roundness and yield are improved; but when the time increases to 10 min, the pellet yield decreases, which may be because the time is too long, increasing the number and intensity of collisions between the pellets, making the pellets fragile and reducing the yield, but still higher than that when the rounding time is 4 min. Therefore, the rounding time of 6-10 min is selected for orthogonal test.

[0106] Orthogonal test: The extrusion speed core affects the uniformity of the strip, which indirectly determines the particle size distribution. The rounding speed dominates the pellet roundness and the risk of breaking, which needs to be controlled in the "breakage-tumble balance interval". The rounding time needs to be matched with the speed, with "just reaching the best roundness" as the critical point. L9(34) orthogonal table is selected for test to optimize the combination of the three.

[0107] Based on the single-factor experiments of extrusion speed, rounding speed and rounding time, three factor levels are set respectively as shown in Table 24. L9(34) orthogonal table is selected for test, and the weights of pellet yield, bulk density and roundness are calculated by G1-entropy method as 0.5388, 0.2050 and 0.2562 respectively. The orthogonal test results are shown in Table 25, and the variance analysis results are shown in Table 26.

[0108] Table 24 Orthogonal test factor level table

[0109] Table 25 L9(34) orthogonal experimental design table and results

[0110] Table 26 Variance analysis of pellet process orthogonal test

[0111] The variance analysis results show that the influence degree of each factor on the pellet properties is B>A>C, i.e. the rounding speed>the extrusion speed>the rounding time, and the rounding speed B has a significant effect on the experimental results. The best combination of the pellet preparation process is selected by combining each factor as A1B3C2, i.e. the extrusion speed 10 Hz, the rounding speed 50 Hz and the rounding time 8 min.

[0112] Verification experiment and results: In order to accurately evaluate the stability of the pellet preparation process, 3 batches of pellet samples are prepared in parallel according to the best preparation process for verification. The results are shown in Table 27, and the relative standard deviation of the comprehensive score is 1.49%, which shows that the determined pellet preparation process is reasonable and feasible.

[0113] Table 27 Pellet preparation process verification experiment

[0114] Example 4 Quality evaluation of the chrysohnic acid self-microemulsifying pellets: (1) Pellet morphology The appearance, color and morphological characteristics of the pellets were observed by visual observation and microscopy. The results showed that (Table 27) the pellets were white spherical bodies with smooth surfaces under visual observation. The pellets were observed under a microscope at two magnifications (32x and 56x) and were found to be round or oval in shape with smooth surfaces and uniform sizes, indicating that the preparation process was reasonable and stable. Figure 8

[0115] (2) Type of emulsion after reconstitution: The emulsion formed after reconstitution of the chrysohnic acid self-microemulsifying pellets was still an O / W type emulsion, indicating that the solidification process did not affect the emulsion type of the chrysohnic acid self-microemulsion.

[0116] (3) It is particularly important to determine whether the pellets can continue to meet the requirements of particle size and dispersity after redispersion. The chrysohnic acid self-microemulsion pellets were ground into fine powder, 1 g of the powder was taken and placed in a 50 mL volumetric flask, then purified water was added to constant volume, and after ultrasonic dissolution, the supernatant was centrifuged, diluted 2 times and filtered for determination. The results (Table 28) showed that the particle size, PDI and absolute value of Zeta potential of the chrysohnic acid self-microemulsion increased to varying degrees after solidification, which may be due to the dissolution of the pellet excipients causing an increase in particle size, but still met the requirements of self-microemulsion emulsion. The increase in the absolute value of Zeta potential to some extent indicates that the solidification technology can improve the stability of the self-microemulsion.

[0117] Table 28 Investigation of the redispersibility of chrysohnic acid self-microemulsion pellets

[0118] (4) Influence factor test: The self-microemulsion pellets were placed in glass bottles, sealed with lids, and then observed for appearance and sampled for average particle size and PDI at the fifth day and tenth day under high temperature (60°C ± 2°C), high humidity (relative humidity 90% ± 5%) or strong light irradiation environment (4500 ± 500 lx). The results showed that the appearance of the self-microemulsion pellets was white under high temperature, high humidity and strong light, and the average particle size and PDI did not change significantly, indicating that the self-microemulsion pellets had good stability, as shown in Table 29.

[0119] Table 29 Results of the influence factor experiment

[0120] ​(5) Accelerated stability test: The microemulsion pellets were taken and placed in plastic bottles with caps sealed, stored at temperature 40℃±2℃, relative humidity 75%±5% for 6 months. At 0, 1, 2, 3, 6 months, the appearance was observed and the average particle size and PDI were measured. The results are shown in Table 30. The appearance of the microemulsion pellets was still white spherical after 6 months, and the average particle size did not change significantly, indicating that the microemulsion pellets had good stability.

[0121] Table 30 Results of accelerated stability test

[0122] (6) Prescription determination: The final prescription of the chrysin self-microemulsion pellets is: chrysin self-microemulsion 20% + lactose 26.7% + microcrystalline cellulose 53.3% + hydroxypropyl methyl cellulose 3% + water 50%. The pellets prepared by the prescription have good roundness and uniform particle size distribution, meeting the requirements.

[0123] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A chicoric acid self-microemulsion, characterized in that, Including chicoric acid and self-microemulsifying drug delivery system carriers; The self-microemulsifying drug delivery system carrier includes an oil phase and a mixed emulsifier, wherein the mixed emulsifier is composed of an emulsifier and a co-emulsifier; The concentration of chicoric acid is 68~73 mg / g, the mass fraction of the oil phase is 17~18%, and the mass ratio (Km) of emulsifier and co-emulsifier in the mixed emulsifier is 2.35~2.

45.

2. The chicoric acid self-microemulsion as described in claim 1, characterized in that, The concentration of chicoric acid was 70 mg / g, the mass fraction of the oil phase was 18%, and the mass ratio (Km) of the emulsifier and co-emulsifier in the mixed emulsifier was 2.

4.

3. The chicoric acid self-microemulsion as described in claim 1, characterized in that, The oil phase is propylene glycol monooctanoate (Capryol 90). Alternatively, the emulsifier may be polyoxyethylene castor oil EL-35; Alternatively, the co-emulsifier may be 1,2-propanediol.

4. The chicoric acid self-microemulsion as described in claim 1, characterized in that, The particle size of chicoric acid self-microemulsion is 14~16 nm.

5. A chicoric acid self-microemulsion microsphere, characterized in that, Includes the chicoric acid self-microemulsion and solid adsorbent as described in any one of claims 1 to 4.

6. The chicoric acid self-microemulsion microspheres as described in claim 5, characterized in that, The solid adsorbent is composed of lactose and microcrystalline cellulose; preferably, the mass ratio of lactose to microcrystalline cellulose is 1:(1~2), more preferably 1:

2.

7. The chicoric acid self-microemulsion microspheres as described in claim 5, characterized in that, The mass ratio of chicoric acid microemulsion to solid adsorbent is 1:(3.5~5.5), preferably 1:

4.

8. The chicoric acid self-microemulsion microspheres as described in claim 5, characterized in that, Chicoric acid microemulsions and microcapsules also include binders and humectants; Preferably, the adhesive is hydroxypropyl methylcellulose; more preferably, the amount of hydroxypropyl methylcellulose used is 2.5~3.5 wt% of the chicoric acid self-emulsion microspheres, preferably 3 wt%; Preferably, the wetting agent is water; more preferably, the amount of water used is 45-50 wt% of chicoric acid microemulsion microspheres, preferably 50 wt%.

9. The method for preparing chicoric acid self-microemulsion microspheres according to any one of claims 5 to 8, characterized in that, include: Chicoric acid self-microemulsion pellets were prepared by extrusion spheronization.

10. The preparation method according to claim 9, characterized in that, The extrusion speed is 8~12 Hz, the rounding speed is 45~55 Hz, and the rounding time is 7.5~8.5 min; The preferred extrusion speed is 10 Hz, the rounding speed is 50 Hz, and the rounding time is 8 min.

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