Cough-relieving tea formula oral self-microemulsion as well as preparation method and application thereof

Abstract

The invention belongs to the field of pharmaceutical preparations, and particularly relates to a cough-relieving tea formula oral self-microemulsion as well as a preparation method and application thereof. The cough-relieving tea formula oral self-microemulsion is prepared from the following components in percentage by mass: 27.3 to 50 percent of semen armeniacae amarae extract, 16.7 to 36.4 percent of fistular onion stalk extract, 11.4 to 26.7 percent of mixed oil phase, 7.4 to 17.8 percent of emulsifier and 4.0 to 8.9 percent of co-emulsifier, wherein the mixed oil phase is prepared from zanthoxylum oil, lard oil, oleic acid and ethyl oleate. The preparation method comprises the following steps: weighing the mixed oil phase, the emulsifier and the co-emulsifier according to the prescription, stirring for 1-40 minutes by using a vortex mixer with the rotating speed of 100-600r. Min <-1 > at the temperature of 15-60 DEG C, adding the mixture into pure water, adding the bitter apricot kernel extract and the fistular onion stalk extract, uniformly stirring, and filtering to obtain the product. The oral self-microemulsion is guided by the traditional Chinese medicine theory, a folk dietary therapy cough relieving prescription is explored, the oral self-microemulsion is prepared from the active ingredients of the pepper, the fistular onion stalk and the bitter apricot kernel in the prescription and the lard oil by using the modern preparation technology, and the oral self-microemulsion has the advantages of small particle size, small PDI and good stability, and lays a solid foundation for research and development of export products in the market.

Description

Technical Field

[0001] The invention relates to the field of pharmaceutical preparations, and mainly relates to an oral self-microemulsion of a cough-relieving tea prescription, and a preparation method and application thereof. Background Art

[0002] Cough is a common type of respiratory disease, which is caused by stimulation of the medullary cough center. Clinically, modern medicine mostly uses anti-allergic, anti-inflammatory, acid suppression and other methods to treat cough, using antitussives, antihistamines and decongestants for treatment, but the treatment effect is not good. Although it can relieve symptoms, long-term use has more adverse reactions, the disease is prone to relapse, and patient compliance is poor.

[0003] By consulting relevant literature and preliminary network pharmacology research, it was found that pepper, scallion, bitter almond and lard all have certain therapeutic effects on cough, but people usually take them by decocting them in water, which has a poor taste and is inconvenient to operate. In addition, the prescription contains a large amount of volatile oil as the effective ingredient, and the storage time should not be too long.

[0004] The self-microemulsion drug delivery system (SMEDDS) is a uniformly mixed system composed of a surfactant, a co-surfactant and an oil phase. At present, the self-microemulsion drug delivery system has been widely used in traditional Chinese medicine, chemical medicine, health products, cosmetics and other fields. In the field of traditional Chinese medicine, by optimizing the drug formula, the solubility of poorly soluble drugs in the body can be effectively improved, thereby achieving uniform and rapid diffusion of emulsion droplets in the gastrointestinal tract, thereby significantly enhancing the ability of drug molecules to cross biological membranes. In addition, the self-microemulsion drug delivery system can simultaneously encapsulate multiple effective ingredients of traditional Chinese medicine, which is in line with the concept of traditional Chinese medicine compatibility and can achieve sustained release, efficacy enhancement and toxicity reduction.

[0005] Research reports show that the self-microemulsion prepared with Chinese medicine volatile oil as the oil phase can not only improve the solubility of the drug and the stability of the volatile oil, but also improve the bioavailability of the drug. Based on this, the present invention is based on the properties of the self-microemulsion drug delivery system, combined with the principle of "drug-adjuvant integration", extracts the volatile oils of prickly ash, scallion, and bitter almond, and the volatile oil and lard are the oil phases, and are co-loaded in the same system with flavonoids, amino acids, celluloses, and trace elements, etc., to prepare the "cough tea" oral microemulsion, in order to achieve the purpose of improving the solubility and stability of the active ingredients of the drug, and to improve the taste, and to facilitate the use and carrying of consumers, and to lay a solid foundation for the development of oral cough products to enter the market. Summary of the invention

[0006] The purpose of the present invention is to provide an oral self-microemulsion of a cough-relieving tea recipe.

[0007] Another object of the present invention is to provide a method for preparing an oral self-microemulsion of a cough-relieving tea recipe.

[0008] Another object of the present invention is to provide an application of an oral self-microemulsion of a cough-relieving tea recipe in the preparation of cough-relieving medicines.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] The cough-relieving tea prescription oral self-microemulsion of the invention is composed of 27.3%-50% of bitter almond extract, 16.7%-36.4% of scallion extract, 11.4%-26.7% of mixed oil phase, 7.4%-17.8% of emulsifier and 4.0%-8.9% of auxiliary emulsifier in mass fraction.

[0011] Preferably, the cough-relieving tea oral self-microemulsion of the present invention is composed of 42.9% by mass of bitter almond extract, 28.6% by mass of scallion extract, 11.4% by mass of mixed oil phase, 11.4% by mass of emulsifier and 5.7% by mass of co-emulsifier.

[0012] The mixed oil phase in the self-microemulsion of the present invention consists of a drug adjuvant and an oil phase in a mass ratio of 1:1; the drug adjuvant consists of pepper oil: lard in a mass ratio of 1:3; and the oil phase consists of oleic acid: ethyl oleate in a mass ratio of 9:1.

[0013] The emulsifier of the self-microemulsification of the present invention is any one of Tween-80, Tween-40, span-80, lecithin, polyoxyethylene hydrogenated castor oil, glyceryl monostearate, whey protein, soybean lecithin, and caprylic acid capric acid macrogol glyceride.

[0014] Preferably, the emulsifier of the self-microemulsification of the present invention is polyoxyethylene hydrogenated castor oil.

[0015] The auxiliary emulsifier of the self-microemulsification of the present invention is any one of anhydrous ethanol, 1,2-propylene glycol, polyethylene glycol-400, gum arabic, beeswax and glycerol.

[0016] Preferably, the co-emulsifier of the self-microemulsification of the present invention is anhydrous ethanol.

[0017] The preparation method of the cough-relieving tea oral self-microemulsion of the present invention comprises weighing a mixed oil phase, an emulsifier and an auxiliary emulsifier according to a prescription, stirring at a temperature of 15-60° C. and a speed of 100-600 r·min –1 After stirring for 1-40 minutes in a vortex mixer, add into pure water, add bitter almond extract and scallion extract, stir evenly, filter, and obtain.

[0018] Preferably, the preparation method of the present invention is to weigh the mixed oil phase, emulsifier and co-emulsifier according to the prescription, and stir at a temperature of 60°C and a stirring speed of 400 r·min –1After stirring in a vortex mixer for 20 minutes, add into pure water, add bitter almond extract and scallion extract, stir evenly, filter, and obtain.

[0019] The invention discloses an application of the cough-relieving tea prescription oral self-microemulsion in preparing cough-relieving medicines.

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention uses modern preparation technology to prepare a folk food therapy recipe for treating cough into an oral self-microemulsion. According to the properties of the self-microemulsion drug delivery system and the principle of "combining medicine and adjuvant", the volatile oils of pepper, scallion and bitter almond are extracted, and the volatile oil and lard are the oil phase, which can not only improve the solubility of the drug and the stability of the volatile oil, but also improve the bioavailability of the drug. In the prescription, pepper, scallion, bitter almond and lard are all medicine and food, common household ingredients, safe and reliable.

[0022] 2. The cough-relieving tea oral self-microemulsification system prepared by the present invention has the advantages of high drug loading, small particle size, small PDI and good stability. The preparation method is simple and easy, and can be used for large-scale industrial production, with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 System suitability test chromatogram;

[0024] Figure 2 In vitro HPLC standard curve of amygdalin;

[0025] Figure 3 Equilibrium solubility of amygdalin in different oil phases (x±s, n=3);

[0026] Figure 4 Equilibrium solubility of amygdalin in different emulsifiers (x±s, n=3);

[0027] Figure 5 Equilibrium solubility of amygdalin in different co-emulsifiers (x±s, n=3);

[0028] Figure 6 Under the condition that the ratio of (pepper oil-lard):(oleic acid-ethyl oleate) was 1:9, the microemulsions formed when the ratio of oleic acid:ethyl oleate was 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1 were investigated respectively;

[0029] Figure 7 Under the condition of (pepper oil-lard): (oleic acid-ethyl oleate) being 2:8, the microemulsions formed when oleic acid:ethyl oleate was 9:1, 8:2, 7:3, 6:4, and 5:5 were investigated respectively;

[0030] Figure 8Under the condition of (pepper oil-lard): (oleic acid-ethyl oleate) being 3:7, the microemulsions formed when the ratio of oleic acid:ethyl oleate was 9:1, 8:2, 7:3, 6:4, and 5:5 were investigated respectively;

[0031] Fig. 9 Pseudo-ternary phase diagram of microemulsion system with different emulsifiers;

[0032] Fig.10 Pseudo-ternary phase diagram of microemulsion system with different co-emulsifiers;

[0033] Fig.11 Pseudo-ternary phase diagram of microemulsion system at different Km;

[0034] Fig.12 2D contour plots and 3D response surfaces of particle size;

[0035] Fig.13 Two-dimensional contour plot and three-dimensional response surface of PDI;

[0036] Fig.14 Comparison of blank microemulsion and drug-loaded microemulsion prepared by the optimal formulation and preparation process; DETAILED DESCRIPTION

[0037] The technical solution of the present invention is described in detail below in conjunction with specific embodiments. The following embodiments are only used for explanation and illustration, and do not constitute a limitation on the technical solution of the present invention.

[0038] Example 1

[0039] The cough-relieving tea prescription oral self-microemulsion is composed of 42.9% bitter almond extract, 28.6% scallion extract, 11.4% mixed oil phase (composed of 1.4% pepper oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate), 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol.

[0040] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.4% prickly ash oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate, 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 400 r·min –1 The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 42.9% of bitter almond extract and 28.6% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0041] Example 2

[0042] The cough-relieving tea prescription oral self-microemulsion is composed of 33.3% bitter almond extract, 22.2% scallion extract, 26.7% mixed oil phase (composed of 3.3% prickly ash oil, 10% lard, 12% oleic acid, 1.4% ethyl oleate), 11.6% polyoxyethylene hydrogenated castor oil, and 6.2% anhydrous ethanol.

[0043] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 3.3% prickly ash oil, 10% lard, 12% oleic acid, 1.4% ethyl oleate, 11.6% polyoxyethylene hydrogenated castor oil, and 6.2% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 400 r·min –1 The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 33.3% of bitter almond extract and 22.2% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0044] Example 3

[0045] The cough-relieving tea prescription oral self-microemulsion is composed of 33.3% bitter almond extract, 22.2% scallion extract, 17.8% mixed oil phase (composed of 2.2% prickly ash oil, 6.7% lard, 8% oleic acid, 0.9% ethyl oleate), 17.8% polyoxyethylene hydrogenated castor oil, and 8.9% anhydrous ethanol.

[0046] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 2.2% prickly ash oil, 6.7% lard, 8% oleic acid, 0.9% ethyl oleate, 17.8% polyoxyethylene hydrogenated castor oil, and 8.9% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 400 r·min –1 The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 33.3% of bitter almond extract and 22.2% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0047] Example 4

[0048] The cough-relieving tea prescription oral self-microemulsion is composed of 42.9% bitter almond extract, 28.6% scallion extract, 17.1% mixed oil phase (composed of 2.1% pepper oil, 6.4% lard, 7.7% oleic acid, 0.9% ethyl oleate), 7.4% polyoxyethylene hydrogenated castor oil, and 4% anhydrous ethanol.

[0049] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 2.1% prickly ash oil, 6.4% lard, 7.7% oleic acid, 0.9% ethyl oleate, 7.4% polyoxyethylene hydrogenated castor oil, and 4% anhydrous ethanol, and stir at a temperature of 60°C and a stirring speed of 400 r·min –1The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 42.9% of bitter almond extract and 28.6% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0050] Example 5

[0051] The cough-relieving tea prescription oral self-microemulsion is composed of 50% bitter almond extract, 16.7% scallion extract, 13.4% mixed oil phase (composed of 1.7% prickly ash oil, 5% lard, 6% oleic acid, 0.7% ethyl oleate), 13.2% polyoxyethylene hydrogenated castor oil, and 6.7% anhydrous ethanol.

[0052] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.7% prickly ash oil, 5% lard, 6% oleic acid, 0.7% ethyl oleate, 13.2% polyoxyethylene hydrogenated castor oil, and 6.7% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 400 r·min –1 The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 50% of the bitter almond extract and 16.7% of the scallion extract were added, stirred evenly, and filtered to obtain the product.

[0053] Example 6

[0054] The cough-relieving tea prescription oral self-microemulsion is composed of 27.3% bitter almond extract, 36.4% scallion extract, 14.5% mixed oil phase (composed of 1.8% pepper oil, 5.5% lard, 6.5% oleic acid, 0.7% ethyl oleate), 14.5% polyoxyethylene hydrogenated castor oil, and 7.3% anhydrous ethanol.

[0055] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.8% prickly ash oil, 5.5% lard, 6.5% oleic acid, 0.7% ethyl oleate, 14.5% polyoxyethylene hydrogenated castor oil, and 7.3% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 400 r·min –1 The mixture was stirred in a vortex mixer for 20 minutes, then added into pure water, and 27.3% of bitter almond extract and 36.4% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0056] Example 7

[0057] The cough-relieving tea prescription oral self-microemulsion is composed of 42.9% bitter almond extract, 28.6% scallion extract, 11.4% mixed oil phase (composed of 1.4% pepper oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate), 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol.

[0058] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.4% prickly ash oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate, 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol, at a temperature of 15°C, using a stirring speed of 600 r·min –1 The mixture was stirred in a vortex mixer for 40 minutes, then added into pure water, and 42.9% of bitter almond extract and 28.6% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0059] Example 8

[0060] The cough-relieving tea prescription oral self-microemulsion is composed of 42.9% bitter almond extract, 28.6% scallion extract, 11.4% mixed oil phase (composed of 1.4% pepper oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate), 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol.

[0061] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.4% prickly ash oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate, 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 100 r·min –1 The mixture was stirred in a vortex mixer for 40 minutes, then added into pure water, and 42.9% of bitter almond extract and 28.6% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0062] Example 9

[0063] The cough-relieving tea prescription oral self-microemulsion is composed of 42.9% bitter almond extract, 28.6% scallion extract, 11.4% mixed oil phase (composed of 1.4% pepper oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate), 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol.

[0064] The preparation method of the above-mentioned cough-relieving tea oral self-microemulsion is as follows: weigh the prescription amount of 1.4% prickly ash oil, 4.3% lard, 5.1% oleic acid, 0.6% ethyl oleate, 11.4% polyoxyethylene hydrogenated castor oil, and 5.7% anhydrous ethanol, at a temperature of 60°C, using a stirring speed of 600 r·min –1 The mixture was stirred in a vortex mixer for 1 min, then added into pure water, and 42.9% of bitter almond extract and 28.6% of scallion extract were added, stirred evenly, and filtered to obtain the product.

[0065] In order to further verify the reliability of the present invention and screen out the best solution, the inventor conducted a series of experiments, as follows:

[0066] 1. Methodological investigation

[0067] 1.1 Instruments and reagents

[0068] Instruments and reagents are shown in Table 1

[0069] Table 1 Instruments and reagents

[0070]

[0071] 1.2 Establishment of in vitro detection method for amygdalin

[0072] 1.2.1 Chromatographic conditions

[0073] Chromatographic column: Unitary C18 column (250 mm × 4.6 mm, 5 μm); mobile phase: methanol-water (25:75); column temperature: 35 °C; flow rate: 1 mL min –1 ; Detector: UVD; Detection wavelength: 210nm.

[0074] 1.2.2 Preparation of reference solution

[0075] Accurately weigh 1.25 mg of amygdalin reference substance, place it in a 10 mL volumetric flask, add 50% methanol to dissolve and make up to volume as a stock solution.

[0076] 1.2.3 Preparation of test solution

[0077] Accurately weigh 50 mg of A folk cough-relieving tea recipe-SMEDDS, place it in a 10 mL brown volumetric flask, add methanol to dilute to the scale, shake well, ultrasonicate for 10 min, filter with a microporous filter membrane, and determine according to chromatographic conditions.

[0078] 1.2.4 System suitability test

[0079] Accurately pipette an appropriate amount of the stock solution and add the mobile phase to make a mass concentration of 100 μg mL –1 The amygdalin reference solution was measured according to the chromatographic conditions, and the theoretical plate number and separation were calculated. The results showed that the separation between the amygdalin peak and its adjacent peaks in the test sample was >1.5, and the retention time was moderate. Under the chromatographic conditions, the theoretical plate number of the chromatographic column was 10158 calculated based on the amygdalin peak. Therefore, it is feasible to determine the content of amygdalin using this analytical method. See the chromatogram for details. Figure 1 .

[0080] 1.2.5 Standard curve drawing

[0081] Accurately measure the predetermined volume of stock solution and dilute to 10 mL with fluidity. Use a stepwise dilution strategy to accurately take out 8 mL, 8 mL, 5 mL, 5 mL, and 5 mL of sample solution and dilute to obtain specific concentrations of 125 μg mL -1 , 100 μg·mL -1 , 80μg·mL -1 , 40 μg·mL -1 , 20μg·mL -1 , 10μg·mL -1 and 0.10 μg mL -1 After all the reference solutions were prepared, they were filtered through a microporous membrane with a pore size of 0.22 μm. Instrumental determination was performed according to the established chromatographic analysis conditions, and the peak area data of each reference solution was recorded. Based on the obtained experimental data, a linear relationship model between the concentration of amygdalin and the chromatographic peak area was constructed, and a linear regression analysis was performed to verify the accuracy and reliability of its quantitative analysis. The standard curve is y=9165.8x–15544(R 2 =0.9991), the mass concentration of amygdalin is 0.10~125μg·mL –1 The internal linearity is good. The standard curve is shown in Figure 2 .

[0082] 1.2.6 Recovery test

[0083] Accurately pipette a predetermined volume of amygdalin standard stock solution and add an appropriate amount of mobile phase to prepare a series of amygdalin standard solutions with different concentrations, with specific concentrations of 23.296 μg mL -1 、66.56μg·mL -1 and 104 μg·mL -1 . These solutions were tested using established chromatographic analysis conditions to ensure the accuracy and reliability of the experimental results. In order to further verify the accuracy of the method, we conducted three independent parallel measurements of the amygdalin standard solution at each concentration level, and recorded the peak area data obtained from each measurement in detail. These measured peak area data were substituted into the previously established amygdalin standard curve equation, and the corresponding amygdalin concentration values ​​were calculated one by one.

[0084] Recovery rate = (actual measured concentration / theoretical concentration) × 100%

[0085] By calculating with the above formula, we can obtain the recovery rate corresponding to each peak area, so as to comprehensively evaluate the detection accuracy of the amygdalin standard solution under the experimental conditions. The results are as follows: The recovery rates of low, medium and high concentrations were calculated to be 97.02% (RSD = 0.8379%), 97.58% (RSD = 0.4786%), and 100.28% (RSD = 0.2881%), respectively. As shown in Table 2, the recovery rate of amygdalin is between 95% and 105%, and the RSD is less than 2%, indicating that the recovery rate results are good and meet the methodological requirements.

[0086] Table 2 Recovery rate experiment of different concentrations of amygdalin under in vitro HPLC method (n=3)

[0087]

[0088] 1.2.7 Precision test

[0089] Under chromatographic conditions, 70 μg mL -1 The amygdalin sample was measured six times in three consecutive days, the peak area data was recorded, and the precision analysis was performed using the standard curve equation. After calculation, the intra-day precision of the sample reached 0.39%, and the inter-day precision was 1.15%, both meeting the requirement of RSD < 2%, indicating that the precision of the amygdalin solution at different concentrations was good and met the precision standard of the experimental design. The results are shown in Table 3.

[0090] Table 3 Precision results of amygdalin at the concentrations measured by in vitro HPLC method (n=3)

[0091]

[0092] 1.2.8 Stability test

[0093] When establishing the in vitro standard curve of amygdalin, a concentration of 104 μg mL -1 Then, the standard solution of amygdalin was diluted step by step with the mobile phase to obtain three concentration levels of low, medium and high samples, which were 20, 40 and 80 μg mL -1. A time series analysis of these samples was performed at room temperature, covering multiple time points from 0 to 24 hours, to evaluate the stability of amygdalin under in vitro conditions. At each preset time point, the samples were filtered through a 0.22μm PES microporous filter membrane to remove possible impurities or particles. Then, chromatographic analysis was performed according to the established in vitro liquid chromatography conditions for amygdalin, the peak area data of each sample was recorded, and the corresponding amygdalin concentration value was inferred using the standard curve equation. By comparing the concentration changes at different concentrations, we were able to systematically evaluate the stability performance of this in vitro HPLC method in the analysis of amygdalin, and the results are shown in Table 4.

[0094] Table 4 Stability test of different concentrations of amygdalin under in vitro HPLC method

[0095]

[0096] 1.2.9 Repeatability test

[0097] When establishing the in vitro standard curve of amygdalin, 100 μg mL -1 Amygdalin standard solution was diluted with the mobile phase to obtain 20, 40, and 80 μg mL -1 Three gradient concentration samples. After the samples were filtered through a 0.22 μm PES microporous filter membrane, chromatographic analysis was performed according to the established conditions of in vitro liquid chromatography of amygdalin. Each sample was measured five times, and the corresponding amygdalin concentration value was calculated using the pre-established standard curve equation. The repeatability of the in vitro HPLC method was evaluated by comparing the repeated measurement results at these three concentrations. The results are shown in Table 5.

[0098] Table 5 Repeatability experiment of different concentrations of amygdalin under in vitro HPLC method (n=5)

[0099]

[0100] 1.3 Summary

[0101] In this experiment, the HPLC conditions for amygdalin were established. The method has strong specificity and is used to detect the solubility and content of amygdalin in different media in vitro. A standard curve for amygdalin was established based on the HPLC conditions, and a linear regression was performed on the peak area (y) with the mass concentration (x). The standard curve is y = 9165.8x–15544 (R 2 =0.9991), the mass concentration of amygdalin is between 0.10 and 125 μg mL -1 The linear relationship is good within the range. Through a comprehensive evaluation of recovery, precision, stability and repeatability, it is confirmed that the method meets strict methodological standards and has high reliability and accuracy.

[0102] 2. Prescription screening of amygdalin SMEDDS

[0103] 2.1 Instruments and reagents

[0104] Instruments and reagents are shown in Tables 6 and 7.

[0105] Table 6 Instruments

[0106]

[0107] Table 7 Reagents

[0108]

[0109]

[0110] The pepper oil used in this study was prepared in the laboratory. The preparation method is as follows:

[0111] The pepper used in the experiment was purchased from Langjia Village, Wutan Town, Jiangjin District, Chongqing City, and was identified by Professor Xie Junli of Guizhou University of Traditional Chinese Medicine as the peel of the Zanthoxylum bungeanum plant of the Rutaceae family.

[0112] (1) Dry the peppercorns and crush them in a grinder. Sieve through a No. 5 sieve and store for later use.

[0113] (2) Preparation of deep eutectic solvent (DES solvent):

[0114] Choline chloride was prepared and mixed with urea, glycerol, lactic acid, 1,3-butanediol and glucose in molar ratios of 1:3, 1:3, 1:3, 1:3 and 2:1 respectively to prepare a DES solvent with a water content of 30%. The solvent was heated in a water bath at 60° C. and continuously stirred with a glass rod until it was dissolved into a transparent liquid. The heating was stopped and the solvent was cooled for later use.

[0115] (3) Take dried Zanthoxylum bungeanum powder, add it into a low eutectic solvent, and ultrasonically extract Zanthoxylum bungeanum oil, the solid-liquid ratio is 3.615 g / mL, the ultrasonic time is 14.5 min, the ultrasonic power is 200 W, and after the ultrasonic is completed, steam distillation is used for extraction for 2 h, and the distillate is collected to obtain Zanthoxylum bungeanum oil.

[0116] 2.2 Methods and Results

[0117] Sichuan pepper oil: lard (1:3) was determined as the oil phase, and the compatibility with the emulsifiers used in the solubility experiment was investigated at room temperature in the ratio of oil phase to each emulsifier of 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, and 1:9. The results showed that soybean lecithin, whey protein, glyceryl monostearate, Span-80, and lecithin did not form emulsions, while Tween-80, polyoxyethylene hydrogenated castor oil, and caprylic / capric macrogol glycerides all formed emulsions, but the granules were obvious and the emulsification effect was poor.

[0118] 2.2.1 Determination of equilibrium solubility of amygdalin in different media

[0119] The equilibrium solubility of amygdalin was determined by the classic shake bottle method. Each excipient was accurately weighed, and an excess of amygdalin extract was added. The mixture was vortexed for 3 min to mix evenly, and then oscillated in a constant temperature water bath at 37 °C for 24 h and rotated at 12000 r / min. –1 Centrifuge at high speed for 10 minutes, and gently aspirate the supernatant. Dilute with methanol according to the established dilution ratio, and use the "1.2.1" analysis method to accurately measure the equilibrium solubility of amygdalin.

[0120] The results showed that there were significant differences in the equilibrium solubility of amygdalin in different emulsifiers. Among them, soy lecithin and whey protein had higher solubility, while polyoxyethylene hydrogenated castor oil and Tween-80 had relatively lower solubility. The specific ranking is shown in Table 8. Based on the preliminary experimental data, we selected polyoxyethylene hydrogenated castor oil and Tween-80 as candidate emulsifiers. In addition, in the selection of auxiliary emulsifiers, 1,2-propylene glycol, glycerol, gum arabic, anhydrous ethanol and polyethylene glycol 400 all had high solubility, so we decided to use anhydrous ethanol, 1,2-propylene glycol, glycerol and polyethylene glycol 400 as candidate auxiliary emulsifiers. The equilibrium solubility of amygdalin in different media is shown in Figure 3 , Figure 4 , Figure 5 .

[0121] Table 8 Solubility of amygdalin in different excipients (Mean±SD, n=3)

[0122]

[0123] 2.2.2 Oil phase screening

[0124] 2.2.2.1 Investigation of oil phase emulsification ability

[0125] Accurately weigh 0.5 g each of ethyl oleate, glyceryl monostearate, castor oil, trilauryl glyceryl, oleic acid, and isopropyl myristate, add an equal amount of Tween-80 as an emulsifier, and add 5 mL of pure water and stir until emulsion is formed. The results are shown in Table 9.

[0126] Table 9 Screening of emulsification ability of different oil phases

[0127]

[0128]

[0129] 2.2.2.2 Preparation of two oil phases and screening of mixed oil phase

[0130] The emulsification effect of pepper oil-lard (hereinafter referred to as excipient) alone with each emulsifier is poor. The pepper oil and lard in the prescription are mixed with the above preferred oil phase in a 1:1 ratio to investigate the optimal result. The results are shown in Table 10.

[0131] Table 10 Screening of mixed oil phases prepared from different oil phases and auxiliary oil phases

[0132]

[0133] 2.2.2.3 Preparation of three oil phases and screening of mixed oil phase

[0134] One oil phase did not work well with the auxiliary material, so a ratio of 2:1:1 was used for screening. The results are shown in Table 11.

[0135] Table 11 Screening of mixed oil phases made from two different oil phases and auxiliary oil phases

[0136]

[0137] 2.2.2.4 Investigation of the optimal ratio of mixed oil phase

[0138] The effect of the auxiliary-preferred oil phase is not good. Considering the toxicity of isopropyl nutmeg, (pepper oil-lard)-(oleic acid-ethyl oleate) is used as the mixed oil phase to investigate the optimal ratio. Under the conditions of (pepper oil-lard): (oleic acid-ethyl oleate) of 1:9, 2:8, 3:7, 4:6, 5:5, the microemulsion effect formed when oleic acid:ethyl oleate is 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9 was investigated respectively, and the results are shown in Table 12.

[0139] 2.2.2.5 Determination of oil phase emulsification ability

[0140] Take the emulsion prepared in 2.2.2.4 and centrifuge it at 3000r / min. –1 After centrifugation for 15 minutes, take out the samples and observe whether there is stratification. Some results are shown in Figure 6 , Figure 7 , Figure 8 . The absorbance of the unstratified uniform emulsion and its 100-fold dilution was measured under UV at λ=550nm. According to the formula for the physical stability of the emulsion:

[0141] E=(A1-A2) / A1×100%

[0142] E is the key parameter for emulsion stability; A1 is the absorbance of the original emulsion before dilution; A2 is the absorbance of the emulsion after centrifugation. Under the same conditions, the smaller the E, the more stable the emulsion. When the ratio of oleic acid: ethyl oleate is 4:6, 3:7, 2:8, and 1:9, the emulsions formed are stratified. The other results are shown in Table 12.

[0143] Table 12 Investigation on the optimal ratio of mixed oil phase

[0144]

[0145] The final preferred oil phase is (pepper oil-lard): (oleic acid-ethyl oleate) at 1:1, and oleic acid:ethyl oleate at 9:1.

[0146] 2.2.3 Emulsifier type screening

[0147] 2.2.3.1 Investigation of the optimal HLB value range

[0148] The HLB value of Tween-80 is 15.0, and the HLB value of Span-80 is 4.3. Weigh different proportions of Tween-80 and Span-80 in a vial, stir evenly, and prepare a mixed emulsifier with an HLB value of 8 to 15. There is no suitable HLB value at room temperature; considering that adding glycerin or gum arabic as an additive still does not produce a uniform emulsion after centrifugation, consider using 50 to 60 ° C for preparation. The HLB formula of the composite emulsifier is as follows:

[0149] HLB AB =(W A HLB B +W B HLB A ) / (W A +W B )

[0150] Where W A is the mass proportion of component A in the mixture, W B Represents the mass percentage of component B, HLB A Represents the hydrophile-lipophile balance value of A, HLB B The corresponding value of B. HLB AB It refers to the hydrophile-lipophile balance value of the emulsifier after mixing.

[0151] Weigh 1.2 g of the preferred oil phase and 1.0 g of the emulsifier in a 15 mL EP tube, vortex for 3 min to fully disperse it, and rotate at 3000 r / min. -1 Centrifuge for 15 minutes, take out and observe whether there is stratification or uneven lighting. The results are shown in Table 13.

[0152] Table 13 Mixed emulsifier preparation results

[0153]

[0154] The results show that at 60°C, the emulsion is more stable when the HLB value of the oil phase is in the range of 9.864-14.9, and there is no stratification after centrifugation. It is stratified in the range of 4.3-9.864. Therefore, the optimal HLB value is determined to be 9.864-15. 2.2.3.2 Preliminary compatibility of oil phase and surfactant

[0155] Pepper-lard and oleic acid-ethyl oleate were used as oil phase components and matched with different types of surfactants. In order to ensure the consistency of the experiment, the total mass of the oil phase was set to 0.5g, and the emulsification performance under different ratios was explored by adjusting the mass ratio of emulsifier to oil phase (drug auxiliary-ethyl oleate-oleic acid) (9:1, 8:2, 7:3, 6:4, 5:5 respectively). At room temperature, we used a magnetic stirrer to maintain a constant speed to ensure that the oil phase and the surfactant were fully mixed. Subsequently, we added 200 times the amount of water and continued to stir at a constant speed to form an emulsion. Finally, we evaluated the emulsification performance in detail according to the standards in Table 14 and obtained the results in Table 15.

[0156] Table 14 Evaluation criteria for oil phase and surfactant compatibility

[0157]

[0158]

[0159] Table 15 Compatibility study between oil phase auxiliary drug-ethyl oleate-oleic acid and emulsifier

[0160]

[0161] 2.2.3.3 Study on the stability of emulsifier

[0162] Use the preferred oil phase, Tween-80, polyoxyethylene hydrogenated castor oil, and caprylic / capric acid macrogol glycerides as emulsifiers, accurately weigh 0.6 g of oil phase and 0.4 g of emulsifier, vortex mix evenly at 60°C, add 100 times of pure water, start timing at the same time, take samples at 30s, 60s, 90s, 120s, 180s, and 240s, and use a UV spectrophotometer to measure the absorbance at a wavelength of 550nm. The results are shown in Table 16.

[0163] Table 16 Absorbance values ​​of different emulsifiers at different times

[0164]

[0165] 2.2.4 Screening the dosage range through pseudo-ternary phase diagram

[0166] 2.2.4.1 Drawing of pseudo-ternary phase diagram of blank microemulsion

[0167] In the process of preparing microemulsion, this study adopted the water titration method. First, the emulsifier and the co-emulsifier were mixed in different proportions (Km = 2:1, 1:1, 1:2, 1:3, 1:4), and stirred for 5 minutes using a magnetic stirrer to ensure sufficient mixing. Subsequently, the oil phase and the mixed emulsifier were mixed in a series of specific proportions (1:9 to 9:1) and stirred at a constant temperature of 25°C until the critical phase transition point was reached. This point can be judged by the system changing from turbid to clear or from clear to turbid, and the mass fractions of the oil phase, mixed emulsifier and water phase when this point is reached are recorded. During the experiment, the changes of the microemulsion from W / O type to gel type and then to O / W type were observed, and the numerical changes of each phase were recorded in detail. With oil phase (oil), mixed emulsifier (S / A) and water phase (water) as the three vertices of the ternary phase diagram, the microemulsion and gel areas are drawn by connecting the recorded points according to the mass fraction data of each component at the critical point. By comparing the area sizes of these areas, the optimal formula combination is preliminarily screened out.

[0168] 2.2.4.2 Screening emulsifiers through pseudo-ternary phase diagram

[0169] According to the results of the oil phase screening test, pepper oil-lard-oleic acid-ethyl oleate was used as the oil phase, anhydrous ethanol was used as the co-emulsifier, Tween-80 and polyoxyethylene hydrogenated castor oil were used as emulsifiers, and microemulsions were prepared when Km=2:1, and a pseudo-ternary phase diagram was drawn. When polyoxyethylene hydrogenated castor oil was used as the emulsifier, the area of ​​the microemulsion region was the largest, indicating that the microemulsion system can be better adjusted. Therefore, polyoxyethylene hydrogenated castor oil was selected as the emulsifier for the blank microemulsion. The results are shown in Fig. 9 , A and B correspond to the pseudo-ternary phase diagrams of the microemulsion system when Tween-80 and polyoxyethylene hydrogenated castor oil are emulsifiers, respectively. The gray area in the figure is the gel area.

[0170] 2.2.4.3 Screening of emulsifiers through pseudo-ternary phase diagram

[0171] According to the experimental results of oil phase screening and emulsifier screening, pepper oil-lard-oleic acid-ethyl oleate was selected as the oil phase, polyoxyethylene hydrogenated castor oil was selected as the emulsifier, anhydrous ethanol, 1,2-propylene glycol, glycerol, and polyethylene glycol-400 were used as co-emulsifiers, and microemulsions were prepared when Km=2:1, and a pseudo-ternary phase diagram was drawn. Among the three, the microemulsion area formed by polyethylene glycol-400 is the largest, but compared with anhydrous ethanol, which is also a short-chain monohydric alcohol, it is more toxic to the human body. Therefore, this experiment selected anhydrous ethanol as the co-emulsifier of the blank microemulsion. Results are shown in Fig.10 , A, B, C, and D correspond to the pseudo-ternary phase diagrams of the microemulsion system when 1,2-propylene glycol, glycerol, polyethylene glycol-400, and anhydrous ethanol are emulsifiers, respectively. The gray area in the figure is the gel area.

[0172] 2.2.4.4Km screening

[0173] According to the experimental results of oil phase screening, emulsifier screening and co-emulsifier screening, pepper oil-lard-oleic acid-ethyl oleate was used as the oil phase, polyoxyethylene hydrogenated castor oil was used as the emulsifier, and anhydrous ethanol was used as the co-emulsifier. Microemulsions were prepared at Km=3:1, 2:1, 1:1, and 1:2, and pseudo-ternary phase diagrams were drawn. When Km=1:1 and 1:2, the microemulsion range was too small. When Km=2:1 and 3:1, they both had a larger microemulsion area. However, considering the food safety of polyoxyethylene hydrogenated castor oil, Km=2:1 was selected as the Km of the blank microemulsion. The results are shown in Fig.11 , A and B correspond to the pseudo-ternary phase diagrams of the microemulsion system when Km is 2:1 and 3:1, respectively. The gray area in the figure is the gel area.

[0174] 2.3 Discussion and Results

[0175] 2.3.1 Discussion

[0176] According to the equilibrium solubility data of amygdalin in different oil phases and emulsifiers, the solubility of amygdalin in the pre-selected excipients is relatively large. According to the prescription, the oil phase is determined to be pepper oil-lard (1:3) (hereinafter referred to as the excipient). According to the single factor experiment, the emulsification ability is investigated with different emulsifiers. The self-emulsification effect is limited, and there are large oil droplets on the surface. Tween-80 is used as an emulsifier to further select the commonly used oil phases with better emulsification ability, and one oil phase is selected and mixed with the excipient according to (1:1) to test the emulsification ability. The results showed that the self-emulsification ability was good but the stability was poor. Further investigation showed that two oil phases were selected and mixed with the drug excipients in the ratio of (1:1:2). The results showed that the drug excipients-isopropyl nutmeg-oleic acid and the drug excipients-isopropyl nutmeg-ethyl oleate were better. Considering the toxicity of isopropyl nutmeg, (pepper oil-lard)-(oleic acid-ethyl oleate) was used as the mixed oil phase and the optimal ratio was investigated. The final mixed oil phase was (pepper oil-lard):(oleic acid-ethyl oleate) in the ratio of 1:1, of which oleic acid:ethyl oleate was 9:1.

[0177] During the emulsification process, the hydrophilic-hydrophobic balance (HLB) value of the emulsifier directly reflects the relative strength of the lipophilicity and hydrophilicity of the emulsifier. Specifically, the lower the HLB value of the emulsifier, the higher the lipophilicity, and the higher the HLB value, the stronger the hydrophilicity. In this study, the HLB value range of the selected oil phase was set to 9.864 to 14.9, aiming to screen out the most suitable emulsifier. The HLB value of polyoxyethylene hydrogenated castor oil is 13.3, while the HLB value of Tween-80 is 14.9, both of which meet the standards of O / W emulsifiers. Experimental evaluation found that the emulsification effect of polyoxyethylene hydrogenated castor oil is slightly better. Co-emulsifiers themselves usually do not have independent emulsification capabilities, so when selecting, priority should be given to alcohol compounds that have good compatibility with emulsifiers and small molecular weights. They can effectively improve the emulsification properties of emulsifiers while promoting drug dissolution.

[0178] 2.3.2 Summary

[0179] This chapter first determined the solubility of amygdalin in different excipients, and screened out the optimal mixed oil phase as (pepper oil-lard): (oleic acid-ethyl oleate) at a ratio of 1:1, and oleic acid:ethyl oleate at a ratio of 9:1. Then, through the compatibility, stability, and pseudo-ternary phase diagram of the emulsifier, it was determined that the emulsifier was polyoxyethylene hydrogenated castor oil. The pseudo-ternary phase diagram determined that the co-emulsifier was anhydrous ethanol and the optimal Km was 2:1.

[0180] 3. Response surface design to optimize prescription

[0181] 3.1 Instruments and reagents

[0182] Instruments and reagents are shown in Tables 17 and 18.

[0183] Table 17 Instruments

[0184]

[0185] Table 18 Reagents

[0186]

[0187] 3.2 Response surface design

[0188] 3.2.1D-Optimal Mixture Design

[0189] Referring to the results of the pseudo-ternary phase diagram, the total amount of oil phase, surfactant, and co-surfactant was set to 100%, and the D-optimal mixing design ratio was designed using Design Expert 11.1 software. The self-microemulsion was prepared according to the design ratio. The preparation temperature was 60°C, and the self-microemulsion was diluted with 30 times the amount of pure water at 60°C after stirring for 5 minutes using a vortex mixer. After gentle stirring and emulsification, the particle size and PDI of the microemulsion were examined to determine the optimal prescription ratio. The designed ratio and the results of the investigation are shown in Table 19.

[0190] Table 19D-Optimal mixture design and results

[0191]

[0192] 3.2.2 Data model fitting and response surface analysis

[0193] Using Design Expert 11.1 software, the experimental results were fitted with a model with the oil phase dosage (X1), surfactant dosage (X2), and co-surfactant dosage (X3) as influencing factors, and particle size (Y1) and PDI (Y2) as evaluation indicators. The regression analysis results are shown in Tables 20 and 21. Model P < 0.05, indicating that the model is significant for all response parameters.

[0194] It is concluded that the independent variable has a significant effect on particle size and PDI. The coefficients of the variables in the equation are positive, indicating that the factor is positively correlated with the response value, while negative values ​​indicate negative correlation. The fitting equations are Y1=104.36X1+17.48X2+12354.54X3-19.85X1X2-21375.44X1X3-21825.41X2X3+20050.42X1X2X3-104.74X1X2(X1-X2)+9863.20X1X3(X1-X3)+11073.70X2X3(X2-X3), R 2 =0.9984;

[0195] Y2=0.0647X1+0.2440X2-33.73X3-0.0513X1X2+58.31X1X3+60.49X2X3-55.88X1X

[0196] 2X3+0.3419X1X2(X1-X2)-25.86X1X3(X1-X3)-32.12X2X3(X2-X3), R 2 =0.8989

[0197] Then, according to the regression analysis results, the two-dimensional contour lines and three-dimensional response diagrams of each variable with particle size and PDI as dependent variables were obtained. The results are shown in Fig.12 , Fig.13 It can be seen that the amount of oil phase and surfactant has a greater influence on the self-microemulsification formation.

[0198] Table 20 Particle size, PDI cubic model analysis Response 1: Particle size

[0199]

[0200] Response 2:PDI

[0201]

[0202]

[0203] Table 21 Summary of particle size and PDI model fitting

[0204]

[0205] Using three-dimensional renderings and contour map techniques, we were able to clearly reveal how changes in the proportions of oil, emulsifier, and co-emulsifier in the preparation of microemulsions affect the drug loading and particle size of the microemulsions. Specifically, with the decrease in the oil phase content and the increase in the amount of emulsifier used, the particle size and polydispersity index (PDI) of the microemulsion both showed a decreasing trend. Based on these response data, we adopted corresponding strategies: by reducing the oil phase ratio and increasing the amount of emulsifier used, the uniformity of the microemulsion was effectively improved, and the effective regulation of the microemulsion particle size was achieved. 3.2.3 Optimal prescription and verification test

[0206] The optimal formula predicted by Design Expert 11.1 software is 41.4% oil phase, 40% surfactant, 18.6% co-surfactant, and the predicted microemulsion particle size is 44.6nm, and the PDI is 0.075. The verification was carried out according to the predicted optimized formula, repeated 3 times, and the deviation was calculated. The deviation between the predicted value and the actual value of the index is less than 5%, indicating that the equation prediction accuracy is good. Therefore, the optimal self-microemulsification formula is obtained: the oil phase is (pepper oil-lard): (oleic acid-ethyl oleate) is 1:1, oleic acid: ethyl oleate 9:1, accounting for a total of 41.4%, surfactants account for 40.0%, and co-surfactants account for 18.6%. The results are shown in Tables 22 and 23.

[0207] Table 22 Prediction of experimental data range

[0208]

[0209] Table 23D-Verification of the optimal mixture experimental design (x±s, n=3)

[0210]

[0211]

[0212] As can be seen from the table above, the average particle size of the three groups of microemulsions prepared under the optimal conditions is 44.03nm, and the average PDI is 0.088. Through data comparison and analysis, it can be seen that the predicted values ​​of all samples fall within the theoretically expected error tolerance range. The deviation calculation formula is: deviation = (predicted value-measured value) / predicted value×100%. The calculation results show that the deviation of all samples is less than 5%, which proves that the constructed mathematical model has a high degree of accuracy in prediction, and also confirms the scientific nature of the experimental method and the credibility of the experimental results.

[0213] 3.3 Discussion and Results

[0214] 3.3.1 Discussion

[0215] According to the pharmacopoeia and prescriptions, the dosage of Zanthoxylum bungeanum is 3 to 6 g. Volatile oil is one of the active ingredients of Zanthoxylum bungeanum, and its content accounts for about 0.7% to 9.0%. Excessive use of emulsifiers can cause harm to the human body. Combined with the national regulations that the use limit range of food-grade emulsifiers in common foods is 0.01 to 10 g / kg, the final fixed prescription amount was determined to be 1 g, and the response surface design used 40 to 60% of the oil phase, 26 to 40% of the surfactant, and 14 to 20% of the co-surfactant.

[0216] According to preliminary experiments, when the water phase was used as an influencing factor for response surface design, some of the test groups were gels and the particle size could not be measured. In addition, the amount of water added after the microemulsion system was formed by water phase titration had almost no effect on the particle size, so the D-optimal mixture design was used instead.

[0217] 3.3.2 Summary

[0218] The experiments in this chapter obtained the optimal self-microemulsification formula: the oil phase is (pepper oil-lard): (oleic acid-ethyl oleate) in a ratio of 1:1, oleic acid:ethyl oleate in a ratio of 9:1, accounting for a total of 41.4%, surfactants accounting for 40.0%, and co-surfactants accounting for 18.6%.

[0219] 4. Investigation of self-microemulsification dosage and optimal preparation process

[0220] 4.1 Instruments and reagents

[0221] Instruments and reagents are shown in Tables 24 and 25.

[0222] Table 24 Instruments

[0223]

[0224] Table 25 Reagents

[0225]

[0226]

[0227] 4.2 Investigation of drug dosage in self-microemulsification

[0228] According to the solubility of the active ingredient amygdalin in water (8.3g·100mL – ) 1 , and the dosage of bitter almonds and green onion in the Chinese Pharmacopoeia. According to the optimal prescription obtained by D-optimal mixing design, each excipient was accurately weighed, totaling 1g. After stirring for 5 minutes at 60°C using a vortex mixer, it was diluted to 100mL with pure water at 60°C. According to the table below, bitter almond and green onion extracts were added, stirred evenly, and filtered to prepare 12 groups of self-microemulsions with different dosages. The particle size and PDI were measured using a particle size analyzer at 10000r·min –1 Centrifuge for 30 minutes to measure its centrifugal stability. The particle size and PDI results of different dosages are shown in Table 26. With the increase of drug loading, the particle size and PDI of the microemulsion gradually increase after microemulsification, but the difference is not large; the centrifugal stability test results show that the microemulsion samples prepared at different concentrations maintain their original clear and transparent state after centrifugation, and no stratification or coagulation is observed, which verifies their good physical stability. Therefore, the drug was finally loaded according to the maximum drug dosage of the pharmacopoeia, that is, 1.5g of bitter almond extract and 1.0g of scallion extract were added.

[0229] Table 26 Particle size and PDI after self-microemulsion emulsification at different dosages (x±s, n=12)

[0230]

[0231] 4.3 Investigation of the optimal preparation process of self-microemulsion

[0232] According to the optimal formula obtained by D-optimal mixing design, each excipient was accurately weighed and the dosage was determined. A single factor experiment was conducted, and other processes were kept unchanged. The results were investigated at different temperatures (15, 20, 30, 40, 50, 60°C), different magnetic stirring speeds (100, 200, 300, 400, 500, 600 r·min –1 ) and different stirring times (1, 5, 10, 20, 40 min), measured the emulsification time, observed the uniformity of the emulsified appearance, and determined the size of the emulsion particles. The results showed that the optimal preparation process was 60 ° C, 400 r / min –1 The stirring time is 20 minutes. The results are shown in Tables 27-29. The final microemulsion is as follows Fig.14 .

[0233] Table 27 Effect of preparation temperature on self-microemulsification ( n=6)

[0234]

[0235] Table 28 Effect of stirring speed on self-microemulsification ( n=5)

[0236]

[0237] Table 29 Effect of stirring time on self-microemulsification ( n=5)

[0238]

[0239] 4.4 Summary

[0240] The drug loading was 1.5 g of bitter almond extract and 1.0 g of scallion extract. The results showed that the optimal preparation process conditions were 60°C and 400 r / min. –1 , stirring time 20min.

[0241] Although the present invention has been described in detail above by means of general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A cough-relieving tea prescription oral self-microemulsion, characterized in that: The self-microemulsion consists of 27.3%-50% bitter almond extract, 16.7%-36.4% scallion extract, 11.4%-26.7% mixed oil phase, 7.4%-17.8% emulsifier and 4.0%-8.9% auxiliary emulsifier in mass fraction.

2. The self-microemulsion according to claim 1, characterized in that The self-microemulsion consists of 42.9% by mass of bitter almond extract, 28.6% by mass of scallion extract, 11.4% by mass of mixed oil phase, 11.4% by mass of emulsifier and 5.7% by mass of co-emulsifier.

3. The self-microemulsion according to any one of claims 1 or 2, characterized in that The mixed oil phase consists of a drug adjuvant and an oil phase in a mass ratio of 1:1; the drug adjuvant consists of pepper oil: lard in a mass ratio of 1:3; and the oil phase consists of oleic acid: ethyl oleate in a mass ratio of 9:

1.

4. The self-microemulsion according to any one of claims 1 or 2, characterized in that The emulsifier is any one of Tween-80, Tween-40, span-80, lecithin, polyoxyethylene hydrogenated castor oil, glyceryl monostearate, whey protein, soybean lecithin, and caprylic acid capric acid macrogol glyceride.

5. The self-microemulsion according to claim 4, characterized in that The emulsifier is polyoxyethylene hydrogenated castor oil.

6. The self-microemulsion according to any one of claims 1 or 2, characterized in that The auxiliary emulsifier is any one of anhydrous ethanol, 1,2-propylene glycol, polyethylene glycol-400, gum arabic, beeswax, and glycerol.

7. The self-microemulsion according to claim 6, characterized in that The auxiliary emulsifier is anhydrous ethanol.

8. A method for preparing the cough-relieving tea oral self-microemulsion according to claim 1, characterized in that: The preparation method comprises: weighing a mixed oil phase, an emulsifier and an auxiliary emulsifier according to a prescription, stirring at a temperature of 15-60° C. and a stirring speed of 100-600 r·min –1 After stirring for 1-40 minutes in a vortex mixer, add into pure water, add bitter almond extract and scallion extract, stir evenly, filter, and obtain.

9. The preparation method according to claim 8, characterized in that: The preparation method comprises weighing a mixed oil phase, an emulsifier and an auxiliary emulsifier according to a prescription, stirring at a temperature of 60° C. and a stirring speed of 400 r·min –1 After stirring in a vortex mixer for 20 minutes, add into pure water, add bitter almond extract and scallion extract, stir evenly, filter, and obtain.

10. Use of the cough-relieving tea oral self-microemulsion according to claim 1 in preparing cough-relieving medicines.

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