Emodin piperazine co-crystal, methods of preparation and compositions and uses thereof

Abstract

This invention discloses a rhein-piperazine cocrystal, its preparation method, its composition, and its uses. Specifically, this invention discloses a novel chemical entity with rhein-piperazine cocrystal as a pharmaceutically active ingredient; a method for preparing the rhein-piperazine cocrystal; and the application of the rhein-piperazine cocrystal as a pharmaceutically active ingredient in the preparation of drugs for the prevention and treatment of bacterial, fungal, and viral infections, as well as for antitumor, antimalarial, diabetes, Alzheimer's disease, and sepsis treatments, belonging to the field of pharmaceutical technology.

Description

Technical Field

[0001] This invention relates to emodin-piperazine cocrystals, their preparation methods, compositions, and uses. Specifically, this invention discloses a cocrystal formed from emodin and piperazine: emodin-piperazine cocrystal; a method for preparing the emodin-piperazine cocrystal; and the application of the emodin-piperazine cocrystal as a pharmaceutical active ingredient in the preparation of drugs for the prevention and treatment of bacterial, fungal, and viral infections, as well as for antitumor, antimalarial, diabetes, Alzheimer's disease, and sepsis drugs, belonging to the field of pharmaceutical technology. Background Technology

[0002] Drug cocrystallization refers to the process by which an active pharmaceutical ingredient (API) and a cocrystal conformer (CCF) with a specific stoichiometric ratio form a new chemical entity through non-bonded interactions. It is an important method in new drug development. Forming cocrystallization can potentially improve the physicochemical properties of drugs, such as stability, solubility, and permeability, thereby enhancing their drug-like properties.

[0003] This invention uses emodin as the active ingredient, its chemical name is 1,3,8-trihydroxy-6-methylanthraquinone, and its molecular formula is C2. 15 H 10 O5, with the structural formula shown in Figure a. Piperazine is used as another active substance in this invention; its chemical name is hexahydropyrazine, and its molecular formula is C4H. 10 N2, the structural formula is shown in b.

[0004]

[0005] Emodin is an anthraquinone derivative. Its physicochemical properties show it to be an orange-yellow crystalline powder, odorless, and bitter in taste. It is soluble in ethanol or alkaline solutions, slightly soluble in ether or chloroform, and insoluble in water. It possesses antitumor activity and is also effective in treating inflammation and cardiovascular diseases. [1,2] Currently, the main commercially available form of emodin is emodin capsules. However, due to its poor water solubility and poor absorption in the stomach, emodin has a poor oral effect, resulting in low bioavailability and limiting its efficacy in the body. Therefore, taking effective measures to improve the water solubility of emodin to better exert its therapeutic effects is of great significance.

[0006] Piperazine is a pyrazine derivative and an important pharmaceutical intermediate. The clinically used form is piperazine hydrochloride, which has anthelmintic, abdominal pain-relieving, anemia-treating, digestive-promoting, and appetite-enhancing effects.

[0007] Regarding the polymorphism and eutectic study of emodin: Two polymorphs of emodin, crystal type I and crystal type II, have been discovered so far.[3,4] And seven solvates, namely emodin-water solvate, emodin-methanol solvate, emodin-ethanol solvate, emodin-acetone solvate, emodin-acetonitrile solvate, emodin-chloroform solvate, and emodin dioxane solvate. [5.6] This patent uses emodin monohydrate. There are four reported types of emodin eutectic and salt forms, including emodin-berberine hydrochloride salt. [7] Emodin-berberine hydrochloride ethanol compound [7] emodin-nicotinamide cocrystal [8] Cocrystals with emodin-carbamazepine [9] .

[0008] Because emodin has poor solubility, poor absorption in the stomach, and limited oral efficacy, its bioavailability is limited. This invention, through crystal engineering technology, has discovered a novel emodin-piperazine co-crystal solid substance completely different from those reported in previous studies. While improving the solubility of emodin, in vivo pharmacokinetic experiments in rats revealed that the emodin-piperazine co-crystal achieved unexpected technical effects in improving the rate and extent of emodin bioabsorption. Furthermore, in vivo evaluation in mice showed that the emodin-piperazine co-crystal has good therapeutic effects on lipopolysaccharide (LPS)-induced sepsis and sepsis-induced encephalopathy.

[0009] To address the problems of existing technologies, this invention proposes a method for preparing a eutectic of emodin and piperazine, as well as its applications. Summary of the Invention

[0010] The technical problem to be solved by this invention:

[0011] One of the technical problems to be solved by the present invention is to provide the existence state and characterization method of the eutectic substance of emodin and piperazine.

[0012] The second technical problem to be solved by this invention is to provide a method for preparing rhein-piperazine cocrystals.

[0013] The third technical problem to be solved by the present invention is to provide a pure product containing emodin-piperazine cocrystal, or a mixed solid substance containing any non-zero proportion of emodin-piperazine cocrystal, and a pharmaceutical composition thereof.

[0014] The fourth technical problem to be solved by this invention is to provide a pharmaceutical composition using emodin-piperazine cocrystal as the active pharmaceutical ingredient, wherein the daily dosage of the emodin-piperazine cocrystal is in the range of 5–3000 mg. The pharmaceutical composition includes tablets, capsules, pills, injectable preparations, granules, powders, microcapsules, drop pills, suppositories, films, patches, aerosols, sprays, sustained-release preparations, or controlled-release preparations.

[0015] The fifth technical problem to be solved by this invention is to provide a rhein-piperazine cocrystal that exhibits better solubility in pure water (pH 7.0) compared to rhein.

[0016] The sixth technical problem to be solved by this invention is to provide a method in which the bioavailability of rhein-piperazine cocrystal is improved in vivo due to the cocrystal material, thereby exerting an effective therapeutic effect.

[0017] The seventh technical problem to be solved by this invention is the application of rhein-piperazine cocrystal as an active pharmaceutical ingredient in the preparation of drugs for the prevention and treatment of bacterial, fungal, and viral infections, as well as for anti-tumor, anti-malarial, diabetes, Alzheimer's disease, and sepsis.

[0018] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0019] 1. Morphological characteristics of rhein-piperazine eutectic samples:

[0020] 1.1 The present invention relates to a eutectic compound of emodin and piperazine, characterized in that emodin and piperazine form a eutectic in a molar ratio of 2:1.

[0021] 1.2 The emodin-piperazine eutectic of this invention, when analyzed by single-crystal X-ray diffraction, exhibits monoclinic crystal system symmetry, space group P21 / c, and cell parameters as follows: β = 140.02°. Unit cell volume. The molecular formula is C 15 H 10 O 5. (C4H 10 N2) 0.5 Appendix Figure 1 Provide a projection diagram of the molecular stereostructure of the rhein-piperazine cocrystal, with appendix. Figure 2 The unit cell packing diagram of the emodin-piperazine cocrystal is given, and Table 1 gives the coordinate parameters of the non-hydrogen atoms in the emodin-piperazine cocrystal.

[0022] Table 1. Coordinate parameters of non-hydrogen atoms in the rhein-piperazine cocrystal.

[0023]

[0024]

[0025] 1.3 The emodin-piperazine eutectic of the present invention, when analyzed by powder X-ray diffraction using CuK... α Under radiation experimental conditions, the diffraction peak positions are: 2 - Theta value (°) or d value. The relative intensity of diffraction peaks: peak height (Height%) or peak area (Area%) has the following characteristics (Table 2, Figure 3 The X-ray diffraction pattern and data of the physical mixture of emodin and piperazine powder are shown in Table 3. Figure 4 The powder X-ray diffraction patterns of the emodin-piperazine cocrystal and the physical mixture of emodin and piperazine show significant differences in the number, position, intensity, and topology of diffraction peaks, indicating that the emodin-piperazine cocrystal and the physical mixture of emodin and piperazine are neither the same nor equivalent.

[0026] Table 2. Powder X-ray diffraction peak values ​​of rhein-piperazine cocrystals

[0027]

[0028] Table 3. Powder X-ray diffraction peaks of the physical mixture of emodin and piperazine

[0029]

[0030]

[0031] 1.4 The emodin-piperazine cocrystals involved in this invention are characterized by the following properties when analyzed using attenuated total reflectance Fourier transform infrared spectroscopy: 3484, 3276, 3060, 2950, ​​2876, 2748, 2393, 1888, 1660, 1621, 1608, 1589, 1561, 1483, 1470, 1460, 1448, 1 369, 1315, 1305, 1260, 1228, 1204, 1188, 1176, 1134, 1096, 1055, 1029, 993, 937 ,909,881,855,824,767,717,666,637,609,582,548,514,467,455,435,406cm -1 There is an infrared spectral characteristic peak at this location, with an allowable deviation of ±2cm for the infrared spectral characteristic peak. -1 . ( Figure 5 ).

[0032] 1.5 The emodin-piperazine eutectic of the present invention is characterized in that, when analyzed by differential scanning calorimetry (DSC), it exhibits an exothermic peak at 249±3℃ and an endothermic peak at 258±3℃ in the DSC spectrum when the heating rate is 10℃ per minute. Figure 6 The DSC superposition spectrum of the emodin, piperazine, and emodin-piperazine cocrystal is shown in [reference needed]. Figure 7 The DSC spectra of emodin, piperazine, and the emodin-piperazine cocrystal show significant differences in the number and position of endothermic / exothermic peaks, indicating that the emodin-piperazine cocrystal is a new phase different from the raw materials of emodin and piperazine.

[0033] 2. Characteristics of the preparation methods for rhein-piperazine eutectics and mixed solid substances:

[0034] The methods for preparing the emodin-piperazine cocrystals involved in this invention include the following methods:

[0035] 2.1 The suspension stirring method for the emodin-piperazine cocrystal of the present invention involves using a single solvent system of methanol, n-propanol, isopropanol, acetonitrile, acetone, dioxane, or tetrahydrofuran, or a mixed solvent prepared by mixing the above solvents in different proportions. Emodin and piperazine are weighed in a 2:1 molar ratio, and 0.5–20 mL of organic solvent is added. The mixture is stirred at 100–400 r / min for 24–72 h at a temperature of 20–45 °C. The product is then dried to obtain the emodin-piperazine cocrystal.

[0036] 2.2 The preparation method of the emodin-piperazine cocrystal by the present invention includes the following steps: (1) Emodin and piperazine are placed in a mortar at a molar ratio of 2:1 and ground evenly to obtain a mixture;

[0037] (2) Take the mixture obtained in step (1) and grind it in a clockwise direction, adding organic solvent dropwise every 15 minutes. The amount of solvent added each time is 2 mL / g to 10 mL / g. Grind for 1 to 6 hours. The organic solvent is selected from any one or more of methanol, ethanol, acetonitrile, acetone, and isopropanol, and mixed solvents prepared by different ratios.

[0038] (3) Dry the product obtained in step (2) to obtain a solid product of rhein-piperazine cocrystal.

[0039] 2.3 The mechanochemical preparation method of the emodin-piperazine cocrystal of the present invention is selected from mechanical ball milling, wherein the molar ratio of emodin to piperazine is 1.5:1 to 2.5:1, preferably 1.9:1 to 2.1:1; the mechanochemical method is selected from mechanical ball milling, wherein the ball-to-material ratio of the ball milling method is 1:1 to 10:1, preferably 6:1 to 10:1; the ball milling speed is 20 r / min to 400 r / min; and the grinding time is 1 to 72 h.

[0040] 2.4 The solvent evaporation preparation method of the emodin-piperazine cocrystal of the present invention uses isopropanol as a single solvent or isopropanol / water (v / v, 4:1) mixed solvent. Emodin and piperazine samples are dissolved in the solvent at a molar ratio of 2:1 at a temperature of 15℃ to 60℃. The total mass of emodin-piperazine to the solid-liquid ratio of organic solvent is 1mg / mL to 50mg / mL. The mixture is stirred for 2h to 24h and placed under an ambient temperature of 20℃ to 40℃ and an ambient relative humidity of 10% to 90% for slow solvent evaporation for 7-30 days to obtain crystals of emodin-piperazine cocrystal that meet the requirements of single crystal X-ray diffraction.

[0041] 2.5 The mixed solid substance containing emodin-piperazine cocrystals involved in this invention is prepared by mixing the emodin-piperazine cocrystals obtained by the above method with other chemical substances in any non-zero proportion and using conventional methods.

[0042] 3. Pharmaceutical formulations containing emodin-piperazine cocrystals, dosage characteristics, and pharmaceutical uses: 3.1 The pharmaceutical compositions of the present invention contain emodin-piperazine cocrystals and a pharmaceutically acceptable carrier. 3.2 The pharmaceutical compositions of the present invention contain a mixed solid substance of emodin-piperazine cocrystals and a pharmaceutically acceptable carrier.

[0043] 3.3 The daily dosage of the pharmaceutical composition of the present invention, which is the rhein-piperazine cocrystal, is in the range of 5 to 3000 mg.

[0044] 3.4 The pharmaceutical composition of the present invention is characterized in that the pharmaceutical composition is various tablets, capsules, pills, injectable preparations, granules, powders, micro-pellets, droplets, suppositories, films, patches, aerosols, sprays, sustained-release preparations or controlled-release preparations.

[0045] 3.5 This invention relates to the use of emodin-piperazine cocrystals, mixed solid substances containing emodin-piperazine cocrystals, or pharmaceutical compositions in the preparation of drugs for the prevention and treatment of bacterial, fungal, and viral infections, as well as for antitumor, antimalarial, diabetes, Alzheimer's disease, and sepsis treatments.

[0046] This invention relates to pharmaceutical compositions using the rhein-piperazine cocrystal of the present invention as the active ingredient. The pharmaceutical composition can be prepared according to methods known in the art. It can be formulated into any dosage form suitable for human or animal use by combining the rhein-piperazine cocrystal of the present invention with one or more pharmaceutically acceptable solid or liquid excipients and / or adjuvants. The content of the rhein-piperazine cocrystal of the present invention in its pharmaceutical composition is in the range of 10% to 90% by weight.

[0047] The rhein-piperazine cocrystal of the present invention can be administered in unit dose form, and the route of administration can be enteric or non-enteric, mainly orally.

[0048] The preferred dosage form for administration in this invention is a solid dosage form. Solid dosage forms can be tablets (including regular tablets, enteric-coated tablets, lozenges, dispersible tablets, chewable tablets, effervescent tablets, orally disintegrating tablets), capsules (including hard capsules, soft capsules, and enteric-coated capsules), granules, powders, microcapsules, droplets, suppositories, films, patches, aerosols, sprays, etc.

[0049] The rhein-piperazine cocrystal of this invention can be formulated into ordinary preparations, as well as sustained-release preparations, controlled-release preparations, targeted preparations, and various microparticle delivery systems.

[0050] To formulate the rhein-piperazine cocrystal of the present invention into tablets, a wide variety of excipients known in the art can be used, including diluents, binders, wetting agents, disintegrants, lubricants, and flow aids. Diluents can be starch, dextrin, sucrose, glucose, lactose, mannitol, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, dicalcium phosphate, calcium carbonate, etc.; wetting agents can be water, ethanol, isopropanol, etc.; binders can be starch paste, dextrin, syrup, honey, glucose solution, microcrystalline cellulose, gum arabic paste, gelatin paste, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, acrylic resin, carbomer, polyvinylpyrrolidone, polyethylene glycol, etc.; disintegrants can be dry starch, microcrystalline cellulose, low-substituted hydroxypropyl cellulose, cross-linked polyvinylpyrrolidone, cross-linked sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate and citric acid, polyoxyethylene sorbitol fatty acid ester, sodium dodecyl sulfonate, etc.; lubricants and flow aids can be talc, silica, stearate, tartaric acid, liquid paraffin, polyethylene glycol, etc.

[0051] Tablets can also be further processed into coated tablets, such as sugar-coated tablets, film-coated tablets, enteric-coated tablets, or bilayer and multilayer tablets.

[0052] To formulate the drug delivery unit into capsules, the active ingredient, the rhein-piperazine cocrystal of the present invention, can be mixed with a diluent and a gliding agent, and the mixture can be directly placed into hard or soft capsules. Alternatively, the active ingredient, the rhein-piperazine cocrystal of the present invention, can be first formed into granules or microspheres with a diluent, binder, and disintegrant, and then placed into hard or soft capsules. Various diluents, binders, wetting agents, disintegrants, and gliding agents used to prepare tablets of the rhein-piperazine cocrystal of the present invention can also be used to prepare capsules of the rhein-piperazine cocrystal of the present invention.

[0053] In addition, colorants, preservatives, flavorings, tasters or other additives may be added to pharmaceutical preparations if necessary.

[0054] To achieve the intended therapeutic purpose and enhance the therapeutic effect, the drug of the present invention can be administered using any known method of drug administration.

[0055] The dosage of the rhein-piperazine cocrystal pharmaceutical composition of the present invention can vary widely depending on the nature and severity of the disease to be prevented or treated, the individual condition of the patient or animal, the route of administration, and the dosage form. The above dosage can be administered as a single unit or divided into several units, depending on the physician's clinical experience and the administration regimen, including the use of other treatment methods.

[0056] The rhein-piperazine cocrystal or composition of the present invention can be taken alone or in combination with other therapeutic or symptomatic drugs. When the rhein-piperazine cocrystal of the present invention has a synergistic effect with other therapeutic drugs, its dosage should be adjusted according to the actual situation.

[0057] 4. Beneficial technical effects of the present invention: the safety, stability, solubility and bioactivity advantages of the rhein-piperazine cocrystal.

[0058] 4.1 The DSC spectrum of the rhein-piperazine cocrystal of the present invention ( Figure 6 There are no endothermic peaks indicating the loss of crystallization solvent or water of crystallization on its thermogravimetric analysis chromatogram ( Figure 8 In addition to the weight loss peak of 0.5 molecule piperazine in the range of 120-280℃ and the weight loss peak of emodin decomposition in the range of 280-500℃, there is no weight loss step of crystallization solvent or water of crystallization in the range of 30-120℃, indicating that the emodin piperazine cocrystal does not contain any crystallization solvent and has good safety.

[0059] 4.2 The rhein-piperazine cocrystal of the present invention, compared with piperazine which is extremely unstable under high temperature, high humidity and light conditions, can remain stable under high temperature, high humidity and light conditions, and has good drug stability advantages. Figure 9 ).

[0060] 4.3 The rhein-piperazine cocrystal of the present invention exhibits a significantly better solubility in pure water (pH 7.0) than rhein itself. The equilibrium solubility of the rhein-piperazine cocrystal in water is 303.85 μg / mL, while the raw rhein is undetectable in pure water.

[0061] 4.4 The rhein-piperazine cocrystal of the present invention has significant advantages in terms of bioabsorption rate and absorption extent compared with rhein raw material. Figure 10 ).

[0062] 4.55 The biological effects of the drug and its pharmaceutical composition developed using the rhein-piperazine cocrystal as the active ingredient, after intraperitoneal injection, in the drug administration experiment on LPS-induced intracerebral inflammation in C57BL / 6 mice, the anti-inflammatory effect of the rhein-piperazine cocrystal was significantly better than that of rhein itself. Figure 11 Biological scores were also assessed, and the behavioral scores of mice in the emodin-piperazine cocrystal group were significantly lower at 24 hours, and better than those in the emodin group. Attached Figure Description

[0063] Figure 1 Molecular stereoscopic projection diagram of emodin-piperazine cocrystal

[0064] Figure 2 Unit packing diagram of emodin-piperazine cocrystal molecules

[0065] Figure 3 Powder X-ray diffraction pattern of emodin-piperazine cocrystal

[0066] Figure 4 Powder X-ray diffraction pattern of a physical mixture of emodin and piperazine

[0067] Figure 5 Infrared absorption spectrum of rhein-piperazine cocrystal

[0068] Figure 6 Differential scanning calorimetry of rhein-piperazine cocrystal

[0069] Figure 7 Differential scanning calorimetry superimposed spectra of emodin, piperazine, and emodin-piperazine cocrystals

[0070] Figure 8 Thermogravimetric analysis of emodin-piperazine cocrystals

[0071] Figure 9 Stability Study Spectra of Emodin Piperazine Cocrystal

[0072] Figure 10 Pharmacokinetic curves of rhein-piperazine cocrystal and rhein

[0073] Figure 11 Evaluation of the anti-inflammatory activity of rhein-piperazine cocrystal and rhein in mouse brain (# indicates comparison with control group, #P<0.05, ###P<0.001; * indicates comparison with model group, *P<0.05, **P<0.01, ***P<0.001) Detailed Implementation

[0074] To better illustrate the technical solution of the present invention, the following embodiments are provided, but the present invention is not limited thereto.

[0075] Example 1

[0076] Preparation method 1 of rhein-piperazine cocrystal:

[0077] Weigh out 2:1 molar ratios of emodin and piperazine and place them in a clean container. Add 0.5–20 mL of organic solvent and stir at a suitable temperature (20℃–45℃) and a speed of 100–400 r / min for an appropriate time (24 h–72 h). Filter the resulting suspension and dry it under vacuum, by natural filtration or evaporation. Perform powder X-ray diffraction analysis on the suspension. The diffraction pattern is similar to… Figure 3 The consistency indicates that the obtained sample is a eutectic of rhein piperazine.

[0078] Table 4. Specific examples of preparation method 1 (suspension stirring method)

[0079]

[0080] Preparation method 2 of rhein-piperazine cocrystal:

[0081] Weigh appropriate amounts of emodin and piperazine at a 2:1 molar ratio and place them in a clean mortar. Grind them evenly to obtain a physical mixture of emodin and piperazine. Add a certain volume of organic solvent dropwise every 15 minutes, with each addition being 2 mL / g to 10 mL / g. Grind the mixture clockwise for 1 to 6 hours, and then dry the resulting product. Perform powder X-ray diffraction analysis on it; its diffraction pattern is similar to... Figure 3 The consistency indicates that the obtained sample is a eutectic of rhein piperazine.

[0082] Table 5. Specific examples of preparation method 2 (liquid addition grinding method)

[0083]

[0084] Preparation method 3 of rhein-piperazine cocrystal:

[0085] A mechanochemical preparation method was used. Emodin and piperazine were weighed in a 2:1 molar ratio and placed in a clean ball mill jar. The mixture was ground at a specific ball-to-particle ratio and rotation speed. After grinding for a certain time, the resulting product was dried. Powder X-ray diffraction analysis was performed on the ground sample, and its diffraction pattern was consistent with... Figure 3 The consistency indicates that the obtained sample is a eutectic of rhein piperazine.

[0086] Table 6. Specific examples of preparation method 3 (ball milling method)

[0087]

[0088] Preparation method 4 of rhein-piperazine cocrystal:

[0089] Weigh 1 mmol of emodin and 0.5 mmol of piperazine into a 20 mL beaker, add 10 mL of methanol, stir for 24 h at a suitable temperature (20–50 °C), filter, and place in an environment with a temperature of 20–40 °C and a relative humidity of 10%–90% for 7 days to allow the solvent to evaporate slowly, thus obtaining crystals of emodin-piperazine eutectic that meet the requirements of single-crystal X-ray diffraction.

[0090] Example 2

[0091] Stability characteristics of rhein-piperazine cocrystals:

[0092] Light exposure test: 50 mg of emodin-piperazine cocrystal was placed under light for 5 days and 10 days, and powder X-ray diffraction analysis was performed on it. Its diffraction pattern was compared with... Figure 3 The consistency indicates that the sample is a eutectic of emodin and piperazine, which is stable under light conditions.

[0093] High-temperature test: 50 mg of rhein-piperazine cocrystal was placed under high-temperature conditions for 5 days and 10 days, and powder X-ray diffraction analysis was performed on it. Its diffraction pattern was similar to... Figure 3 The consistency indicates that the sample is a eutectic of emodin and piperazine, which is stable under high temperature conditions.

[0094] High humidity test: 50 mg of rhein-piperazine cocrystal was placed under high humidity conditions for 5 days and 10 days, and powder X-ray diffraction analysis was performed on it. Its diffraction pattern was compared with... Figure 3 The consistency indicates that the sample is a eutectic of emodin and piperazine, which is stable under high humidity conditions.

[0095] Stability studies of rhein-piperazine cocrystals have demonstrated that they remain stable for up to 10 days under high temperature, high humidity, and light conditions, exhibiting excellent drug stability.

[0096] Example 3

[0097] The rhein-piperazine cocrystal of the present invention improves the solubility of rhein raw material in pure water (pH 7.0).

[0098] The equilibrium solubility concentration of emodin was used as the evaluation index. The content was determined by high-performance liquid chromatography (HPLC) at a wavelength of 254 nm, and the sample dissolution concentration was calculated using the external standard method. The data are shown in Table 7.

[0099] Table 7. Equilibrium solubility data of rhein-piperazine cocrystal and rhein.

[0100]

[0101] The experimental data show that the maximum concentration of the emodin-piperazine cocrystal in pure water is significantly improved compared with that of emodin itself. Specifically, the emodin-piperazine cocrystal has higher solubility, which is of great significance for improving the speed and extent of emodin bioabsorption.

[0102] Example 4

[0103] In vivo bioabsorption advantages of rhein-piperazine cocrystals

[0104] Based on the SD rat animal model, the pharmacokinetic behavior of emodin raw material and emodin piperazine cocrystal in rats was investigated by solid gavage administration. The relevant pharmacokinetic parameters obtained in the experiment are shown in Table 8. The pharmacokinetic time curves of emodin raw material and emodin piperazine cocrystal were plotted with blood collection time (min) as the x-axis and blood drug concentration (μg / mL) as the y-axis. Figure 10 ).

[0105] Table 8. Pharmacokinetic Related Parameters

[0106]

[0107] By comparing the pharmacokinetic parameters of emodin raw material and emodin-piperazine cocrystal, it can be seen that the time to peak concentration of emodin after cocrystal formation is T. max The time has been moved from 11.0h to 8.6h, C max The concentrations increased by approximately 1.3 times, AUC(0-t) by approximately 1.4 times, and AUC(0-∞) by approximately 2.1 times. This indicates that the formation of the eutectic accelerates the absorption rate and increases the degree of absorption of emodin, which is of great significance for the rapid and stable exertion of the pharmacological activity of emodin.

[0108] Example 5

[0109] In vivo biological activities of rhein-piperazine cocrystals:

[0110] In the drug administration experiment on LPS-induced intracranial inflammation in C57BL / 6 mice, the positive control group (sevieria sodium) showed significantly lower levels of TNF-α and IL-1β in the hippocampus compared to the model group. The emodin group and the emodin-piperazine co-crystal group showed even better results, suggesting that the emodin-piperazine co-crystal has a good therapeutic effect on sepsis-induced encephalopathy (Table 9). Figure 11 The mice were observed and scored at 6, 12, and 24 hours after administration. The behavioral scores showed that, compared with the model group, the behavioral scores of mice in the emodin and emodin-piperazine cocrystal groups were significantly lower at 24 hours, with the emodin-piperazine cocrystal group showing better results. This suggests that the emodin-piperazine cocrystal has an ameliorative effect on LPS-induced sepsis (Table 10).

[0111] Table 9. Effects of emodin and emodin-piperazine cocrystal on inflammatory factors in brain tissue of septic mice.

[0112]

[0113] Table 10 Effects of emodin and emodin-piperazine cocrystal on the behavior of septic mice at different time points.

[0114]

[0115] Example 6

[0116] Preparation method 1 of combination drug formulation (tablets):

[0117] A method for preparing a combination drug tablet, characterized by using rhein-piperazine cocrystal and several excipients as excipients for preparing the combination drug tablet, and preparing tablet samples with each tablet containing 5-500 mg of cocrystal in a certain proportion. Table 11 gives the tablet formulation proportions:

[0118] Table 11 Formulation for the preparation of emodin-piperazine cocrystal combination drug tablets

[0119]

[0120]

[0121] The method for preparing tablet formulations using rhein-piperazine cocrystals as raw materials is as follows: several excipients are mixed evenly with the raw material and directly compressed into tablets; or the excipients are mixed and granulated by dry method, then mixed evenly with the raw material and compressed into tablets.

[0122] Preparation method 2 for combination drug formulations (tablets):

[0123] A method for preparing a combination drug tablet, characterized by using rhein-piperazine cocrystal and several excipients as excipients for preparing the combination drug tablet, and preparing tablet samples with each tablet containing 5-500 mg of cocrystal in a certain proportion. Table 12 gives the tablet formulation proportions:

[0124] Table 12 Formulation for the preparation of emodin-piperazine cocrystal combination drug tablets

[0125]

[0126] The method for preparing tablet formulations using rhein-piperazine cocrystals as raw materials is as follows: several excipients are mixed evenly with the raw materials, an appropriate amount of 1% sodium carboxymethyl cellulose solution is added to form a soft material, which is then granulated by sieving, the wet granules are dried, sieved and sized, magnesium stearate and talc are added and mixed evenly, and then compressed into tablets to obtain the final product.

[0127] Preparation method 3 of combination drug formulation (capsule):

[0128] A method for preparing a combination drug capsule, characterized by using rhein-piperazine cocrystal as the active pharmaceutical ingredient (API) and several excipients as excipients for preparing the combination drug capsule, and preparing capsule samples with a drug content of 5-500 mg per tablet according to a certain ratio. Table 13 shows the capsule formulation ratio:

[0129] Table 13. Active pharmaceutical ingredients and excipients for emodin-piperazine cocrystal combination drug capsule formulations.

[0130]

[0131]

[0132] The method for preparing capsules from rhein-piperazine cocrystal as a raw material is as follows: several excipients are mixed evenly with the raw material, an appropriate amount of 1% sodium carboxymethyl cellulose solution is added, wet granules are prepared, dried, sieved and granulated, magnesium stearate is added and mixed evenly, and then inserted into capsules; or the granulation step is not used, but the rhein-piperazine cocrystal raw material is directly mixed evenly with several excipients and excipients, sieved, and directly filled into capsules.

[0133] Example 7

[0134] Dosage of the rhein-piperazine cocrystal combination drug 1 (tablets):

[0135] A pharmaceutical composition developed using rhein-piperazine cocrystal as the active pharmaceutical ingredient is characterized in that the rhein-piperazine cocrystal is the active pharmaceutical ingredient, and the daily dose is 200 mg. It can be prepared into ordinary tablets of 100 mg twice daily or tablets of 200 mg once daily.

[0136] Dosage of the rhein-piperazine cocrystal combination drug 2 (capsules):

[0137] A pharmaceutical composition developed using emodin-piperazine cocrystal as the active pharmaceutical ingredient is characterized by using emodin-piperazine cocrystal as the active pharmaceutical ingredient, with a daily dose of 500 mg, which can be prepared as either 250 mg capsules twice daily or 500 mg capsules once daily.

[0138] Issues requiring clarification: The dosage of the active ingredient in the emodin-piperazine cocrystal pharmaceutical composition involved in this invention is influenced by many factors, such as patient age, body surface area, route of administration, frequency of administration, and treatment purpose, all of which result in different dosages per administration; differences in absorption and blood drug concentration between samples also contribute to this. Therefore, the appropriate dosage range for each use of the emodin-piperazine cocrystal component in this invention is 0.005–20 mg / kg body weight, preferably 0.01–10 mg / kg body weight. Different total dosage regimens of the emodin-piperazine cocrystal active ingredient should be formulated according to the specific treatment needs, and can be administered in multiple or single doses.

[0139] References

[0140] [1]Dong X, Fu J, Yin X, et al. Emodin: a review of its pharmacology, toxicity and pharmacokinetics[J]. Phytotherapy Research, 2016, 30(8): 1207-1218.

[0141] [2]Li Q,Gao J,Pang X,et al.Molecular mechanisms of action of emodin:As an anti-cardiovascular disease drug[J].Frontiers in Pharmacology,2020,11:559607.

[0142] [3]Li M,Zhang Q,Wang J R,et al.Mechanochromism triggered fluorescentcolorswitching among polymorphs of a natural fluorescence pigment[J].ChemicalCommunications,2016,52(75):11288-11291.

[0143] [4]Delgadillo D A,Burch J E,Kim L J,et al.High-throughputidentification ofcrystalline natural products from crude extracts enabled bymicroarray technology andmicroED[J].ACS Central Science,2023,10(1):176-183.

[0144] [5]Zhu J C,Liang Y,Wang H S,et al.1,3,8-Trihydroxy-6-methylanthraquinonemonohydrate[J].Acta Crystallographica Section E:StructureReports Online,2007,63(1):o233-o235.

[0145] [6]Li M,Zhang Q,He H,et al.Vapor triggered fluorescent color changesamongsolvates of Emodin[J].Journal of Materials Chemistry C,2017,5(24):5970-5976.

[0146] [7]Deng Y,Zhang Y,Huang Y,et al.Preparation,crystal structures,andoralbioavailability of two cocrystals of emodin with berberine chloride[J].Crystal Growth&Design,2018,18(12):7481-7488.

[0147] [8]Li M,Li Z,Zhang Q,et al.Fine-tuning the colors of natural pigmentemodin withsuperior stability through cocrystal engineering[J].CrystalGrowth&Design,2018,18(10):6123-6132.

[0148] [9]Huang D,Chan H C S,Wu Y,et al.Phase solubility investigation andtheoreticalcalculations on drug-drug cocrystals of carbamazepine with Emodin,Paeonol[J].Journal of Molecular Liquids,2021,329:115604.

Claims

1. A rhein-piperazine cocrystal, characterized in that, Emodin and piperazine form a eutectic in a 2:1 molar ratio.

2. The rhein-piperazine eutectic according to claim 1, characterized in that, When analyzed using single-crystal X-ray diffraction, it exhibits monoclinic crystal system symmetry, space group P21 / c, and cell parameters as follows: β = 140.02°; unit cell volume The molecular formula is C 15 H 10 O5 . (C4H 10 N2) 0.5 .

3. The rhein-piperazine cocrystal according to claim 1, characterized in that, When using powder X-ray diffraction analysis with CuK α Under radiation experimental conditions, the diffraction peak positions are: 2 - Theta value (°) or d value. The relative intensity of diffraction peaks: peak height (Height%) or peak area (Area%) has the following characteristics:

4. The emodin-piperazine cocrystal according to claim 1, characterized in that, when analyzed using attenuated total reflectance Fourier transform infrared spectroscopy, exhibit infrared spectral characteristic peaks at 3484, 3276, 3060, 2950, 2876, 2748, 2393, 1888, 1660, 1621, 1608, 1589, 1561, 1483, 1470, 1460, 1448, 1369, 1315, 1305, 1260, 1228, 1204, 1188, 1176, 1134, 1096, 1055, 1029, 993, 937, 909, 881, 855, 824, 767, 717, 666, 637, 609, 582, 548, 514, 467, 455, 435, 406 cm -1 wherein the infrared spectral characteristic peaks have a permissible deviation of ± 2 cm -1 .

5. The rhein-piperazine cocrystal according to claim 1, characterized in that, When analyzed using differential scanning calorimetry, the DSC spectrum showed an exothermic peak at 249±3℃ and an endothermic peak at 258±3℃ when the heating rate was 10℃ per minute.

6. The method for preparing the rhein-piperazine cocrystal according to any one of claims 1-5, characterized in that, A suspension stirring method was used, employing a single solvent system of methanol, n-propanol, isopropanol, acetonitrile, acetone, dioxane, and tetrahydrofuran, or a mixed solvent prepared from the above solvents in different proportions. Emodin and piperazine were weighed in a 2:1 molar ratio, and 0.5–20 mL of organic solvent was added. The mixture was stirred at 100–400 r / min for 24–72 h at a temperature of 20–45 °C. The product was then dried to obtain the emodin-piperazine cocrystal.

7. The method for preparing the rhein-piperazine cocrystal according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Place rhein and piperazine raw materials in a mortar at a molar ratio of 2:1 and grind them evenly to obtain a mixture; (2) Take the mixture obtained in step (1) and grind it in a clockwise direction, adding organic solvent dropwise every 15 minutes. The amount of solvent added each time is 2 mL / g to 10 mL / g. Grind for 1 to 6 hours. The organic solvent is selected from any one or more of methanol, ethanol, acetonitrile, acetone, and isopropanol, and mixed solvents prepared by different ratios. (3) Dry the product obtained in step (2) to obtain a solid product of rhein piperazine eutectic.

8. The method for preparing the rhein-piperazine cocrystal according to any one of claims 1-5, characterized in that, The mixture of emodin and piperazine raw materials in a certain molar ratio is prepared by a mechanochemical method. The molar ratio of emodin to piperazine is 1.5:1 to 2.5:1, preferably 1.9:1 to 2.1:

1. The mechanochemical method is selected from mechanical ball milling, wherein the ball-to-material ratio is 1:1 to 10:1, preferably 6:1 to 10:1; the ball milling speed is 20 r / min to 400 r / min; and the grinding time is 1 to 72 h.

9. The method for preparing the rhein-piperazine cocrystal according to any one of claims 1-5, characterized in that, The solvent evaporation method was adopted, using isopropanol as a single solvent or an isopropanol / water (v / v, 4:1) mixture. The emodin and piperazine samples were dissolved in the solvent at a molar ratio of 2:1 at a temperature of 15℃ to 60℃. The total mass of emodin and piperazine to the solid-liquid ratio of organic solvent was 1 mg / mL to 50 mg / mL. The mixture was stirred for 2 h to 24 h and then placed in an environment with a temperature of 20℃ to 40℃ and a relative humidity of 10% to 90% for slow solvent evaporation for 7 to 30 days to obtain crystals of emodin and piperazine eutectic that meet the requirements of single-crystal X-ray diffraction.

10. A mixed solid substance containing a eutectic of emodin and piperazine, characterized in that, The amount of the emodin-piperazine cocrystal as described in any one of claims 1-5 is 1-99.9%, preferably 10-99.9%, more preferably 50-99.9%, and most preferably 85-99.9%.

11. A pharmaceutical composition, characterized in that, The product contains an effective dose of the emodin-piperazine cocrystal of any one of claims 1-5 and a pharmaceutically acceptable carrier.

12. A pharmaceutical composition, characterized in that, The mixed solid substance containing an effective dose of the emodin-piperazine cocrystal as described in claim 10 and a pharmaceutically acceptable carrier.

13. The pharmaceutical composition according to any one of claims 11 or 12, characterized in that, The daily dosage of rhein-piperazine cocrystals ranges from 5 to 3000 mg.

14. The pharmaceutical composition according to any one of claims 11 or 12, characterized in that, The dosage form of the pharmaceutical composition is tablet, capsule, pill, injectable preparation, granule, powder, micro-pellet, drop, suppository, film, patch, aerosol, spray, sustained-release preparation or controlled-release preparation.

15. The use of the emodin-piperazine cocrystal of any one of claims 1-5, or the mixed solid substance containing the emodin-piperazine cocrystal of claim 10, or the pharmaceutical composition of any one of claims 11 or 12, in the preparation of medicaments for the prevention and treatment of bacterial, fungal, and viral infections, as well as for antitumor, antimalarial, diabetes, Alzheimer's disease, and sepsis.

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