Paeoniflorin monohydrate crystalline form A and its preparation method and use

Abstract

The present invention provides paeoniflorin crystalline form A and its preparation method and use. [Solution] This crystalline form A was characterized by means of XRD, IR, DSC, TGA, etc. The powder diffraction pattern of this crystalline form A measured by X-ray powder diffraction using Cu Kα has diffraction peaks at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 13.57°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 20.45°±0.2°, and 25.60°±0.2°. Paeoniflorin crystalline form A of the present invention has low hygroscopicity and good physical stability, making it a preferred crystalline form for medicinal use.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of pharmaceutical solid chemistry, and particularly relates to crystalline form A of paeoniflorin monohydrate and its preparation method and use. [Background technology]

[0002] The chemical name of paeoniflorin is (1aR,2S,3aR,5R,5aR,5bS)-5b-[(benzoyloxy)methyl]tetrahydro-5-hydroxy-2-methyl-2,5-methano-1H-3,4-dioxacyclobuta [cd] pentalen-1a(2H)-yl, and it has the molecular formula C 23 H 28 O 11 Its molecular weight is 480.45 and its chemical structure is as follows: JPEG2026500850000002.jpg59170

[0003] Paeoniflorin is a pinanmonoterpenosides found primarily in the roots of plants in the genus Paeony, including the hair root family Peony, Peony, and Purple Peony. Paeoniflorin possesses a variety of effects, including sedative, anti-inflammatory, analgesic, immunomodulatory, and cognitive improvement, and is widely used in basic research on nervous system and neurodegenerative diseases, such as senile dementia, stroke, depression, and epilepsy. Recent studies have demonstrated that paeoniflorin has potential therapeutic effects against tumors and metastasis in colorectal cancer and angiogenesis-related diseases. Abd El-Aal et al.'s study demonstrated that paeoniflorin possesses anti-angiogenic properties and is a promising therapeutic agent for chronic liver fibrosis and angiogenesis-related diseases, preventing late-stage serious complications, tumors, and metastasis (Exp Parasitol, 2019, 197, 85-92). In addition, literature has shown that paeoniflorin has protective effects against carbon tetrachloride-induced acute liver injury and liver fibrosis (Genomics and Applied Biology, 2018, 37(8):3693-3698) and ischemia-reperfusion-induced liver injury (Am J Transl Res, 2018, 10(3):1012-1021). It also has significant protective effects against rotenone-induced SH-SYSY damage (Chinese Journal of Clinical Pharmacology, 2018, 34(10):1187-1190). It has also been shown to be effective in the prevention and treatment of diabetic nephropathy (DN) and diabetic retinopathy (DR) (Biosci Trends, 2018, 12(2):168-176).

[0004] Paeoniflorin is an amorphous white powder with high hygroscopicity, which easily absorbs moisture during storage, affecting its drug development. Although research into the medicinal uses of paeoniflorin has progressed steadily, research into its polymorphism is relatively slow, and the Cambridge Crystal Database has not included any crystal data for paeoniflorin for many years. Its high water solubility and hygroscopicity are probably the reasons why it is difficult to obtain its crystals.

[0005] Polymorphism is the phenomenon in which a substance exists in two or more solid forms depending on the conformation and arrangement of molecules in the crystal lattice. Polymorphism can be defined in two ways: narrow and broad. In the narrow sense, polymorphism refers to a substance with the same chemical composition but with different molecular arrangements in the crystal. In the broad sense, polymorphism also includes amorphous forms and solvates (pseudopolymorphs). Polymorphism is common in small molecule compounds. Polymorphism also exists and is equally common in active pharmaceutical ingredients (APIs). Different crystalline forms of polymorphic drugs often have different physicochemical properties, such as color, morphology, melting point, density, solubility, and compressibility. These differences in physicochemical properties directly affect a drug's bioavailability, stability, manufacturability, and even quality, safety, and efficacy. Neglecting to address drug crystallinity issues can ultimately lead to serious consequences and potentially hinder drug development.

[0006] Paeoniflorin has poor stability during storage and is highly hygroscopic, so there is a strong need for cultivation. It is necessary to cultivate and discover a crystalline form that can meet the requirements of drug formulation engineering and has good bioavailability and physicochemical stability. Summary of the Invention

[0007] The present inventors comprehensively adopted a new crystal nucleation method and crystallization conditions, and after further research, found a new crystalline form of paeoniflorin, which they named crystalline form A. Research has shown that crystalline form A has low hygroscopicity and good physical stability, which is obviously superior to the known amorphous phase, and is a more suitable pharmaceutical solid form.

[0008] The present invention aims to provide stable crystalline form A of paeoniflorin monohydrate. Specifically, the crystalline form A of paeoniflorin monohydrate of the present invention is characterized in that its X-ray powder diffraction pattern has diffraction peaks at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 13.57°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 20.45°±0.2°, and 25.60°±0.2°.

[0009] In a preferred embodiment, the X-ray powder diffraction pattern of the crystalline form A of paeoniflorin monohydrate further has diffraction peaks at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 10.26°±0.2°, 10.67°±0.2°, 13.57°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 18.72°±0.2°, 20.45°±0.2°, and 25.60°±0.2°.

[0010] Preferably, the X-ray powder diffraction pattern is obtained at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 10.26°±0.2°, 10.67°±0.2°, 13.57°±0.2°, 14.93°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 18.72°±0.2° , 20.45°±0.2°, 21.47°±0.2°, 21.71°±0.2°, 22.28°±0.2°, 24.15°±0.2°, 25.37°±0.2°, 25.60°±0.2°, 27.39°±0.2°, 28.29°±0.2°, 31.20°±0.2°, 32.34°±0.2°, and 32.86°±0.2°.

[0011] Preferably, the X-ray powder diffraction pattern has characteristic diffraction peaks at the following 2θ angles: 6.73°, 7.94°, 10.26°, 10.67°, 13.57°, 14.93°, 15.53°, 15.98°, 17.16°, 17.62°, 18.72°, 20.45°, 21.47°, 21.71°, 22.28°, 24.15°, 25.37°, 25.60°, 27.39°, 28.29°, 31.20°, 32.34°, and 32.86°.

[0012] In a preferred embodiment, crystalline form A is monoclinic, the space group is P21, the unit cell parameters are a=11.0212(3) Å, b=8.4530(2) Å, c=12.9201(3) Å, α=90°, β=92.0860°, γ=90°, and the unit cell volume is 1202.87 Å. 3 is.

[0013] In other words, the crystalline form A of paeoniflorin monohydrate provided by the present invention has an XRPD pattern substantially as shown in FIG.

[0014] In a preferred embodiment, it is monoclinic, the space group is P21, the unit cell parameters are a=11.0212(3) Å, b=8.4530(2) Å, c=12.9201(3) Å, α=90°, β=92.0860°, γ=90°, and the unit cell volume is 1202.87 Å. 3 is.

[0015] In a preferred embodiment, the differential scanning calorimetry analysis graph has characteristic endothermic peaks at 125.8°C ± 3.00°C, preferably the differential scanning calorimetry analysis graph is substantially as shown in Figure 2, preferably the thermal weight loss analysis graph is substantially as shown in Figure 3, and preferably the infrared spectrum (IR) graph is substantially as shown in Figure 4.

[0016] The present invention provides a method for preparing the crystalline form A of paeoniflorin monohydrate, which is characterized by being one of the following methods:

[0017] Method (1) Cooling method: Paeoniflorin is dissolved in a solvent within the temperature range of 20 to 90°C, and then the solution is gradually cooled to 0 to 19°C to obtain a suspension, and the solvent is removed to obtain the crystalline form A of paeoniflorin monohydrate; or Paeoniflorin is dissolved in a solvent within the temperature range of 20 to 90°C, and the solvent is gradually evaporated and removed at room temperature to obtain the crystalline form A of paeoniflorin monohydrate.

[0018] Method (2) Suspension method: Add an excess amount of paeoniflorin to a solvent at 25-50°C, suspend for 8-96 hours, and then centrifuge the resulting suspension to obtain a lower solid, which is crystalline form A; or, centrifuge the suspension and evaporate the resulting supernatant at 25-90°C to obtain crystalline form A of paeoniflorin monohydrate.

[0019] The solvent used in methods (1) and (2) is preferably one or more selected from the group consisting of dichloromethane, chloroform, diethyl ether, n-hexane, n-heptane, methyl isobutyl ketone, and tetrahydrofuran, and more preferably dichloromethane or chloroform.

[0020] The present invention provides a pharmaceutical composition comprising a therapeutically effective amount of paeoniflorin monohydrate crystalline form A according to any one of claims 1 to 5 and a pharmaceutically acceptable carrier. Specifically, the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of paeoniflorin monohydrate crystalline form A and pharmaceutical adjuvants. Typically, a pharmaceutical composition or formulation is prepared by mixing or contacting a therapeutically effective amount of paeoniflorin monohydrate crystalline form A with one or more pharmaceutical adjuvants, and the pharmaceutical composition or formulation is prepared by a method well known in the pharmaceutical art.

[0021] The pharmaceutical composition can be formulated into a predetermined dosage form and administered by a suitable route. For example, it can be administered orally, parenterally (including subcutaneously, intramuscularly, intravenously, or intradermally), rectally, transdermally, intranasally, or intravaginally. Dosage forms suitable for oral administration include tablets, capsules, granules, powders, pills, powders, lozenges, solutions, syrups, or suspensions, which are suitable for immediate release, delayed release, or controlled release of the active pharmaceutical ingredient as needed; dosage forms suitable for parenteral administration include aqueous or non-aqueous sterile injection solutions, emulsions, or suspensions; dosage forms suitable for rectal administration include suppositories or enemas; dosage forms suitable for transdermal administration include ointments, creams, and patches; dosage forms suitable for nasal administration include aerosols, sprays, and nasal drops; dosage forms suitable for vaginal administration include suppositories, tampons, gels, pastes, or sprays. Preferably, the crystalline forms of the present invention have surprisingly low hygroscopicity and stability in water or aqueous ethanol solutions, making them suitable for preparation into tablets, suspensions, capsules, disintegrating tablets, immediate release, sustained release and controlled release tablets; more preferably tablets, suspensions and capsules.

[0022] Pharmaceutically acceptable excipients in the pharmaceutical compositions, in the case of solid oral dosage forms, include, but are not limited to, diluents such as starch, pregelatinized starch, lactose, powdered cellulose, microcrystalline cellulose, calcium hydrogen phosphate, tricalcium phosphate, mannitol, sorbitol, and sugars; binders such as gum arabic, guar gum, gelatin, polyvinylpyrrolidone, hydroxypropyl cellulose, hydroxypropyl methylcellulose, and polyethylene glycol; disintegrants such as starch, sodium starch glycolate, pregelatinized starch, crospovidone, croscarmellose sodium, and colloidal silicon dioxide; lubricants such as stearic acid, magnesium stearate, zinc stearate, sodium benzoate, and sodium acetate; glidants such as colloidal silicon dioxide; complexing agents such as various grades of cyclodextrins and resins; and release rate modifying agents such as hydroxypropyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, methyl cellulose, methyl methacrylate, and waxes. Other useful pharmaceutically acceptable excipients include, but are not limited to, film-forming agents, plasticizers, colorants, flavoring agents, viscosity modifiers, preservatives, antioxidants, etc. Tablets may be coated with a coating layer, for example, a shellac barrier coating, a sugar coating, or a polymer coating, and the polymer in the coating layer, for example, hydroxypropylmethylcellulose, polyvinyl alcohol, ethylcellulose, methacrylic polymers, hydroxypropylcellulose, or starch, may also contain anti-adherents such as silica, talc, opacifying agents such as titanium dioxide, and colorants such as iron oxide colorants. For liquid oral dosage forms, suitable excipients include water, oils, alcohols, glycols, flavoring agents, preservatives, stabilizers, colorants, etc.; aqueous or non-aqueous sterile suspensions may contain suspending agents and thickeners; suitable excipients for aqueous suspensions include synthetic or natural gums, for example, gum arabic, xanthan gum, alginates, dextran, sodium carboxymethylcellulose, methylcellulose, polyvinylpyrrolidone, or gelatin.For parenteral administration, the excipient of water or non-aqueous sterile injection solution is generally sterile water, physiological saline or aqueous glucose solution, and may contain buffers, antioxidants, bacteriostatic agents, and solutes that can make the pharmaceutical composition isotonic with blood. Each excipient must be acceptable, compatible with other ingredients in the formulation, and not harmful to the patient. When used to prepare emergency medication for stroke treatment, powder injections are preferred.

[0023] Pharmaceutical compositions can be prepared by methods well known to those skilled in the art.When preparing pharmaceutical compositions, crystalline form A of the present invention is mixed with one or several pharmaceutically acceptable excipients, and optionally mixed with one or several other pharmaceutically active ingredients.For example, tablets, capsules, granules can be prepared by processes such as mixing, granulating, tableting or capsule filling; powders are prepared by mixing the pharmacoactive ingredients and excipients that are finely divided into suitable sizes; solutions and syrups can be prepared by dissolving the pharmacoactive ingredients in suitable flavored water or aqueous solution; suspensions can be prepared by dispersing the pharmacoactive ingredients in pharmacoactive carriers. In particular, the wet granulation method for solid preparations, such as tablet wet granulation, involves mixing dry solids such as active ingredients, fillers, and binders, wetting them with, for example, water or alcohol, forming the wet solids into agglomerates or granules, continuing the wet granulation until a desired uniform particle size is obtained, and then drying the granules. The resulting dried granules are then mixed with disintegrants, lubricants, anti-adherents, etc., and compressed into tablets using a tablet press; if necessary, they are coated with an appropriate coating powder.

[0024] The present invention provides use of the crystalline form A of paeoniflorin monohydrate in the preparation of a medicament for inflammation-related or nervous system diseases, including but not limited to senile dementia, Parkinson's disease, epilepsy, Huntington's chorea, stroke, depressive pain, acute myocardial ischemia, atherosclerosis, acute liver injury and liver fibrosis, diabetic nephropathy and diabetic retinopathy, etc.

[0025] It has been reported that paeoniflorin has a definite anti-inflammatory effect and can reduce the occurrence of inflammatory storm, which can reduce the damage to the body caused by inflammatory storm, including but not limited to acute cerebral ischemia, inflammatory storm caused by new coronavirus, etc. Therefore, the present invention provides the use of the above-mentioned paeoniflorin monohydrate crystalline form A in the preparation of a drug for inflammatory storm-related diseases. [Effects of the Invention]

[0026] The present invention has the following excellent technical effects compared to the prior art. Although the inventors have obtained several crystalline forms of paeoniflorin in the laboratory, the original experimental files are kept in the applicant's experimental files. The other crystalline forms of paeoniflorin are significantly different from the crystalline form A provided by the present invention in terms of both excellent hygroscopicity and solubility, so the specific parameters of these crystalline forms are not described herein. Among all the crystalline forms, the crystalline form A provided by the present invention has good stability and low hygroscopicity, which can effectively prevent crystal transformation during drug storage and development, and can prevent changes in bioavailability and efficacy. At the same time, the crystalline form A provided by the present invention has high solubility, meets the requirements of bioavailability and efficacy, and can be appropriately prepared into aqueous or powder formulations, which can be used for emergency use. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is an X-ray powder diffraction (XRPD) pattern of crystalline form A of paeoniflorin monohydrate in Example 1. [Figure 2] 1 is a graph of differential scanning calorimetry (DSC) of crystalline form A of paeoniflorin monohydrate in Example 1. [Figure 3] 1 is a graph of thermogravimetric analysis (TG) of crystalline form A of paeoniflorin monohydrate in Example 1. [Figure 4] 1 is an infrared spectroscopy (IR) graph of crystalline form A of paeoniflorin monohydrate in Example 1. [Figure 5]FIG. 1 is a crystal structure diagram of crystalline form A of paeoniflorin monohydrate. [Figure 6] FIG. 1 is a comparison diagram of X-ray powder diffraction (XRPD) between crystalline form A and amorphous paeoniflorin monohydrate. [Figure 7] FIG. 1 is a comparison diagram of the hygroscopicity of crystalline form A of paeoniflorin monohydrate and amorphous form in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The compounds of the present invention can be prepared by various synthetic methods known to those skilled in the art, including the specific embodiments listed below, embodiments obtained by combining other chemical synthetic methods with them, and equivalent alternative forms known to those skilled in the art. Preferred embodiments include, but are not limited to, the examples of the present invention. It is obvious that those skilled in the art can make modifications and improvements to the embodiments without departing from the spirit of the present invention.

[0029] As used herein, the term "therapeutically effective amount" or "therapeutically effective amount" is that amount of an active compound or agent that elicits the biological or medical response that a researcher, veterinarian, physician, or other clinician desires in a tissue, system, animal, individual, or human.

[0030] The term "treatment" as used herein refers to one or more of the following: (1) disease prevention: e.g., preventing a disease, condition, or disorder in a subject who is predisposed to the disease, condition, or disorder but who has not yet contracted or manifested the disease, condition, or disorder; (2) disease inhibition: e.g., inhibiting a disease, condition, or disorder in a subject who has or manifests the disease, condition, or disorder; and (3) disease amelioration: e.g., improving a disease, condition, or disorder (i.e., reversing the pathology and / or symptoms), e.g., reducing the severity of the disease, in a subject who has or manifests the disease, condition, or disorder.

[0031] As used herein, the term "polymorphism" refers to different crystalline forms of the same compound, including, but not limited to, other solid molecular forms, including hydrates and solvates of the same compound. The phenomenon in which the same drug molecule forms multiple crystalline forms is called drug polymorphism, and drug polymorphism is a common phenomenon observed in solid drugs. Drug compounds with such polymorphism are known to affect pharmacological activity, solubility, bioavailability, stability, etc., due to differences in their physicochemical properties. Therefore, when polymorphism exists for a compound useful as a pharmaceutical, it is desirable to produce a highly useful crystalline compound from among these polymorphs.

[0032] As used herein, the term "X-ray powder diffraction pattern" refers to an experimentally observed diffraction pattern or parameters derived therefrom. An X-ray powder diffraction pattern is characterized by peak positions and peak intensities.

[0033] The terms "crystal" or "crystal form" as used herein refer to a crystal characterized by an X-ray diffraction pattern. Those skilled in the art will understand that the physicochemical properties discussed herein are characterized, and that experimental error depends on instrument conditions, sample preparation, and sample purity. In particular, those skilled in the art know that X-ray diffraction patterns vary depending on instrument conditions. In particular, the relative intensities of X-ray diffraction patterns may also change with changes in experimental conditions, so the order of peak intensities cannot be the sole or decisive factor. Furthermore, experimental error in peak angles is typically 5% or less, and errors in these angles should also be considered, with an error of ±0.2° typically being tolerated. Peak angles generally shift due to experimental factors such as sample height, but a certain degree of shift is usually tolerated. Therefore, those skilled in the art will understand that the X-ray diffraction pattern of the crystalline form of the present invention does not necessarily have to be completely identical to the X-ray diffraction patterns of the examples described herein. Any crystalline form having the same or similar characteristic peaks in these patterns is within the scope of the present invention. One skilled in the art can compare the patterns described in this invention with the pattern of one unknown crystalline form to confirm that the two patterns reflect the same crystalline form or different crystalline forms.

[0034] The following preparation examples are provided below to further illustrate the present invention, but the scope of the present invention is not limited thereto. The methods and apparatus used in the present invention are conventional methods and apparatuses in the art unless otherwise specified.

[0035] The experimental conditions for the present invention are as follows.

[0036] The present invention relates to a novel crystalline form A of paeoniflorin, characterized by solid-state methods such as X-ray powder diffraction (XRPD), thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy (IR), and single crystal X-ray diffraction (SCXRD).

[0037] XRPD analysis: A Bruker D8 advance diffractometer (Bruck Instruments, Germany) was used for detection at room temperature, employing Cu Kα radiation (λ=1.5418 Å), scanning from 3 to 40 degrees as the 2θ angle, and a scanning speed of 0.1° / s.

[0038] In the powder X-ray powder diffraction pattern of a sample, the diffraction pattern obtained from a specific crystalline form tends to be characteristic. Differences in crystallization conditions, particle size, relative content of the mixture, and other test conditions can cause preferred orientation effects in the diffraction pattern, resulting in changes in the relative intensity of certain bands (especially at low angles) in the spectrum. Therefore, the relative intensity of diffraction peaks is not specific to the target crystal, and when determining whether a known crystalline form is identical, attention should be paid to the peak position rather than the relative intensity. Furthermore, when determining whether a crystalline form is identical, it is important to keep in mind the overall concept, since a specific "dI / I1" data set represents a single phase, rather than a single diffraction line. Furthermore, when identifying a mixture, if some diffraction lines are missing due to a decrease in content, it is not necessary to rely on all of the bands observed in the high-purity sample; even a single band may be characteristic of a given crystal.

[0039] DSC analysis: Measured using a PerkinElmer DSC8500 differential scanning calorimeter in a nitrogen atmosphere at a heating rate of 10°C / min.

[0040] TG analysis: Using a Netzsch TG209F3 thermogravimetric analyzer manufactured by NETZSCH, Germany, temperature range: 30 to 400°C, scanning rate: 10°C / min, purge gas: 25 mL / min.

[0041] IR analysis: Nicolet-Magna FT-IR750 infrared spectrometer from Nicolet, USA, was used at room temperature from 4000 cm to 350 cm -1 The wave number was detected.

[0042] SCXRD analysis: All single crystal X-ray diffraction (SCXRD) experimental data in this study were measured using a Bruker D8 Venture X-ray single crystal diffractometer manufactured by Bruker Instruments, Inc. Measurement conditions: graphite monochromator, Cu-Kα radiation (λ = 1.54178 Å); temperature: room temperature (296 K); voltage: 50 kV; current: 30 mA.

[0043] DVS analysis: All dynamic moisture sorption analyses (SCXRD) in this study were performed using a DVS advantage type sorption meter manufactured by SMS, UK, with a relative humidity range of 0-95% and a temperature of 25°C.

[0044] Specific examples of the preparation method and performance test of crystalline form A of the present invention are described below. [Example]

[0045] 1 g of paeoniflorin (self-prepared in the laboratory, lot number 98%PF_20180930, purity ≥ 98%) was homogeneously mixed with 40 mL of ethyl acetate and stirred with a magnetic stirrer at 800 rpm at 50°C. Complete dissolution was achieved by cooling to 4°C while continuing to stir. The suspension was obtained, filtered, and dried under reduced pressure at room temperature. 0.91 g of crystalline form A was obtained as a white-off-white crystalline powder, with a yield of 91%.

[0046] The X-ray powder diffraction (XRPD) pattern of the crystalline form A of paeoniflorin monohydrate in Example 1 is shown in Figure 1; the thermogravimetric analysis (TG) graph is shown in Figure 2; the differential scanning calorimetry (DSC) graph is shown in Figure 3; and the infrared spectroscopy (IR) graph is shown in Figure 4. The water of crystallization is derived from water molecules in the air or solvent.

[0047] When examined by a single crystal X-ray diffractometer, the crystalline form A of paeoniflorin monohydrate in Example 1 is a monoclinic crystal, the space group is P21, the unit cell parameters are a = 11.0212(3) Å, b = 8.4530(2) Å, c = 12.9201(3) Å, α = 90°, β = 92.0860°, γ = 90°, and the volume of the unit cell is 1202.87 Å. 3 is.

[0048] Crystalline Form A is very stable after 15 days of accelerated storage in a stability cabinet (40°C / 75%RH) without converting to amorphous or other crystalline forms.

[0049] According to TG and DSC, the phase transition and weight loss temperatures are both above 100°C, indicating excellent thermal stability.

[0050] Crystal form A has low hygroscopicity, does not cause wet blocking, and has good powder performance and fluidity.

[0051] Crystalline form A has good water solubility, exceeding 20 mg / mL in water, and is readily soluble. [Example]

[0052] 1 g of paeoniflorin was homogeneously mixed with 10 mL of methyl ethyl ketone, and the mixture was stirred using a magnetic stirrer at a rotation speed of 800 rpm at room temperature for 12 hours to obtain a suspension, which was then filtered and dried under reduced pressure at 20-30°C. The obtained crystalline form A was 0.93 g of a white to off-white crystalline powder, with a yield of 93%.

[0053] The X-ray powder diffraction (XRPD) pattern of the resulting product is similar to FIG. [Example]

[0054] 1 g of paeoniflorin was homogeneously mixed with 10 mL of methyl ethyl ketone / n-hexane (v / v, 1:1), stirred with a magnetic stirrer at 800 rpm, and suspended at room temperature for 12 hours to obtain a suspension, which was then filtered and dried under reduced pressure at 20-30°C. The resulting crystalline form A was a white-off-white crystalline powder (0.96 g) with a yield of 96%.

[0055] The X-ray powder diffraction (XRPD) pattern of the resulting product is similar to FIG. [Example]

[0056] 1 g of paeoniflorin was homogenously mixed with 10 mL of tetrahydrofuran / n-heptane (v / v, 1:1), stirred with a magnetic stirrer at 800 rpm, and suspended at room temperature for 12 hours to obtain a suspension, which was filtered and dried under reduced pressure at 20-30°C. The resulting crystalline form A was 0.95 g of a white to off-white crystalline powder, with a yield of 95%.

[0057] The X-ray powder diffraction (XRPD) pattern of the resulting product is similar to FIG. [Example]

[0058] 500 mg of paeoniflorin was added to 20 mL of acetonitrile / n-hexane (v / v, 1:1), stirred with a magnetic stirrer at 600 rpm, and heated to 50°C until completely dissolved. The mixture was gradually evaporated at 20-30°C and dried under reduced pressure. The resulting crystalline form A was 401 mg of a white-off-white crystalline powder, with a yield of 80%.

[0059] The X-ray powder diffraction (XRPD) pattern of the resulting product is similar to FIG. [Example]

[0060] 500 mg of paeoniflorin was added to 20 mL of acetonitrile / dichloromethane (v / v, 1:1), stirred with a magnetic stirrer at 600 rpm, and heated to 50°C until completely dissolved. The mixture was gradually evaporated at 20-30°C and dried under reduced pressure. The resulting crystalline form A was 405 mg of a white-off-white crystalline powder, with a yield of 81%.

[0061] The X-ray powder diffraction (XRPD) pattern of the resulting product is similar to FIG. [Example]

[0062] [Hygroscopicity comparison test] Using commercially available paeoniflorin (Aladdin, Lot No. K2011169, purity ≥ 98%) as amorphous powder, a comparison of the X-ray powder diffraction pattern of crystalline form A of the present invention is shown in Figure 6, and a comparison of the moisture absorption analysis pattern of crystalline form A of the present invention is shown in Figure 7. As shown in Figure 7, the amorphous form adsorbs 11.1% of water at 80% RH, showing hygroscopicity, while crystalline form A of paeoniflorin monohydrate of the present invention adsorbs only 0.3% of water at 80% RH.

[0063] Conclusion: The crystalline form A of paeoniflorin of the present invention has significantly lower hygroscopicity than amorphous form, significantly reducing the storage and transportation costs of paeoniflorin. Crystalline form A does not form wet agglomerates and has good powder flowability, which is convenient for formulation engineering and advantageous for quality control and dosage control in formulation engineering. Generally, readily soluble crystalline forms have a certain degree of hygroscopicity. Crystalline form A provided by the present invention, even with low hygroscopicity, exhibits high solubility in water and can be formulated into emergency powder injections. The inventors have also obtained other crystalline forms of paeoniflorin in the laboratory. Because these forms differ significantly from crystalline form A provided by the present invention in terms of their excellent hygroscopicity and solubility, the specific parameters of these crystalline forms are not described herein.

[0064] The crystalline form A of the present invention exhibits various advantageous physicochemical properties and is an ideal pharmaceutical crystalline form.

Claims

1. Crystalline form A of paeoniflorin monohydrate is characterized in that the X-ray powder diffraction pattern has diffraction peaks at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 13.57°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 20.45°±0.2°, and 25.60°±0.2°.

2. The X-ray powder diffraction pattern of the crystalline form A of paeoniflorin monohydrate further has diffraction peaks at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 10.26°±0.2°, 10.67°±0.2°, 13.57°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 18.72°±0.2°, 20.45°±0.2°, and 25.60°±0.2°; Preferably, the X-ray powder diffraction pattern is obtained at the following 2θ angles: 6.73°±0.2°, 7.94°±0.2°, 10.26°±0.2°, 10.67°±0.2°, 13.57°±0.2°, 14.93°±0.2°, 15.53°±0.2°, 15.98°±0.2°, 17.16°±0.2°, 17.62°±0.2°, 18.72°±0.2°, 20.45°±0.2°, 21. Crystalline form A of paeoniflorin monohydrate according to claim 1, characterized in that it has characteristic diffraction peaks at 47°±0.2°, 21.71°±0.2°, 22.28°±0.2°, 24.15°±0.2°, 25.37°±0.2°, 25.60°±0.2°, 27.39°±0.2°, 28.29°±0.2°, 31.20°±0.2°, 32.34°±0.2°, and 32.86°±0.2°.

3. It is a monoclinic crystal, the space group is P21, the unit cell parameters are a = 11.0212(3) Å, b = 8.4530(2) Å, c = 12.9201(3) Å, α = 90°, β = 92.0860°, γ = 90°, and the unit cell volume is 1202.87 Å. ３ 2. The crystalline form A according to claim 1, wherein

4. The XRPD pattern of paeoniflorin monohydrate crystalline form A is substantially as shown in FIG.

5. It is a monoclinic crystal, the space group is P21, the unit cell parameters are a = 11.0212(3) Å, b = 8.4530(2) Å, c = 12.9201(3) Å, α = 90°, β = 92.0860°, γ = 90°, and the unit cell volume is 1202.87 Å. ３ The crystalline form A according to any one of claims 1 to 4, wherein

6. 6. Crystalline Form A according to any one of claims 1 to 5, wherein a differential scanning calorimetry analysis graph has characteristic endothermic peaks at 125.8°C ± 3.00°C, preferably a differential scanning calorimetry analysis graph substantially as shown in Figure 2, preferably a thermal weight loss analysis graph substantially as shown in Figure 3, and preferably an infrared spectrum (IR) graph substantially as shown in Figure 4.

7. 6. A method for preparing the crystalline form A of paeoniflorin monohydrate according to any one of claims 1 to 5, wherein the preparation method is one of the following methods: Method (1) Cooling method: Paeoniflorin is dissolved in a solvent at a temperature of 20-90°C, and then the solution is gradually cooled to 0-19°C to obtain a suspension, and the solvent is removed to obtain the crystalline form A of paeoniflorin monohydrate; or Paeoniflorin is dissolved in a solvent at a temperature of 20-90°C, and the solvent is gradually evaporated and removed at room temperature to obtain the crystalline form A of paeoniflorin monohydrate; Method (2) Suspension method: adding an excess amount of paeoniflorin to a solvent at 25-50°C, suspending for 8-96 hours, and then centrifuging the resulting suspension to obtain a lower solid, which is crystalline form A; or centrifuging the suspension and volatilizing the resulting supernatant at 25-90°C to obtain crystalline form A of paeoniflorin monohydrate. The solvent used in methods (1) and (2) is preferably one or more selected from the group consisting of dichloromethane, chloroform, diethyl ether, n-hexane, n-heptane, methyl isobutyl ketone, and tetrahydrofuran.

8. A pharmaceutical composition comprising a therapeutically effective amount of crystalline form A of paeoniflorin monohydrate according to any one of claims 1 to 5 and a pharmaceutically acceptable carrier.

9. Use of crystalline form A of paeoniflorin monohydrate according to any one of claims 1 to 5 in the preparation of a drug for inflammation-related or nervous system diseases, including but not limited to senile dementia, Parkinson's disease, epilepsy, Huntington's chorea, stroke, depressive pain, acute myocardial ischemia, atherosclerosis, acute liver injury and liver fibrosis, diabetic nephropathy and diabetic retinopathy, etc.

10. Use of the crystalline form A of paeoniflorin monohydrate according to any one of claims 1 to 5 in the preparation of a medicament for diseases associated with inflammatory storm.

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