Dihydroquercetin and pyridinecarboxylic acid cocrystal, its preparation method, pharmaceutical composition, and uses.

Abstract

This invention belongs to the field of pharmaceutical technology and discloses a cocrystal of dihydroquercetin and pyridinecarboxylic acid, its preparation method, composition, and uses. Specifically, this invention discloses a novel dihydroquercetin and pyridinecarboxylic acid cocrystal using dihydroquercetin (as shown in formula a) as the active pharmaceutical ingredient and pyridinecarboxylic acid (as shown in formula b) as the cocrystal ligand; a method for preparing the dihydroquercetin and pyridinecarboxylic acid cocrystal; and the application of the dihydroquercetin and pyridinecarboxylic acid cocrystal as the active pharmaceutical ingredient in the preparation of antioxidants, free radical scavengers, cell protectants, and antivirals.

Description

Technical Field

[0001] This invention discloses a cocrystal of dihydroquercetin and pyridinecarboxylic acid, its preparation method, its composition, and its uses. Specifically, this invention discloses a cocrystal formed by dihydroquercetin and pyridinecarboxylic acid; a method for preparing the dihydroquercetin and pyridinecarboxylic acid cocrystal; and the application of the dihydroquercetin and pyridinecarboxylic acid cocrystal as a pharmaceutical active ingredient in the preparation of antioxidant, free radical scavenging and cell protection, antiviral, antidiabetic, and antitumor drugs, belonging to the field of pharmaceutical technology. Background Technology

[0002] Dihydroquercetin (Taxifolin), with the molecular formula C2... 15 H 12 O7, with the molecular structure shown in a. Dihydroquercetin is a dihydroflavonol compound belonging to the P group of vitamins. It is also known as (2R,3R)-3,3',4',5,7-pentahydroxyflavone, taxol, and piperidine, and is widely found in larch, Douglas fir, and Scots pine. It possesses various pharmacological effects, including antioxidant, antitumor, anti-apoptotic, anti-inflammatory, cardioprotective, hypoglycemic, vascular endothelial cell function improvement, antiplatelet aggregation, and bone metabolism influencing properties. [1-4] It also has a good protective effect on the liver and a positive protective effect against brain injury caused by reperfusion, and has received increasing attention in recent years. However, due to its poor water solubility and low bioavailability, it cannot be widely used in clinical applications. (Wu Weiwei) [5] The solubility of dihydroquercetin was improved by preparing dihydroquercetin nanoparticles and dihydroquercetin-γ-cyclodextrin inclusion complexes. Literature review revealed that two crystalline forms (I and II) of dihydroquercetin have been reported. [6] Crystal form I is dihydroquercetin dipentahydrate, whose crystal structure has been reported. Crystal form II of dihydroquercetin is a hydrate, but its crystal structure has not yet been reported. This invention is based on the principles of crystal engineering, using dihydroquercetin as the active pharmaceutical ingredient (API) and pyridinecarboxylic acid as a cocrystal former (CCF). The molecular formula of pyridinecarboxylic acid is C6H5NO2, and its structural formula is shown in b.

[0003]

[0004] A search of domestic and international patents and literature revealed no reports of cocrystals of dihydroquercetin and pyridinecarboxylic acid. Summary of the Invention

[0005] One of the objectives of this invention is to provide the state and description of the co-crystal of dihydroquercetin and pyridinecarboxylic acid.

[0006] The second objective of this invention is to provide a method for preparing a cocrystal of dihydroquercetin and pyridinecarboxylic acid.

[0007] The third objective of this invention is to provide a pure product containing a cocrystal of dihydroquercetin and pyridinecarboxylic acid, or a mixed solid drug and its composition containing any non-zero proportion of a cocrystal of dihydroquercetin and pyridinecarboxylic acid.

[0008] The fourth objective of this invention is to provide a pharmaceutical composition using a cocrystal of dihydroquercetin and pyridinecarboxylic acid as the active pharmaceutical ingredient, with a daily dosage ranging from 5 to 3000 mg. The pharmaceutical composition includes tablets, capsules, pills, injectable formulations, sustained-release or controlled-release formulations.

[0009] The fifth objective of this invention is to provide a cocrystal of dihydroquercetin and pyridinecarboxylic acid that exhibits significantly superior solubility compared to dihydroquercetin alone.

[0010] The sixth objective of this invention is to provide a raw material for the use of dihydroquercetin and pyridinecarboxylic acid cocrystal and mixed solid substances containing dihydroquercetin and pyridinecarboxylic acid cocrystal as active pharmaceutical ingredients, and its application in the preparation of antioxidant, free radical scavenging and cell protection, antiviral, antidiabetic and antitumor drugs.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] 1. Morphological characteristics of the dihydroquercetin / pyridinecarboxylic acid cocrystal sample:

[0013] 1.1 The dihydroquercetin-pyridinecarboxylic acid co-crystal of the present invention is formed by dihydroquercetin and pyridinecarboxylic acid in a molar ratio of 1:1.

[0014] 1.2 The dihydroquercetin-pyridinecarboxylic acid 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: α = 90°, β = 103.423°, γ = 90°. Unit cell volume. Molecular formula MF=C 15 H 12 O7·C6H5NO2. (Attached) Figure 1 Provide a projected molecular stereostructure diagram of the cocrystal of dihydroquercetin and pyridinecarboxylic acid, with appended diagrams. Figure 2 The unit cell packing diagram along the a-axis of the dihydroquercetin-pyridinecarboxylic acid cocrystal is given, and Table 1 gives the coordinate parameters of the non-hydrogen atoms in the dihydroquercetin-pyridinecarboxylic acid cocrystal.

[0015] Table 1. Coordinate parameters of non-hydrogen atoms in the dihydroquercetin-pyridinecarboxylic acid cocrystal.

[0016]

[0017] 1.3 The dihydroquercetin and pyridinecarboxylic acid cocrystal involved in this invention, when analyzed using powder X-ray diffraction with CuK... α Under radiation experimental conditions, the diffraction peak position is determined by the 2-Theta value (°) or d value. The relative intensity peak height (Height%) or peak area (Area%) of diffraction peaks is represented as follows (Table 2, Figure 3 The theoretical powder diffraction pattern, experimental powder diffraction pattern, and superimposed powder X-ray diffraction pattern of the dihydroquercetin / pyridinecarboxylic acid cocrystal are shown in the figure. Figure 4 As shown. By Figure 4 It can be seen that the PXRD pattern of the dihydroquercetin-pyridinecarboxylic acid cocrystal is different from that of dihydroquercetin and pyridinecarboxylic acid alone, indicating that a new phase has been formed. Furthermore, the theoretical powder pattern of the dihydroquercetin-pyridinecarboxylic acid cocrystal is basically consistent with the experimental powder pattern, indicating that the obtained dihydroquercetin-pyridinecarboxylic acid cocrystal is a pure crystal.

[0018] Table 2. Powder X-ray diffraction peak values ​​of the dihydroquercetin / pyridinecarboxylic acid cocrystal sample.

[0019]

[0020] 1.4 The dihydroquercetin / pyridinecarboxylic acid cocrystal of the present invention, when analyzed using attenuated total reflectance Fourier transform infrared spectroscopy, showed the following values ​​at 3672, 3421, 3086, 2987, 2884, 2723, 2630, 2161, 1661, 1627, 1594, 1521, 1472, 1444, 1388, 1358, 1293, 1271, 1210, 1188, 1154, 1142, 1082, 1027, 1010, 996, 952, 861, 823, 814, 783, 758, 685, and 669 cm⁻¹ -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 ).

[0021] 1.5 The dihydroquercetin-pyridinecarboxylic acid cocrystal of the present invention, when analyzed by differential scanning calorimetry (DSC), exhibits an endothermic peak at 218℃±3℃ in its DSC spectrum within the temperature range of 30–270℃ at a heating rate of 10℃ per minute. A comparative DSC spectrum of dihydroquercetin, pyridinecarboxylic acid, and the dihydroquercetin-pyridinecarboxylic acid cocrystal is shown below. Figure 6 The DSC spectra of the dihydroquercetin / pyridinecarboxylic acid cocrystal differ significantly from those of dihydroquercetin and pyridinecarboxylic acid in terms of the number and position of endothermic / exothermic peaks, indicating that the dihydroquercetin / pyridinecarboxylic acid cocrystal is a new cocrystal material.

[0022] 2. Characteristics of the preparation methods for dihydroquercetin and pyridinecarboxylic acid eutectic and mixed solid substances:

[0023] 2.1 The present invention relates to a method for preparing a eutectic of dihydroquercetin and pyridinecarboxylic acid, wherein dihydroquercetin and pyridinecarboxylic acid are fed in a 1:1 molar ratio, and dihydroquercetin-pyridinecarboxylic acid is prepared by a mechanochemical method. The mechanochemical method is preferably a liquid-addition ball milling method, wherein the ball-to-material ratio in the liquid-addition ball milling method is 1:1 to 10:1, preferably 4:1 to 6:1; the ball milling speed is 20 r / min to 400 r / min; the organic solvent added is selected from any one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, isoamyl alcohol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane, and cyclohexane, combined in different proportions to form a mixed solvent; the amount of solvent added is 0.01 to 100 ml; and the milling time is 0.1 to 10 hours.

[0024] 2.2 The present invention relates to a method for preparing a cocrystal of dihydroquercetin and pyridinecarboxylic acid, wherein dihydroquercetin and pyridinecarboxylic acid are added to a clean container in a molar ratio of 1:1, and an organic solvent is added to form a suspension. The suspension is stirred at room temperature for 0.5 to 4 days. The obtained suspension is dried by solvent evaporation, filtration and natural drying, or filtration and vacuum drying to obtain the cocrystal of dihydroquercetin and pyridinecarboxylic acid. The organic solvent is preferably a mixed solvent prepared by combining one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, isoamyl alcohol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane, and cyclohexane in different proportions; the total mass of dihydroquercetin and pyridinecarboxylic acid to the solid-liquid ratio of the organic solvent is maintained within the range of 1 mg / ml to 500 mg / ml.

[0025] 2.3 The present invention relates to a method for preparing a co-crystal of dihydroquercetin and pyridinecarboxylic acid, wherein dihydroquercetin and pyridinecarboxylic acid are fed in a 1:1 molar ratio, and a solution crystallization method is used to prepare the co-crystal of dihydroquercetin and pyridinecarboxylic acid. The solvent used in the solution crystallization method is any one or more organic solvents combined in different proportions to form a mixed solvent; the organic solvent is selected from any one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, isoamyl alcohol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane, and cyclohexane combined in different proportions to form a mixed solvent; the crystallization temperature is 4-60℃, and the crystallization time is 12h-30d.

[0026] 2.4 The mixed solid material containing dihydroquercetin and pyridinecarboxylic acid cocrystal and other components involved in this invention is prepared by mixing the dihydroquercetin and pyridinecarboxylic acid cocrystal component obtained by the above method with other chemical components in any non-zero proportion and by conventional methods.

[0027] 3. Characteristics of the dihydroquercetin / pyridinecarboxylic acid cocrystal composition, dosage, and pharmaceutical formulation:

[0028] 3.1 The pharmaceutical composition of the present invention is characterized by containing an effective dose of a cocrystal of dihydroquercetin and pyridinecarboxylic acid, or a mixed solid substance containing a cocrystal of dihydroquercetin and pyridinecarboxylic acid and a pharmaceutically acceptable carrier.

[0029] 3.2 The pharmaceutical composition of the present invention uses dihydroquercetin and pyridinecarboxylic acid cocrystal as the active pharmaceutical ingredient, and the daily dosage is in the range of 5 to 3000 mg.

[0030] 3.3 The pharmaceutical composition of the present invention is characterized in that the pharmaceutical composition is various tablets, capsules, pills, injectable preparations, sustained-release preparations or controlled-release preparations.

[0031] 3.4 This invention relates to the application of dihydroquercetin and pyridinecarboxylic acid cocrystals or mixed solid substances containing dihydroquercetin and pyridinecarboxylic acid cocrystals in any proportion in the preparation of antioxidant, free radical scavenging and cell protection, antiviral, antidiabetic and antitumor drugs.

[0032] This invention relates to pharmaceutical compositions using the dihydroquercetin and pyridinecarboxylic acid cocrystal of this 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 dihydroquercetin and pyridinecarboxylic acid cocrystal of this invention with one or more pharmaceutically acceptable solid or liquid excipients and / or adjuvants. The content of the dihydroquercetin and pyridinecarboxylic acid cocrystal in its pharmaceutical composition is in the range of 10% to 90% by weight.

[0033] The dihydroquercetin and pyridinecarboxylic acid cocrystal of the present invention can be administered in unit dose form, and the route of administration can be enteric or non-enteric, such as oral, intravenous, intramuscular, subcutaneous, nasal, oral mucosa, eye, lung and respiratory tract, skin, vagina, rectum, etc.

[0034] 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.

[0035] The dihydroquercetin and pyridinecarboxylic acid cocrystal of the present invention can be formulated into ordinary preparations, as well as sustained-release preparations, controlled-release preparations, targeted preparations, and various microparticle delivery systems.

[0036] In order to co-crystallize the dihydroquercetin of the present invention with pyridinecarboxylic acid 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.

[0037] 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.

[0038] To formulate the drug delivery unit into capsules, the active ingredient, the dihydroquercetin cocrystal of the present invention, can be mixed with a diluent and a flow aid, and the mixture can be directly placed into hard capsules or soft capsules. Alternatively, the active ingredient, the dihydroquercetin cocrystal of the present invention, can be first formed into granules or microspheres with a diluent, binder, and disintegrant, and then placed into hard capsules or soft capsules. Various diluents, binders, wetting agents, disintegrants, and flow aids used to prepare the dihydroquercetin cocrystal capsules of the present invention can also be used to prepare the capsules of the dihydroquercetin cocrystal of the present invention.

[0039] In addition, colorants, preservatives, flavorings, tasters or other additives may be added to pharmaceutical preparations if necessary.

[0040] 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.

[0041] The dosage of the dihydroquercetin and pyridinecarboxylic acid 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.

[0042] The dihydroquercetin cocrystal or composition thereof of the present invention can be taken alone or in combination with other therapeutic or symptomatic drugs. When the dihydroquercetin cocrystal of the present invention has a synergistic effect with other therapeutic drugs, its dosage should be adjusted according to the actual situation.

[0043] 4. Beneficial technical effects of the present invention:

[0044] Advantages of dihydroquercetin cocrystal in terms of safety, solubility, stability, and bioactivity.

[0045] 4.1 The dihydroquercetin and pyridinecarboxylic acid cocrystal of the present invention does not contain any crystallization solvent, and the pyridinecarboxylic acid used as the cocrystal ligand is safe for human use, thus having good advantages in drug safety.

[0046] 4.2 The stability of the dihydroquercetin / pyridinecarboxylic acid cocrystal of the present invention is significantly better than that of dihydroquercetin ( Figure 7 ).

[0047] 4.3 The antioxidant activity of the dihydroquercetin cocrystal and pyridinecarboxylic acid cocrystal of the present invention is significantly better than that of dihydroquercetin (Table 7). Attached Figure Description

[0048] Figure 1 Projected molecular stereostructure of the dihydroquercetin / pyridinecarboxylic acid cocrystal.

[0049] Figure 2 Unit cell packing diagram of the dihydroquercetin / pyridinecarboxylic acid cocrystal along the a-axis.

[0050] Figure 3 Powder X-ray diffraction pattern of dihydroquercetin and pyridinecarboxylic acid cocrystal

[0051] Figure 4 Theoretical powder diffraction pattern, experimental powder diffraction pattern, and superimposed powder X-ray diffraction pattern of dihydroquercetin and pyridinecarboxylic acid cocrystal are shown.

[0052] Figure 5 Infrared absorption spectrum of dihydroquercetin cocrystal with pyridinecarboxylic acid

[0053] Figure 6 DSC comparison spectra of dihydroquercetin, pyridinecarboxylic acid, and a cocrystal of dihydroquercetin and pyridinecarboxylic acid. Figure 7 Stability spectrum of dihydroquercetin cocrystal with pyridinecarboxylic acid and dihydroquercetin. Detailed Implementation

[0054] To better illustrate the technical solution of the present invention, the following embodiments are provided, but the present invention is not limited thereto.

[0055] Example 1

[0056] Method 1 for preparing dihydroquercetin and pyridinecarboxylic acid cocrystal samples:

[0057] As shown in the table below, appropriate amounts of dihydroquercetin and pyridinecarboxylic acid were placed in a mortar at a molar ratio of 1:1, along with a suitable amount of organic solvent. The mixture was then manually ground for an appropriate time, and powder X-ray diffraction analysis was performed. The diffraction pattern was compared with... Figure 3 The consistency indicates that the obtained sample is a co-crystal of dihydroquercetin and pyridinecarboxylic acid.

[0058] Table 3. Preparation method of dihydroquercetin and pyridinecarboxylic acid cocrystal 1. Specific examples

[0059]

[0060] Method 2 for preparing dihydroquercetin and pyridinecarboxylic acid cocrystal samples:

[0061] As shown in the table below, appropriate amounts of dihydroquercetin and pyridinecarboxylic acid were placed in a ball mill jar at a molar ratio of 1:1. An appropriate amount of organic solvent was added, a suitable ball-to-particle ratio was selected, an appropriate rotation speed was set, and the milling time was appropriate. Powder X-ray diffraction analysis was then performed, and the diffraction pattern was compared with... Figure 3 The consistency indicates that the obtained sample is a co-crystal of dihydroquercetin and pyridinecarboxylic acid.

[0062] Table 4. Specific Examples of the Preparation Method of Dihydroquercetin and Pyridinecarboxylic Acid Cocrystal

[0063]

[0064] Method 3 for preparing dihydroquercetin and pyridinecarboxylic acid cocrystal samples:

[0065] As shown in the table below, take appropriate amounts of dihydroquercetin and pyridinecarboxylic acid in a 1:1 molar ratio and place them in a clean vial or conical flask. Add an appropriate amount of organic solvent, stir at room temperature for an appropriate time, filter to remove insoluble matter, and let the filtrate stand at room temperature until a solid precipitates. Filter, dry, or allow the solvent to evaporate at room temperature, and perform powder X-ray diffraction analysis. The diffraction pattern is similar to... Figure 3 The consistency indicates that the obtained sample is a co-crystal of dihydroquercetin and pyridinecarboxylic acid.

[0066] Table 5. Specific Examples of the Preparation Method of Dihydroquercetin and Pyridinecarboxylic Acid Cocrystal

[0067]

[0068] Method 4 for preparing dihydroquercetin and pyridinecarboxylic acid cocrystal samples:

[0069] As shown in the table below, appropriate amounts of dihydroquercetin and pyridinecarboxylic acid were placed in clean vials or conical flasks, and a suitable amount of organic solvent was added to prepare a saturated solution. A co-crystal of dihydroquercetin and pyridinecarboxylic acid was obtained by solvent evaporation. The obtained crystals were dried, ground, and then subjected to powder X-ray diffraction analysis. The diffraction pattern is consistent with... Figure 1 The consistency indicates that the obtained sample is a co-crystal of dihydroquercetin and pyridinecarboxylic acid.

[0070] Table 6. Preparation methods of dihydroquercetin and pyridinecarboxylic acid cocrystals: 4 specific examples

[0071]

[0072] Example 2

[0073] Stability characteristics of dihydroquercetin / pyridinecarboxylic acid cocrystal:

[0074] Referring to the guidelines for accelerated stability studies of solid dosage forms in Part IV, General Provisions 9001 of the 2020 edition of the Chinese Pharmacopoeia, dihydroquercetin and dihydroquercetin / pyridinecarboxylic acid cocrystal samples were placed under high temperature (60℃±1℃), high humidity (90%±5%, 25℃), and light irradiation (4500lx±500lx, 25℃) conditions, respectively. The samples were removed at 0, 5, and 10 days, and PXRD was used to determine their stability. The study investigated whether the phase composition of dihydroquercetin changed, thereby examining the stability differences between the cocrystal of dihydroquercetin and pyridinecarboxylic acid and dihydroquercetin alone. The results showed that after 5 days at high temperature, the PXRD pattern of dihydroquercetin exhibited new small diffraction peaks at 25.08° and 27.90°, while the PXRD pattern of the cocrystal of dihydroquercetin and pyridinecarboxylic acid remained unchanged. This indicates that the cocrystal of dihydroquercetin and pyridinecarboxylic acid is significantly more stable than dihydroquercetin alone. Figure 7 .

[0075] Example 3

[0076] Antioxidant characteristics of the dihydroquercetin / pyridinecarboxylic acid cocrystal:

[0077] The antioxidant screening model of DPPH was used to investigate the difference in antioxidant capacity between dihydroquercetin cocrystal and dihydroquercetin. The results showed that the antioxidant capacity of dihydroquercetin cocrystal was better than that of dihydroquercetin alone.

[0078] Diphenylpicrylhydrazine radical (DPPH) is a relatively stable lipid free radical with one free electron on its nitrogen atom. Its ethanol solution is purple, exhibiting a maximum absorption peak at 515 nm. Upon the addition of an antioxidant, DPPH captures an electron and pairs with the free electron, causing the purple color to fade and the substance to become colorless. The absorption at 515 nm disappears, and the degree of fading is quantitatively related to the number of electrons it accepts. Based on this principle, a spectrophotometer is used to detect the change in absorbance after the DPPH free radical reacts with the sample solution, reflecting the sample's ability to donate hydrogen atoms and scavenge free radicals for antioxidant purposes.

[0079] Experimental methods

[0080] Prepare an ethanol solution of DPPH radicals (25 μL / mL). Take 3 mL of the DPPH radical ethanol solution and mix it with 100 μL of ethanol solution, 100 μL of dihydroquercetin ethanol solution, and 100 μL of dihydroquercetin and pyridinecarboxylic acid cocrystal ethanol solution, respectively. Incubate the above mixed samples in a water bath at 37 °C for 20 min, and then measure the absorbance at a wavelength of 515 nm using a SpectraMax M5 spectrophotometer (Molecular Devices, USA).

[0081] Calculation method

[0082] Sample DPPH scavenging rate (%) = (blank OD - sample OD) / blank OD × 100%

[0083] In the formula, blank OD is the absorbance of the control group (excluding sample), and sample OD is the absorbance of the experimental group (containing dihydroquercetin and dihydroquercetin and pyridinecarboxylic acid cocrystal sample).

[0084] The evaluation results of the DPPH free radical scavenging and antioxidant effects of the dihydroquercetin-pyridinecarboxylic acid cocrystal and dihydroquercetin are shown in Table 7.

[0085] Table 7 Comparison of DPPH free radical scavenging results between dihydroquercetin / pyridinecarboxylic acid cocrystal and dihydroquercetin.

[0086]

[0087] The results showed that in the range of 0.98-250 μM, the IC50 of the dihydroquercetin cocrystal with pyridinecarboxylic acid was [missing value]. 50 The value of 30.01 μM was significantly lower than that of dihydroquercetin (72.89 μM), indicating that the cocrystal of dihydroquercetin and pyridinecarboxylic acid significantly improved the DPPH free radical scavenging ability compared to dihydroquercetin.

[0088] Example 4

[0089] Preparation method 1 of combination drug formulation (tablets):

[0090] A method for preparing a combination drug tablet, characterized by using dihydroquercetin and pyridinecarboxylic acid cocrystals, and using several excipients as excipients for preparing the combination drug tablet, and preparing tablet samples with each tablet containing 10-500 mg of cocrystals according to a certain ratio. Table 8 gives the tablet formulation ratio:

[0091] Table 8. Formulation for the preparation of dihydroquercetin and pyridinecarboxylic acid cocrystal combination drug tablets.

[0092]

[0093] The method for preparing tablet formulations using dihydroquercetin and pyridinecarboxylic acid cocrystal as raw materials is as follows: several excipients are mixed evenly with the raw materials and directly compressed into tablets; or the excipients are mixed and granulated by dry method, then mixed evenly with the raw materials and compressed into tablets.

[0094] Preparation method 2 for combination drug formulations (tablets):

[0095] A method for preparing a combination drug tablet, characterized by using dihydroquercetin and pyridinecarboxylic acid cocrystals, and using several excipients as excipients for preparing the combination drug tablet, and preparing tablet samples with each tablet containing 5-500 mg of cocrystals according to a certain ratio. Table 9 gives the tablet formulation ratio:

[0096] Table 9. Formulation for the preparation of dihydroquercetin and pyridinecarboxylic acid cocrystal combination drug tablets.

[0097]

[0098] The method for preparing tablet formulations using dihydroquercetin and pyridinecarboxylic acid cocrystal 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.

[0099] Preparation method 2 of combination drug formulation (capsule):

[0100] A method for preparing a combination drug capsule, characterized by using dihydroquercetin and pyridinecarboxylic acid 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 10 gives the capsule formulation ratio:

[0101] Table 10. Active pharmaceutical ingredient and excipient formulations of dihydroquercetin and pyridinecarboxylic acid cocrystal combination drug capsules.

[0102]

[0103] The method for preparing capsules using dihydroquercetin and pyridinecarboxylic acid cocrystal as 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, and the dihydroquercetin and pyridinecarboxylic acid cocrystal is directly mixed evenly with several excipients and excipients, sieved, and directly filled into capsules.

[0104] Example 5

[0105] Dosage of the dihydroquercetin and pyridinecarboxylic acid cocrystal combination drug 1 (tablets):

[0106] A pharmaceutical composition developed using a cocrystal of dihydroquercetin and pyridinecarboxylic acid as the active pharmaceutical ingredient is characterized by the cocrystal of dihydroquercetin and pyridinecarboxylic acid as the active pharmaceutical ingredient, with a daily dose of 150 mg, which can be prepared as a 50 mg tablet three times a day or a 150 mg tablet once a day.

[0107] Dosage of the dihydroquercetin and pyridinecarboxylic acid cocrystal combination drug 2 (capsules):

[0108] A pharmaceutical composition developed using a cocrystal of dihydroquercetin and pyridinecarboxylic acid as the active pharmaceutical ingredient is characterized by using a cocrystal of dihydroquercetin and pyridinecarboxylic acid as the active pharmaceutical ingredient, with a daily dose of 1200 mg, which can be prepared as 4 100 mg capsules three times a day or 2 300 mg capsules twice a day.

[0109] Issues requiring clarification: The dosage of the dihydroquercetin and pyridinecarboxylic acid 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, resulting in variations in dosage per administration; differences in absorption and blood drug concentration between samples, etc. Therefore, the appropriate dosage range for each administration of the dihydroquercetin and pyridinecarboxylic acid cocrystal component in this invention is 0.05–300 mg / kg body weight, preferably 0.1–50 mg / kg body weight. Different total dosage regimens of the dihydroquercetin and pyridinecarboxylic acid cocrystal component should be formulated according to the actual treatment needs, and can be administered in multiple or single doses.

[0110] References

[0111] [1]Wang X, Li X, Chen D. Evaluation of antioxidant activity of isoferulic acid in vitro[J]. Natural Product Communications, 2011(9).

[0112] [2] Yu Qijian. Synergistic antioxidant and inhibitory effects of verbascoside and dihydroquercetin on HepG2 cell proliferation [D]. Shandong Agricultural University, 2016.

[0113] [3]Liu IM, Hsu FL, Chen CF, et al. Antihyperglycemic action of isoferulic acid in streptozotocin-induced diabetic rats[J]. British Journal ofPharmacology, 2000, 129(4): 631-636.

[0114] [4]Sakai S,Kawamata H,Kogure T,et al.Inhibitory effect of ferulicacid and isoferulic acid on the production of macrophage inflammatoryprotein-2in response to respiratory syncytial virus infection in RAW264.7cells[J].Mediators ofInflammation,1999,8(3):173-175.

[0115] [5] Li Yanwei. Study on the expression of PD-L1 and its regulatory mechanism in human colon cancer cells by dihydroquercetin.

[0116] [6]Moura F, Pinna N, Vivani R, et al. Exploring Taxifoliin Polymorphs: Insights on Hydrate and Anhydrous Forms[J].Pharmaceutics, 2021,13:1328.

[0117] [7]Liu L,Liu M,Zhang Y,et al.The role of 3-OH in the self-assembly ofpharmaceutical cocrystals of dihydroflavonol with 4,4’-bipyridine[J].NewJournal of Chemistry,2021,45:1626-1633.

Claims

1. A cocrystal of dihydroquercetin and pyridinecarboxylic acid, characterized in that, Dihydroquercetin and pyridinecarboxylic acid form a eutectic in a 1:1 molar ratio. When using powder X-ray diffraction analysis with CuK α Under radiation experimental conditions, the diffraction peak positions (2-Theta value, º) or d value (Å) and the relative intensity of the diffraction peaks (peak height, Height%) or peak area, Area%) have the following characteristics: 。 2. The dihydroquercetin and pyridinecarboxylic acid cocrystal according to claim 1, characterized in that, When analyzed using single-crystal X-ray diffraction, it exhibits monoclinic crystal symmetry, space group P21 / c, and unit cell parameters: a = 7.369 Å, b = 18.003 Å, c = 14.443 Å, α = 90°, β = 103.423°, γ = 90°, and unit cell volume V = 1863.93 Å. 3 .

3. The dihydroquercetin and pyridinecarboxylic acid cocrystal according to claim 1 or 2, characterized in that, When using infrared spectroscopy for analysis, the values ​​at 3672, 3421, 3086, 2987, 2884, 2723, 2630, 2161, 1661, 1627, 1594, 1521, 1472, 1444, 1388, 1358, 1293, 1271, 1210, 1188, 1154, 1142, 1082, 1027, 1010, 996, 952, 861, 823, 814, 783, 758, 685, and 669 cm⁻¹ -1 There is an infrared spectral characteristic peak at this location, with an allowable deviation of ±2cm. -1 .

4. The dihydroquercetin and pyridinecarboxylic acid co-crystal according to claim 1 or 2, characterized in that, When analyzed using differential scanning calorimetry, an endothermic peak is observed at 218°C ± 3°C in the DSC spectrum when the heating rate is 10°C per minute.

5. A method for preparing the dihydroquercetin and pyridinecarboxylic acid cocrystal according to any one of claims 1-4, characterized in that, Dihydroquercetin and pyridinecarboxylic acid were fed in a 1:1 molar ratio to prepare a dihydroquercetin-pyridinecarboxylic acid cocrystal using a mechanochemical method.

6. The preparation method according to claim 5, wherein the mechanochemical method is a solvent-assisted grinding method, that is, dihydroquercetin and pyridinecarboxylic acid raw materials with a molar ratio of 1:1 are mixed in a mortar or ball mill, an organic solvent is added to the mixed powder, and the mixture is ground at room temperature and collected to obtain a dihydroquercetin-pyridinecarboxylic acid cocrystal. The organic solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane, or cyclohexane; the ball milling speed is 20 r / min to 400 r / min, the liquid addition volume is 0.01 to 100 ml, and the grinding time is 0.1 to 10 hours.

7. The preparation method according to claim 6, wherein the organic solvent is selected from isoamyl alcohol.

8. A method for preparing the dihydroquercetin and pyridinecarboxylic acid cocrystal according to any one of claims 1-4, characterized in that, Dihydroquercetin and pyridinecarboxylic acid were added to a clean container at a molar ratio of 1:1, and an organic solvent was added to form a suspension. The suspension was stirred at room temperature for 0.1 to 4 days. The obtained suspension was dried by solvent evaporation, filtration and natural drying, or filtration and vacuum drying to obtain a cocrystal of dihydroquercetin and pyridinecarboxylic acid.

9. The preparation method according to claim 8, wherein the organic solvent used is selected from any one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane, and cyclohexane, and is a mixed solvent prepared by combining them in different proportions; the total mass of dihydroquercetin and pyridinecarboxylic acid and the solid-liquid ratio of the organic solvent are maintained within the range of 1 mg / ml to 500 mg / ml.

10. The preparation method according to claim 9, wherein the organic solvent is selected from isoamyl alcohol.

11. A method for preparing the dihydroquercetin and pyridinecarboxylic acid cocrystal according to any one of claims 1-4, characterized in that, The dihydroquercetin and pyridinecarboxylic acid were added to a clean container in a molar ratio of 1:1 using the solvent evaporation method. An organic solvent was added and mixed evenly to prepare a saturated solution. The dihydroquercetin and pyridinecarboxylic acid cocrystal was then obtained by solvent evaporation.

12. The preparation method according to claim 11, wherein the organic solvent used is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, pentanol, n-hexanol, ethylene glycol, acetonitrile, acetone, ethyl acetate, dioxane, tetrahydrofuran, n-hexane or cyclohexane single solvent system or mixed solvent prepared by different proportions of the above solvents, and the crystallization temperature is 4-60°C and the crystallization time is 12h-30d.

13. The preparation method according to claim 12, wherein the organic solvent is selected from isoamyl alcohol.

14. A mixed solid substance containing a eutectic of dihydroquercetin and pyridinecarboxylic acid and other components, characterized in that, The amount of the dihydroquercetin and pyridinecarboxylic acid cocrystal as described in any one of claims 1-4 is 1-99.9%.

15. The mixed solid material of claim 14, wherein the amount of the dihydroquercetin and pyridinecarboxylic acid eutectic is selected from any one of the following: 10-99.9%, 50-99.9%, or 85-99.9%.

16. A pharmaceutical composition, characterized in that, The product contains an effective dose of the dihydroquercetin cocrystal with pyridinecarboxylic acid as described in any one of claims 1-4 and a pharmaceutically acceptable carrier.

17. A pharmaceutical composition, characterized in that, The substance comprises an effective dose of the dihydroquercetin and pyridinecarboxylic acid cocrystal mixed solid material as described in claim 14 or 15 and a pharmaceutically acceptable carrier.

18. The pharmaceutical composition according to claim 16 or claim 17, characterized in that, The daily dosage of dihydroquercetin cocrystal with pyridinecarboxylic acid is in the range of 5 to 3000 mg.

19. The pharmaceutical composition according to claim 16 or claim 17, characterized in that, The pharmaceutical composition is selected from tablets, capsules, pills or injectable preparations.

20. The pharmaceutical composition according to claim 16 or claim 17, characterized in that, The pharmaceutical composition is selected from sustained-release or controlled-release formulations.

21. The use of the dihydroquercetin and pyridinecarboxylic acid cocrystal as described in any one of claims 1-4 and / or the dihydroquercetin and pyridinecarboxylic acid cocrystal mixed solid material as described in claim 14 in the preparation of antioxidant, free radical scavenging and cell protection, antiviral, antidiabetic and antitumor drugs.

22. Use of the pharmaceutical composition according to any one of claims 16 or 17 in the preparation of antioxidant, free radical scavenging and cell protection, antiviral, antidiabetic and antitumor drugs.

Images