Axitinib tartrate crystal form and preparation method thereof

Abstract

The invention belongs to the technical field of crystal form drug molecules, and particularly relates to an axitinib tartrate crystal form as well as a preparation method and application thereof. The axitinib tartrate crystal form provided by the invention makes significant progress in the aspects of solubility and light stability, and the preparation method of the crystal form is simple to operate, good in reproducibility and suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of crystalline drug molecules, and in particular to an axitinib tartrate crystalline form and a preparation method thereof. Background Art

[0002] Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptor (VEGFR) / platelet-derived growth factor (PDGFR) receptor tyrosine kinase (RTK) developed by Pfizer, USA, for inhibiting early to late stage cancer. It was approved for marketing by the US FDA on January 27, 2012, with the trade name of On April 29, 2015, Axitinib was approved by CFDA for use in adult patients with advanced renal cell carcinoma (RCC) who have failed treatment with a tyrosine kinase inhibitor or cytokine. Its chemical name is: N-methyl-2-[3-((E)-2-pyridin-2-yl-vinyl)-1H-indol-6-ylsulfonyl]-benzamide, and its structural formula is as follows:

[0003]

[0004] Due to the many problems of photosensitivity and poor solubility of axitinib itself, people in this field are trying to develop different crystal forms to obtain axitinib crystal forms that are more suitable for pharmaceutical use. Patent WO2006048751A1 attempts to study axitinib crystal forms, and discloses axitinib crystal forms I, II, III, IV, VI, VII and VIII, but simply changing the axitinib crystal form does not significantly improve its solubility. For example, the solubility of crystal form IV in an aqueous solution with a pH of about 1 is about 0.55 mg / ml, in an aqueous solution with a pH of about 2, the solubility is only 0.157 mg / ml, and in an aqueous solution with a pH of about 6.5, the solubility is only 2 μg / ml; at the same time, it is reported that in order to improve the water solubility of axitinib, 7 axitinib acid salt compounds were prepared, and their solubility was improved, but they were significantly degraded when exposed to high-intensity light, and all of them were photosensitive axitinib salts. Patent CN200880016453.6 discloses multiple crystal forms including crystal form XXV, crystal form XVI, crystal form XLI, crystal form IX, crystal form XII and crystal form XV. Crystal form XXV and crystal form XLI have not been significantly improved in terms of solubility and bioavailability.

[0005] Due to the many problems of photosensitivity and poor solubility of axitinib itself, people in this field are trying to develop different crystal forms to obtain axitinib crystal forms that are more suitable for pharmaceutical use. However, according to current reports, from the perspective of bioavailability, stability and manufacturability, among the many publicly available axitinib crystal forms, only crystal form IV and crystal form XLI are available. Due to the extreme instability of crystal form IV under light exposure, the original Pfizer company finally selected crystal form XLI with relatively less light exposure degradation as the marketed crystal form (see CHMP evaluation report). However, those skilled in the art know from the report of patent CN200880016453.6 that the potency of marketed crystal form XLI after light exposure is reduced to 89%. In order to achieve pharmaceutical safety and effectiveness, the preparation process using the light shielding process is still inevitable. However, some subsequent developments and studies of axitinib solvate crystal forms, axitinib salt crystal forms, and axitinib new crystal forms still have defects in drug safety, solubility, bioavailability or photostability.

[0006] For example, patent WO2015067224A1 further characterized 7 axitinib acid salts by powder diffraction data based on the 7 available axitinib acid salt compounds disclosed in patent WO2006048751A1. Patent CN201510509413.7 discloses the preparation of a crystalline form A of axitinib fumarate, in which the molar ratio of axitinib to fumaric acid is 1:1. After irradiation with light, axitinib fumarate degraded by 0.13%. CN202010787156.4 discloses a crystalline form B of axitinib fumarate, in which the molar ratio of axitinib to fumaric acid is 1:1.5; the axitinib fumarate crystalline form B powder sample was irradiated for 10 days, and the appearance and drug content did not change significantly. However, the water adsorption rate was 1.5% at 95% RH. CN202011575325.4 provides a crystal form of axitinib maleate, in which the molar ratio of axitinib to maleic acid is 1:1, and two molecules of axitinib, two molecules of maleic acid, and two molecules of water constitute the basic unit of the crystal form. CN202011585244.2 provides a crystal form of axitinib malate, in which the basic unit of the malate crystal form is composed of one molecule of axitinib, one molecule of malic acid, and one molecule of water. CN202011575299.5 provides a crystal form of axitinib salicylate, in which the basic unit of the salicylate crystal form is composed of two molecules of axitinib and two molecules of salicylic acid. CN202011573595.1 provides a crystal form of axitinib citrate, in which the basic unit of the citrate crystal form is composed of one molecule of axitinib, one molecule of citric acid, and one molecule of water. These axitinib salts have achieved beneficial effects in terms of stability, solubility, and permeability.

[0007] As we all know, the crystal form of the drug has a great influence on the stability, solubility, permeability, bioavailability, etc. of the solid drug preparation. The excellent crystal form suitable for the preparation of solid preparations generally needs to meet various requirements such as stability, solubility, and bioavailability. A new salt form of a drug refers to a new eutectic substance (CCF) introduced by proton transfer, which self-assembles with the active pharmaceutical ingredient (APT) under the action of hydrogen bonds to form a supramolecular crystal with a fixed stoichiometric ratio. In the preclinical drug development stage, new drug development companies usually use the active pharmaceutical ingredient (APT) to improve the drug's solubility, dissolution rate, permeability, hygroscopicity, stability, bioavailability, and other physical and chemical properties by salting. Compared with nanocrystals, solid dispersants, and new drug dosage form technologies, drug salt forms have obvious advantages in improving drug solubility, dissolution rate, permeability, hygroscopicity, stability, and bioavailability.

[0008] In order to better utilize axitinib salt crystals in drug synergistic therapy, the present invention provides a simple and easy-to-operate method for preparing high-purity axitinib tartrate crystals, thereby more efficiently exerting the medicinal value of axitinib. Summary of the invention

[0009] In view of the deficiencies in the prior art, an object of the present invention is to provide axitinib tartrate crystalline form and a preparation method thereof; the salt has definite main crystallographic parameters and atomic spatial positions; and has achieved significant improvements in stability, solubility, permeability, etc.

[0010] The specific technical contents of the present invention are as follows:

[0011] In a first aspect, the present invention provides a tartrate salt of axitinib in which two molecules of axitinib, three molecules of tartaric acid and six molecules of water constitute a basic unit of the crystal form.

[0012] Preferably, the axitinib tartrate crystalline form uses Cu-Kα radiation, and the X-ray diffraction spectrum expressed as 2θ has characteristic peaks at 20.79±0.2°, 22.61±0.2°, 25.11±0.2°, 29.26±0.2°, 29.72±0.2°, 32.05±0.2°, and 37.52±0.2°.

[0013] Preferably, the axitinib tartrate crystalline form uses Cu-Kα radiation, and the X-ray diffraction spectrum expressed in 2θ has characteristic peaks at 11.78±0.2°, 17.02±0.2°, 18.87±0.2°, 20.22±0.2°, 20.79±0.2°, 22.61±0.2°, 22.89±0.2°, 25.11±0.2°, 26.97±0.2°, 29.26±0.2°, 29.72±0.2°, 32.05±0.2°, 35.48±0.2°, 35.89±0.2°, 36.69±0.2°, 37.52±0.2°, and 43.98±0.2°.

[0014] Preferably, the axitinib tartrate crystalline form, using Cu-Kα radiation, has characteristic peaks that meet the following Figure 3 The X-ray powder diffraction pattern is shown.

[0015] Preferably, the crystallographic parameters of the axitinib tartrate salt crystal form are: monoclinic system, space group P21; unit cell parameters are: α=90°,β=96.5290(10)°,γ=90°,unit cell volume

[0016] Preferably, the axitinib tartrate crystalline form has two endothermic peaks in the differential scanning calorimetry (DSC) curve, which are 89.35° C. and 186.83° C. respectively.

[0017] The second aspect of the present application provides a method for preparing axitinib tartrate crystal form, and the specific preparation steps include: dissolving axitinib and tartaric acid in solvent A, heating to dissolve to obtain a transparent solution, cooling and standing to crystallize, filtering, washing, and vacuum drying to obtain axitinib tartrate crystal form.

[0018] Preferably, the solvent A is selected from a mixed solvent of acetic acid-methanol-water, acetic acid-ethanol-water, acetic acid-acetone-water, acetic acid-isopropanol-water, formic acid-methanol-water, formic acid-ethanol-water, formic acid-acetone-water and formic acid-isopropanol-water.

[0019] Furthermore, the solvent A is selected from a mixed solvent of formic acid-ethanol-water, formic acid-methanol-water, formic acid-acetone-water, and formic acid-isopropanol-water.

[0020] Preferably, the molar ratio of axitinib to tartaric acid is 1:1.2-1.9; preferably, the molar ratio of axitinib to tartaric acid is 1:1.4-1.7.

[0021] Preferably, the mass-to-volume ratio of axitinib to solvent A in the system is 2-5:1, wherein the mass is measured in mg and the volume is measured in mL.

[0022] Preferably, the dissolving and heating temperature is 50-60°C.

[0023] Preferably, the cooling and crystallization temperature is 0-30°C, preferably, the cooling and crystallization temperature is 10-20°C.

[0024] Preferably, the crystallization time is 48 to 72 hours.

[0025] Preferably, the drying temperature is 25-30° C., and the drying time is 5-9 hours.

[0026] Preferably, the solvent for washing the filter cake is selected from one of ethanol, methanol, acetone and isopropanol.

[0027] In a third aspect, the present invention provides a pharmaceutical composition comprising the axitinib tartrate crystalline form of the present invention and other pharmaceutically acceptable components.

[0028] Preferably, the other pharmaceutically acceptable components include other active ingredients, excipients, fillers, etc. that can be used in combination.

[0029] Preferably, the pharmaceutical composition of the present invention can be prepared by the following method: using standard and conventional techniques, the compound of the present invention is combined with a pharmaceutically acceptable solid or liquid carrier, and optionally combined with pharmaceutically acceptable auxiliary agents and excipients to prepare a usable dosage form.

[0030] Preferably, the pharmaceutical composition is in the form of a spray, tablet, capsule, powder injection, liquid injection, etc.

[0031] The fourth aspect of the present application provides a use of axitinib tartrate crystal form as an active ingredient in the preparation of anticancer drugs.

[0032] Confirmation of crystal structure

[0033] The axitinib tartrate crystal form provided by the present invention is subjected to X-ray single crystal diffraction test and analysis. The X-ray single crystal diffraction instrument and test conditions involved in the present invention are: Rigaku XtaLAB Synergy X-ray single crystal diffractometer, test temperature 293 (2) K, CuKa radiation, ω scanning mode data collection and Lp correction. The structure is analyzed by direct method, the difference Fourier method is used to find all non-hydrogen atoms, all hydrogen atoms on carbon and nitrogen are obtained by theoretical hydrogenation, and the least squares method is used to refine the structure.

[0034] The crystallographic data obtained by testing and analyzing the axitinib tartrate salt prepared by the present invention are (Table 1): Its crystallographic parameters are: monoclinic system, space group is P21; unit cell parameters are: α=90°,β=96.5290(10)°,γ=90°,unit cell volume ORTEP of the axitinib tartrate crystalline form of the present invention Figure 1 It shows that two molecules of axitinib are combined with three molecules of tartaric acid and six molecules of water. The stacking diagram of the axitinib tartrate salt crystalline form of the present invention is shown in the attached Figure 2 shown.

[0035] Table 1 Main crystallographic data of axitinib tartrate

[0036]

[0037]

[0038] The X-ray powder diffraction test instrument and test conditions involved in the present invention are as follows: X-ray powder diffractometer: PANalytIIcal E; Cu-Kα; sample stage: flat plate; incident light path: BBHD; diffraction light path: PLXCEL; voltage 45kv, current 40mA; divergence slit: 1 / 4; anti-scattering slit: 1; Soller slit: 0.04rad; step size: 0.5s; scanning range: 3-50°.

[0039] According to the above crystallographic data, the corresponding characteristic peaks in the X-ray powder diffraction pattern (Cu-Kα) are shown in Figure 3 And Table 2.

[0040] Table 2 PXRD peaks of axitinib tartrate salt

[0041]

[0042]

[0043] The TGA / DSC thermal analysis tester and test conditions in the present invention are as follows: TGA / DSC thermal analyzer: METTLER TOLEDO TGA / DSC3+; dynamic temperature section: 30-300°C; heating rate: 10°C / mIVn; program section gas N2; gas flow: 50mL / mIVn; crucible: aluminum crucible 40μl.

[0044] The TGA / DSC test results of the axitinib tartrate crystalline form prepared by the method of the present invention are as follows: Figure 4 As shown, the DSC test results have two endothermic peaks, corresponding to temperatures of 89.35° C. and 186.83° C., respectively. According to the TGA test results, it can be seen that there are two weight loss steps, and the first step indicates that the crystal contains six molecules of water. Combined with the DSC / TGA test results, it is shown that the crystal prepared by the present invention is axitinib tartrate crystal.

[0045] All samples prepared in the examples have the same crystallographic parameters and X-ray powder diffraction spectra as described above.

[0046] The axitinib tartrate crystal provided by the present invention has achieved significant improvements in stability, solubility, permeability, etc. After long-term photostability inspection, the tartrate has good photostability. The axitinib tartrate crystal has a regular shape, uniform particle size, clear crystallographic main parameters and exact atomic spatial positions, and a simple preparation method, which is suitable for industrial production and large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 : ORTEP diagram of axitinib tartrate crystalline form.

[0048] Figure 2 : Stacking diagram of axitinib tartrate crystalline form.

[0049] Figure 3 : X-ray powder diffraction pattern of axitinib tartrate crystalline form.

[0050] Figure 4 : DSC-TGA diagram of axitinib tartrate salt crystal. DETAILED DESCRIPTION

[0051] The present invention is further illustrated by the following examples. It should be correctly understood that the examples of the present invention are only used to illustrate the present invention, rather than to limit the present invention. Therefore, simple improvements to the present invention based on the method of the present invention are all within the scope of protection claimed by the present invention.

[0052] Materials used in the experiment: Axitinib can be purchased or prepared according to the method disclosed in patent WO2006048745. The axitinib crystal form required for the comparative experiment can be prepared according to the existing technology or purchased; the materials used in other experiments without indicating the source and specification are all commercially available analytically pure or chemically pure.

[0053] Example 1

[0054] 409 mg of axitinib and 258 mg of tartaric acid were added to a mixed solvent of 20 mL of formic acid, 50 mL of ethanol and 40 mL of water, heated to 60°C and stirred to dissolve, refluxed for 3 hours, slowly cooled to 10-20°C, and then allowed to stand at a controlled temperature for crystallization for 48 hours, filtered, and the filter cake was washed with ethanol, and vacuum dried at 30°C for 6 hours to obtain axitinib tartrate salt crystal with a yield of 95.00% and a purity of 99.79%.

[0055] Example 2

[0056] 773 mg of axitinib and 478 mg of tartaric acid were added to a mixed solvent of 40 mL of formic acid, 80 mL of methanol and 80 mL of water, heated to 60°C and stirred to dissolve, refluxed for 3 hours, slowly cooled to 10-20°C, and then allowed to stand for crystallization for 36 hours under controlled temperature, filtered, and the filter cake was washed with methanol, and vacuum dried at 25°C for 6 hours to obtain axitinib tartrate salt crystal with a yield of 94.86% and a purity of 99.75%.

[0057] Example 3

[0058] 382 mg of axitinib and 235 mg of tartaric acid were added to a mixed solvent of 20 mL of formic acid, 40 mL of acetone and 40 mL of water, heated to 55°C and stirred to dissolve, refluxed for 3 hours, slowly cooled to 10-20°C, and then allowed to stand for crystallization for 36 hours under controlled temperature, filtered, and the filter cake was washed with acetone, and vacuum dried at 25°C for 6 hours to obtain axitinib tartrate salt crystal with a yield of 92.10% and a purity of 99.73%.

[0059] Example 4

[0060] 484 mg of axitinib and 291 mg of tartaric acid were added to a mixed solvent of 20 mL of formic acid, 40 mL of isopropanol and 40 mL of water, heated to 60°C and stirred to dissolve, refluxed for 3 hours, slowly cooled to 10-20°C, and then allowed to stand for crystallization for 36 hours under controlled temperature, filtered, and the filter cake was washed with isopropanol, and vacuum dried at 25°C for 6 hours to obtain axitinib tartrate salt crystal with a yield of 91.96% and a purity of 99.72%.

[0061] Verification example:

[0062] The present invention investigates the above-prepared axitinib crystal form in terms of stability, hygroscopicity, solubility, permeability, etc. The specific implementation contents are as follows:

[0063] 1. Photostability test

[0064] The crystal form obtained in Example 1 was stored at 25°C (RH 45%) under strong light irradiation (4500 Lx±500 Lx), and samples were taken after 5 days and 10 days, and the purity was tested by HPLC. The results are shown in Table 3.

[0065] Table 3 Results of photostability test of axitinib crystals

[0066]

[0067] The results of the photostability test show that after 10 days under strong light irradiation, the axitinib tartrate crystal prepared by the present invention has good photostability. It is found that Examples 1 to 4 have similar stability test results.

[0068] 2. Moisture absorption test

[0069] The axitinib tartrate crystal form obtained in Example 1, the axitinib fumarate crystal form B in CN202010787156.4 (prepared by repeating Example 1), and the axitinib maleate crystal form in CN202011575325.4 (prepared by repeating Example 1) were taken for hygroscopicity test.

[0070] The hygroscopicity test method and conditions refer to the Chinese Pharmacopoeia 2020 Edition Part IV General Chapter 9103 Guiding Principles for Drug Hygroscopicity Test

[0071] Among them, the description of hygroscopic characteristics and the definition of hygroscopic weight gain are:

[0072] Deliquescent: Absorbs sufficient water to form a liquid.

[0073] Highly hygroscopic: weight gain due to moisture absorption is not less than 15%.

[0074] Hygroscopic: Weight gain due to moisture absorption is less than 15% but not less than 2%.

[0075] Slightly hygroscopic: weight gain due to moisture absorption is less than 2% but not less than 0.2%.

[0076] No or almost no hygroscopicity: weight gain due to moisture is less than 0.2%.

[0077] The results of the hygroscopicity test are shown in Table 4.

[0078] Table 4 Hygroscopicity investigation results

[0079]

[0080] Conclusion: The axitinib tartrate crystal obtained by the present invention is hygroscopic and easily deliquesced by high humidity. The humidity needs to be controlled to ensure the long-term storage of the crystal drug. PXRD detection was performed on the crystal after moisture absorption to test whether each crystal was stable. In addition, through thermal stability investigation, the crystal water will be lost when the temperature is higher than 35°C, which affects the stability. It needs to be stored at low temperature.

[0081] 3. Solubility test

[0082] Test method: Take water, 0.01 mol / L hydrochloric acid solution, and pH 6.8 PBS buffer as the medium, take an excess of the cocrystal obtained in Example 1, add it to the above medium, and stir at 37°C for 72 hours. Repeat the sampling three times, filter, take an appropriate amount of the filtrate, dilute, and use HPLC to detect the solubility in each medium.

[0083] Table 5 Solubility of Axitinib in different media (mg / ml)

[0084]

[0085] The solubility test results show that the axitinib tartrate crystal form prepared by the present invention has a significant improvement in solubility compared to the available crystal form disclosed in the prior art. It was found that Examples 1 to 4 have similar solubility test results.

[0086] 4. Permeability test

[0087] Test conditions: The permeability test was carried out using the Franz diffusion cell method at a water temperature of (37±0.5)℃.

[0088] Dialysis membrane (model: MW 14000Da, Himedia, India): treated with 10% sodium bicarbonate solution, 10 MmEDTA solution, and deionized water at 70 °C for 20 min respectively; the treated dialysis membrane was placed in a diffusion cell (effective surface area 4.15 cm 2 ); the donor chamber was respectively taken from Example 1 and CN202010787156.4, the crystal form B of axitinib fumarate (prepared by repeating Example 1) (based on the amount of axitinib, 10 mg) and suspended in 2 ml of distilled water; the receptor chamber was filled with phosphate buffer (pH = 7.4), maintained at room temperature, bubbles were removed, and magnetic stirring was performed at 45 ± 5 RPM; the cumulative permeation amount was tested after 24 hours.

[0089] Table 6 Cumulative permeation of axitinib (mg / cm 2 )

[0090] sample <![CDATA[Penetration accumulation amount (mg / cm 2 )]]> Example 1 0.3869 Axitinib fumarate crystal form B 0.1897

Claims

1. A crystalline form of axitinib tartrate, characterized in that: The basic unit of the axitinib tartrate crystal form is composed of two molecules of axitinib combined with three molecules of tartaric acid and six molecules of water.

2. The axitinib tartrate crystalline form according to claim 1, characterized in that: Using Cu-Kα radiation, the X-ray diffraction spectrum expressed in 2θ has characteristic peaks at 20.79±0.2°, 22.61±0.2°, 25.11±0.2°, 29.26±0.2°, 29.72±0.2°, 32.05±0.2°, and 37.52±0.2°.

3. The axitinib tartrate crystalline form according to claim 1, characterized in that: Using Cu-Kα radiation, the X-ray diffraction spectrum expressed in 2θ has characteristic peaks at 11.78±0.2°, 17.02±0.2°, 18.87±0.2°, 20.22±0.2°, 20.79±0.2°, 22.61±0.2°, 22.89±0.2°, 25.11±0.2°, 26.97±0.2°, 29.26±0.2°, 29.72±0.2°, 32.05±0.2°, 35.48±0.2°, 35.89±0.2°, 36.69±0.2°, 37.52±0.2°, and 43.98±0.2°.

4. The axitinib tartrate crystalline form according to claim 1, characterized in that: Using Cu-Kα radiation, its characteristic peaks conform to the X-ray powder diffraction pattern shown in FIG3 .

5. The axitinib tartrate crystalline form according to claim 1, characterized in that: Its crystallographic parameters are: monoclinic system, space group is P21; unit cell parameters are: α=90°,β=96.5290(10)°,γ=90°,unit cell volume 6. The method for preparing the axitinib tartrate salt crystal according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: dissolving axitinib and tartaric acid in solvent A, heating to dissolve to obtain a transparent solution, cooling and standing to crystallize, filtering, washing, and vacuum drying to obtain axitinib tartrate crystal form.

7. The preparation method according to claim 6, characterized in that: The solvent A is selected from a mixed solvent of acetic acid-methanol-water, acetic acid-ethanol-water, acetic acid-acetone-water, acetic acid-isopropanol-water, formic acid-methanol-water, formic acid-ethanol-water, formic acid-acetone-water and formic acid-isopropanol-water.

8. The preparation method according to claim 6, characterized in that: The molar ratio of axitinib to tartaric acid is 1:1.2-1.9; preferably, the molar ratio of axitinib to tartaric acid is 1:1.4-1.

7.

9. The preparation method according to claim 6, characterized in that The dissolving and heating temperature is 50-60°C; the cooling and crystallizing temperature is 0-30°C, preferably, the cooling and crystallizing temperature is 10-20°C.

10. Use of the axitinib tartrate crystal form according to any one of claims 1 to 5 as an active ingredient in the preparation of anti-tumor drugs.

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