WO2025241792A1 - New crystal forms of elacestrant dihydrochloride, and preparation method therefor and use thereof - Google Patents

Abstract

The present invention discloses a plurality of new crystal forms of elacestrant dihydrochloride, wherein the X-ray powder diffraction pattern of the crystal form APTI-I plotted against 2θ angle has characteristic peaks at 9.6°±0.2°, 12.0°±0.2°, 13.5°±0.2°, 20.5°±0.2°, 21.9°±0.2°, and 22.4°±0.2°. The crystal form has a good stability, a yield of up to 92.3%, a purity of up to 99.90%, and a low amount of a residual organic solvent, and the preparation thereof is simple to operate and easy to control, and is more suitable for industrial scale-up production. The purities of the crystal forms APTI-II and APTI-III provided by the present invention can reach 99.92% and 99.95%, respectively, which can provide more options for purification during the production process of elacestrant or the salts thereof.

Description

Novel crystal form of ellastrone dihydrochloride, its preparation method and applications Technical Field

This invention relates to the crystal form of organic compounds, and more specifically, to a novel crystal form of ellastrone dihydrochloride, its preparation method, and its uses.

Background Technology

Breast cancer is one of the most common malignant tumors among women worldwide, and the number of patients is increasing year by year. It is predicted that by 2030, there will be 8.25 million breast cancer patients globally. According to clinical statistics, approximately 60% to 75% of breast cancer patients are estrogen receptor (ER) positive. Common treatments for ER+ breast cancer include estrogen receptor modulators, aromatase inhibitors, ovarian function inhibitors, and CDK4/6 inhibitors. Among these, estrogen receptor degraders (SERDs) can more effectively block the ER receptor signaling pathway and induce its degradation. Elestrant, a next-generation selective SERD developed by Radius Health and Takeda, has received priority review and fast track designation from Stemline, a biopharmaceutical company under the Menarini Group, and was approved for marketing by the FDA in January 2023. In September 2023, elestrant was approved for marketing by the European Commission. It is used for patients with ER+/HER2-, ESR1-mutant metastatic breast cancer whose disease has progressed after endocrine therapy. This is the first oral SERD approved by the FDA, and also the first time the FDA has approved a new therapy for ER+/HER2- advanced metastatic breast cancer with ESR1 mutations.

The chemical name of ellastatin is (R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl)-5,6,7,8-tetrahydronaphthalene-2-ol, and it is currently mainly administered in the form of ellastatin dihydrochloride. Its chemical structure is shown below.

As is well known, for the same drug molecule, polymorphism can occur during the microscopic molecular stacking process due to different stacking methods. Furthermore, during the crystallization process to form a solid form, water or solvents usually participate in crystal stacking, resulting in hydrated or solvate crystal forms. Crystal form typically affects the physicochemical properties of drugs, such as chemical stability, hygroscopicity, solubility, and tableting performance, ultimately influencing drug storage, transportation, and even the final drug formulation and efficacy. Therefore, screening for a superior crystal form can enable drugs to better exert their therapeutic effects.

Currently, existing technologies have reported studies on the crystal forms of alastan dihydrochloride, for example:

Existing technology WO2018129419A discloses three forms of elastoside dihydrochloride: Form 1, Form 2, and Form 3. Forms 1 and 2 are amorphous and will transform into Form 3 (hydrate) under certain humidity conditions. Form 3 will transform into amorphous Form 2 under low humidity. Based on DSC and variable-temperature XRPD analysis, Form 2 is a metastable crystalline form and will transform into Form 1. Therefore, the temperature ranges for all three crystalline forms are relatively narrow, posing a risk of transformation.

The prior art WO2020010216A discloses ilexatran dihydrochloride form 1b, which has good stability but is prone to aggregation, which has a certain impact on subsequent formulations.

Existing technology WO2023064519A discloses forms 6, 7, and 9, where form 6 is a DMSO solvate and form 7 is a n-propanol solvate. Form 9 is obtained by amorphous material undergoing crystal transformation at 75% humidity. Form 9 is difficult to scale up and poses a risk of reproducibility issues.

The prior art WO2023/227029A discloses the crystal form CSII of lasrasil dihydrochloride. This crystal form needs to be prepared in a chloroform system. Chloroform is a Class II solvent with a low residual limit, which poses a high risk to the production of pharmaceutical products.

It is evident that the crystal forms of these ellastrand dihydrochloride salts reported in the existing technology are not ideal. Therefore, there is a need for a crystal form that is more suitable for industrial production and for preparing drugs containing ellastrand dihydrochloride salts or for purifying ellastrand or its salts.

Summary of the Invention

The purpose of this invention is to provide a new crystal form of ellastrone hydrochloride.

In a first aspect, the present invention provides an alasin dihydrochloride in crystal form APTI-I, which, when irradiated with Cu-Kα, exhibits characteristic peaks in its XRPD spectrum, expressed in 2θ angles, at 9.6°±0.2°, 12.0°±0.2°, 13.5°±0.2°, 20.5°±0.2°, 21.9°±0.2°, and 22.4±0.2°.

In another preferred embodiment, the X-ray powder diffraction (XRPD) pattern of the APTI-I crystal form of the alasin dihydrochloride also has one or more characteristic peaks selected from the following:

6.1°±0.2°, 7.9°±0.2°, 12.3°±0.2°, 14.1°±0.2°, 17.0°±0.2°, 17.2°±0.2°, 17.5°±0.2°, 17.8°±0.2°, 18.7°±0.2°, 19.1°±0.2°, 19.8°±0.2°, 21.3°±0.2° 22.2°±0.2°, 22.7°±0.2°, 24.2°±0.2°, 24.5°±0.2°, 24.7°±0.2°, 25.0°±0.2°, 25.3°±0.2°, 26.4°±0.2°, 27.2°±0.2°, 27.4°±0.2°, 27.7°±0.2°, 28.7±0.2°.

In another preferred embodiment, the differential scanning calorimetry (DSC) spectrum of the APTI-I crystal form of the alastan dihydrochloride exhibits endothermic peaks at 71.6±5℃ and 197.6±5℃.

In another preferred embodiment, the thermogravimetric analysis (TGA) spectrum of the APTI-I crystal form of the alastan dihydrochloride shows a weight loss of approximately 1.5% to 3.8% at 30–120°C.

In another preferred embodiment, the thermogravimetric analysis (TGA) spectrum of the APTI-I crystal form of the alastan dihydrochloride shows a step weight loss of approximately 2.06% between 30 and 120 °C.

In another preferred embodiment, the thermogravimetric analysis (TGA) spectrum of the APTI-I crystal form of the alastan dihydrochloride shows a weight loss of approximately 3.76% in the range of 30°C to 120°C.

In a preferred embodiment, the thermogravimetric analysis (TGA) spectrum of the APTI-I crystal form of the alastan dihydrochloride after heating showed a weight loss of approximately 1.63% in the range of 30°C to 120°C.

In a preferred embodiment, the XRPD pattern of the APTI-I crystal form of the alasin dihydrochloride is substantially consistent with that in Figure 1.

In another preferred embodiment, the APTI-I crystal form of the alasin dihydrochloride provided by the present invention, when subjected to Cu-Kα radiation, exhibits a characteristic peak at at least one of the following 2θ angles in its XRPD spectrum: 9.6°±0.2°, 12.0°±0.2°, and 20.5°±0.2°. In another preferred embodiment, the XRPD spectrum of the APTI-I crystal form further comprises one or more characteristic peaks selected from the following:

6.1°±0.2°, 7.9°±0.2°, 12.3°±0.2°, 13.5°±0.2°, 14.1°±0.2°, 17.0°±0.2°, 17.2°±0.2°, 17.5°±0.2°, 17.8°±0.2°, 18.7°±0.2°, 19.1°±0.2°, 19.8°±0.2°, 21.3°±0.2°, 21.9°± 0.2°, 22.2°±0.2°, 22.4°±0.2°, 22.7°±0.2°, 24.2°±0.2°, 24.5°±0.2°, 24.7°±0.2°, 25.0°±0.2°, 25.3°±0.2°, 26.4°±0.2°, 27.2°±0.2°, 27.4°±0.2°, 27.7°±0.2°, 28.7±0.2°.

In a second aspect, the present invention provides a method for preparing the crystalline form APTI-I of alastan dihydrochloride, comprising the following steps:

After stirring the alastan dihydrochloride in a mixture of organic solvent and water, the mixture was separated and dried to obtain the crystalline form APTI-I.

In another preferred embodiment, the organic solvent is selected from methanol, ethanol, n-propanol, isopropanol, acetone, 2-butanone, acetonitrile, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, or combinations thereof, more preferably, acetonitrile or acetone.

In another preferred embodiment, the volume ratio of the organic solvent to water is 3 to 9:1, more preferably 7 to 9:1.

In another preferred embodiment, the weight-to-volume ratio of ellastatin dihydrochloride to the mixture is 0.05–0.2 g/mL.

In another preferred embodiment, when ellastatin dihydrochloride is stirred in the mixture, the system temperature is 20–60°C and the stirring time is 8–48 h.

In another preferred embodiment, the drying temperature is 40–60°C and the time is 8–24 hours.

In a third aspect, the present invention provides a crystal form APTI-II of arasyl group dihydrochloride, which, when irradiated with Cu-Kα, has characteristic peaks at 7.0°±0.2°, 13.9°±0.2°, 15.8°±0.2°, 21.9°±0.2°, and 23.5°±0.2° in its XRPD spectrum expressed at 2θ angles.

In another preferred embodiment, the XRPD spectrum of the APTI-II crystal form also has one or more characteristic peaks selected from the following:

8.1°±0.2°, 8.8°±0.2°, 11.7°±0.2°, 12.5°±0.2°, 14.9°±0.2°, 17.4°±0.2°, 18.7°±0.2°, 19.5°±0.2°, 20.9°±0.2°, 24.4°±0.2°, 25.3°±0.2°, 26.2°±0.2°, 26.9°±0.2°, 28.0°±0.2°, 28.6°±0.2°, 29.7°±0.2°, 30.9°±0.2°, 38.0°±0.2°.

In another preferred embodiment, the thermogravimetric analysis (TGA) spectrum of the APTI-II crystal form shows a step weight loss of approximately 12.7% between 30°C and 170°C.

In another preferred embodiment, the XRPD pattern of the APTI-II crystal form is substantially consistent with that in Figure 6.

In another preferred embodiment, the crystalline form APTI-II is a 2-ethoxyethanol solvate of ellastridium dihydrochloride. In yet another preferred embodiment, the ratio of ellastridium molecules to 2-ethoxyethanol molecules in the crystalline form APTI-II is 1:1.

In a fourth aspect, the present invention provides a method for preparing the crystalline form APTI-II of alastan dihydrochloride, comprising the following steps:

After stirring arastridium dihydrochloride in 2-ethoxyethanol, the mixture was allowed to stand and separated, and then dried to obtain the crystalline form APTI-II.

In another preferred embodiment, in the method for preparing the crystalline form APTI-II, the weight-to-volume ratio of allassyl hydrochloride to 2-ethoxyethanol is 0.05–0.2 g/mL.

In another preferred embodiment, in the preparation method of crystal form APTI-II, the system is first stirred at 40-60°C for 6-10 hours, then stirred at 0-40°C for 6-10 hours, and finally stirred at 40-60°C for 6-10 hours.

In another preferred embodiment, in the preparation method of crystal form APTI-II, the standing process is to stand at room temperature for 6 to 9 days.

In another preferred embodiment, the drying temperature is 40–60°C and the drying time is 8–24 h in the preparation method of the APTI-II crystal form.

In a fifth aspect, the present invention provides a crystal form APTI-III of arasyldihydrochloride, which, when irradiated with Cu-Kα, has characteristic peaks at 11.3°±0.2°, 11.8°±0.2°, 13.4°±0.2°, 18.2°±0.2°, 21.2°±0.2°, and 25.8°±0.2° in its XRPD spectrum expressed in 2θ angles.

In another preferred embodiment, the XRPD spectrum of the APTI-III crystal form also has one or more characteristic peaks selected from the following:

5.6°±0.2°, 10.3°±0.2°, 11.0°±0.2°, 12.5°±0.2°, 14.9°±0.2°, 15.4°±0.2°, 18.8°±0.2°, 19.3°±0.2°, 20.1°±0.2°, 20.5°±0.2°, 22.0°±0.2°, 23.0°±0.2°, 24.0°±0.2°, 26.3°±0.2°, 27.2°±0.2°, 27.6°±0.2°, 29.9°±0.2°;

In another preferred embodiment, the differential scanning calorimetry spectrum of the APTI-III crystal form exhibits endothermic peaks at 112.5℃±5℃ and 227.8℃±5℃.

In another preferred embodiment, the XRPD pattern of the APTI-III crystal form is substantially consistent with that in Figure 8.

In another preferred embodiment, the elastoside dihydrochloride crystal form APTI-III is a DMF solvate of elastoside dihydrochloride. In another preferred embodiment, the ratio of elastoside molecules to DMF molecules in the elastoside dihydrochloride crystal form APTI-III is 1:1.

In a sixth aspect, the present invention provides a method for preparing the crystal form APTI-III of the above-mentioned alastan dihydrochloride, comprising the following steps:

Alirastriol dihydrochloride was added to DMF, heated to dissolve, cooled to crystallize, separated, and dried to obtain the crystalline form APTI-III.

In another preferred embodiment, in the method for preparing the APTI-III crystal form, the heating temperature is 80–100°C and the cooling temperature is 10–30°C.

In another preferred embodiment, in the preparation method of crystalline APTI-III, the weight-to-volume ratio of ellastrin dihydrochloride to DMF is 10–25 mg/mL.

In another preferred embodiment, the drying temperature is 40–60°C and the drying time is 8–24 h in the preparation method of the APTI-III crystal form.

In a sixth aspect of the invention, the use of elasitran dihydrochloride in crystal form APTI-I, APTI-II or APTI-III in the preparation of a medicament containing elasitran dihydrochloride or in the purification of elasitran or its salts is provided.

Attached Figure Description

Figure 1 shows the XRPD pattern of APTI-I, the crystal form of ellasigroup dihydrochloride;

Figure 2 shows the DSC spectrum of APTI-I, the crystal form of ellasigroup dihydrochloride;

Figure 3 shows the TGA spectrum of the crystal form APTI-I of the alastan dihydrochloride prepared in Example 1;

Figure 4 shows the PLM pattern of APTI-I, the crystal form of alastan dihydrochloride prepared in Example 2;

Figure 5 shows the PSD pattern of the crystal form APTI-I of the alastan dihydrochloride prepared in Example 2;

Figure 6 shows the XRPD pattern of APTI-II, the crystal form of allergic dihydrochloride;

Figure 7 shows the TGA spectrum of the crystal form APTI-II of allergan dihydrochloride;

Figure 8 shows the XRPD pattern of APTI-III, the crystal form of ellasigroup dihydrochloride;

Figure 9 shows the DSC spectrum of the crystalline form APTI-III of allergan dihydrochloride;

Figure 10 shows the TGA spectrum of the crystal form APTI-I of the alastan dihydrochloride prepared in Example 2;

Figure 11 is a superimposed image of the XRPD patterns of the APTI-I crystal obtained in Example 2 before and after vacuum drying at 80°C for 24 hours;

Figure 12a shows the TGA spectrum of the APTI-I crystal obtained in Example 2 after vacuum drying at 80°C for 24 hours;

Figure 12b shows the DSC spectrum of the APTI-I crystal obtained in Example 2 after vacuum drying at 80°C for 24 hours.

Figure 13a is a superimposed image of the XRPD patterns of the APTI-I crystal obtained in Example 2 before and after grinding;

Figure 13b is a superimposed image of the XRPD patterns of the APTI-I crystal obtained in Example 3 before and after grinding;

Figure 14 is an overlay of the XRPD patterns of the APTI-I crystal obtained in Example 2 after being placed at 25℃/60%RH and 40℃/70%RH for 2 weeks, and the XRPD patterns before placement.

Figure 15a is a superimposed XRPD pattern of different water activity competing with the crystal form APTI-I prepared in Example 2 and the prior art form 1.

Figure 15b is a superimposed XRPD pattern of different water activity competing with the crystal form APTI-I prepared in Example 3 and the prior art form 1.

Figure 16 shows the XRPD pattern of Form 1 prepared according to the prior art WO2018129419A1 in Comparative Example 1;

Figure 17 shows the PSD pattern of Form 1 prepared according to the prior art WO2018129419A1 in Comparative Example 1;

Figure 18 shows the XRPD pattern of Form 2 prepared according to the prior art WO2018129419A1 in Comparative Example 2;

Figure 19 shows the DSC spectrum of Form 2 prepared according to the prior art WO2018129419A1 in Comparative Example 2;

Figure 20 is a superimposed image of the XRPD spectra before and after mixing and pulping in Comparative Example 2;

Figure 21 shows the XRPD pattern of Form 3 prepared according to the prior art WO2018129419A1 in Comparative Example 3;

Figure 22 is a superimposed image of the XRPD spectra of Comparative Example 3 before and after room temperature air drying;

Figure 23 is an overlay of the XRPD patterns of the crystal form APTI-I obtained in the embodiment of the present invention and the Form 1, Form 2 and Form 3 disclosed in the prior art.

Figure 24 is an overlay of the XRPD spectra of tablet excipients, tablets of crystalline APTI-I, and crystalline APTI-I (from top to bottom);

Figure 25 is an overlay of the XRPD pattern of APTI-I tablets after being exposed to light, 40℃/75%RH, and 25℃/60%RH for 10 days, and the XRPD pattern of freshly prepared APTI-I tablets (from top to bottom).

Figure 26 is an overlay of the XRPD pattern of APTI-I tablets after being exposed to light, 40℃/75%RH, and 25℃/60%RH for 20 days, and the XRPD pattern of freshly prepared APTI-I tablets (from top to bottom).

Figure 27 shows the dissolution rate comparison curves of APTI-I tablets and Form 1 tablets in a 1.2 pH buffer.

Figure 28 shows the dissolution rate comparison curves of APTI-I tablets and Form 1 tablets in a 4.5 pH buffer.

Figure 29 shows the dissolution rate comparison curves of APTI-I tablets and Form 1 tablets in a 6.8 pH buffer.

Figure 30 shows a comparison curve of the dissolution rate in water for tablets of form APTI-I and form 1.

Detailed Implementation

To address the shortcomings of existing technologies, the inventors of this application conducted in-depth research on the crystal forms of ellastrantrine dihydrochloride and unexpectedly discovered a new crystal form, APTI-I, which exhibits superior efficacy in preparing pharmaceutical formulations. This new form boasts high yield, low organic solvent residue, and a simple preparation method, making it suitable for scale-up production. Furthermore, in the competition regarding water activity, this crystal form unexpectedly demonstrates a wider water activity stability range than previously disclosed crystal forms (e.g., forms 1 and 3 disclosed in WO2018129419), providing greater operational flexibility and reducing production and storage risks. Moreover, this crystal form exhibits stable physicochemical properties at high temperatures and under varying temperature and humidity conditions, and its good product flowability makes it suitable for preparing a variety of formulations. The inventors of this application also obtained new crystal forms APTI-II and APTI-III, with purities reaching 99.92% and 99.95%, respectively. These high-purity crystal forms offer more options for the purification research and application of ellastrantrine active pharmaceutical ingredient. Based on these findings, this invention was completed.

In the description of this invention, "room temperature" refers to 0-40°C, for example, 5-35°C, 15-28°C, 20-25°C, 28°C, etc. are all considered room temperature.

The crystal form of arasyl group dihydrochloride is APTI-I.

The APTI-I iris group dihydrochloride crystal form provided by this invention, when irradiated with Cu-Kα, exhibits characteristic peaks in its XRPD spectrum expressed at 2θ angles at 9.6°±0.2°, 12.0°±0.2°, 13.5°±0.2°, 20.5°±0.2°, 21.9°±0.2°, and 22.4°±0.2°, or in its XRPD spectrum expressed at 2θ angles at 9.6°±0.2°, 12.0°±0.2°, and 20.5°±0.2°.

Furthermore, using Cu-Kα radiation, the XRPD spectra of the APTI-I dihydrochloride crystal form provided by this invention, expressed in 2θ angles, are obtained at 6.1°±0.2°, 7.9°±0.2°, 9.6°±0.2°, 12.0°±0.2°, 12.3°±0.2°, 13.5°±0.2°, 14.1°±0.2°, 17.0°±0.2°, 17.2°±0.2°, 17.5°±0.2°, 17.8°±0.2°, 18.7°±0.2°, and 19.1°±0.2°. Characteristic peaks are observed at 19.8°±0.2°, 20.5°±0.2°, 21.3°±0.2°, 21.9°±0.2°, 22.2°±0.2°, 22.4°±0.2°, 22.7°±0.2°, 24.2°±0.2°, 24.5°±0.2°, 24.7°±0.2°, 25.0°±0.2°, 25.3°±0.2°, 26.4°±0.2°, 27.2°±0.2°, 27.4°±0.2°, 27.7°±0.2°, and 28.7±0.2°.

Furthermore, using Cu-Kα radiation, the X-ray powder diffraction pattern of the APTI-I crystal form of the alasin dihydrochloride provided by this invention, expressed in 2θ angles, exhibits characteristic peaks as shown in Table 1:

Table 1

Furthermore, using Cu-Kα radiation, the XRPD pattern of APTI-I, the alasin group dihydrochloride crystal form provided by the present invention, expressed in 2θ angle, is consistent with that in Figure 1.

Furthermore, the DSC spectrum of the APTI-I dihydrochloride crystal form provided by the present invention is consistent with that in Figure 2.

Furthermore, the TGA spectrum of the APTI-I dihydrochloride crystal form provided by the present invention is consistent with that in Figure 3.

Furthermore, the TGA spectrum of the APTI-I dihydrochloride crystal form provided by the present invention is consistent with that in Figure 10.

Furthermore, polarized light microscopy (PLM) observation of the APTI-I crystal form of the alasin group dihydrochloride provided by the present invention shows that the crystal morphology is blocky, uniformly distributed, and without agglomeration.

Furthermore, the PLM observation results of APTI-I, the alasin dihydrochloride crystal form provided by the present invention, are shown in Figure 4.

Furthermore, the crystal form APTI-I of the ellastan dihydrochloride provided by the present invention is ellastan dihydrochloride hydrate.

Furthermore, the water content of the APTI-I crystal form of elastoside dihydrochloride provided by the present invention is 1.5% to 3.8% (by weight). In some specific embodiments, the ratio of elastoside dihydrochloride molecules to water molecules in the APTI-I crystal form of elastoside dihydrochloride provided by the present invention is 1:1. In some specific embodiments, the ratio of elastoside dihydrochloride molecules to water molecules in the APTI-I crystal form of elastoside dihydrochloride provided by the present invention is 1:0.5. In some specific embodiments, the ratio of elastoside dihydrochloride molecules to water molecules in the APTI-I crystal form of elastoside dihydrochloride provided by the present invention is 1:0.6.

In some specific embodiments, the preparation method of ellastatin dihydrochloride crystal form APTI-I provided by the present invention includes the following steps: stirring ellastatin dihydrochloride in a mixture of organic solvent and water, separating, and drying to obtain crystal form APTI-I. The weight-to-volume ratio of ellastatin dihydrochloride to the mixture is 0.05–0.2 g/mL, the volume ratio of organic solvent to water is 3–9:1, the system temperature during stirring is 20–60°C, the stirring time is 8–48 h, and the drying temperature is 40–60°C for 8–24 h.

The organic solvents include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, acetone, 2-butanone, acetonitrile, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and N,N-dimethylacetamide.

New crystal form of arasyl group dihydrochloride, APTI-II

The APTI-II crystal form of the alasin dihydrochloride provided by this invention, when irradiated with Cu-Kα, exhibits characteristic peaks at 7.0°±0.2°, 13.9°±0.2°, 15.8°±0.2°, 21.9°±0.2°, and 23.5°±0.2° in its XRPD spectrum expressed at 2θ angles.

Furthermore, using Cu-Kα radiation, the XRPD spectra of the APTI-II dihydrochloride crystal form of the present invention, expressed in 2θ angles, are obtained at 7.0°±0.2°, 8.1°±0.2°, 8.8°±0.2°, 11.7°±0.2°, 12.5°±0.2°, 13.9°±0.2°, 14.9°±0.2°, 15.8°±0.2°, 17.4°±0.2°, and 18.7°. Characteristic peaks are observed at ±0.2°, 19.5°±0.2°, 20.9°±0.2°, 21.9°±0.2°, 23.5°±0.2°, 24.4°±0.2°, 25.3°±0.2°, 26.2°±0.2°, 26.9°±0.2°, 28.0°±0.2°, 28.6°±0.2°, 29.7°±0.2°, 30.9°±0.2°, and 38.0°±0.2°.

Furthermore, using Cu-Kα radiation, the X-ray powder diffraction pattern of the APTI-II crystal form of the alasin dihydrochloride provided by this invention, expressed in 2θ angles, exhibits characteristic peaks as shown in Table 2:

Table 2

Furthermore, the XRPD pattern of the APTI-II crystal form of the alasin dihydrochloride provided by the present invention is consistent with that in Figure 6.

Furthermore, the thermogravimetric analysis (TGA) spectrum of the APTI-II crystal form of ellastridium dihydrochloride provided by the present invention shows a step weight loss of approximately 12.7% at 170°C.

Furthermore, the TGA spectrum of the APTI-II crystal form of the alasin dihydrochloride provided by the present invention is consistent with that in Figure 7.

Furthermore, the crystalline form APTI-II of ellastrone dihydrochloride provided by the present invention is a 2-ethoxyethanol solvate of ellastrone dihydrochloride. In some specific embodiments, the ratio of ellastrone molecules to 2-ethoxyethanol molecules in crystalline form APTI-II is 1:1.

In some specific embodiments, the preparation method of the crystalline form APTI-II of ellastatin dihydrochloride according to the present invention includes: stirring ellastatin dihydrochloride (solid) in 2-ethoxyethanol, allowing it to stand and separate, and drying to obtain crystalline form APTI-II. The weight-to-volume ratio of ellastatin dihydrochloride to 2-ethoxyethanol is 0.05–0.2 g/mL; during stirring, the system is first stirred at 40–60°C for 6–10 h, then at 0–40°C for 6–10 h, and finally at 40–60°C for 6–10 h; the standing process is carried out at room temperature for 6–9 days. The drying temperature is 40–60°C, and the drying time is 8–24 h.

A new crystalline form of ilastrone dihydrochloride, APTI-III .

The APTI-III crystal form of the alasin dihydrochloride provided by the present invention, when irradiated with Cu-Kα, exhibits characteristic peaks at 11.3±0.2°, 11.8±0.2°, 13.4±0.2°, 18.2±0.2°, 21.2±0.2°, and 25.8±0.2° in its XRPD spectrum expressed at 2θ angles.

Furthermore, using Cu-Kα radiation, the XRPD spectra of the APTI-III crystal form of the alasin dihydrochloride provided by this invention, expressed in 2θ angles, are obtained at 5.6±0.2°, 10.3±0.2°, 11.0±0.2°, 11.3±0.2°, 11.8±0.2°, 12.5±0.2°, 13.4±0.2°, 14.9±0.2°, and 15.4±0.2°. Characteristic peaks are observed at 18.2±0.2°, 18.8±0.2°, 19.3±0.2°, 20.1±0.2°, 20.5±0.2°, 21.2±0.2°, 22.0±0.2°, 23.0±0.2°, 24.0±0.2°, 25.8±0.2°, 26.3±0.2°, 27.2±0.2°, 27.6±0.2°, and 29.9±0.2°.

Furthermore, using Cu-Kα radiation, the XRPD spectrum of the APTI-III crystal form of the alasin dihydrochloride provided by this invention, expressed at a 2θ angle, exhibits characteristic peaks as shown in Table 3:

Table 3

Furthermore, using Cu-Kα radiation, the XRPD pattern of the APTI-III crystal form of the alasin dihydrochloride provided by the present invention, expressed in 2θ angles, is consistent with that in Figure 8.

Furthermore, the DSC spectrum of APTI-III, the alasin group dihydrochloride crystal form provided by the present invention, is consistent with that in Figure 9.

Furthermore, the ellastan dihydrochloride crystal form APTI-III provided by this invention is an N,N-dimethylformamide (DMF) solvate of ellastan dihydrochloride. In some specific embodiments, the ratio of ellastan molecules to DMF molecules in crystal form APTI-III is 1:1.

In some specific embodiments, the method for preparing the crystalline form APTI-III of arasyldine dihydrochloride provided by the present invention includes the following:

Alirastan dihydrochloride was added to DMF, heated to dissolve, cooled to crystallize, separated, and dried to obtain crystalline APTI-III. The heating temperature was 80–100℃, the cooling temperature was 0–30℃, the drying temperature was 40–60℃, and the drying time was 8–24 h. The weight-to-volume ratio of alirastan dihydrochloride to DMF was 10–25 mg/mL.

Compared with the prior art, the beneficial effects of the novel crystalline form of arasyldihydrochloride of the present invention are as follows:

1. The APTI-I crystalline form provided by this invention has a wider water activity range for preparation compared to forms 1 and 3 disclosed in the prior art. The preparation operation is simple and easy to control, with high yield and high purity, making it more suitable for large-scale industrial production. This APTI-I crystalline form is stable under different temperatures and humidity levels, which is beneficial for storage. Furthermore, this crystalline form exhibits good crystal dispersion and flowability, which is advantageous for later formulation use. Therefore, this APTI-I crystalline form demonstrates superior practicality in early-stage production, mid-stage storage, and late-stage formulation.

2. The APTI-II and APTI-III crystal forms prepared by this invention have high purity, providing more options for purification during the production of alastan or its salts.

The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and parts by weight.

General Method

1. XRPD spectral determination method

X-ray powder diffractometer: BRUKER AXS D2 PHASER X-ray powder diffractometer; Radiation source: Intensity ratio α1/α2 is 0.5; Generator kV: 30.0 kV; Generator mA: 10.0 mA; Scan range: 3.0～40.0°.

2. DSC Measurement Method

METTLEER DSC1 differential scanning calorimeter temperature program: 30℃～250℃, temperature increase of 10℃ per minute.

3. TGA determination method

Instrument model: METTLEER TGA/DSC1 thermogravimetric analyzer. Temperature program: 30℃～300℃, 10℃ increase per minute.

Comparative Example 1: Preparation of Form 1 disclosed in prior art WO2018129419A1

Aqueous leprasant dihydrochloride aqueous solution was rotary evaporated at 50℃ to obtain amorphous leprasant dihydrochloride. 20 mL of ethanol was added and stirred at 50℃ for 4 h. The mixture was then filtered under reduced pressure and dried under vacuum at 50℃ for 16 h to obtain 4.2 g of white solid, which is the Form 1 disclosed in prior art WO2018129419A1 (its XRPD spectrum is shown in Figure 16), with a purity of 99.77%. The product showed severe agglomeration during filtration. The PSD results are shown in Figure 17, with a D90 of 355.9 μm. The agglomerates were difficult to disperse, which is not conducive to subsequent formulation.

Comparative Example 2: Preparation of Form 2 disclosed in prior art WO2018129419A1

200 mg of leprastran dihydrochloride (solid) was weighed and dissolved in 2 mL of methanol at 50 °C. After naturally cooling to room temperature, it was added dropwise to 6 mL of ethyl acetate, resulting in the precipitation of a large amount of white solid. The solid was filtered under reduced pressure and sampled for analysis, which was the Form 2 disclosed in prior art WO2018129419A1 (its XRPD spectrum is shown in Figure 18). Its DSC results (see Figure 19) showed that after melting at 163 °C, recrystallization occurred at 170 °C, consistent with the data for Form 2 disclosed in prior art WO2018129419A1. Form 2 was further stirred in a methanol/ethyl acetate system at 50 °C for 1 h, transforming into Form 1 disclosed in prior art WO2018129419A1. Form 2 is metastable and amorphous, posing a significant risk of crystal transformation and is difficult to replicate (see Figure 20 for a comparison of the XRPD spectra of Form 2 and the product obtained after stirring (stirring) in a methanol/ethyl acetate system at 50 °C for 1 h).

Comparative Example 3: Preparation according to Form 3 disclosed in prior art WO2018129419A1

Weigh 1g of ellastatin dihydrochloride, add it to 3mL of water and stir at room temperature for 1 day. Filter to obtain 267mg of white solid, which is the Form 3 disclosed in prior art WO2018129419A1 (see Figure 21 for its XRPD diagram). After air drying at room temperature, the product transforms into crystal form APTI-I (see Figure 22 for a comparison of the XRPD diagrams of Form 3 and the crystal form it becomes after air drying at room temperature). The crystal form is unstable, and due to the high solubility of ellastatin dihydrochloride in water, the yield is less than 26.7%.

Example 1: Preparation of APTI-I crystal form of alastan dihydrochloride

200 mg of elastosan dihydrochloride (solid) was added to the reaction flask, along with 2 mL of a mixed solvent of acetonitrile: _H₂O (volume ratio 8:1). The mixture was magnetically stirred at 50 °C for 2 days (48 hours), filtered, and then vacuum dried at 50 °C for 16 hours, yielding 182 mg of solid with a purity of 99.81%. XRPD analysis of the solid was performed, and the results were consistent with Figure 1. DSC analysis was performed, and the results were consistent with Figure 2. TGA analysis was performed, and the results were consistent with Figure 3. The product's KF was 1.95%, meaning that each molecule of the APTI-I crystal form contains approximately 0.6 ppm of water. After deducting the water content, the yield was 89%. Organic solvent residue analysis showed that the product had 41 ppm of acetonitrile residue, far below the ICH limit (the ICH limit for acetonitrile is 410 ppm).

Example 2: Preparation of APTI-I crystal form of alastan dihydrochloride

1.60 g of ellastatin dihydrochloride solid was added to the reaction flask, along with 15 mL of a 9:1 (volume ratio) acetone: _H₂O mixture. The mixture was magnetically stirred at 50 °C for 2 days (48 hours), filtered, and then vacuum dried at 50 °C for 6 hours to obtain 1.53 g of solid with a purity of 99.90%. XRPD analysis of the obtained solid showed results consistent with Figure 1; DSC analysis showed results consistent with Figure 2; and TGA analysis showed results consistent with Figure 10. The product's KF was 3.3%, meaning that each molecule of the APTI-I crystal form contains approximately one water molecule. After deducting water, the yield was 92.3%. Organic solvent residue analysis showed that the acetone residue in the product was 89 ppm, far below the ICH limit (5000 ppm for acetone). The prepared material was tested by polarized light PLM, and the results are shown in Figure 4. The product is a block crystal with a uniform particle size distribution, which is more conducive to granulation and tableting in the formulation. The PSD test will show that the product basically presents a normal distribution (see Figure 5). Compared with Form 1 (see Figure 17), its particle distribution is more uniform.

Example 3: High-temperature stability test of APTI-I crystal form of alastan dihydrochloride

The APTI-I crystalline form of ellastatin dihydrochloride prepared in Example 2 was placed in a vacuum-dried environment at 80°C for 24 hours. Samples were taken for testing, and its XRPD spectrum was consistent with that before drying (see Figure 11, showing the overlay of XRPD spectra before and after vacuum drying at 80°C for 24 hours). The TGA test results for this crystalline form are shown in Figure 12a, the DSC results are shown in Figure 12b, and the KF results show a water content of approximately 1.65%, or about 0.5 water molecules. The purity before and after drying was 99.90%, with no chemical degradation observed. Based on this, this crystalline form can withstand high-temperature granulation during formulation without the influence of high-temperature dehydration.

The XRPD patterns and DSC results of the crystal forms obtained from Example 1, Example 2, and Example 3 (after vacuum drying at 80°C for 24 hours, yielded the APTI-I crystal form from Example 2) were consistent, with differences only in TGA data and water content. Based on this, it is inferred that the obtained APTI-I crystal form of ellasyl group dihydrochloride is a porous hydrate, with each molecule containing 0.5–1 water molecules.

Example 4: Stability test of APTI-I grinding of Alaskin dihydrochloride crystal form

200 mg of the ellastan dihydrochloride crystal form APTI-I (HPLC purity 99.90%) prepared in Example 2 was weighed and manually dry-ground in an agate mortar for 30 min. The XRPD was then measured and compared with the XRPD before dry grinding. The results are shown in Figure 13a. The comparison showed that the crystal form did not change before and after grinding, and the purity was 99.87%, with no significant change in purity.

200 mg of the crystal form obtained from the dried ellaxizone dihydrochloride APTI-I crystal form of Example 3 (HPLC purity 99.90%) was weighed and manually dry-ground in an agate mortar for 30 min. The XRPD was then measured and compared with the XRPD before dry grinding. The results are shown in Figure 13b. The comparison revealed that the crystal form remained unchanged before and after grinding, with a purity of 99.90%. The purity showed no significant change, indicating that this crystal form is stable even after dry granulation in formulations.

Example 5: Temperature and Humidity Stability Test of APTI-I Crystal Form of Alaskin Dihydrochloride

The APTI-I crystalline form of lassyl group dihydrochloride from Example 2 was packaged in PE bags and aluminum foil bags and placed at 25°C/60%RH and 40°C/70%RH for 2 weeks, respectively. Its XRPD was measured and compared with the XRPD of the crystalline form before placement. The overlay of the XRPD spectra of crystalline form APTI-I before and after placement is shown in Figure 14.

Table 4 summarizes the parameters of the grinding stability and temperature and humidity stability experiments of APTI-I dihydrochloride crystal form of Example 2 and the purity results of the obtained products.

Table 4

As can be seen from Figure 14 and Table 4, the crystal form and purity of the alastan dihydrochloride in Example 2 remained essentially unchanged after grinding for 30 minutes and being placed at 25°C/60%RH and 40°C/70%RH for 2 weeks.

Example 6: Competition Experiment of Water Activity Suspension of Alaskin Dihydrochloride Crystal Form APTI-I

Equal amounts of the alastan dihydrochloride crystal form APTI-I obtained in Example 2 and the form 1 obtained according to the prior art WO2018129419 were weighed and magnetically stirred for 2 days at room temperature in saturated solutions of acetone/water, either alone or in a mixture, with water activities of 0, 0.2, 0.3, 0.4, 0.6, 0.7, 0.8, and 1. XRPD was then measured, and the results are shown in Figure 15a. The results show that the water activity range of 0–0.2 corresponds to form 1, 0.3–0.7 corresponds to form APTI-1, and 0.8–1 corresponds to form 3. The APTI-1 crystal form has a wider water activity preparation range.

Equal amounts of the crystal form APTI-I obtained from the alastan dihydrochloride of Example 2, which was vacuum dried at 80°C for 24 hours, and the crystal form 1 obtained according to the prior art WO2018129419 were weighed and magnetically stirred for 2 days at room temperature in saturated solutions of acetone/water, either alone or in mixtures, with water activities of 0, 0.2, 0.3, 0.4, 0.6, 0.7, 0.8, and 1. The XRPD was then measured, and the results are shown in Figure 15b. The results show that the water activity range of 0–0.2 is for crystal form 1, 0.3–0.7 is for crystal form APTI-1, and 0.8–1 is for crystal form 3. Crystal form APTI-1 has a wider water activity preparation range.

Example 7: Flowability of APTI-I crystal form of lassitran dihydrochloride

In formulation processes, the compressibility coefficient *c* is commonly used to evaluate the flowability of powders or granules. The compressibility coefficient is calculated as *c* = (ρf - ρ0) / ρf, where ρf is the tap density and ρ0 is the bulk density. According to the USP General Charters: <1174> Powder Flow evaluation criteria, the flowability of the APTI-I crystal form from Example 2 of this invention was evaluated. The results showed that the bulk density ρ0 was 0.231 g/mL, the tap density was 0.269 mg/mL, and the compressibility coefficient *c* was 14.1, indicating good flowability (11-15).

Example 8: Preparation of APTI-II crystal form of alastan dihydrochloride

1 g of ellastrin dihydrochloride (solid) and 30 mL of 2-ethoxyethanol were added to the reaction flask. The mixture was stirred at 50 °C for 8 h, then cooled to room temperature and stirred for another 8 h. The mixture was then heated to 50 °C and stirred for another 8 h. After cooling to room temperature and standing for 7 days, the mixture was filtered and dried to obtain 1.02 g of solid. XRPD test results were consistent with Figure 6, indicating the presence of the APTI-II crystal form. TGA results were consistent with Figure 7. The 1H NMR results showed that the molecular ratio of ellastrin dihydrochloride to 2-ethoxyethanol in this crystal form was 1:1, and the purity was 99.92%.

Example 9: Preparation of APTI-III crystal form of alastan dihydrochloride

200 mg of ellastatin dihydrochloride (solid) and 12 mL of DMF were added to the reaction flask. The mixture was heated to 90 °C and stirred until dissolved. Then, the mixture was slowly cooled to 25 °C, and a white solid precipitated. The solid was filtered and dried to obtain 172 mg of solid. The XRPD test results were consistent with Figure 8, indicating that the crystal form was APTI-III. The DSC results were consistent with Figure 9. The 1H NMR results showed that the molecular ratio of ellastatin dihydrochloride to DMF in this crystal form was 1:1, and the purity of the product was 99.95%.

Example 10: Preparation of tablets of elastotran dihydrochloride crystal form APTI-I and tablets of form 1 disclosed in prior art WO2018129419A1

The components and preparation processes of Form 1 tablets and APTI-I crystalline tablets are shown in Tables 5 and 6 below, respectively.

Table 5. Composition and dosage of tablets:

In Table 5, “API” refers to Form 1 or crystal form APTI-I.

Table 6. Tablet Preparation Process

Example 11: Stability Study of Alirastane Dihydrochloride Crystal Form APTI-I Tablets

The XRPD spectra obtained by detecting excipients, tablets of crystalline APTI-I, and crystalline APTI-I are shown in Figure 24.

After exposing APTI-I crystalline tablets to light and at 40℃/75%RH and 25℃/60%RH for 10 or 20 days, samples were taken for XRPD analysis. The results are shown in Table 7, Figures 25 and 26. The results show that the APTI-I crystalline form did not change significantly after being exposed to light under these conditions, indicating that the tablets have stable physicochemical properties.

Table 7

Example 12: Dissolution study of tablets of form APTI-I and form 1 of ellastatin dihydrochloride

Tablets of APTI-I and form 1 were placed in buffer solutions and water at different pH values. Samples were taken at 10, 15, 20, 30, 45, 60, 90, and 120 min to determine the concentration of ellaxiclostrid, and dissolution curves were plotted (see Figures 27-30). The results showed that both crystal forms had relatively high dissolution rates, and APTI-I did not affect drug release relative to form 1.

In summary, the APTI-I crystal form of ellastrantrine dihydrochloride obtained by this invention is a novel crystal form, distinct from existing publicly available crystal forms, and possesses a completely new XRPD spectrum. Compared to forms 1 and 3 obtained in the original research, this crystal form exhibits a wider water activity stability range, thus demonstrating better crystal form stability and facilitating large-scale production. Furthermore, compared to form 2 obtained in the original research, APTI-I does not pose a crystal transformation risk in solution, and compared to form 3, APTI-I is stable during drying and does not pose a crystal transformation risk. Moreover, APTI-I exhibits excellent physicochemical stability under conditions of 25℃/60%RH and 40℃/75%RH, as well as under grinding conditions. The product crystals are blocky with uniform particle size distribution, high purity, and high yield. The crystal form preparation exhibits high solvent selectivity, and residual solvent is easily controlled. As a solid drug, it demonstrates excellent performance in production, storage, transportation, and subsequent formulation processing, providing a superior choice for crystal form selection in drug development.

The APTI-II and APTI-III crystal forms of arasyldihydrochloride obtained by this invention are also new crystal forms that are different from the existing disclosed crystal forms, and have higher purity, providing more options for product purification.

Claims (13)

A crystal form of arasyl dihydrochloride, APTI-I, is characterized by characteristic peaks in its XRPD spectrum, expressed in 2θ angles, obtained using Cu-Kα radiation, at 9.6°±0.2°, 12.0°±0.2°, 13.5°±0.2°, 20.5°±0.2°, 21.9°±0.2°, and 22.4°±0.2°. According to claim 1, the crystalline form APTI-I of arasyldihydrochloride is characterized in that the crystalline form APTI-I further has one or more features selected from the following: (i) Its XRPD spectrum also has one or more characteristic peaks selected from the following:
6.1°±0.2°, 7.9°±0.2°, 12.3°±0.2°, 14.1°±0.2°, 17.0°±0.2°, 17.2°±0.2°, 17.5°±0.2°
17.8°±0.2°, 18.7°±0.2°, 19.1°±0.2°, 19.8°±0.2°, 21.3°±0.2°, 22.2°±0.2°, 22.7°±0.2°, 24.2°±0.2°, 24.5°±0.2°, 24.7°±0.2°, 25.0°±0.2°, 25.3°±0.2°, 26.4°±0.2°, 27.2°±0.2°, 27.4°±0.2°, 27.7°±0.2°, 28.7±0.2°. (ii) The differential scanning calorimetry spectrum shows endothermic peaks at 71.6±5℃ and 197.6±5℃. (iii) Its thermogravimetric analysis (TGA) spectrum at 30–120℃ shows a weight loss of approximately 1.5–3.8%. (iv) Its XRPD pattern is basically consistent with that in Figure 1. (v) The differential scanning calorimeter is basically consistent with that in Figure 2. (vi) Its thermogravimetric analysis spectrum is basically consistent with that of Figure 3 or Figure 10. A crystal form of arasyl dihydrochloride, APTI-I, is characterized by having a characteristic peak at at least one of the following three angles when XRPD spectrum, expressed in 2θ angle, is irradiated using Cu-Kα radiation: 9.6°±0.2°, 12.0°±0.2°, and 20.5°±0.2°. According to claim 3, the crystalline form APTI-I of arasyldihydrochloride is characterized in that the crystalline form APTI-I further has one or more features selected from the following: (i) Its XRPD spectrum also has one or more characteristic peaks selected from the following:
6.1°±0.2°, 7.9°±0.2°, 12.3°±0.2°, 13.5°±0.2°, 14.1°±0.2°, 17.0°±0.2°, 17.2°±0.2°
17.5°±0.2°, 17.8°±0.2°, 18.7°±0.2°, 19.1°±0.2°, 19.8°±0.2°, 21.3°±0.2°, 21.9°±0.2°, 22.2°±0.2°, 22.4°±0.2°, 22.7°±0.2°, 24.2°±0.2°, 24.5°±0.2°, 24.7°±0.2°, 25.0°±0.2°, 25.3°±0.2°, 26.4°±0.2°, 27.2°±0.2°, 27.4°±0.2°, 27.7°±0.2°, 28.7±0.2° (ii) The differential scanning calorimetry spectrum shows endothermic peaks at 71.6±5℃ and 197.6±5℃. (iii) Its thermogravimetric analysis (TGA) spectrum at 30–120℃ shows a weight loss of approximately 1.5–3.8%. (iv) Its XRPD pattern is basically consistent with that in Figure 1. (v) The differential scanning calorimeter is basically consistent with that in Figure 2. (vi) Its thermogravimetric analysis spectrum is basically consistent with that of Figure 3 or Figure 10. The method for preparing the crystalline form APTI-I of ellastatin dihydrochloride according to any one of claims 1-4 is characterized in that the preparation method comprises the following steps: After stirring the alastan dihydrochloride in a mixture of organic solvent and water, the mixture was separated and dried to obtain the crystalline form APTI-I. The method for preparing araxanthan dihydrochloride according to claim 5 is characterized in that the organic solvent is selected from methanol, ethanol, n-propanol, isopropanol, acetone, 2-butanone, acetonitrile, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, or combinations thereof, more preferably acetonitrile or acetone, and/or The volume ratio of the organic solvent to water is 3–9:1, more preferably 7–9:1, and/or The weight-to-volume ratio of ellastatin dihydrochloride to the mixture is 0.05–0.2 g/mL, and/or During stirring, the system temperature is 20–60℃, the stirring time is 8–48 h, and/or The drying temperature is 40–60℃, and the time is 8–24 hours. An APTI-II crystal form of arasyl dihydrochloride is characterized by characteristic peaks at 7.0°±0.2°, 13.9°±0.2°, 15.8°±0.2°, 21.9°±0.2°, and 23.5°±0.2° when XRPD spectrum is expressed in 2θ angle using Cu-Kα radiation. According to claim 7, the crystalline form APTI-II of arasyldihydrochloride is characterized in that the crystalline form APTI-II further comprises one or more features selected from the following: (i) Its XRPD spectrum also has one or more characteristic peaks selected from the following:
8.1°±0.2°, 8.8°±0.2°, 11.7°±0.2°, 12.5°±0.2°, 14.9°±0.2°, 17.4°±0.2°, 18.7°±
0.2°, 19.5°±0.2°, 20.9°±0.2°, 24.4°±0.2°, 25.3°±0.2°, 26.2°±0.2°, 26.9°±0.2°, 28.0°±0.2°, 28.6°±0.2°, 29.7°±0.2°, 30.9°±0.2°, 38.0°±0.2° (ii) Its thermogravimetric analysis spectrum shows a step between 30 and 170°C, indicating a weight loss of approximately 12.7%. (ii) Its XRPD diagram is basically the same as that in Figure 6. The method for preparing APTI-II, the irisyl group dihydrochloride crystal form according to claim 7 or 8, is characterized in that the preparation method comprises the following steps: After stirring arasyltrimethylammonium dihydrochloride in 2-ethoxyethanol, the mixture was allowed to stand, separated, and dried to obtain crystalline APTI-II. Preferably, the weight-to-volume ratio of ellastatin dihydrochloride to 2-ethoxyethanol is 0.05–0.2 g/mL, and/or Preferably, during stirring, the system is first stirred at 40–60°C for 6–10 hours, then at 0–40°C for 6–10 hours, and finally at 40–60°C for 6–10 hours, and/or Preferably, the standing period is 6 to 9 days at room temperature, and/or Preferably, the drying temperature is 40-60℃ and the drying time is 8-24h. An APTI-III dihydrochloride crystal form of alasin group is characterized by characteristic peaks at 11.3±0.2°, 11.8±0.2°, 13.4±0.2°, 18.2±0.2°, 21.2±0.2°, and 25.8±0.2° when its XRPD spectrum is expressed in 2θ angles using Cu-Kα radiation. According to claim 10, the new crystalline form APTI-III of ellasyl group dihydrochloride is characterized in that the crystalline form APTI-III further has one or more features selected from the following: (i) Its XRPD spectrum also has one or more characteristic peaks selected from the following:
5.6±0.2°, 10.3±0.2°, 11.0±0.2°, 12.5±0.2°, 14.9±0.2°, 15.4±0.2°, 18.8±0.2°, 19.3±0.2°
20.1±0.2°, 20.5±0.2°, 22.0±0.2°, 23.0±0.2°, 24.0±0.2°, 26.3±0.2°, 27.2±0.2°, 27.6±0.2°, 29.9±0.2° (ii) The differential scanning calorimetry spectrum shows endothermic peaks at 112.5±5℃ and 227.8±5℃. (iii) Its XRPD spectrum is basically consistent with that in Figure 8. The method for preparing the crystalline form APTI-III of arasyldone dihydrochloride according to claim 10 or 11 is characterized in that the preparation method comprises the following steps: Alirastan dihydrochloride was added to N,N-dimethylformamide, heated to dissolve, cooled to crystallize, separated, and dried to obtain crystalline form APTI-III. Preferably, the heating temperature is 80–100°C, the cooling temperature is 0–30°C, and/or Preferably, the weight-to-volume ratio of ellastatin dihydrochloride to N,N-dimethylformamide is 10–25 mg/mL, and/or Preferably, the drying temperature is 40–60℃ and the drying time is 8–24 hours. Use of elasitran dihydrochloride in crystal form APTI-I, APTI-II or APTI-III in the preparation of a drug containing elasitran dihydrochloride or in the purification of elasitran or its salts.