阅读说明：本技术 十六烷基曲前列环素晶体和其制备方法 (Hexadecyl treprostinil crystal and preparation method thereof ) 是由 魏士益 郑建邦 于 2020-09-28 设计创作，主要内容包括：本发明提供十六烷基曲前列环素(C-(16)TR)的稳定结晶形式I和形式II以及其制备方法。所述十六烷基曲前列环素的稳定结晶形式I和形式II在商业考虑的储存、调配、装运和操作等方面存在优势。(The present invention provides hexadecyl treprostinil (C) 16 TR) and stable crystalline forms I and II and methods for their preparation. The stable crystalline forms I and II of the hexadecyltreprostinil are advantageous for commercial considerations of storage, formulation, shipping and handling.)

1. A crystalline form I of Hexadecyl Treprostinil characterized by an X-ray powder diffraction (XRPD) pattern comprising its six most intense characteristic peaks at the following 2 θ reflection angles: 3.3 +/-0.2 degrees, 6.6 +/-0.2 degrees, 14.2 +/-0.2 degrees, 18.9 +/-0.2 degrees, 21.3 +/-0.2 degrees and 22.5 +/-0.2 degrees.

2. The crystalline form I of hexadecyltreprostinil of claim 1, wherein the XRPD pattern further comprises characteristic peaks at the following 2 θ reflection angles: 13.8 +/-0.2 degrees, 15.3 +/-0.2 degrees, 16.9 +/-0.2 degrees, 17.8 +/-0.2 degrees, 19.8 +/-0.2 degrees, 20.6 +/-0.2 degrees, 20.9 +/-0.2 degrees, 24.4 +/-0.2 degrees and 24.8 +/-0.2 degrees.

3. The crystalline form I of hexadecyltreprostinil of claim 1, wherein the XRPD pattern is substantially as shown in figure 1.

4. Crystalline form I of hexadecyltreprostinil according to claim 1, further having a differential scanning calorimetry (DSC thermogram) comprising an endothermic peak with a peak onset temperature of 52.2 ± 1 ℃ and a peak maximum of 54.5 ± 1 ℃.

5. The crystalline form I of hexadecyltreprostinil of claim 4, wherein the DSC thermogram is substantially shown in figure 2.

6. The crystalline form I of hexadecyltreprostinil of claim 1, further having a molar ratio in cm^-1A 1% KBr fourier transform infrared FTIR spectrum comprising peaks in units: 3445 + -4 cm^-1、3402±4cm^-1、2958±4cm^-1、2919±4cm^-1、2871±4cm^-1、2854±4cm^-1、1733±4cm^-1、1606±4cm^-1、1585±4cm^-1、1474±4cm^-1、1443±4cm^-1、1416±4cm^-1、1374±4cm^-1、1357±4cm^-1、1331±4cm^-1、1309±4cm^-1、1271±4cm^-1、1247±4cm^-1、1229±4cm^-1、1202±4cm^-1、1167±4cm^-1、1148±4cm^-1、1122±4cm^-1、1088±4cm^-1、1039±4cm^-1、1023±4cm^-1、1000±4cm^-1、982±4cm^-1、968±4cm^-1、917±4cm^-1、889±4cm^-1、784±4cm^-1、772±4cm^-1、734±4cm^-1、719±4cm^-1、708±4cm^-1。

7. The crystalline form I of hexadecyltreprostinil of claim 6, wherein the FTIR spectrum is substantially shown in figure 3.

8. A process for preparing crystalline form I of hexadecyltreprostinil according to claim 1, comprising the steps of:

dissolving cetyl treprostinil in a first solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof;

reducing the temperature and/or adding a second solvent selected from the group consisting of acetonitrile, water, and mixtures thereof to the homogeneous solution; and

stirring until a precipitate is formed.

9. The method of claim 8, further comprising the steps of:

adding the second solvent or a mixture of the first solvent and the second solvent to rinse the precipitate;

filtering the precipitate, thereby isolating crystalline form I of the hexadecyltreprostinil; and

optionally drying the crystalline form I of the hexadecyltreprostinil.

10. A crystalline form II of hexadecyltreprostinil characterized by an XRPD pattern comprising its six most intense characteristic peaks at the following 2 θ reflection angles: 3.4 +/-0.2 degrees, 6.1 +/-0.2 degrees, 9.4 +/-0.2 degrees, 20.3 +/-0.2 degrees, 21.6 +/-0.2 degrees and 23.4 +/-0.2 degrees.

11. The crystalline form II of hexadecyltreprostinil of claim 10, wherein the XRPD pattern further comprises characteristic peaks at the following 2 Θ reflection angles: 7.0 +/-0.2 degrees, 9.0 +/-0.2 degrees, 12.2 +/-0.2 degrees, 12.7 +/-0.2 degrees, 17.5 +/-0.2 degrees, 18.0 +/-0.2 degrees, 18.5 +/-0.2 degrees, 19.1 +/-0.2 degrees and 19.4 +/-0.2 degrees.

12. The crystalline form II of hexadecyltreprostinil of claim 10, wherein the XRPD pattern is substantially shown in figure 4.

13. The crystalline form II of hexadecyltreprostinil of claim 10, further having a DSC thermogram with endothermic peaks with a peak onset temperature of 54.6 ± 1 ℃ and a peak maximum of 56.9 ± 1 ℃.

14. The crystalline form II of hexadecyltreprostinil of claim 13, wherein the DSC thermogram is substantially shown in figure 5.

15. The crystalline form II of hexadecyltreprostinil of claim 10, further having a molar ratio in cm^-1A 1% KBr FTIR spectrum comprising peaks in units: 3515 +/-4 cm^-1、3443±4cm^-1、3291±4cm^-1、3034±4cm^-1、2953±4cm^-1、2922±4cm^-1、2851±4cm^-1、1769±4cm^-1、1730±4cm^-1、1605±4cm^-1、1584±4cm^-1、1469±4cm^-1、1456±4cm^-1、1437±4cm^-1、1395±4cm^-1、1371±4cm^-1、1347±4cm^-1、1330±4cm^-1、1311±4cm^-1、1295±4cm^-1、1286±4cm^-1、1271±4cm^-1、1259±4cm^-1、1235±4cm^-1、1218±4cm^-1、1209±4cm^-1、1189±4cm^-1、1171±4cm^-1、1148±4cm^-1、1115±4cm^-1、1070±4cm^-1、1053±4cm^-1、1030±4cm^-1、1019±4cm^-1、989±4cm^-1、946±4cm^-1、926±4cm^-1、909±4cm^-1、893±4cm^-1、878±4cm^-1、790±4cm^-1、765±4cm^-1、726±4cm^-1、704±4cm^-1。

16. The crystalline form II of hexadecyltreprostinil of claim 15, wherein the FTIR spectrum is substantially shown in figure 6.

17. A process for preparing crystalline form II of hexadecyltreprostinil according to claim 10, comprising the steps of:

dissolving cetyl treprostinil in a third solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof;

reducing the temperature and/or adding a fourth solvent selected from the group consisting of: pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, cycloheptane, and mixtures thereof; and

stirring until a precipitate is formed.

18. The method of claim 17, further comprising the steps of:

adding the fourth solvent or a mixture of the third solvent and the fourth solvent to rinse the precipitate;

filtering the precipitate, thereby isolating crystalline form II of the hexadecyltreprostinil; and

optionally drying the crystalline form II of the hexadecyl treprostinil.

Technical Field

The present invention relates generally to solid forms of prostacyclin derivatives, and in particular to solid crystalline forms of hexadecyltreprostinil (Hexadecyl Treprostinil) and methods for their preparation.

Background

Hexadecyl treprostinil (C)₁₆TR) is a synthetic benzoprostacyclin analog used as a prodrug for treprostinil. Scheme a below shows the structure of treprostinil and hexadecyltreprostinil. From a pharmacological point of view, hexadecyl treprostinil is very important. Inhaled treprostinil formulated in lipid nanoparticles is a long-acting pulmonary vasodilator compared to infused treprostinil used to treat Pulmonary Arterial Hypertension (PAH)Provide significantly lower plasma concentrations and may be applied to reduce toxicity, provide preferred tolerability and more convenient dosing schedules, for example, in palm pharmaceutical therr, 49,104-111, Drug Research,68,605-614 and US 2015/148414:

procedure A

Drug Research,68,605-614 and US 2017/0320813 have disclosed synthetic processes for hexadecyltreprostinil. However, these reports reveal that the prepared hexadecyltreprostinil is an off-white waxy solid. Waxy solids are generally well known as amorphous forms of Active Pharmaceutical Ingredients (APIs). Amorphous APIs are unsatisfactory in terms of thermal stability, purity and homogeneity compared to crystalline APIs. In addition, waxy solids typically have high viscosities, are difficult to operate commercially, and avoid loss of adhesion on the vessel. Since there are no other reports disclosing crystalline forms of hexadecyl treprostinil, the benefits of conventional crystallization processes for preparing hexadecyl treprostinil crystals cannot be evaluated based on prior art literature.

Therefore, there is a need for a process for the preparation of stable crystalline forms of hexadecyltreprostinil. Stable crystals of hexadecyltreprostinil have defined physicochemical properties that provide constant operating parameters, such as solubility for routine pharmaceutical formulation and stable bioabsorption for pharmacological treatment. In addition, the stable crystalline form of treprostinil has advantages in terms of storage, formulation, handling and shipping and commercial considerations

Disclosure of Invention

One aspect of the present invention provides a stable solid form of crystalline form I of hexadecyl treprostinil and a process for its preparation.

In one embodiment, the present invention provides a process for preparing crystalline form I of hexadecyltreprostinil comprising dissolving hexadecyltreprostinil in a first solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide, and a mixture thereof to form a homogeneous solution; reducing the temperature and/or adding a second solvent selected from the group consisting of acetonitrile, water, and mixtures thereof to the homogeneous solution; and stirring until a precipitate is formed.

In one embodiment, the present invention provides crystalline form I of hexadecyltreprostinil having an X-ray powder diffraction (XRPD) pattern exhibiting its six most intense characteristic peaks at the following 2 Θ reflection angles: 3.3 +/-0.2 degrees, 6.6 +/-0.2 degrees, 14.2 +/-0.2 degrees, 18.9 +/-0.2 degrees, 21.3 +/-0.2 degrees and 22.5 +/-0.2 degrees.

In one embodiment, the present invention provides crystalline form I of hexadecyltreprostinil having a Differential Scanning Calorimetry (DSC) thermogram with an endothermic peak with a peak onset temperature of 52.2 ± 1 ℃ and a peak maximum of 54.5 ± 1 ℃.

One aspect of the present invention provides a stable solid form of crystalline form II of hexadecyl treprostinil and a process for its preparation.

In one embodiment, the present invention provides a process for preparing crystalline form II of hexadecyltreprostinil comprising dissolving hexadecyltreprostinil in a third solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide, and a mixture thereof to form a homogeneous solution; reducing the temperature and/or adding a fourth solvent selected from the group consisting of: pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, cycloheptane, and mixtures thereof; and stirring until a precipitate is formed.

In one embodiment, the present invention provides crystalline form II of hexadecyltreprostinil having an XRPD pattern exhibiting its six most intense characteristic peaks at the following 2 Θ reflection angles: 3.4 +/-0.2 degrees, 6.1 +/-0.2 degrees, 9.4 +/-0.2 degrees, 20.3 +/-0.2 degrees, 21.6 +/-0.2 degrees and 23.4 +/-0.2 degrees.

In one embodiment, the present invention provides crystalline form II of hexadecyltreprostinil having a DSC thermogram with an endothermic peak with a peak onset temperature of 54.6 ± 1 ℃ and a peak maximum of 56.9 ± 1 ℃.

The present invention provides solid forms of crystalline form I and form II of hexadecyltreprostinil that can be stably stored at room temperature and that do not result in crystalline form conversion for commercial handling.

Brief description of the drawings

Figure 1 shows an X-ray powder diffraction (XRPD) pattern of crystalline form I of hexadecyltreprostinil.

Figure 2 shows a Differential Scanning Calorimetry (DSC) thermogram for crystalline form I of hexadecyltreprostinil.

Figure 3 shows a Fourier Transform Infrared (FTIR) spectrum of crystalline form I of cetyltreprostinil.

Figure 4 shows an X-ray powder diffraction (XRPD) pattern of crystalline form II of hexadecyltreprostinil.

Figure 5 shows a Differential Scanning Calorimetry (DSC) thermogram for crystalline form II of hexadecyltreprostinil.

Figure 6 shows a Fourier Transform Infrared (FTIR) spectrum of crystalline form II of hexadecyltreprostinil.

Detailed Description

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. The use of any and all examples, or exemplary language (such as) and (e) herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention, nor is the language in the specification necessarily to be construed as indicating any non-claimed method or condition as essential to the practice of the invention.

Beraprost-314 d crystalline form II and preparation thereof

In one aspect of the invention, a method of preparing crystalline form I of hexadecyl treprostinil comprises the steps of:

(a) dissolving crude hexadecyl treprostinil in a first solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof;

(b) reducing the temperature and/or adding a second solvent selected from the group consisting of acetonitrile, water, and mixtures thereof to the homogeneous solution;

(c) stirring until a precipitate is formed;

(d) filtering the precipitate, thereby isolating crystalline form I of hexadecyl treprostinil; and

(e) optionally drying the crystalline form I of hexadecyltreprostinil.

In the present invention, the first solvent for dissolving crude hexadecyltreprostinil is selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof, preferably ethanol and propanol. The volume of the first solvent depends on the type of solvent used and may be from about 0.5ml to about 100ml, preferably from about 1ml to about 50ml, and more preferably from about 2ml to about 20ml or from about 5ml to about 10ml per 1g of crude hexadecyltreprostinil. The crude hexadecyltreprostinil may be dissolved in the first solvent at a temperature in the range of about 0 ℃ to about 80 ℃, preferably about 10 ℃ to about 60 ℃, and more preferably room temperature to about 40 ℃.

In one embodiment of the invention, the temperature of the homogeneous solution is reduced to a temperature in the range of about-30 ℃ to about 50 ℃, preferably about-20 ℃ to about 40 ℃, and more preferably about-10 ℃ to about 30 ℃.

The choice of the second solvent is an important factor as to whether crystalline form I of hexadecyl treprostinil can be formed. In one embodiment, the volume of the second solvent selected from the group consisting of acetonitrile, water, and mixtures thereof is dependent on the type of solvent used, and may be from about 0.5ml to about 200ml, from about 1ml to about 150ml, or from about 2ml to about 100ml per 1ml of the first solvent. The second solvent may be added at a temperature in the range of about-30 ℃ to about 50 ℃, preferably about-20 ℃ to about 40 ℃, and more preferably about-10 ℃ to about 30 ℃.

In one embodiment of the invention, the precipitation of crystals may be carried out at a temperature in the range of from about-30 ℃ to about 50 ℃, preferably from about-20 ℃ to about 40 ℃ and more preferably from about-10 ℃ to about 30 ℃.

In one embodiment of the present invention, the step of filtering out the precipitate comprises washing the precipitate with a second solvent or a mixture of the first solvent and the second solvent. In the mixed solvent, the ratio of the first solvent to the second solvent may be from about 1: 1 to about 1: 100, preferably from about 1: 10 to about 1: 50.

In one embodiment of the invention, crystalline form I of hexadecyl treprostinil has an X-ray powder diffraction (XRPD) pattern exhibiting its five most intense characteristic peaks at the following 2 Θ reflection angles: 3.3 +/-0.2 degrees, 6.6 +/-0.2 degrees, 14.2 +/-0.2 degrees, 18.9 +/-0.2 degrees, 21.3 +/-0.2 degrees and 22.5 +/-0.2 degrees. In one embodiment, the XRPD pattern of crystalline form I of hexadecyl treprostinil further comprises characteristic peaks at the following 2 Θ reflection angles: 13.8 +/-0.2 degrees, 15.3 +/-0.2 degrees, 16.9 +/-0.2 degrees, 17.8 +/-0.2 degrees, 19.8 +/-0.2 degrees, 20.6 +/-0.2 degrees, 20.9 +/-0.2 degrees, 24.4 +/-0.2 degrees and 24.8 +/-0.2 degrees. More preferably, the XRPD pattern of crystalline form I of hexadecyltreprostinil is in accordance with figure 1. Specific data for crystalline form I of hexadecyl treprostinil are shown in table 1.

TABLE 1

In one embodiment, the present invention provides crystalline form I of hexadecyl treprostinil having an XRPD pattern substantially as shown in figure 1.

In one embodiment, the present invention provides crystalline form I of hexadecyl treprostinil having a Differential Scanning Calorimetry (DSC) thermogram with an endothermic peak with a peak onset temperature of 52.2 ± 1 ℃ and a peak maximum of 54.5 ± 1 ℃. In one aspect, the invention provides crystalline form I having hexadecyl treprostinil having a DSC thermogram substantially as shown in figure 2.

In one embodiment, the present invention provides crystalline form I of hexadecyl treprostinil having a length in cm^-1A 1% KBr Fourier Transform Infrared (FTIR) spectrum comprising peaks in units: 3445 + -4 cm^-1、3402±4cm^-1、2958±4cm^-1、2919±4cm^-1、2871±4cm^-1、2854±4cm^-1、1733±4cm^-1、1606±4cm^-1、1585±4cm^-1、1474±4cm^-1、1443±4cm^-1、1416±4cm^-1、1374±4cm^-1、1357±4cm^-1、1331±4cm^-1、1309±4cm^-1、1271±4cm^-1、1247±4cm^-1、1229±4cm^-1、1202±4cm^-1、1167±4cm^-1、1148±4cm^-1、1122±4cm^-1、1088±4cm^-1、1039±4cm^-1、1023±4cm^-1、1000±4cm^-1、982±4cm^-1、968±4cm^-1、917±4cm^-1、889±4cm^-1、784±4cm^-1、772±4cm^-1、734±4cm^-1、719±4cm^-1、708±4cm^-1. In one aspect, the present invention provides crystalline form I of hexadecyl treprostinil having a 1% KBr FTIR spectrum substantially as shown in figure 3.

Due to the organic solvent system used in the process of the present invention, the precipitated crystalline form I of hexadecyltreprostinil has a dense solid character and is therefore easily filtered out. Residual solvent can be easily removed at room temperature under high vacuum. In addition, dry crystalline form I of hexadecyltreprostinil has a granular character that is easier to weigh for commercial handling than waxy solid forms of hexadecyltreprostinil with high viscosity.

In addition, crystalline form I of hexadecyltreprostinil is a stable crystalline form that exhibits good stability without other crystalline forms or degraded impurity products for six months at room temperature. Analysis of crystalline form I of hexadecyltreprostinil remained in the range of about 98.0% to about 102.0% even after thirty-six months at typical storage temperatures (about 5 ℃ to about-20 ℃).

Crystalline form II of hexadecyl treprostinil and its preparation

In one embodiment of the present invention, the method of preparing crystalline form II of hexadecyl treprostinil comprises the steps of:

(a) dissolving crude hexadecyl treprostinil in a third solvent selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof;

(b) reducing the temperature and/or adding a fourth solvent selected from the group consisting of: pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, cycloheptane, and mixtures thereof;

(c) stirring until a precipitate is formed;

(d) filtering the precipitate, thereby isolating crystalline form II of hexadecyl treprostinil; and

(e) optionally drying the crystalline form II of hexadecyltreprostinil.

In the present invention, the third solvent for dissolving crude hexadecyltreprostinil is selected from the group consisting of: diethyl ether, isopropyl ether, methyl tert-butyl ether, methyl isobutyl ketone, ethyl acetate, isopropyl acetate, toluene, xylene, acetone, dichloromethane, 1, 4-dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, benzyl alcohol, dimethyl sulfoxide, dimethylacetamide, dimethylformamide and mixtures thereof, preferably ethyl acetate and toluene. The volume of the third solvent depends on the type of solvent used and may be from about 0.5ml to about 100ml, preferably from about 1ml to about 50ml, and more preferably from about 2ml to about 20ml or from about 1ml to about 10ml per 1g of crude hexadecyltreprostinil. The crude hexadecyltreprostinil may be dissolved in the third solvent at a temperature in the range of about 0 ℃ to about 80 ℃, preferably about 10 ℃ to about 60 ℃, and more preferably room temperature to about 40 ℃.

In one embodiment of the invention, the temperature of the homogeneous solution is reduced to a temperature in the range of about-30 ℃ to about 50 ℃, preferably about-20 ℃ to about 40 ℃, and more preferably about-10 ℃ to about 30 ℃.

The choice of the fourth solvent is an important factor as to whether crystalline form II of hexadecyl treprostinil can be formed. In one embodiment, the volume of the fourth solvent selected from the group consisting of: pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, cycloheptane, and mixtures thereof, and may be about 0.5ml to about 200ml, about 1ml to about 150ml, or about 2ml to about 100ml per 1ml of the third solvent. The fourth solvent may be added at a temperature in the range of about-30 ℃ to about 50 ℃, preferably about-20 ℃ to about 40 ℃, and more preferably about-10 ℃ to about 30 ℃.

In one embodiment of the invention, the precipitation of crystals may be carried out at a temperature in the range of from about-30 ℃ to about 50 ℃, preferably from about-20 ℃ to about 40 ℃ and more preferably from about-10 ℃ to about 30 ℃.

In one embodiment of the present invention, the step of filtering out the precipitate comprises washing the precipitate with a fourth solvent or a mixture of a third solvent and a fourth solvent. In the mixed solvent, the ratio of the third solvent to the fourth solvent may be from about 1: 1 to about 1: 100, preferably from about 1: 10 to about 1: 50.

In one embodiment of the invention, crystalline form II of hexadecyl treprostinil has an XRPD pattern exhibiting its six most intense characteristic peaks at the following 2 Θ reflection angles: 3.4 +/-0.2 degrees, 6.1 +/-0.2 degrees, 9.4 +/-0.2 degrees, 20.3 +/-0.2 degrees, 21.6 +/-0.2 degrees and 23.4 +/-0.2 degrees. In one embodiment, the XRPD pattern of crystalline form II of hexadecyl treprostinil further comprises characteristic peaks at the following 2 Θ reflection angles: 7.0 +/-0.2 degrees, 9.0 +/-0.2 degrees, 12.2 +/-0.2 degrees, 12.7 +/-0.2 degrees, 17.5 +/-0.2 degrees, 18.0 +/-0.2 degrees, 18.5 +/-0.2 degrees, 19.1 +/-0.2 degrees and 19.4 +/-0.2 degrees. More preferably, the XRPD pattern of crystalline form II of hexadecyl treprostinil is in accordance with fig. 4. Specific data for crystalline form II of hexadecyl treprostinil are shown in table 2.

TABLE 2

In one embodiment, the present invention provides crystalline form II of hexadecyl treprostinil having an XRPD pattern substantially as shown in figure 4.

In one embodiment, the present invention provides a crystalline form II of hexadecyltreprostinil having a DSC thermogram with an endothermic peak with a peak onset temperature of 54.6 ± 1 ℃ and a peak maximum of 56.9 ± 1 ℃. In one aspect, the present invention provides crystalline form II of hexadecyl treprostinil having a DSC thermogram substantially as shown in figure 5.

In one embodiment, the present invention provides a crystalline form II of hexadecyl treprostinil having a size in cm^-1A 1% KBr FTIR spectrum comprising peaks in units: 3515 +/-4 cm^-1、3443±4cm^-1、3291±4cm^-1、3034±4cm^-1、2953±4cm^-1、2922±4cm^-1、2851±4cm^-1、1769±4cm^-1、1730±4cm^-1、1605±4cm^-1、1584±4cm^-1、1469±4cm^-1、1456±4cm^-1、1437±4cm^-1、1395±4cm^-1、1371±4cm^-1、1347±4cm^-1、1330±4cm^-1、1311±4cm^-1、1295±4cm^-1、1286±4cm^-1、1271±4cm^-1、1259±4cm^-1、1235±4cm^-1、1218±4cm^-1、1209±4cm^-1、1189±4cm^-1、1171±4cm^-1、1148±4cm^-1、1115±4cm^-1、1070±4cm^-1、1053±4cm^-1、1030±4cm^-1、1019±4cm^-1、989±4cm^-1、946±4cm^-1、926±4cm^-1、909±4cm^-1、893±4cm^-1、878±4cm^-1、790±4cm^-1、765±4cm^-1、726±4cm^-1、704±4cm^-1. In one aspect, the present invention provides crystalline form II of hexadecyl treprostinil having a 1% KBr FTIR spectrum substantially as shown in figure 6.

Due to the organic solvent system used in the process of the present invention, the precipitated crystalline form II of hexadecyltreprostinil has a dense solid character and is therefore easily filtered out. Residual solvent can be easily removed at room temperature under high vacuum. In addition, dry crystalline form II of hexadecyltreprostinil has a granular character that is easier to weigh for commercial handling than waxy solid forms of hexadecyltreprostinil with high viscosity.

In addition, crystalline form II of hexadecyl treprostinil is a stable crystalline form that exhibits good stability without other crystalline forms or degraded impurity products for six months at room temperature. Analysis of crystalline form II of hexadecyltreprostinil remained in the range of about 98.0% to about 102.0% even after thirty-six months at ordinary storage temperatures (about 5 ℃ to about-20 ℃).

Examples of the invention

X-ray powder diffraction (XRPD) analysis: XRPD patterns were collected on a Bruker D2 PHASER diffractometer with a fixed divergence slit and a 1D LYNXEYE detector. The sample (approximately 100mg) was placed flat on the sample holder. The prepared samples were analyzed using CuK α radiation at a power of 10mA and 30kV over a 2 θ range of 2 ° to 50 °, with a step size of 0.02 ° and a step time of 1 second. CuK β radiation is removed by a diverging beam nickel filter.

Differential Scanning Calorimetry (DSC) analysis: DSC thermograms were collected on a TA discover DSC25 instrument. The sample (approximately 5mg) was weighed into an aluminum pan with a crimped-on aluminum lid. The prepared samples were analyzed from 10 ℃ to 100 ℃ under a nitrogen flow (approximately 50ml/min) at a scan rate of 10 ℃/min. The melting temperature and heat of fusion were calibrated by indium (In) before measurement.

Fourier Transform Infrared (FTIR) analysis: FTIR spectra were collected on a Perkin Elmer SPECTRUM 100 instrument. The sample was mixed with potassium bromide (KBr) using an agate mortar and pestle at a ratio (w/w) of about 1: 100. The mixture is pressed into the granulation die at a pressure of about 10 to 13 tons for 2 minutes. At 4cm^-1From 4000cm at resolution^-1To 650cm^-1The resulting disc was scanned 4 times against the collected background. Data were baseline corrected and normalized.

Example 1

Preparation of crude hexadecyl treprostinil

2- (((1R,2R, 3aS,9aS) -2-hydroxy-1- ((S) -3-hydroxyoctyl) -2,3,3a,4,9,9 a-hexahydro-1H-cyclopenta [ b ] naphthalen-5-yl) oxy) acetic acid (40.0g, 102.4mmol) was dissolved in 600ml dimethylformamide, followed by addition of 42.0g of potassium carbonate and 72.0g of 1-iodohexadecane and stirring at 60 ℃ for 1 hour. Subsequently, the reaction mixture was slowly cooled to 10 ℃, and 650ml of water and 650ml of ethyl acetate and 50.0g of magnesium sulfate were added to the reaction mixture to conduct extraction. The extraction solution was evaporated under vacuum at room temperature to give the crude product. The crude product was then purified by silica gel chromatography using a mixture of hexane and ethyl acetate as gradient exhibitor to yield 58.6g of an off-white waxy solid (crude hexadecyltreprostinil).

Example 2

Preparation of crystalline form I of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.00g from example 1) and propanol (5ml) were heated to 40 ℃ to dissolve and then cooled to room temperature. Water (5ml) was slowly added dropwise and the mixture was stirred in an ice water bath for 18 hours until solid precipitation occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.92g of crystalline form I of hexadecyltreprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 1, 2, and 3.

Example 3

Preparation of crystalline form I of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.01g from example 1) and ethanol (6ml) were heated to 40 ℃ to dissolve and then cooled to room temperature. Acetonitrile (30ml) was slowly added dropwise and the mixture was stirred in an ice-water bath for 18 hours until solid precipitation occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.90g of crystalline form I of hexadecyltreprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 1, 2, and 3.

Example 4

Preparation of crystalline form I of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.00g from example 1) and toluene (5ml) were heated to 40 ℃ to dissolve. Acetonitrile (50ml) was slowly added dropwise and the mixture was stirred in an ice-water bath for 20 hours until solid precipitation occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.91g of crystalline form I of hexadecyltreprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 1, 2, and 3.

Example 5

Preparation of crystalline form II of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.01g from example 1) and ethyl acetate (1ml) were heated to 40 ℃ to dissolve and then cooled to room temperature. N-hexane (30ml) was slowly added dropwise and the mixture was stirred in an ice-water bath for 18 hours until precipitation of solids occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.88g of crystalline form II of hexadecyl treprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 4, 5, and 6.

Example 6

Preparation of crystalline form II of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.00g from example 1) and toluene (3ml) were heated to 40 ℃ to dissolve and then cooled to room temperature. N-heptane (40ml) was slowly added dropwise and the mixture was stirred in an ice water bath for 24 hours until precipitation of the solid occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.85g of crystalline form II of hexadecyl treprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 4, 5, and 6.

Example 7

Preparation of crystalline form II of hexadecyl treprostinil

Crude hexadecyltreprostinil (1.01g from example 1) and methyl tert-butyl ether (3ml) were heated to 40 ℃ to dissolve. N-pentane (30ml) was slowly added dropwise and the mixture was stirred in an ice-water bath for 18 hours until precipitation of the solid occurred. Subsequently, the resulting suspension was filtered and washed, and then dried under high vacuum at room temperature for 24 hours, yielding 0.85g of crystalline form II of hexadecyl treprostinil. XRPD, DSC, and FTIR results were the same as shown in fig. 4, 5, and 6.

Although the present invention has been described with reference to illustrative examples, it is to be understood that any modifications or alterations that may be readily accomplished by those skilled in the art will be within the scope of the disclosure of this specification and the appended claims.