CRYSTAL FORM OF TREPROSTINIL SODIUM SALT AND PREPARATION METHOD THEREFOR

Abstract

Disclosed are a new crystal form of treprostinil sodium salt (the structural formula thereof is shown as formula I) and a preparation method therefor. Specifically, disclosed are a five and half hydrates of the treprostinil sodium salt and some dehydrated crystal forms thereof. The new crystal form has better stability and hygroscopicity. As a treprostinil crude drug, the new crystal form can meet the requirements for storage and loading and transportation, is stable in terms of quality and can guarantee the controllable quality of subsequent preparation products.

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Claims

1.-10. (canceled)

11. A five-and-a-half hydrate of Treprostinil sodium salt, or a hydrate partially dehydrated crystal form I thereof, or a hydrate partially dehydrated crystal form II thereof, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the five-and-a-half hydrate of Treprostinil sodium salt has characteristic peaks at the following 2Theta angle positions: 4.3°±0.2°, 8.7°±0.2° and 17.6°±0.2°; the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form I of the five-and-a-half of Treprostinil sodium salt has characteristic peaks at the following 2Theta angle positions: 4.8°±0.2°, 9.6°±0.2° and 19.3°±0.2°; and the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form I of the five-and-a-half of Treprostinil sodium salt has characteristic peaks at the following 2Theta angle positions: 5.3°±0.2°, 10.6°±0.2° and 16.0°±0.2°.

12. The five-and-a-half hydrate of Treprostinil sodium salt of claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern thereof further has characteristic peaks at the following 2Theta angle positions: 13.1°±0.2°, 19.7°±0.2° and 24.3°±0.2°.

13. The five-and-a-half hydrate of Treprostinil sodium salt of claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern thereof is as shown in FIG. 1.

14. A method for preparing the five-and-a-half hydrate of Treprostinil sodium salt of claim 11, wherein the method comprises the following steps: (1) dissolving Treprostinil in sodium hydroxide aqueous solution; and (2) adding acetonitrile to the sodium hydroxide solution of Treprostinil for crystallization.

15. The five-and-a-half of Treprostinil sodium salt according to claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form I further has characteristic peaks at the following 2Theta angle positions: 20.9°±0.2°, 22.1°±0.2° and 23.5°±0.2°.

16. The five-and-a-half of Treprostinil sodium salt according to claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form I as shown in FIG. 5.

17. The five-and-a-half hydrate of Treprostinil sodium salt according to claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form II further has characteristic peaks at the following 2Theta angle positions: 20.1°±0.2°, 21.4°±0.2° and 26.8°±0.2°.

18. The five-and-a-half of Treprostinil sodium salt according to claim 11, wherein the powder X-ray diffraction (Cu-Ka, 1.54178 Å) pattern of the hydrate partially dehydrated crystal form I as shown in FIG. 6.

19. A pharmaceutical composition, wherein the pharmaceutical composition comprises the five-and-a-half hydrate of Treprostinil sodium salt according to claim 11 and/or the partially dehydrated crystal form I thereof and/or the partially dehydrated crystal form II thereof, and pharmaceutically acceptable carriers.

20. A method for treating a disease or disorder, wherein comprising a step of: administering to a subject in need thereof the five-and-a-half hydrate of Treprostinil sodium salt according to claim 11 and/or the partially dehydrated crystal form I thereof and/or the partially dehydrated crystal form II thereof and/or a pharmaceutical composition comprising the same, alone or in combination with other drugs; wherein the disease or disorder is selected from the group consisting of pulmonary hypertension, lung hypertension, pulmonary fibrosis, interstitial pulmonary disease, chronic obstructive pulmonary disease, asthma, ischemic disease, heart failure, arteriosclerosis, postoperative anticoagulation, central retinal vein occlusion, thrombotic microangiopathy, peripheral vascular disease, and heart-lung transplantation.

Description

DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1: the XRPD pattern of the five-and-a-half hydrate of Treprostinil sodium salt.

[0044] FIG. 2: Single crystal analysis results of the five-and-a-half hydrate of Treprostinil sodium salt.

[0045] FIG. 3: Comparison of XRPD patterns of monohydrate (Form A) and polyhydrate (Form C) provided by WO2016055819.

[0046] FIG. 4: Comparison of XRPD patterns of five-and-a-half hydrate of Treprostinil sodium salt from three consecutive batches.

[0047] FIG. 5: XRPD pattern of the partially dehydrated crystal form I of the five-and-a-half hydrate of Treprostinil sodium salt.

[0048] FIG. 6: XRPD pattern of the partially dehydrated crystal form II of the five-and-a-half hydrate of Treprostinil sodium salt.

DETAILED DESCRIPTION OF THE INVENTION

[0049] After a long-term and in-depth research, the inventor surprisingly found that the Treprostinil sodium salt can form a five-and-a-half hydrate, which has good crystallinity, excellent stability and hygroscopicity, and also shows good purification effect, and the crystal forms I and II formed by partial dehydrated from the five-and-a-half hydrate also have good crystallinity. The present invention has been completed on this basis.

[0050] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In the following examples, the test methods without specific conditions are usually in accordance with conventional conditions or the conditions recommended by the manufacturer.

Terms

[0051] XRPD X-Ray Powder Diffraction

[0052] DVS Dynamic Vapor Sorption

[0053] Rel. Int. Relative Intensity

[0054] wt % weight percentage

Example 1

Preparation of Treprostinil Free Acid

[0055] With reference to the preparing method of Treprostinil free acid reported in document “J. Org. Chem. 2004, 69, 1890-1902”, using (1R,2R,3aS,9aS)-2,3,3a,4,9,9a-hexahydro-1-[(3S)-3-hydroxyoctyl]-1H-phenyl[f]indene-2,5-diol as the starting material, 34.5 g of Treprostinil free acid was obtained with HPLC purity of 98.9%.

Example 2

Preparation of Five-and-a-Half Hydrate of Treprostinil Sodium Salt

[0056] 1 g of crude Treprostinil was weighed and added into a 50 ml pear-shaped bottle, 1.5 ml 7 wt % sodium hydroxide aqueous solution was added, and stirred until clear.

[0057] Under stirring conditions, 28.5 mL acetonitrile was slowly added in dropwise to form a suspension. The suspension was stirred overnight at 25° C.

[0058] The solids were filtered out, and dried at 25±2 & RH 60±5% for 1 day to give 1.2 g white solid, with a yield of ˜90%. The purity of the solid was determined by high performance liquid chromatography, the morphology was characterized by XRPD, and the water content was determined by Karl Fischer method. The specific test methods are as follows.

[0059] High performance liquid chromatography: Column: Agilent Proshell C18, column temperature: 30° C., flow rate: 0.5 ml/min, detection wavelength: 210 nm.

[0060] XRPD: Cu target, Ka wavelength, tube voltage 40 KV, tube current 40 mA. Scan range: 3-40° 2-Theta; step: 0.02°; scan speed: 1 step/second.

[0061] Karl Fischer method: volumetric water titrator.

[0062] The results of liquid chromatography analysis showed that the purity of crude Treprostinil was increased from 98.9% to 99.9% after being crystallized into five-and-a-half hydrate of Treprostinil sodium salt. There is an obvious effect in removing impurities.

[0063] Karl Fischer titration results showed that the water content after drying is 20.9 wt %.

[0064] The XRPD pattern of five-and-a-half hydrate of Treprostinil sodium salt is as shown in FIG. 1. The main diffraction peaks and relative intensities thereof are as shown in Table 1.

TABLE-US-00001 TABLE 1 XRPD data of five-and-a-half hydrate of Treprostinil sodium salt Pos. [°2Th.] Rel. Int. [%] 4.3 79.4 8.7 100.0 11.9 1.0 13.1 1.0 16.5 1.2 17.6 14.6 18.0 1.0 19.2 1.1 19.7 4.6 21.5 1.2 21.7 2.2 23.0 1.6 24.3 2.9 30.9 1.0 31.0 1.1 35.6 1.6

[0065] The single crystal diffraction pattern of five-and-a-half hydrate of Treprostinil sodium salt is as shown in FIG. 2. The single crystal diffraction results shown that the number of crystal water is 5.5. The unit cell parameters are shown in Table 2.

TABLE-US-00002 TABLE 2 Unit cell parameters of five-and-a-half hydrate of Treprostinil sodium salt Crystal system Orthogonal crystal system Space group P2.sub.12.sub.12.sub.1 a/Å 7.6983(2) b/Å 18.0393(4) c/Å 39.1744(10) α/° 90 β/° 90 γ/° 90 Flack parameter 0.05(3)

[0066] Different crystallization process parameters including concentration of sodium hydroxide, volume of acetonitrile and temperature were screened, the operation steps are as described above. As shown in Table 3, the results showed that the same crystal forms of five-and-a-half hydrate of Treprostinil sodium salt are obtained with different crystallization process parameters.

TABLE-US-00003 TABLE 3 Summary of products obtained with different crystallization process parameters Treprostinil Sodium Aceto- Temper- Crystal form of free acid hydroxide nitrile ature product 1 g 1.5 ml 10 wt % 28.5 ml 25 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt 1 g 1.5 ml 10 wt % 50 ml 25 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt 1 g 1.5 ml 10 wt % 75 ml 25 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt five-point-five hydrate 1 g 1.5 ml 10 wt % 28.5 ml 5 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt 1 g 1.5 ml 7 wt % 28.5 ml 5 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt 1 g 1.5 ml 7 wt % 50 ml 25 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt 1 g 1.5 ml 7 wt % 75 ml 25 Five-and-a-half sodium hydroxide hydrate of aqueous solution Treprostinil sodium salt

Example 3

[0067] Treprostinil Sodium Salt as Described in U.S. Pat. No. 9,550,716

[0068] Treprostinil sodium salt was prepared according to the method described in U.S. Pat. No. 9,550,716, as follows:

[0069] 1.5 g of crude Treprostinil was dissolved in 37 ml acetone and heated to 30° C., 0.9 ml 5M NaOH was added slowly dropwise, and maintained at 30° C. and stirred for 15 minutes. After the reaction system was stirred at room temperature for 1 hour, white crystals precipitated. Then the reaction system was placed in the ice water bath and stirred for another hour. The solid was filtered and washed with acetone. It is found that the solid became sticky rapidly during washing and filtration. After resulting solids was dried at room temperature, 0.8 g solid was obtained with a yield of ˜52%.

[0070] The solid was placed at a condition of 25 degrees and 80% relative humidity for 24 hours, and it was found that the solid deliquesced into a viscous solution, which showed that the solid was extremely hygroscopic and could not meet the requirements of drugs for product quality stability.

Example 4

Treprostinil Sodium Salt as Described in WO2016055819

[0071] Treprostinil sodium salt was prepared according to the method described in WO 2016055819, but the crystal form described in this patent can not be obtained. The specific processes are as follows:

[0072] Form A

[0073] 0.25 g crude Treprostinil was dissolved in 3.3 ml ethanol, and added 87 mg sodium carbonate monohydrate, stirred at room temperature for 16 hours under N.sub.2 protection. The pH value of the solution was tested and is 6, which was failed to meet the requirement of pH 7-9 as described in WO2016055819, because the solubility of sodium carbonate in ethanol was low. After filtering out the insoluble sodium carbonate, the ethanol solution was placed in a rotary evaporator to give oil, then 2 ml of water-saturated methyl tert-butyl ether was added and stirred overnight to give white viscous semi-solids, which was determined as amorphous by polarizing microscope.

[0074] Form B

[0075] 0.25 g crude Treprostinil was dissolved in 3.3 ml ethanol, and 87 mg sodium carbonate monohydrate was added, stirring at room temperature for 16 hours under N.sub.2 protection, the pH of the solution was tested is 6, which failed to meet the requirement of pH 7-9 described in WO2016055819, because the solubility of sodium carbonate in ethanol was low. After filtering out the insoluble sodium carbonate, the ethanol solution was put on a rotary evaporator to give an oil, then 2 ml of methyl tert-butyl ether was added and stirred overnight to give a white viscous semi-solid, which was confirmed as amorphous by polarizing microscope.

[0076] According to the description of WO2016055819, both Form A and Form B are converted into Form C at 60% relative humidity, indicating that the solid-state stability of both crystal forms cannot meet the requirements for commercial production of Treprostinil sodium salt APIs/formulations.

[0077] Polyhydrate Form C

[0078] According to the description of WO2016055819, Form C can only be obtained by transformation of Form A and/or Form B, and it is not disclosed that Form C can be obtained directly by crystallization. By comparing the XRPD patterns of monohydrate (Form A) and polyhydrate (Form C) provided by WO2016055819 (FIG. 4), it can be found that Form C is not a single crystal form, but should be a mixture of Form A (diffraction peak marked with *) and other crystal forms (diffraction peak marked with ∇). As a mixed crystal form, it is difficult to ensure that the mixing ratio remains constant from batch to batch, thus the polyhydrate Form C cannot meet the requirements for crystalline stability in the commercial production of Treprostinil sodium salt APIs/formulations.

Example 5

Hygroscopicity of Five-and-a-Half Hydrate of Treprostinil Sodium Salt

[0079] Hygroscopicity is one of the key physicochemical properties of drugs and has a significant impact on drug stability, powderological properties and subsequent processing procedure. The hygroscopicity of five-and-a-half hydrate of Treprostinil sodium salt was evaluated by dynamic vapor sorption (DVS), and the results are shown in Table 4.

TABLE-US-00004 TABLE 4 Water content of five-and-a-half hydrate of Treprostinil sodium salt at the following humidity (RH %)/temperature (° C.) Humidity/Temperature Water content wt % 40.0/25° C. 18.6 45.0/25° C. 18.7 50.0/25° C. 18.7 55.0/25° C. 18.8 60.0/25° C. 18.8 65.0/25° C. 18.9 70.0/25° C. 18.9 75.0/25° C. 19.0 80.0/25° C. 19.7 85.0/25° C. 19.9 90.0/25° C. 20.5 95.0/25° C. 22.6

[0080] When the relative humidity increased from 40% to 80%, the increasing value of the water content, i.e., hygroscopicity, of five-and-a-half hydrate of Treprostinil sodium salt is 1.1 wt %. According to the definition of hygroscopicity in European Pharmacopoeia, its hygroscopicity is slight hygroscopicity, which proves that after forming the five-and-a-half hydrate, Treprostinil sodium salt can keep a low level of hygroscopicity within the range of conventional humidity, thus ensuring that the quality of Treprostinil sodium salt API is stable.

Example 6

[0081] five-and-a-half hydrate of Treprostinil sodium salt was placed in a watch glass, spread into a thin layer with no more than 1 mm thickness and placed into a stability test chamber at 40±2° C. and 75±5% relative humidity for 6 months.

[0082] The purity of samples after stability test was determined by HPLC, the water content of samples after stability test was determined by Karl Fischer titration, and the crystal form of samples after stability test was determined by XRPD. The results are shown in Table 5. The five-and-a-half hydrate of Treprostinil sodium salt showed excellent chemical stability and solid-state stability, that fully met the requirements of API for stability.

TABLE-US-00005 TABLE 5 Accelerated stability of five-and-a-half hydrate of Treprostinil sodium salt Purity Water Time Appearance % % crystal form 0 day Off-white 99.97 20.1 five-and-a-half hydrate of powder Treprostinil sodium salt 1 month Off-White 99.97 20.4 five-and-a-half hydrate of powder Treprostinil sodium salt 3 months Off-white 99.96 20.0 five-and-a-half hydrate of powder Treprostinil sodium salt 6 months Off-white 99.98 20.2 five-and-a-half hydrate of powder Treprostinil sodium salt

Example 7

Stability of Crystallization Process of Five-and-a-Half Hydrate of Treprostinil Sodium Salt

[0083] Three consecutive batches of five-and-a-half hydrate of Treprostinil sodium salt were prepared by process of Example 2 of the present invention, and the results are shown in Table 6 and FIG. 4. The results of the three batches showed that the crystallization process has good repeatability, stable product quality and completely meets the requirements for commercial production.

TABLE-US-00006 TABLE 6 Data of five-and-a-half hydrate of Treprostinil sodium salt from three consecutive batches Batch number water, % Purity, % 1# 20.4 99.9 2# 20.3 99.9 3# 20.4 99.9

Example 8

Partially Dehydrated Form I of the Five-and-a-Half Hydrate of Treprostinil Sodium Salt

[0084] The five-and-a-half hydrate of Treprostinil sodium salt was placed in a sealed container, and the ambient relative humidity was controlled at 30%. After the weight was completely constant, the solid morphology was characterized by XRPD.

[0085] The XRPD pattern of partially dehydrated crystal from I of the five-and-a-half hydrate of Treprostinil sodium salt is shown in FIG. 5. The main diffraction peaks and relative intensities are shown in Table 7.

TABLE-US-00007 TABLE 7 XRPD data of dehydrated crystal from I of the five- and-a-half hydrate of Treprostinil sodium salt Pos. [°2Th.] Rel. Int. [%] 4.8 100.0 9.6 67.2 15.6 1.0 19.3 7.5 20.9 4.7 22.1 1.7 23.5 1.4 25.1 1.3 26.1 1.2 26.8 1.0 29.4 1.0 30.6 1.1 39.1 1.2

Example 9

[0086] Partially Dehydrated Crystalline from II of the Five-and-a-Half of Treprostinil Sodium Salt

[0087] The five-and-a-half hydrate of Treprostinil sodium salt was placed in a sealed container, and the ambient relative humidity was controlled at 10%. After the weight was constant, the solid morphology was characterized by XRPD.

[0088] The XRPD pattern of the partially dehydrated crystal form II of the five-and-a-half hydrate of Treprostinil sodium salt is shown in FIG. 6. The main diffraction peaks and relative intensities are shown in Table 8. It can be seen from the XRPD pattern that the partial dehydrated crystal form II of the five-and-a-half hydrate of Treprostinil sodium salt is mixed with a small amount of partial dehydrated crystal form I of the five-and-a-half hydrate of Treprostinil sodium salt.

TABLE-US-00008 TABLE 8 XRPD data of dehydrated crystal form II of the five- and-a-half hydrate of Treprostinil sodium salt Pos. [°2Th.] Rel. Int. [%] 5.3 100.0 10.6 53.6 16.0 2.9 20.1 0.7 21.4 4.6 26.8 2.3

Example 10

[0089] Comparison of Water Solubility of the Five-and-a-Half Hydrate of Treprostinil Sodium Salt, Dehydrated Crystal Form I of the Five-and-a-Half Hydrate of Treprostinil Sodium Salt, Partially Dehydrated Crystal Form II of the Five-and-a-Half Hydrate of Treprostinil Sodium Salt and Treprostinil Free Acid

[0090] 20 mg of Treprostinil free acid was weighed and added into a volumetric flask, 200 mL of water was added, and placed in a water bath pot (temperature was controlled at 25±2° C.), shook strongly for 30 seconds every 5 minutes, and the dissolution within 30 minutes was observed. Results showed that the Treprostinil free acid was insoluble and its water solubility is less than 0.1 mg/ml.

[0091] About 100 mg of the five-and-a-half hydrate of Treprostinil, the partially dehydrated crystal form I of five-and-a-half hydrate of Treprostinil sodium, the partially dehydrated crystalline II of five-and-a-half hydrate of Treprostinil sodium was weighed and added into volumetric flasks, 1 mL of water was added, and placed in a water bath pot (temperature was controlled at 25±2° C.), shook strongly for 30 seconds every 5 minutes, and the dissolution within 30 minutes was observed. The results showed that five-and-a-half hydrate of Treprostinil, partially dehydrated crystal form I of five-and-a-half hydrate of Treprostinil sodium salt and partially dehydrated crystal form II of five-and-a-half hydrate of Treprostinil sodium salt are completely dissolved, and the solubility are more than 100 mg/ml.

[0092] The water solubility of the five-and-a-half hydrate of Treprostinil sodium salt and the partially dehydrated crystal form I and partially dehydrated crystal form II thereof are far better than that of Treprostinil free acid. Solubility is the key factor that restricts the release of drugs in vivo, and insufficient solubility will lead to the uncompleted release of drugs and then affect their bioavailability. Therefore, the five-and-a-half hydrate of Treprostinil sodium salt and partially dehydrated crystal form I and partially dehydrated crystal form II thereof have better effect on practical application.

[0093] All documents referred to in the present invention are incorporated by reference herein as if each document is individually incorporated by reference. Further, it should be understood that upon reading the above teaching of the present invention, various modifications or modifications may be made to the present invention by those skilled in the art, and those equivalents also fall within the scope defined by the appended claims of the present application.