Rivaroxaban co-crystals and methods of making the same

Abstract

The present application relates to a co-crystal of rivaroxaban and a preparation method thereof, and also relates to a pharmaceutical composition containing the co-crystal, and also relates to application of the co-crystal in preparation of a medicine for anticoagulation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medicine, and relates to a co-crystal of rivaroxaban and a preparation method thereof, a pharmaceutical composition containing the co-crystal, and application of the co-crystal in preparation of a medicine for anticoagulation therapy. BACKGROUND

[0002] Rivaroxaban (chemical name 5-chloro-N-({(5S)-2-oxo-3-[4-(3-oxo-4-morpholinyl)phenyl]-1,3-oxazolidin-5-yl}methyl)-2-thiophenecarboxamide, formula 1) is the first oral direct factor Xa inhibitor in the world, which can selectively and competitively inhibit free and bound Xa, thereby inhibiting thrombin generation and thrombus formation, and is clinically used for prevention and treatment of thrombus. Compared with the traditional anticoagulant drug warfarin, rivaroxaban is more efficient and safer, and does not need special drug monitoring, and has a good application prospect. However, rivaroxaban belongs to the biological classification (BCS) of class II drugs, and low solubility leads to low dose uniformity of in vivo absorption, dose-dependent characteristics (absolute bioavailability is lower than 60% at high dose), and a series of problems such as food effect and delay effect, which greatly limit its clinical application.

[0003]

[0004] A drug co-crystal is a multi-component system composed of a fixed stoichiometric ratio of an active pharmaceutical ingredient (API) and a co-crystal ligand (co-crystal former, CCF) through non-covalent bond interactions such as hydrogen bond, van der Waals force, π-π conjugation and halogen bond. The drug co-crystal can improve the physicochemical properties of the drug such as melting point, stability, solubility, compressibility, water absorption and bioavailability without changing the chemical structure of the drug. In recent years, the drug co-crystal has become a new strategy for drug research and development, and shows an attractive application prospect in the field of medicine and biology. SUMMARY

[0005] The inventors have unexpectedly obtained a co-crystal of rivaroxaban, which improves the solubility, dissolution and in vivo relative bioavailability of the poorly soluble rivaroxaban compared with the prior art.

[0006] The present application provides a co-crystal comprising or formed by rivaroxaban and a co-crystal ligand, wherein the co-crystal ligand is p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid or succinic acid.

[0007] The present application also provides a pharmaceutical composition comprising the co-crystal and a pharmaceutically acceptable carrier or excipient.

[0008] The present application also provides a method for preparing the co-crystal, comprising:

[0009] a) placing rivaroxaban and a co-crystal former in a solvent;

[0010] b) heating the mixture obtained in a) until rivaroxaban and the co-crystal former are completely dissolved;

[0011] c) cooling down until crystals precipitate;

[0012] d) optionally isolating the crystals;

[0013] e) optionally drying the crystals.

[0014] The present application also provides another method for preparing the co-crystal, comprising:

[0015] a) dissolving rivaroxaban and a co-crystal former in a solvent;

[0016] b) adding water to the solution obtained in a);

[0017] c) evaporating the solvent and water from the mixture obtained in b);

[0018] d) optionally isolating the crystals;

[0019] e) optionally drying the crystals.

[0020] The present application also provides the use of the co-crystal in the preparation of a medicament for anticoagulation or in the preparation of a medicament for the treatment and / or prevention of coagulation.

[0021] The present application also provides the use of the co-crystal in the preparation of a medicament for anticoagulation or in the preparation of a medicament for the treatment and / or prevention of thrombosis. DETAILED DESCRIPTION

[0023] co-crystal

[0024] The present application provides a co-crystal comprising or formed by rivaroxaban and a co-crystal former, the co-crystal former being p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid or succinic acid.

[0025] In certain embodiments, the co-crystal former is p-hydroxybenzoic acid or 2,4-dihydroxybenzoic acid.

[0026] In certain embodiments, the co-crystal former is p-hydroxybenzoic acid.

[0027] In certain embodiments, the molar ratio of rivaroxaban to co-crystal former in the co-crystal is about 1 :0.1-50.

[0028] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.2 to 10.

[0029] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.5 to 25.

[0030] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.5 to 10.

[0031] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.5 to 5.

[0032] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.5 to 2.

[0033] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :0.8 to 1.5.

[0034] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner in the co-crystals described herein is about 1 :1.

[0035] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :0.8 to 4.

[0036] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :0.8 to 3.

[0037] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :0.8 to 2.5.

[0038] In certain embodiments, the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :0.8 to 1.2.

[0039] In certain embodiments, the co-crystals described herein are co-crystals of rivaroxaban and p-hydroxybenzoic acid or 2,4-dihydroxybenzoic acid.

[0040] In certain embodiments, the co-crystals described herein are co-crystals of rivaroxaban and p-hydroxybenzoic acid or 2,4-dihydroxybenzoic acid, and the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :1.

[0041] In certain embodiments, the co-crystals described herein are co-crystals of rivaroxaban and p-hydroxybenzoic acid or 2,4-dihydroxybenzoic acid, and the molar ratio of the rivaroxaban to the co-crystal forming partner is about 1 :1.

[0042] In certain embodiments, the co-crystals described herein are co-crystals of rivaroxaban and p-hydroxybenzoic acid.

[0043] In certain embodiments, the co-crystal is a co-crystal of rivaroxaban and p-hydroxybenzoic acid, and the molar ratio of rivaroxaban to p-hydroxybenzoic acid is about 1 : 1.

[0044] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has characteristic peaks in an X-ray powder diffraction pattern, in terms of 2 theta angles, obtained using Cu-Ka radiation, at 22.6° ± 0.2°, 17.5° ± 0.2°.

[0045] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has characteristic peaks in an X-ray powder diffraction pattern, in terms of 2 theta angles, obtained using Cu-Ka radiation, at 22.6° ± 0.2°, 17.5° ± 0.2°.

[0046] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has characteristic peaks in an X-ray powder diffraction pattern, in terms of 2 theta angles, obtained using Cu-Ka radiation, at 22.6° ± 0.2°, 17.5° ± 0.2°.

[0047] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has characteristic peaks in an X-ray powder diffraction pattern, in terms of 2 theta angles, obtained using Cu-Ka radiation, at 22.6° ± 0.2°, 17.5° ± 0.2°.

[0048] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has substantially the same X-ray powder diffraction pattern as shown in Figure figure 5 using Cu-Ka radiation.

[0049] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid has substantially the same X-ray powder diffraction pattern as shown in Figure

[0050] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid according to the present application has no characteristic peaks at diffraction angles 2Q (error ±0.2 degrees) of 21.8°±0.2°, 14.4°±0.2°, 15.3°±0.2°, has characteristic peaks at 8.9°±0.2°, 30.0°±0.2°, and has a 2-5 fold increase in relative peak intensity at 17.5±0.2°, 27.3±0.2°, 9.1±0.2°, 18.1±0.2°, 24.8±0.2° in the X-ray powder diffraction pattern expressed in terms of 2Q angles obtained using Cu-Ka radiation as compared to the rivaroxaban drug substance.

[0051] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid according to the present application exhibits a melting endotherm in the range of 170-180 °C as measured by differential scanning calorimetry (DSC).

[0052] In certain embodiments, the co-crystal of rivaroxaban and p-hydroxybenzoic acid according to the present application has substantially the same differential scanning calorimetry curve as shown in Figure figure 8

[0053] pharmaceutical composition

[0054] The present application also provides a pharmaceutical composition comprising the co-crystal of any one of the above, and a pharmaceutically acceptable carrier or excipient.

[0055] In certain embodiments, the co-crystal is present in the pharmaceutical composition in an effective amount for the treatment and / or prevention of a disease or disorder. In certain embodiments, the disease or disorder is coagulation or thrombosis, such as venous thromboembolism (VTE), deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, cerebral thrombosis, or systemic embolism.

[0056] In certain embodiments, the co-crystal is present in the pharmaceutical composition in an effective amount for the treatment and / or prevention of a disease or disorder. In certain embodiments, the disease or disorder is coagulation or thrombosis, such as venous thromboembolism (VTE), deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, cerebral thrombosis, or systemic embolism.

[0057] preparation method one

[0058] The present application also provides a method of preparing the co-crystal of the present application, comprising:

[0059] a) placing rivaroxaban and a co-crystal forming ligand in a solvent;

[0060] b) heating the mixture obtained in a) until the rivaroxaban and the co-crystal forming ligand are completely dissolved;

[0061] c) cooling to allow crystallization;

[0062] d) optionally, isolating the crystals;

[0063] ​e) optionally drying the crystals.

[0064] In certain embodiments, the solvent is selected from an alcohol solvent, an ester solvent, a ketone solvent, an ether solvent, a nitrile solvent, an alkane solvent, a haloalkane solvent, or any combination thereof.

[0065] In certain embodiments, the alcohol solvent is selected from methanol, ethanol, isopropanol, or any combination thereof.

[0066] In certain embodiments, the ester solvent is selected from methyl acetate, ethyl acetate, propyl acetate, or any combination thereof.

[0067] In certain embodiments, the ketone solvent is selected from acetone, methyl isobutyl ketone, or a combination thereof.

[0068] In certain embodiments, the ether solvent is selected from methyl tert-butyl ether, cyclopentyl methyl ether, tetrahydrofuran, or any combination thereof.

[0069] In certain embodiments, the nitrile solvent is acetonitrile.

[0070] In certain embodiments, the alkane solvent is n-hexane.

[0071] In certain embodiments, the haloalkane solvent is dichloromethane.

[0072] In certain embodiments, the solvent is selected from methanol, ethanol, tert-butyl methyl ether, n-hexane, water, or any combination thereof.

[0073] In certain embodiments, the solvent is acetonitrile.

[0074] preparation method two

[0075] The present application also provides another method of making the co-crystal of the present application, comprising:

[0076] a) dissolving the rivaroxaban and the co-crystal forming ligand in a solvent;

[0077] b) adding water to the solution obtained in a);

[0078] c) evaporating the solvent and water from the mixture obtained in b);

[0079] d) optionally isolating the crystals;

[0080] e) optionally drying the crystals.

[0081] In certain embodiments, the solvent is selected from an alcohol solvent, an ester solvent, a ketone solvent, an ether solvent, a nitrile solvent, an alkane solvent, a haloalkane solvent, or any combination thereof.

[0082] In certain embodiments, the alcohol solvent is selected from methanol, ethanol, isopropanol, or any combination thereof.

[0083] In certain embodiments, the ester solvent is selected from methyl acetate, ethyl acetate, propyl acetate, or any combination thereof.

[0084] In certain embodiments, the ketone solvent is selected from acetone, methyl isobutyl ketone, or a combination thereof.

[0085] In certain embodiments, the ether solvent is selected from methyl tert-butyl ether, cyclopentyl methyl ether, tetrahydrofuran, or any combination thereof.

[0086] In certain embodiments, the nitrile solvent is acetonitrile.

[0087] In certain embodiments, the alkane solvent is n-hexane.

[0088] In certain embodiments, the haloalkane solvent is dichloromethane.

[0089] In certain embodiments, the solvent is ethanol.

[0090] use

[0091] The present application also provides use of the co-crystal of the present application in the preparation of a medicament for the treatment and / or prevention of coagulation or thrombosis.

[0092] The present application also provides use of the co-crystal of the present application in the preparation of a medicament for the treatment and / or prevention of coagulation or thrombosis.

[0093] The present application also provides use of the co-crystal of the present application in the preparation of a medicament for the treatment and / or prevention of venous thromboembolism (VTE), deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, cerebral thrombosis, or systemic embolism.

[0094] The present application also provides use of the pharmaceutical composition of the present application in the preparation of a medicament for the treatment and / or prevention of coagulation or thrombosis.

[0095] The present application also provides use of the pharmaceutical composition of the present application in the preparation of a medicament for the treatment and / or prevention of coagulation or thrombosis.

[0096] The present application also provides use of the pharmaceutical composition of the present application in the preparation of a medicament for the treatment and / or prevention of venous thromboembolism (VTE), deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, cerebral thrombosis, or systemic embolism.

[0097] definitions of terms

[0098] In the present application, the scientific and technical terms used herein have the meanings commonly understood by one of ordinary skill in the art, unless otherwise indicated. Also, for better understanding of the present application, the definitions and explanations of the relevant terms are provided below.

[0099] As used herein, the term "substantially the same" to define a graph is intended to mean that the graph is considered identical to a reference graph by one of ordinary skill in the art, taking into account deviations acceptable in the art. Such deviations can be caused by factors known in the art related to instruments, operating conditions, and human factors, among others. For example, one of ordinary skill in the art can appreciate that the onset and peak temperatures of an endotherm measured by differential scanning calorimetry (DSC) can vary significantly from experiment to experiment. In some embodiments, two graphs are considered substantially identical when the positions of the characteristic peaks of the two graphs vary by no more than ±5%, ±4%, ±3%, ±2%, or ±1%. For example, one of ordinary skill in the art can readily identify whether two X-ray diffraction patterns or two DSC patterns are substantially identical. In some embodiments, two X-ray diffraction patterns are considered substantially identical when the 2Θ angles of the characteristic peaks of the two X-ray diffraction patterns vary by no more than ±0.3°, ±0.2°, or ±0.1°.

[0100] As used herein, the term "effective amount" refers to an amount that is sufficient to achieve the desired therapeutic or prophylactic effect, e.g., an amount that achieves a reduction in the symptoms associated with the disease to be treated (e.g., a thrombus), or an amount that is effective to avoid, reduce, prevent, or delay the occurrence of the disease (e.g., a thrombus). Determining such an effective amount is well within the capabilities of one of ordinary skill in the art. Generally, the co-crystals described herein are used in a daily dose of about 1-1000 mg for treatment.

[0101] As used herein, the term "treatment" is intended to mean alleviating, reducing, ameliorating or eliminating the disease state or condition in question. A subject is successfully "treated" if the subject exhibits an observable and / or detectable reduction or improvement in one or more indicators and symptoms following administration of a therapeutically effective amount of the co-crystals or pharmaceutical compositions described herein. It is also understood that the treatment of a disease state or condition includes instances where there is no complete treatment, but some biologically or medically relevant result is achieved.

[0102] As used herein, the term "prevention" is intended to mean avoiding, reducing, preventing, or delaying the occurrence of a disease or disease-related symptoms, and such disease or disease-related symptoms have not yet occurred prior to the administration of the relevant drug. "Prevention" does not require complete prevention of the occurrence of a disease or disease-related symptoms, e.g., a reduction in the risk of a subject developing a particular disease or disease-related symptoms after the administration of the relevant drug, or a lessening of the severity of the relevant symptoms that later occur, can both be considered "prevention" of the occurrence or development of the disease.

[0103] As used herein, the term "about" is understood to be within the normal tolerances of the art, e.g., about can be understood to be within ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.1%, ±0.05%, or ±0.01% of the stated value. Unless otherwise apparent from the context, all numerical values provided herein are modified by the term "about."

[0104] As used herein, the term "pharmaceutically acceptable carrier or excipient" refers to a diluent, adjuvant, or vehicle with which a therapeutic agent is administered, and which is physiologically tolerable to the subject in contact with the tissues of humans and / or other animals at dosages and concentrations employed, and which does not have excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio as in the art.

[0105] Pharmaceutically acceptable carriers that can be employed in the pharmaceutical compositions of the application include, but are not limited to, sterile aqueous, such as water and oils, including those of

[0106] The pharmaceutical compositions described herein can be administered by methods known in the art, for example, but not limited to, administration in any of the following ways: orally, spray inhalation, rectally, nasally, buccal, topically, parenterally, such as subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal, and intracranial injection or infusion, or by means of an external reservoir and pump. Among these, oral, intramuscular or intravenous injection is preferred.

[0107] For these routes of administration, the pharmaceutical compositions of the application can be administered in a suitable dosage form.

[0108] The dosage form can be a solid preparation, a semi-solid preparation, a liquid preparation, or a gaseous preparation, including but not limited to tablets, capsules, powders, granules, lozenges, hard candies, powders, sprays, creams, ointments, suppositories, gels, pastes, lotions, ointments, aqueous suspensions, injectable solutions, suspensions, elixirs, syrups.

[0109] The pharmaceutical composition described in the present application can be prepared by any method well known in the art, for example, by mixing, dissolving, granulating, sugar-coating, milling, emulsifying, lyophilizing, and the like processes.

[0110] Advantages

[0111] The co-crystal of rivaroxaban provided by the present application has one or more of the following advantages compared with the raw material drug of rivaroxaban:

[0112] 1) high solubility;

[0113] 2) high in-vitro dissolution rate;

[0114] 3) high relative bioavailability in vivo.

[0115] In addition, the present application utilizes the principle of crystal engineering, combined with the characteristics of the amide group existing in the structure of rivaroxaban, to increase the intermolecular contact opportunity and accelerate the generation rate of the co-crystal by using the cooling crystallization method or the solvent method.

[0116] The method for preparing the co-crystal provided by the present application has one or more of the following advantages:

[0117] 1) simple operation;

[0118] 2) short preparation time;

[0119] 3) stable quality of the obtained co-crystal;

[0120] 4) strong controllability and good reproducibility of the method;

[0121] 5) low cost. BRIEF DESCRIPTION OF DRAWINGS

[0122] figure 1 The equilibrium solubility results of rivaroxaban and the product obtained in Example 1 of the present application are shown;

[0123] figure 2 The equilibrium solubility results of rivaroxaban and the product obtained in Example 2 of the present application are shown;

[0124] figure 3 The in-vitro dissolution curves of rivaroxaban and the product obtained in Example 1 of the present application are shown;

[0125] figure 4In-vitro dissolution profile of rivaroxaban and the product obtained in Example 2 of the present application is shown.

[0126] figure 5 PXRD pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 of the present application is shown.

[0127] figure 6 PXRD pattern of rivaroxaban raw material is shown.

[0128] figure 7 PXRD comparison pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 of the present application with rivaroxaban, p-hydroxybenzoic acid, physical mixture of rivaroxaban and p-hydroxybenzoic acid is shown.

[0129] figure 8 DSC pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 of the present application is shown.

[0130] figure 9 DSC comparison pattern of rivaroxaban, p-hydroxybenzoic acid, the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 of the present application is shown.

[0131] figure 10 FTIR pattern of rivaroxaban is shown.

[0132] figure 11 FTIR pattern of p-hydroxybenzoic acid is shown.

[0133] figure 12 FTIR pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 of the present application is shown. DETAILED DESCRIPTION

[0134] The embodiments of the present application will be described in detail with examples, but those skilled in the art will understand that the following examples and experimental examples are only for illustrating the present application, and should not be regarded as limiting the scope of the present application. The specific conditions not noted in the examples and experimental examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer, and the reagents or instruments not noted the manufacturer are all the conventional products that can be obtained by purchase.

[0135] The rivaroxaban used in the examples of the present application can be either commercially available (Dalian Mileen Biotechnology Co., Ltd., item number S1109A) or prepared according to the prior art. The co-crystal ligands used are all commercially available, for example, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, succinic acid, nicotinamide, benzamide, urea can be purchased from Sinopharm Chemical Reagent Co., Ltd.; isonicotinic acid can be purchased from Aladdin Reagent Co., Ltd.

[0136] Example 1: Preparation of rivaroxaban co-crystals by cooling crystallization method

[0137] Rivaroxaban and seven co-crystal ligands (p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, succinic acid, nicotinamide, isonicotinic acid, benzamide, urea, respectively) were mixed at a molar ratio of 1:1, then 25 ml of acetonitrile was added, heated to complete dissolution in a water bath at 80°C, stirred for 1 h, then placed at room temperature for 3 h, the solution became turbid, centrifuged at 5000 rpm for 2 min, the precipitate was collected, and the sample was dried under reduced pressure to obtain the product.

[0138] Example 2: Preparation of rivaroxaban co-crystals by solvent method

[0139] Rivaroxaban and seven co-crystal ligands (p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, succinic acid, nicotinamide, isonicotinic acid, benzamide, urea, respectively) were mixed at a molar ratio of 1:1, then dissolved in ethanol solvent, stirred at 200 rpm for 3 h, slowly added water to the solution while stirring, then placed at room temperature to slowly evaporate, when a large amount of crystals were produced, the remaining liquid was removed and dried under reduced pressure to obtain the product.

[0140] Test Example 1: Equilibrium solubility test

[0141] Test method: Water was used as the solvent, excess rivaroxaban raw material and each product obtained from Example 1 and Example 2 were added respectively, a small amount of glass beads was added, sealed and incubated at 37°C, then centrifuged, the supernatant was taken, filtered with a 0.45 μm microporous filter, and the obtained filtrate was the test solution; another 5 mg of rivaroxaban raw material was precisely weighed as the reference substance, diluted to the appropriate concentration as the reference solution. According to the high performance liquid chromatography method, the peak areas of the test solution and the reference solution were determined at 250 nm, and the content and equilibrium solubility were calculated by external standard method.

[0142] Chromatographic conditions:

[0143] Chromatographic column: ZORBAX Eclipse XDB-C18 column (specification: 4.6 mm x 250 mm, 5 μm); mobile phase: acetonitrile-water = 65:35; flow rate: 1 ml / min; detection wavelength: 250 nm; injection volume: 20 μl; column temperature: 30°C.

[0144] The equilibrium solubility results of rivaroxaban and each product obtained from Example 1 are shown in Table 1. figure 1 Among the eight co-crystal ligands, the equilibrium solubility of the products with p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, succinic acid as ligands was greatly improved compared with the rivaroxaban raw material, indicating that co-crystals were formed and the solubility was improved; while the remaining several ligands had no obvious improvement, indicating that co-crystals were not formed.

[0145] The equilibrium solubility results of each product obtained in Example 2 are shown in Table 2 below, which are substantially the same as the equilibrium solubility of each product obtained in Example 1, indicating that the products obtained by the two methods are substantially the same. figure 2 The equilibrium solubility results of each product obtained in Example 2 are shown in Table 2 below, which are substantially the same as the equilibrium solubility of each product obtained in Example 1, indicating that the products obtained by the two methods are substantially the same.

[0146] Test Example 2: In vitro dissolution test

[0147] Test method: 900 ml of aqueous solution was used as the dissolution medium, and an appropriate amount of rivastigmine and each product obtained in the above Example 1 and Example 2 was added, and the dissolution test method (2020 edition of Chinese Pharmacopoeia General 0931 second method) was followed. The operation was carried out at 37°C and the rotation speed was 75 rpm. 5 ml of solution was taken at 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240 min, and 0.45 μm microporous filter membrane was used for filtration to obtain the test solution. Another rivastigmine raw material was precisely weighed and dissolved in the dissolution medium to the appropriate concentration to obtain the reference solution. The chromatographic conditions in Test Example 1 were used, and the peak area of the test solution and the reference solution was determined at 250 nm by high performance liquid chromatography. The dissolution amount at different time points was calculated by external standard method, and the cumulative dissolution curve was drawn.

[0148] The in vitro dissolution curve of each product obtained in Example 1 is shown in Table 3 below. figure 3 The results show that the products of p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid and succinic acid as ligands can be completely dissolved (>80%) within 90 min, indicating that the above three ligands and rivastigmine form a co-crystal, achieving the effect of improving the in vitro dissolution; and the in vitro dissolution of rivastigmine raw material and the products of the remaining ligands is less than 20%, indicating that no co-crystal is formed.

[0149] The in vitro dissolution curve of each product obtained in Example 2 is shown in Table 4 below. figure 4 The in vitro dissolution curve of each product obtained in Example 2 is shown in Table 4 below.

[0150] Test Example 3: Characterization of rivastigmine and p-hydroxybenzoic acid co-crystal

[0151] The rivastigmine and p-hydroxybenzoic acid co-crystal prepared by Example 1 or Example 2 was characterized by X-ray powder diffraction (PXRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and other methods.

[0152] a.The powder diffraction pattern of the drug co-crystal obtained in Example 1 was determined using a Bruker D8 Advance diffractometer (Germany) under the following conditions: Cu, Kα, 40 kV, 40 mV as the light source, a scanning speed of 0.6° / min, a scanning range of 0-90°, and room temperature. The powder diffraction patterns of rivaroxaban, 2,4-dihydroxybenzoic acid, a physical mixture of rivaroxaban and p-hydroxybenzoic acid (molar ratio 1:1) were obtained under the same conditions.

[0153] The co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 had characteristic peaks at 2θ (°) of 22.6°±0.2°, 17.5°±0.2°; also at 27.3°±0.2°, 9.1°±0.2°, 19.6°±0.2°, 26.7°±0.2°, 25.7°±0.2°; also at 16.6°±0.2°, 18.1°±0.2°, 24.8°±0.2°, 20.0°±0.2°, 23.5°±0.2°; also at 8.9°±0.2°, 30.0°±0.2°, using Cu-Kα radiation.

[0154] Specifically, the PXRD pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 is shown in figure 5 The PXRD pattern of the rivaroxaban raw material is shown in figure 6 .

[0155] figure 7 The PXRD comparison pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 with rivaroxaban, p-hydroxybenzoic acid, and a physical mixture of rivaroxaban and p-hydroxybenzoic acid is shown. Both rivaroxaban and p-hydroxybenzoic acid show clear characteristic peaks, indicating that both have crystal structures; the characteristic peaks of the physical mixture of rivaroxaban and p-hydroxybenzoic acid are simply superimposed on the characteristic peaks of rivaroxaban and p-hydroxybenzoic acid, indicating that the API and the ligand p-hydroxybenzoic acid do not interact in the physical mixture; compared with the rivaroxaban raw material, the characteristic peaks of the co-crystal of rivaroxaban and p-hydroxybenzoic acid of the present application at diffraction angles 2θ (error ±0.2 degrees) of 21.8°±0.2°, 14.4°±0.2°, 15.3°±0.2° disappear, characteristic peaks at 8.9°±0.2°, 30.0°±0.2° appear, and the relative peak intensity at 17.5°±0.2°, 27.3°±0.2°, 9.1°±0.2°, 18.1°±0.2°, 24.8°±0.2° increases by 2-5 times, indicating that a new structure is formed in the co-crystal.

[0156] The PXRD pattern of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 2 is substantially the same as figure 5 .

[0157] b. The drug eutectic obtained in Example 1 was determined using a TA Q2000 differential scanning calorimeter (TA Instruments). The test conditions were as follows: approximately 5 mg of sample was packaged in an aluminum disk; heating temperature was 25–300 °C; heating rate was 10.0 °C / min; purge gas was nitrogen at a rate of 50 ml / min; and temperature calibration was performed using NIST indium metal. DSC spectra of rivaroxaban and p-hydroxybenzoic acid were obtained under the same test conditions.

[0158] figure 8 The DSC spectrum of the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 is shown. figure 9 The DSC comparison spectra of rivaroxaban, p-hydroxybenzoic acid, and the cocrystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 are shown. figure 8 and figure 9 As shown, the melting points of rivaroxaban, p-hydroxybenzoic acid, and the eutectic of rivaroxaban and p-hydroxybenzoic acid are 231.7℃, 216.4℃, and 174.3℃, respectively. The change in melting point indicates the formation of a new phase.

[0159] The DSC spectrum of the cocrystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 2 and figure 8 They are basically the same.

[0160] c. The drug cocrystals obtained in Example 1 were determined using a Nicolet 6700 Fourier transform infrared spectrometer (Thermo Fisher Scientific). The test conditions were as follows: KBr dry compression, scanning range 4000–400 cm⁻¹ -1 .

[0161] figure 10 , figure 11 , figure 12 The FTIR spectra of rivaroxaban, p-hydroxybenzoic acid, and the cocrystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1 are shown. As shown in the figure, in the FTIR spectrum of the cocrystal of rivaroxaban and 2,4-dihydroxybenzoic acid prepared in Example 1, the NH absorption peak of rivaroxaban increases from 3353.41 cm⁻¹. -1 Displaced to 3424.14cm -1 The C=O absorption peak is at 1649.90 cm⁻¹. -1 Displaced to 1651.04cm -1 This suggests that the NH bond in rivaroxaban and the C=O bond in 2,4-dihydroxybenzoic acid may form hydrogen bonds.

[0162] The FTIR spectrum of the cocrystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 2 and figure 12Substantially the same.

[0163] Test Example 4: Pharmacokinetic test in beagle dogs

[0164] Test method: 6 male beagle dogs, weighing 9.0±1.2 kg, were randomly divided into two groups: test preparation group (rivastigmine and p-hydroxybenzoic acid co-crystal group) and reference preparation group (rivastigmine drug substance group), 3 in each group. On the day before the experiment, the dogs were fasted for 12 h and allowed to drink water freely. The dogs in the two groups were each given rivastigmine at a dose equivalent to 20 mg per dog. After administration, blood was taken from the leg veins at 10 min, 30 min, 1 h, 1.5 h, 2 h, 3 h, 4 h, 6 h, 8 h, 12 h, and 24 h. After blood collection, the blood was centrifuged in a heparinized blood collection tube for 10 min, and 100 μl of plasma was accurately measured and added to an EP tube, 100 μl of the antihistamine internal standard solution (500 ng / ml) was added, mixed well, 300 μl of acetonitrile was added, vortexed for 3 min, and centrifuged at 14000 r / min for 5 min; 5 μl of supernatant was injected for LC-MS / MS determination and calculation of blood drug concentration, and DASS 2.0 software was used to calculate the pharmacokinetic parameters.

[0165] a. Chromatographic conditions

[0166] Chromatographic column: Agilent narrow Bore RR SB-C18 column (specifications: 2.1 mm x 100 mm, 3.5 μm); mobile phase: methanol: 0.1% formic acid aqueous solution = 30 / 40 (v / v); injection volume: 5 μl; column temperature: 40°C.

[0167] b. Mass spectrometry conditions

[0168] Ion polarity: positive ion; ionization method: pneumatic assisted electrospray ionization (ESI); ion detection method: multiple reaction monitoring (MRM); detection object: RIV [M+H]+, m / z 436.0→144.8, internal standard [M+H]+, m / z 256.2→167.2; fragmentation voltage: 110 V and 160 V, respectively; collision energy: RIV 40 eV, internal standard 30 eV, dry gas flow rate: 10 L / min; nebulization chamber pressure: 50 psi; dry gas temperature: 350°C, capillary voltage: 4000 V.

[0169] c. Pharmacokinetic data processing

[0170] The obtained blood drug concentration data were analyzed by DAS 2.0 analysis software.

[0171] d. Determination results

[0172] The average blood drug concentration (μg / ml) at different time points was calculated to obtain the main pharmacokinetic parameters and relative bioavailability after the beagles orally took the rivaroxaban raw material, the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1, respectively, and the results are shown in Table 1 and Table 2.

[0173] Table 1: Main pharmacokinetic parameters of each preparation, n = 6

[0174]

[0175] Note: AUC 0→Tn , AUC 0→∞ are the areas under the blood drug concentration curves at 0→Tn and 0→∞ time, respectively, C max and T max are the peak concentration and peak time, respectively.

[0176] Table 2: Relative bioavailability results of the tested preparation, n = 6

[0177]

[0178] Note: Relative bioavailability = AUC 受试制剂 / AUC 参比制剂 .

[0179] The above experimental results show that the relative bioavailability (AUC 受试制剂 / AUC 参比制剂 ) of the tested preparation (the co-crystal of rivaroxaban and p-hydroxybenzoic acid prepared in Example 1) and the reference preparation (rivaroxaban raw material) is 148.6%. It can be seen that the co-crystal of rivaroxaban and p-hydroxybenzoic acid provided by the present application can significantly improve the bioavailability of rivaroxaban, which indicates that there is some interaction between the active ingredient and the co-crystal ligand in the co-crystal, thereby promoting the in-vivo absorption of the drug.

[0180] In summary, compared with the prior art, the co-crystal of rivaroxaban provided by the present application has a simple prescription, and imparts new physicochemical properties to the active ingredient rivaroxaban without changing the molecular structure of the drug. The in-vitro dissolution curve and the in-vivo pharmacokinetic experiment results of beagles show that the drug co-crystal provided by the present application is superior to the rivaroxaban raw material and the same proportion of physical mixture, and has the advantages of simple preparation process, low cost, easy operation, stable quality, strong controllability, good reproducibility, high bioavailability, etc., and has potential application value.

Claims

1. A co-crystal formed from rivaroxaban and a co-crystal former, said co-crystal former being p-hydroxybenzoic acid, having substantially the same X-ray powder diffraction pattern as shown in Figure 5 using Cu-Ka radiation.

2. The co-crystal of claim 1, wherein the molar ratio of rivaroxaban to co-crystal former is 1:

1.

3. The co-crystal of claim 1, wherein the co-crystal has a relative peak intensity increase of 2-5 fold at 17.5±0.2°, 27.3±0.2°, 9.1±0.2°, 18.1±0.2°, 24.8±0.2°.

4. The co-crystal of any one of claims 1-3, wherein the co-crystal exhibits a melting endotherm in the range of 170-180°C as measured by differential scanning calorimetry.

5. The co-crystal of claim 4, wherein the co-crystal has substantially the same differential scanning calorimetry curve as shown in Figure 8.

6. A pharmaceutical composition comprising the co-crystal of any one of claims 1 to 5, and a pharmaceutically acceptable carrier or excipient.

7. A method of preparing the co-crystal of any one of claims 1 to 5, comprising: a) placing rivaroxaban and a co-crystal former in a solvent; b) heating the mixture obtained in a) until the rivaroxaban and the co-crystal former are completely dissolved; c) cooling to allow crystallization, wherein the solvent is acetonitrile.

8. The method of claim 7, further comprising one or both of: d) isolating the crystals; e) drying the crystals.

9. A method of preparing the co-crystal of any one of claims 1 to 5, comprising: a) dissolving rivaroxaban and a co-crystal former in a solvent; b) adding water to the solution obtained in a); c) evaporating the solvent and water from the mixture obtained in b), wherein the solvent is ethanol.

10. The method of claim 9, further comprising one or both of: d) isolating the crystals; e) drying the crystals.

11. Use of the co-crystal of any one of claims 1 to 5 in the manufacture of a medicament for anticoagulation, or in the manufacture of a medicament for the treatment and / or prevention of coagulation or thrombosis, or in the manufacture of a medicament for the treatment and / or prevention of venous thromboembolism, deep vein thrombosis, pulmonary embolism, stroke, cerebral thrombosis, or systemic embolism.

12. Use of the pharmaceutical composition of claim 6 in the manufacture of a medicament for anticoagulation, or in the manufacture of a medicament for the treatment and / or prevention of coagulation or thrombosis, or in the manufacture of a medicament for the treatment and / or prevention of venous thromboembolism, deep vein thrombosis, pulmonary embolism, stroke, cerebral thrombosis, or systemic embolism.

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