Crystal form of tenofovir alafenamide salt, preparation method and use thereof

This application is a continuation of International Application No. PCT/CN2017/088538, filed on Jun. 15, 2017, which claims priority to Chinese Application No. 201610402175.4, filed on Jun. 5, 2016. The above-referenced applications are incorporated herein by reference in their entirety.

The present invention relates to novel crystals of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate and its preparation method and use.

Compound 1, tenofovir alafenamide (TAF or GS-7340) is one of the main ingredients in the FDA-approved anti-AIDS drug Genvoya. The drug was developed by Gilead. Tenofovir alafenamide is a nucleic acid reverse transcriptase inhibitor and a potential drug for tenofovir.

The formula of tenofovir alafenamide is C 21 H 29 N 6 O 5 P, which has a molecular weight of 467.5. The chemical structural formula of tenofovir alafenamide is as follows:

Chemical raw materials of active pharmaceutical ingredients (API) must have good purity, stability, physical and chemical properties and operability. These properties are related to the crystalline Form of the drug, and different crystal Forms have different physical and chemical properties. The purpose of improving the stability of the drug preservation and the efficacy of the drug, it is necessary to make the raw API into crystal Form.

A drug may exist in a plurality of crystalline Forms, and different crystal Forms of the same drug may have different dissolution and absorption in the body, thereby affecting the dissolution and release of the Formulation.

The optimal crystalline Form can be discovered by thoroughly studying of the polymorphism of the compound. The optimal crystalline Form is crucial to the efficacy of the drug and the Formulation process which is based on the characteristics of the crystalline Form, thereby effectively ensuring the equivalence of the drug batch to batch.

The physicochemical properties of the pharmaceutically active substance can be improved by selecting the form of its appropriate salt: such as solubility, dissolution rate, stability, purity, and the like. These physical and chemical properties further influence the quality and bioavailability of the drug. However, the choice of counter ion pairs used for salt formation and the formation of salts are not always straightforward, as the physical and chemical properties of different counter ions forming salts with the same compounds can vary widely. Some of salts can improve physical and chemical properties while some salt cannot be improved. Sometimes, the salt even has the poor physical and chemical properties. Therefore, finding and manufacturing a salt for pharmaceutically developable and improving the physical properties of a drug is a practical creation work.

A drug and a salt thereof may exist in a plurality of crystalline form states, and different crystal forms of the same drug and its salt may have different dissolution and absorption in the body, thereby affecting dissolution and release of the preparation.

The research on the polymorphic form of the drug and its salt can find the optimal crystalline form of the drug which is beneficial to the action of the drug, and at the same time, determine the formulation process according to the characteristics of the crystalline form, and effectively ensure the equivalence of the batch drug in the production.

Tenofovir alafenamide hemifumarate is one of the main components of the anti-AIDS drug Genvoya. The Genovya combination also contains other drugs such as Elvitegravir, cobicistat, emtricitabine. In the current technology, when TAF hemifumarate crystal form I (WO2013025788A1) is mixed with emtricitabine to form a tablet, the chemical stability of TAF is affected, and degradation products are easily generated, thereby affecting the quality and efficacy of the combination formulation. In order to solve this difficult problem, we have unexpectedly discovered that the new crystalline form II, monofumarate (form A) and sesquifumarate (form B) of TAF can significantly improve the chemical compatibility of TAF with emtricitabine, which makes this comb formulation more stable and improves quality and shelf life.

A crystalline Form of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate designated as Form II, having an X-ray powder diffraction pattern comprising diffraction peaks at 2θ values: 26.6±0.2, 21.3±0.2, 27.1±0.2, 19.6±0.2, 18.7±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 32.1±0.2, 21.9±0.2, 5.4±0.2, 22.4±0.2, 11.1±0.2, 17.8±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 15.9±0.2, 24.5±0.2, 24.9±0.2, 19.0±0.2, 23.6±0.2, 30.0±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 32.4±0.2, 37.5±0.2, 10.5±0.2, 14.5±0.2, 16.7±0.2, 40.3±0.2. More preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 23.9±0.2, 12.3±0.2, 38.6±0.2, 43.0±0.2, 27.8±0.2, 35.8±0.2.

The melting point of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form II is 106.6±2° C.

A process for the preparation of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form II comprising:

(i) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine free base was dissolved in organic solution.

(ii) Added aliquot fumaric acid into the solution prepared in process (i) to make precipitation of the fumarate salt.

(iii) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate form II was obtained after liquid-solid separation.

A crystalline Form of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate designated as Form A, having an X-ray powder diffraction pattern comprising diffraction peaks at 2θ values: 23.8±0.2, 10.5±0.2, 28.5±0.2, 21.2±0.2, 19.5±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 15.1±0.2, 23.2±0.2, 17.0±0.2, 9.8±0.2, 20.8±0.2, 17.6±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 15.7±0.2, 27.1±0.2, 25.2±0.2, 33.5±0.2, 22.4±0.2, 19.0±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 13.3±0.2, 4.8±0.2, 9.6±0.2, 26.7±0.2, 5.3±0.2, 11.4±0.2. More preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 14.0±0.2, 30.2±0.2, 8.5±0.2, 31.3±0.2, 21.9±0.2, 12.5±0.2.

A process for the preparation of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form A:

(i) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine free base was dissolved in organic solution.

(ii) Added excessive fumaric acid into the solution prepared in process (i) to make precipitation of the fumarate salt.

(iii) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate form A was obtained after liquid-solid separation.

A crystalline Form of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate designated as Form B, having an X-ray powder diffraction pattern comprising diffraction peaks at 2θ values: 10.5±0.2, 21.0±0.2, 10.9±0.2, 27.2±0.2, 22.5±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 28.9±0.2, 27.7±0.2, 24.1±0.2, 18.7±0.2, 13.5±0.2, 20.6±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 4.9±0.2, 14.1±0.2, 11.2±0.2, 16.4±0.2, 23.3±0.2, 19.6±0.2. Preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 14.8±0.2, 15.1±0.2, 12.3±0.2, 38.0±0.2, 17.3±0.2, 15.7±0.2. More preferably, wherein the X-ray powder diffraction pattern further comprises the following 2θ values: 18.1±0.2, 21.8±0.2, 31.8±0.2, 35.0±0.2, 41.7±0.2, 40.0±0.2.

A process for the preparation of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form B comprising:

(i) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine free base was dissolved in organic solution.

(ii) Added excessive fumaric acid into the solution prepared in process (i) to make precipitation of the fumarate salt.

(iii) 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate form B was obtained after liquid-solid separation.

A pharmaceutical composition comprising the crystal Forms A, B and II as an active ingredient.

A pharmaceutical composition comprising the crystal Forms including Form A, B and II as an active ingredient for treatment of virus-related diseases.

The treatment of a virus-related disease. The disease is selected from: hepatitis B virus (HBV) and/or human immunodeficiency virus (HIV) infection.

FIG. 1 is an XRPD diffraction pattern of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form II. 2θ values in unit of degree in accordance with the abscissa. The intensity of diffraction peak as ordinate.

FIG. 2 is a DSC plot of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form II. Temperature in unit of ° C. in accordance with the abscissa. The Heat flow (w/g) as ordinate.

FIG. 3 is a TGA plot of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form II. Temperature in unit of ° C. in accordance with the abscissa. The Weight (%) as ordinate.

FIG. 4 is an XRPD diffraction pattern of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form A. 2θ values in unit of degree in accordance with the abscissa. The intensity of diffraction peak as ordinate.

FIG. 5 is an XRPD diffraction pattern of 9-[(R)-2-[[(S)-[[(S)-1-(isopropoxycarbonyl)ethyl]amino]phenoxyphosphinyl]methoxy]prop yl]adenine fumarate Form B. 2θ values in unit of degree in accordance with the abscissa. The intensity of diffraction peak as ordinate.

The specific embodiments of the present invention are further described in detail below with reference to the drawings and embodiments. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

The X-ray powder diffraction operation and analysis steps in this present disclosure are as follows:

The Rigaku Ultima IV powder diffractometer was used, which was irradiated with Cu—K(R) (40 kV, 40 mA) at room temperature using a D/tex Ultra detector. The scanning range is from 3° to 45° in the 2θ interval, and the scanning speed is 20°/min.

Measurement differences associated with X-ray powder diffraction analysis results are produced by a variety of factors including: (a) errors in sample preparation (e.g., sample height), (b) instrument error, (c) calibration differences, (d) operator error (including errors that occur when determining peak position), and (e) properties of the substance (e.g., preferred orientation error). Calibration errors and sample height errors often result in displacement of all peaks in the same direction. When using a flat sampler, small differences in sample height will result in large displacements of the XRPD peak position. Systematic studies have shown that a 1 mm sample height difference can result in a 2θ peak shift of up to 10. These displacements can be identified from the X-ray diffraction pattern and can be eliminated by compensating for the displacement (using a system calibration factor for all peak position values) or recalibrating the instrument. As described above, the measurement errors from different instruments can be corrected by applying a system calibration factor to make the peak positions consistent.

A differential scanning calorimetry (DSC) analysis was performed on the crystal Forms in Examples, using a TA Q2000 differential scanning calorimeter using an N 2 atmosphere at a temperature rising rate of 10° C./min.

The thermogravimetric (TGA) analysis of the crystal Forms in Examples was carried out using a TA Q500 thermogravimetric analyzer using a N 2 atmosphere at a heating rate of 10° C./min.