WO2024062421A1 - Bexagliflozin in monohydrate, dihydrate or amorphous forms - Google Patents

Abstract

The present invention discloses polymorphs of bexagliflozin or hydraates of bexagliflozin, as crystalline solids, processes for the preparation of the polymorphs/hydrates of bexagliflozin as crystalline solids, pharmaceutical compositions comprising the bexagliflozin (hydrtate) polymorphs thereof and to methods of treatment of diabetes using the said compounds.

Description

  Crystalline Forms of Bexagliflozin, Processes for the Preparation and Use Thereof The present invention relates to polymorphs of bexagliflozin, namely polymorphs of bexagliflozin as crystalline solids, to processes for the preparation of the new polymorphs of bexagliflozin as crystalline solids, to pharmaceutical compositions comprising the polymorphs of bexagliflozin and to methods of treatment using the polymorphs of bexagliflozin. Background Bexagliflozin has the IUPAC name of (1S)-1,5-Anhydro-1-(4-chlor-3-{4-[2-(cyclopropyloxy)ethoxy]benzyl}phenyl)-D-glucitol and has the structure:

Bexagliflozin is one member of a class of medications that modulate sodium-glucose transport proteins in the nephron (the functional units of the kidney), unlike SGLT1 inhibitors that perform a similar function in the intestinal mucosa. The foremost metabolic effect of this is to inhibit re-absorption of glucose in the kidney and therefore lower blood sugar. They act by inhibiting sodium-glucose transport protein 2 (SGLT2). SGLT2 inhibitors are used in the treatment of type II diabetes mellitus (T2DM), modulating blood glucose levels, modulating systolic blood pressure and weight loss in a human subject. Apart from blood sugar control, gliflozins have been shown to provide significant cardiovascular benefit in patients with type II diabetes (T2DM). Several medications of this class have been approved or are currently under development. The ability of a compound to exist in at least one crystal structure or solid-state form is known as polymorphism. Many compounds may exist as polymorph crystals and those compounds may also exist in a solid amorphous state. Until polymorphism of a   compound is discovered, it is highly unpredictable (1) whether a particular compound will exhibit polymorphism, (2) how to make any such unknown polymorphs, and (3) what the properties, such as stability, will be of any such unknown polymorphs. See, e.g., J. Bernstein "Polymorphism in Molecular Crystals", Oxford University Press, (2002). US Pat. Nos. US8987323 B2, US10981942 B2, US9834573 B2, and US10533032 B2 disclose and claim certain crystalline forms of bexagliflozin, as well as anhydrous bexaglfilozin and co-crystal forms of bexagliflozin (e.g. CN108239055A). Bexagliflozin can exist in different crystalline forms, amorphous forms (e.g. EP 2580225 B1) and can form solvates with certain solvents. The single crystal structure of bexagliflozin was determined (Tetrahedron Letters, 57 (2016) 4684–4687) from crystals grown from a methanol water mixture. Alternative polymorphic forms of bexagliflozin are of great commercial interest, because the properties of any solid material depend on the structure, as well as on the nature of the compound itself, different solid-state forms of a compound can and often do exhibit different physical and chemical properties. Differences in chemical properties can be determined through a variety of analytical techniques to be used to characterize, analyze, and compare. And those differences in chemical properties may ultimately be used to differentiate among different solid-state forms that may be discovered to exist. Furthermore, differences in physical properties, such as solubility and bioavailability, of solid-state forms can be important when formulating a pharmaceutical compound. Inventors have discovered a method for preparing bexagliflozin as a monohydrate (Form 1), a polymorph of an anhydrous form (Form 2) and a dihydrate (Form 3). According to one embodiment of the invention, a process for preparing a crystalline monohydrate of bexagliflozin (Form 1) is disclosed. In a separate embodiment, a polymorph of anhydrous bexagliflozin (Form 2) and a method for preparing anhydrous bexagliflozin is disclosed. In a separate embodiment, a crystalline dihydrate of bexagliflozin (Form 3) and a method for preparing the dihydrate of bexagliflozin is disclosed. Definitions   The follow abbreviations are defined herein in Table 1. Table 1 Table of Abbreviations Abbreviations Meaning

  The term “about” or “approximately” means an acceptable error for a particular value as determined by a person of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term “about” or “approximately” means within 1, 2, 3 or 4 standard deviations. In certain embodiments, the term “about” or “approximately” means within 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5% of a given value or range. In certain embodiments and with reference to X- ray powder diffraction two-theta peaks, the terms “about” or “approximately” means within ± 0.2 ^o 2θ. The term “ambient temperature” means one or more room temperatures between about 15 ^oC to about 30 ^oC, such as about 15 ^oC to about 25 ^oC. The term “consisting” is closed and excludes additional, unrecited elements or method steps in the claimed invention. The term “consisting essentially of” is semi-closed and occupies a middle ground between “consisting” and “comprising”. “Consisting essentially of” does not exclude additional, unrecited elements or method steps which do not materially affect the essential characteristic(s) of the claimed invention. The term “comprising” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps in the claimed invention. The term is synonymous with “including but not limited to”. The term “comprising” encompasses three alternatives, namely (i) “comprising”, (ii) “consisting”, and (iii) “consisting essentially of”. The term “crystalline” and related terms used herein, when used to describe a compound, substance, modification, material, component or product, unless otherwise specified, means that the compound, substance, modification, material, component or product is substantially crystalline as determined by X-ray diffraction. See, e.g., Remington: The Science and Practice of Pharmacy, 21st edition, Lippincott, Williams and Wilkins, Baltimore, Md. (2005); The United States Pharmacopeia, 23rd ed., 1843-1844 (1995). The term “pharmaceutical composition” is intended to encompass a pharmaceutically effective amount of the polymorphs of bexagliflozin as crystalline solids and at least one pharmaceutically acceptable excipient. As used herein, the term “pharmaceutical compositions” includes pharmaceutical compositions such as tablets, pills, powders, liquids, suspensions, emulsions, granules, capsules, suppositories, or injection preparations. The term “excipient” refers to a pharmaceutically acceptable organic or inorganic carrier substance. Excipients may be natural or synthetic substances formulated alongside the active   ingredient of a medication, included for the purpose of bulking-up formulations that contain potent active ingredients (thus often referred to as "bulking agents," "fillers," or "diluents"), or to confer a therapeutic enhancement on the active ingredient in the final dosage form, such as facilitating drug absorption or solubility. Excipients can also be useful in the manufacturing process, to aid in the handling of the active substance, such as by facilitating powder flowability or non-stick properties, in addition to aiding in vitro stability such as prevention of denaturation over the expected shelf life. The term “patient” refers to an animal, preferably a human, who has been the object of treatment, observation or experiment. Preferably, the patient has experienced and/or exhibited at least one symptom of the disease or disorder to be treated and/or prevented. Further, a patient may not have exhibited any symptoms of the disorder, disease or condition to be treated and/prevented, but has been deemed by a physician, clinician or other medical professional to be at risk for developing said disorder, disease or condition. The terms “treat”, “treating” and “treatment” refer to the therapeutic attempt at eradication or amelioration of a disease or disorder, or of one or more symptoms associated with the disease or disorder. In certain embodiments, the terms refer to minimizing the spread or worsening of the disease or disorder resulting from the administration of one or more therapeutic agents to a patient with such a disease or disorder. In some embodiments, the terms refer to the administration of the crystalline salt provided herein, with or without other additional active agents, after the onset of symptoms of a disease. Brief Description of the Figures Certain aspects of the embodiments described herein may be more clearly understood by reference to the drawings, which are intended to illustrate but not limit, the invention, and wherein: Figure 1 shows a representative XRPD pattern of a monohydrate of bexagliflozin (Form 1) as a polycrystalline solid. Figure 2 shows representative TGA and DSC analyses of the monohydrate of bexagliflozin (Form 1). Figure 3 is a representative ¹H NMR spectrum of the monohydrate of bexagliflozin (Form 1).

Figure 4 shows representative DVS isotherm of the monohydrate form of bexagliflozin (Form 1).   Figure 5 shows representative DVS kinetic plot of the monohydrate form of bexagliflozin (Form 1). Figure 6 shows a representative XRPD pattern of an invented anhydrous form of bexagliflozin (Form 2) as a polycrystalline solid. Figure 7 shows representative TGA and DSC analyses of an invented anhydrous form of bexagliflozin (Form 2). Figure 8 shows representative DVS isotherm of the anhydrous form of bexagliflozin (Form 2). Figure 9 is a representative ¹H NMR spectrum of the anhydrous form of bexagliflozin (Form 2). Figure 10 shows a DVS

isotherm of the anhydrous form of bexagliflozin (Form 2). Figure 11 is an XRPD overlay of an invented anhydrous form of bexagliflozin (Form 2) as a polycrystalline solid before and after storage at 40 °C, 75 % RH and 25 °C, 75 % RH and after analysis by DVS. Figure 12 shows a representative XRPD pattern of a dihydrate of bexagliflozin (Form 3) as a polycrystalline solid. Figure 13 shows representative TGA and DSC analyses of a dihydrate form of bexagliflozin (Form 3). Figure 14 shows representative DVS isotherm of a dihydrate form of bexagliflozin (Form 3). Figure 15 shows a DVS kinetic isotherm of a dihydrate of bexagliflozin (Form 3). Figure 16 is a representative ¹H NMR spectrum of a dihydrate of bexagliflozin (Form 3).

Figure 17 shows the structure of the dihydrate of bexagliflozin (Form 3). Figure 18 shows the crystal structure of the dihydrate of bexagliflozin (Form 3), showing the atom numbering scheme.   Detailed Description of the Invention According to one embodiment of the, a process for preparing a monohydrate of bexagliflozin (Form 1) as a polycrystalline solid was discovered. In addition, a polymorph of the monohydrate of bexagliflozin, (a dehydration with an onset temperature of 67° C) as a polycrystalline solid was unexpectedly discovered. Figure 1 shows a representative XRPD pattern of the monohydrate of bexagliflozin (Form 1) as a polycrystalline solid. In certain embodiments and depending on time, temperature and humidity, the crystalline monohydrate form of bexagliflozin (Form 1) was stable. The characteristic XRPD 2-theta peaks for the monohydrate of bexagliflozin (Form 1) are summarized in Table 1. Figure 2 shows representative TGA and DSC analyses of the monohydrate of bexagliflozin (Form 1). Table 1 Pos. (°2θ) Relative intensity Pos. (°2θ) Relative intensity (%) (%)

ep ese a ve spec u o e o o y a e o g o s su a zed in Figure 3.

crystalline monohydrate form of bexagliflozin (Form 1) was stable. Purity analysis of an invented monohydrate of bexagliflozin (Form 1) was determined by HPLC. Figure 4 shows representative DVS isotherm of the monohydrate form of bexagliflozin (Form 1). Figure 5 shows representative DVS kinetic plot of the monohydrate form of bexagliflozin (Form 1). Both the monohydrate of bexagliflozin and the invented lower melting point polymorph (melting with an onset temperature of about 67° C) of the monohydrate form of bexagliflozin may be useful as an active ingredient in pharmaceutical formulations. In a separate embodiment, Form 1 was prepared by partial dehydration of a dihydrate form of bexagliflozin (Form 3).   According to a separate embodiment of the invention, there is provided a polymorph of a crystalline anhydrous form of bexagliflozin (Form 2). The invented crystalline polymorph of anhydrous bexagliflozin may be useful as an active ingredient in pharmaceutical formulations. Figure 6 shows a representative XRPD pattern of the anhydrous form of bexagliflozin (Form 2) as a polycrystalline solid. The characteristic XRPD 2-theta peaks for the invented anhydrous form of bexagliflozin (Form 2) are summarized in Table 2. Figure 7 shows representative TGA and DSC analyses of an invented anhydrous form of bexagliflozin (Form 2). Figure 8 shows representative DVS isotherm of an invented anhydrous form of bexagliflozin (Form 2). Figure 9 is a representative ¹H NMR spectrum of an invented anhydrous form of bexagliflozin (Form 2). Figure 10 shows a DVS kinetic isotherm of an invented anhydrous form of bexagliflozin (Form 2). Purity

of an invented anhydrous form of bexagliflozin (Form 2) was determined by HPLC. The invented polycrystalline anhydrous form of bexagliflozin was stable. Figure 11 is an XRPD overlay of an invented anhydrous form of bexagliflozin (Form 2) as a polycrystalline solid before and after storage at 40 °C, 75 % RH and 25 °C, 75 % RH and after analysis by Dynamic Vapour Sorption (DVS). Purity analysis of an invented anhydrous form of bexagliflozin (Form 2) as a polycrystalline solid before and after storage at 25° C 97 % RH (left) and 40° C 75 % RH (right) was confirmed. Table 2 Pos. (°2θ) Relative intensity Pos. (°2θ) Relative intensity (%) (%)

According to a separate embodiment of the invention, there is provided a dihydrate of bexagliflozin (Form 3). Figure 12 shows a representative XRPD pattern of the dihydrate form of bexagliflozin (Form 3) as a polycrystalline solid. The characteristic XRPD 2-theta peaks for the invented dihydrate of bexagliflozin (Form 3) are summarized in Table 3. Figure 13 shows representative TGA and DSC analyses of a dihydrate of bexagliflozin (Form 3). Figure 14 shows representative DVS isotherm of the dihydrate form of bexagliflozin (Form 3).   Purity analysis of the dihydrate of bexagliflozin (Form 3) was confirmed by HPLC. Figure 15 shows a DVS kinetic isotherm of the dihydrate of bexagliflozin (Form 3). Figure 16 is a representative ¹H NMR spectrum of the dihydrate of bexagliflozin (Form 3).

Table 3 Pos. (°2θ) Relative intensity Pos. (°2θ) Relative intensity (%) (%) 41 98 213 360

Crystals of the dihydrate (Form 3) were obtained by slow evaporation from water. A crystal of sufficient size and quality for analysis by single crystal X-ray diffraction was isolated, with approximate dimensions 0.4 x 0.03 x 0.01 mm. The crystal structure of Form 3 was determined at 100(2) K. The crystal structure of Form 3 was solved in the monoclinic space group P2₁ with the final R1 [I>2s(I)] = 4.10 %. The structure was identified as depicted in Figure 17 and Figure 18, and the asymmetric unit found to contain one molecule of Bexagliflozin and two water molecules. Figure 18 shows a view of Form 3 from the crystal structure showing the atom numbering scheme. Anisotropic atomic displacement ellipsoids for the non-hydrogen atoms are shown at the 50 % probability level. Hydrogen atoms are displayed with an arbitrarily small radius. For the structure as presented in Figure , with stereocentres C2, C4, and C5 in the R configuration, and stereocentres C3 and C6 in the S configuration the Flack parameter = 0.022(11). For the inverted structure with C14A and C14B in the R configuration the Flack parameter = 0.979(11). Bexagliflozin as a free base is soluble in water and soluble in weakly acidic media.   The monohydrate form of bexagliflozin as a crystalline solid (Form 1) as described herein was prepared by a process comprising the steps of: (a) contacting bexagliflozin with one or more organic solvents, water or mixtures thereof, and heating to form a solution; and (b) cooling the solution to form a suspension and collecting the solids. In a separate embodiment, monohydrate form of bexagliflozin as a crystalline solid was prepared by partially dehydrating a dihydrate of bexagliflozin dissolved in one or more organic solvents using heating or reduced pressure. The anhydrous form of bexagliflozin as a polycrystalline solid as described herein was prepared by a process comprising the steps of: (a) dissolving bexagliflozin with one or more organic solvents and heating to form a solution, then adding a solvent to effect precipitation; and (b) cooling the solution to form a suspension and collecting the solids. In one embodiment, the organic solvents are isopropyl a mixture of acetate and heptane, with heptane used to induce precipitation of anhydrous bexagliflozin. The dihydrate of bexagliflozin as a polycrystalline solid as described herein was prepared by a process comprising the steps of: (a) contacting bexagliflozin with water and optionally one or more alcohols and heating to form a solution; and (b) cooling the solution to form a suspension and collecting the solids. In one embodiment, the alcohol is methanol. The crystalline bexagliflozin polymorphs in anhydrous form or as a monohydrate form may be optionally recrystallised from a solvent as described above in connection with steps (a) and (b). The crystalline or amorphous products may be dissolved in the solvent and treated for a period of time at one or more temperatures greater than ambient i.e. greater than 30 ^oC and below the boiling point of the reaction mixture as described above in connection with step (a) (e.g. at about 50 to about 60 ^oC). The solution may then be cooled (e.g. to about 5 ^oC) and the recrystallised salt may be recovered, optionally washed and dried as described above. Pharmaceutical compositions comprising the anhydrous or monohydrate form of bexagliflozin (as crystalline solids), methods of treatment comprising the anhydrous or monohydrate form of bexagliflozin and uses thereof In another aspect, the present invention provides a pharmaceutical composition comprising the anhydrous form, dihydrate or monohydrate of bexagliflozin, as described herein, and at least one pharmaceutically acceptable excipient. In one embodiment, the pharmaceutical   composition is an oral dosage form, such as a tablet, capsule, syrup, or dissolution film which may dissolve when placed e.g. under the tongue. In a separate embodiment the pharmaceutical composition is an injectable dosage form. In another aspect, the present invention provides a method for treating Type II diabetes mellitis in a human subject comprising administering a therapeutically effective amount of the anhydrous or monohydrate form of bexagliflozin as described herein to the patient. In another aspect, the present invention provides a method for modulating blood glucose levels in a human subject comprising administering a therapeutically effective amount of the anhydrous or monohydrate form of bexagliflozin as described herein to the patient. In another aspect, the present invention provides a method for modulating weight loss in a human subject comprising administering a therapeutically effective amount of the anhydrous or monohydrate form of bexagliflozin as described herein to the patient. In another aspect, the present invention provides a method for modulating systolic blood pressure levels in a human subject comprising administering a therapeutically effective amount of the anhydrous or monohydrate form of bexagliflozin as described herein to the patient. Embodiments and/or optional features of the invention have been described above. Any aspect of the invention may be combined with any other aspect of the invention, unless the context demands otherwise. Any of the embodiments or optional features of any aspect may be combined, singly or in combination, with any aspect of the invention, unless the context demands otherwise. The invention will now be described further by reference to the following examples, which are intended to illustrate but not limit, the scope of the invention. The crystalline form described herein was characterised using a number of methods known to the skilled person in the art, including single crystal X-ray diffraction, X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy (including solution and solid- state NMR). The chemical purity was determined by standard analytical methods, such as thin layer chromatography (TLC), gas chromatography, high performance liquid chromatography (HPLC), and mass spectrometry (MS). Examples Abbreviations   API active pharmaceutical ingredient EtOH ethanol rpm revolutions per minute RH relative humidity RT room temperature SCXRD single crystal X-ray diffraction Instrument and Methodology Details XRPD Bruker AXS D8 Advance XRPD diffractograms were collected on a Bruker D8 diffractometer using Cu Ka radiation (40 kV, 40 mA) in reflection geometry and a θ-2θ goniometer fitted with a Ge monochromator. The incident beam passes through a 2.0 mm divergence slit followed by a 0.2 mm anti-scatter slit and knife edge. The diffracted beam passes through an 8.0 mm receiving slit with 2.5° Soller slits followed by the Lynxeye Detector. The software used for data collection was Diffrac Plus XRD Commander and data analysis was HighScore Plus. Samples were run under ambient conditions as flat plate specimens using powder as received. The sample was prepared on a polished, zero-background (510) silicon wafer by gently pressing onto the flat surface or packed into a cut cavity. The sample was rotated in its own plane. The details of the standard data collection methods are: ^ Angular range: 2 to 42° 2θ ^ Step size: 0.05° 2θ ^ Collection time: 0.5 s/step (total collection time: 6.40 min) PANalytical Empyrean XRPD diffractograms were collected on a PANalytical Empyrean diffractometer using Cu Ka radiation (45 kV, 40 mA) in transmission geometry. A 0.5° slit, 4 mm mask and 0.04 rad Soller slits with a focusing mirror were used on the incident beam. A PIXcel^3D detector, placed on the diffracted beam, was fitted with a receiving slit and 0.04 rad Soller slits. The software used for data collection was X’Pert Data Collector using X’Pert Operator Interface. The data were analysed and presented using HighScore Plus. The details of the standard screening data collection method are: ^ Angular range: 2.5 to 32.0° 2θ ^ Step size: 0.0130° 2θ   ^ Collection time: 12.75 s/step (total collection time of 2.07 min) Nuclear Magnetic Resonance (NMR) Solution State NMR ¹H NMR spectra were collected on a Bruker 400 MHz instrument equipped with an auto-sampler and controlled by a Avance NEO nanobay console. Samples were prepared in DMSO-d6 solvent, unless otherwise stated. Automated experiments were acquired using ICON-NMR configuration within Topspin software, using standard Bruker-loaded experiments {¹H}. Off-line analysis was performed using ACD Spectrus Processor. Differential Scanning Calorimetry (DSC) DSC data were collected on a TA Instruments Discovery DSC equipped with a 50 position auto-sampler. Typically, 0.5 - 3 mg of each sample, in a pin-holed aluminium pan, was heated at 10 °C/min from 25 °C to 180 °C. A purge of dry nitrogen at 50 ml/min was maintained over the sample. The instrument control software was TRIOS and the data were analysed using TRIOS or Universal Analysis. Thermo-Gravimetric Analysis (TGA)   TGA data were collected on a TA Instruments Discovery TGA, equipped with a 25 position auto-sampler. Typically, 5 - 10 mg of each sample was loaded onto a pre- tared aluminium DSC pan and heated at 10 °C/min from ambient temperature to 350 °C. A nitrogen purge at 25 ml/min was maintained over the sample. The instrument control software was TRIOS and the data were analysed using TRIOS or Universal Analysis. Polarised Light Microscopy (PLM) Samples were studied on a Nikon SMZ1500 polarised light microscope with a digital video camera connected to a DS Camera control unit DS-L2 for image capture. The sample was viewed with appropriate magnification and partially polarised light, coupled to a λ false-colour filter. Scanning Electron Microscopy (SEM) Data were collected on a Phenom Pro Scanning Electron Microscope. A small quantity of sample was mounted onto an aluminium stub using conducting double-sided adhesive tape. A thin layer of gold was applied using a sputter coater (20 mA, 120 s).   Gravimetric Vapour Sorption (GVS) Sorption isotherms were obtained using a Hiden IGASorp moisture sorption analyser, controlled by Isochema HISorp software. The sample temperature was maintained at 25 °C by a Grant LT Ecocool 150 re-circulating water bath. The humidity was controlled by mixing streams of dry and wet nitrogen, with a total flow rate of 250 ml.min^-1. The relative humidity was measured by a calibrated Vaisala RH probe (dynamic range of 0 – 95 %RH), located near the sample. The weight change, (mass relaxation) of the sample as a function of %RH was constantly monitored by the microbalance (accuracy ±0.001 mg).

  P101770WO01  Typically, 20 – 30 mg of sample was placed in a tared mesh stainless steel basket under ambient conditions. The sample was loaded and unloaded at 40 %RH and 25 °C (typical room conditions). A moisture sorption isotherm was performed as outlined below in Table 4 (2 scans giving 1 complete cycle). The standard isotherm was performed at 25 °C at 10 %RH intervals over a 0 – 90 %RH range. Typically, a double cycle (4 scans) was carried out. Data analysis was carried out within the Isochema HISorp 2019 software and exported into Microsoft Excel to present accordingly. Table 2 Method parameters for Hiden IGASorp experiments Parameters Method 1 Method 2 90 0 er

The sample was recovered after completion of isotherm and re-analysed by XRPD. 15     P101770WO01  Chemical Purity Determination by High Performance Liquid Chromatography (HPLC) Purity analysis was performed on an Agilent HP1100/Infinity II 1260 series system equipped with a diode array detector and using OpenLAB software. The full method details are provided below in Table 5: Table 3 HPLC method for chemical purity determinations Parameter Value

Water Determination by Karl Fischer Titration (KF) The water content of each sample was measured on a Metrohm 874 Oven Sample Processor at 150 °C with 851 Titrano Coulometer using Hydranal Coulomat AG oven reagent and nitrogen purge. Weighed solid samples were introduced into a sealed 16     P101770WO01  sample vial. Approximately 10 mg of sample was used per titration and duplicate determinations were made. An average of these results is presented unless otherwise stated. Data collection and analysis were performed using Tiamo software. Single Crystal X-Ray Diffraction (SCXRD) Data were collected on a Rigaku Oxford Diffraction XtaLAB Synergy-S diffractometer equipped with a dualflex source (Cu at Zero), HyPix-6000HE detector and an Oxford Cryosystems Cobra cooling device. The data were collected using Cu Ka radiation as stated in the experimental tables. Structures were solved and refined using the Shelx suite of programs and OLEX was used as an interface to view the structures with and produce figures. Full details can be found in the CIF. Unless otherwise stated, hydrogen atoms attached to carbon were placed geometrically and allowed to refine with a riding isotropic displacement parameter. Hydrogen atoms attached to a heteroatom were located in a difference Fourier synthesis map and were allowed to refine freely with an isotropic displacement parameter. A reference diffractogram for the crystal structure was generated using Mercury. Static Stability Experiments Solid material was placed into open vials at elevated storage conditions, unless otherwise stated. These conditions were achieved using saturated salt solutions at specific temperatures within sealed containers. Storage containers were pre-equilibrated prior to input of samples, as summarized in Table 6. Table 4 Salt solutions used to produce static storage conditions Condition Saturated Salt Solution Temperature (°C)

Experimental Crystallisation Methodologies The choice of crystallisation method has a major influence on which form is produced, and it is therefore important to perform crystallisations using various methods and conditions when looking for polymorphs. 17     P101770WO01  Classical crystallisation methods used in the course of this invention are listed in Table 5 together with the degrees of freedom available for each process. Table 5 Classical crystallisation methods used according to the invention Method Degrees of freedom Solvent or solvent mixture type, temperature, ratio s,

EXAMPLES Crystalline monohydrate of Bexagliflozin (Form 1) Example 1 Procedure 1 Bexagliflozin (30 mg) was dissolved in toluene (5 vol, 150 µl) at 50 °C, 500 rpm. The solution was left for 1 hour before being cooled to 5 °C at 0.1 °C/min. The sample was then transferred to a maturation chamber cycling between room temperature and 50 °C every 4 hours for 3 days. The sample formed a thick suspension and was left to dry uncapped at ambient conditions. Procedure 2 Bexagliflozin (30 mg) was dissolved in isopropyl acetate (5 vol, 150 µl) at 50 °C, 500 rpm. The solution was left for 1 hour before being cooled to 5 °C at 0.1 °C/min. The solution was then transferred to a maturation chamber cycling between room temperature and 50 °C every 4 hours for 3 days. The sample formed a thick suspension and was left to dry uncapped at ambient conditions. 18     P101770WO01  Procedure 3 Bexagliflozin (30 mg) was dissolved in water (50 vol, 1500 µl) at 50 °C, 500 rpm. The resulting oil was left for 1 hour before being cooled to 5 °C at 0.1 °C/min. The sample was then transferred to a maturation chamber cycling between room temperature and 50 °C every 4 hours for 4 days. The sample formed a gum and was dried in a vacuum oven under vacuum at room temperature for 2 days. Procedure 4 Bexagliflozin (30 mg) was dissolved in propylene glycol (ca. 3 vol, 100 µl) at 25 °C, 500 rpm. Water (100 µl) was added dropwise forming a thin suspension. The sample was left to stir for 16 hours forming a solution. An additional aliquot of water (100 µl) was added and left to stir for 2 hours forming a suspension. The solid was isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 5 Bexagliflozin (30 mg) was dissolved in ethylene glycol (ca. 3 vol, 100 µl) at 25 °C, 500 rpm. Water (100 µl) was added dropwise forming a thin suspension. The suspension was left to stir for 16 hours forming a suspension. The solid was then isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 6 Bexagliflozin (100 mg) was weighed into a HPLC vial. TBME (3 vol, 300 µl) was added at 50 °C resulting in a solution. The solution was then cooled to 5 °C at 0.1 °C /min at 500 RPM. After 16 hours at 5 °C, a gel formed and was heated to 25 °C upon which seeds were added. The sample was left to stir at room temperature for 24 hours. A thick suspension formed and was isolated by filtration through a filter frit using positive pressure. Procedure 7 Bexagliflozin (100 mg) was weighed into a HPLC vial, isopropyl acetate (3 vol, 300 µl) was added at 50 °C resulting in a solution. The solution was then cooled to 5 °C at 0.1 °C /min at 500 rpm and left to stir for 3 days upon which a suspension formed. The solid was then isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 8 Bexagliflozin (100 mg) was weighed into a HPLC vial, wet isopropyl acetate (3 vol, 300 µl) was added at 50 °C resulting in a solution. The solution was then cooled to 5 °C at 0.1 °C /min at 500 rpm and left to stir for 16 hours upon which a suspension formed. The solid was then isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. 19     P101770WO01  Procedure 9 Bexagliflozin (100 mg) was weighed into a HPLC vial, propylene glycol (3 vol, 300 µl) was added at 50 °C, 500 rpm resulting in a solution. Heptane (500 µl) was added dropwise to the solution before being cooled to 25 °C and left to stir for 16 hours upon which a suspension formed. The solid was then isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 10 Bexagliflozin (500 mg) was weighed into a 4 ml vial, wet isopropyl acetate (2 vol, 1 ml) was added at 60 °C, 500 rpm resulting in a solution. The solution was cooled to 50 °C and left to stir 30 min before being cooled to 5 °C at 0.1 °C/min. After 16 hours, a suspension formed and the solid was then isolated using a Buchner funnel and filter paper (grade 1). Heptane (2 vol) was used to wash sample and ensure optimum recovery. Yield: 79.4 %. Procedure 10B Bexagliflozin (Form 3, 50 mg) obtained from procedure 15 was weighed into a HPLC vial and placed in the vacuum oven for 1 hour at room temperature under vacuum. After 1 hour, Form 3 had converted to Form 1. Characterization Data for Polycrystalline Monohydrate of Bexagliflozin (Form 1) Form 1 Monohydrate of Bexagliflozin Polycrys

20     P101770WO01  Example 2 Procedure 11 Bexagliflozin (30 mg) was dissolved in TBME (ca. 13 vol, 400 µl) at 50 °C, 500 rpm. Heptane (100 µl) was added dropwise at 50 °C forming a thin suspension. The sample was left to stir for 16 hours forming a gum. The sample was then sonicated for 10 min before being cooled to 5 °C at 0.1 °C/min. After 24 hours, a suspension had formed and the solid was isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 12 Bexagliflozin (100 mg) was weighed into a HPLC vial, isopropyl acetate (3 vol, 300 µl) was added at 80 °C, 500 RPM giving a solution. Heptane (500 µl) was added dropwise before being cooled to 50 °C for 1 hour at which point at thin suspension formed. The sample was then cooled to 5 °C at 1 °C/min and left to stir for 16 hours upon which a gum formed. Additional heptane (3 vol, 300 µl) was added dropwise. The sample was left to stir at 5 °C, 500 rpm for 24 hours. A thick suspension formed and the solid was isolated onto filter paper (grade 1) and was dried in the vacuum oven for 3 hours at room temperature under vacuum. Procedure 13 Bexagliflozin (100 mg) was weighed into a HPLC vial, isopropyl acetate (3 vol, 300 µl) was added at 75 °C, 300 rpm resulting in a solution. Heptane (300 µl) was added dropwise forming a thin suspension, additional drops of isopropyl acetate were added to form a solution. The sample was then cooled to 50 °C for 1 hour, remaining in solution at which point seeds of Form 2 (from procedure 12) were added forming a thin suspension. The sample was then cooled to 5 °C at 0.1 °C/min and left to stir for 16 hours upon which a thick suspension formed. The solid was then isolated using a Buchner funnel and filter paper (grade 1). Heptane (3 vol, 300 µl) was used to wash the sample and ensure optimum recovery. Procedure 14 Bexagliflozin (500 mg) was weighed into a 20 ml vial, isopropyl acetate (3 vol, 1500 µl) was added. The suspension was stirred at 75 °C and 500 rpm where the sample dissolved. Heptane (ca. 1.0 ml) was added dropwise forming a thin suspension, additional drops of isopropyl acetate were added forming a solution. The solution was then cooled to 50 °C at 1 °C/min and held for 30 min. Seeds of Form 2 (from procedure 12) were added to the solution forming a thin suspension. The suspension was then cooled to 20 °C at 0.1 °C/min and left to stir. After 18 hours, a thick suspension formed and the solid was isolated under negative pressure using a Buchner funnel and filter paper (grade 1). Aliquots of heptane (3 x 2.0 ml) were used to wash the sample and ensure optimum recovery. The sample was then dried for 1 hour in a vacuum oven at room temperature under vacuum. Yield 67.1 %. Characterization Data for Polycrystalline Anhydrous form of Bexagliflozin (Form 2) 21     P101770WO01  F^orm 2  _{Anhydrous Bexagliflozin} XRPD  Polycrystalline  t^o   

Dihydrate of Bexagliflozin (Form 3) Example 3 Procedure 15 Bexagliflozin (100 mg) was weighed into a HPLC vial, MeOH (3 vol, 300 µl) was added at 80 °C, 500 rpm resulting in a solution. Water (4.5 vol, 450 µl) was added dropwise forming a thin suspension that was cooled to 5 °C at 1 °C/min and left to stir for 16 hours upon which a thin suspension remained. Additional water (4.5 vol, 450 µl) was added dropwise at 25 °C. The thin suspension was left to stir at 5 °C, 500 rpm for 4 hours. A thick suspension formed and the solid was isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. Procedure 16 Bexagliflozin (100 mg) was weighed into a HPLC vial, MeOH (3 vol, 300 µl) was added at 80 °C, 500 rpm resulting in a solution. Water (5 vol, 500 µl) was added dropwise forming a thin suspension that was cooled to 5 °C at 1 °C/min and left to stir for 16 hours upon which a suspension formed. Solid was isolated using positive pressure through a filter frit and allowed to dry at ambient conditions. 22     P101770WO01  Procedure 17 Bexagliflozin (100 mg) was weighed into a HPLC vial, water (5 vol, 500 µl) was added at 60 °C, 500 rpm. The resulting thin suspension was then cooled to 5 °C at 1 °C/min and left to stir for 18 hours upon which a gel formed. The gel was sonicated for 1 hour before being uncapped and left to stir for a further 2 hours at 5 °C. A white solid formed and was isolated by using a Buchner funnel and filter paper (grade 1). Characterization Data for Dihydrate of Bexagliflozin (Form 3) Form 3  Dihydrate of Bexagliflozin l lli   .  n 

23  

Claims

  P101770WO01  Claims 1. A process for preparing a monohydrate of bexagliflozin, comprising the steps of: (a) contacting bexagliflozin with one or more organic solvents, water or mixtures thereof, and heating to form a solution; and (b) cooling the solution to form a suspension and collecting bexagliflozin as crystalline solids, wherein the X-ray powder diffraction pattern of the monohydrate of bexagliflozin comprises one or more peaks selected from the group consisting of: about 4.0, 8.1, 12.1, 12.8, 14.6, 15.8, 16.1, 17.9, 18.5, 18.8, 19.1, 20.1, 21.4 and 21.7 degrees two-theta ± 0.2 degrees two-theta. 2. The process of claim 1, wherein the crystalline monohydrate of bexagliflozin exhibits a weight loss of 3.5% by weight between 25-200 °C from a thermogravimetric analysis. 3. The process of claim 2, wherein the crystalline monohydrate of bexagliflozin exhibits an endotherm peak (66.6 J/g) with an onset temperature of 75.3 °C from differential scanning calorimetry. 4. The process of claim 1, wherein the crystalline monohydrate of bexagliflozin exhibits a reversible weight change of about 1.8 % by weight by dynamic vapour sorption between 0-90% relative humidity. 5. A process for preparing a monohydrate of bexagliflozin, comprising the step of: dehydrating a dihydrate of bexagliflozin dissolved in one or more organic solvents using heating or reduced pressure. 6. Anhydrous bexagliflozin as a crystalline solid, wherein the X-ray powder diffraction pattern comprises one or more peaks selected from the group consisting of: about 4.0, 8.0, 9.4, 10.1, 12.0, 12.2, 13.6, 15.2, 16.5, 16.8 and 18.6 degrees two-theta ± 0.2 degrees two theta. 7. Anhydrous bexagliflozin of claim 6, exhibiting a weight loss of 0.9 % by weight between 25 – 190 °C from a thermogravimetric analysis. 8. Anhydrous bexagliflozin of claim 7, exhibiting a single endotherm peak (68 J/g) with an onset temperature of 84.5 °C from differential scanning calorimetry. 9. Anhydrous bexagliflozin of claim 6, exhibiting a reversible weight change of about 2.8 % by weight by dynamic vapour sorption between 0-90% relative humidity. 24     P101770WO01  10. The anhydrous form of bexagliflozin of claim 6, prepared by a process comprising the steps of: (a) dissolving bexagliflozin in isopropylacetate and heating to form a solution, then adding heptane; and (b) cooling the solution to form a suspension and collecting the solids. 11. A crystalline dihydrate of bexagliflozin, wherein the dihydrate of bexagliflozin exhibits an X-ray powder diffraction pattern (XRPD) comprising one or more peaks selected from the group consisting of: about 4.1, 7.5, 9.5, 10.2, 12.0, 15.1, 15.9, 17.2, 17.6, 18.3, 18.7, 19.2, 19.6, 19.9, 20.6 and 21.1 degrees two-theta ± 0.2 degrees two-theta. 12. The crystalline dihydrate of bexagliflozin of claim 11, exhibiting a 4.3 % by weight loss between 0 – 200 °C from a thermogravimetric analysis. 13. The crystalline dihydrate of bexagliflozin of claim 12, exhibiting an initial endotherm peak (24 J/g) with an onset temperature of 37.8 °C, followed by 2 further endotherm peaks, from differential scanning calorimetry. 14. A dihydrate of bexagliflozin of claim 11, prepared by a process comprising the steps of: (a) contacting bexagliflozin with water, methanol or a mixture thereof and heating to form a solution; and (b) cooling the solution to form a suspension and collecting the solids. 15. A pharmaceutical composition comprising anhydrous bexagliflozin of claim 6 and at least one pharmaceutically acceptable excipient. 16. A method for treating Type II diabetes mellitis in a human subject comprising the step of: administering a therapeutically effective amount of the pharmaceutical composition of claim 15 to the human subject. 17. A pharmaceutical composition comprising a dihydrate of bexagliflozin of claim 11 and at least one pharmaceutically acceptable excipient. 25