CA2518973A1 - Methods for isolating crystalline form i of 5-azacytidine - Google Patents
Methods for isolating crystalline form i of 5-azacytidine Download PDFInfo
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- CA2518973A1 CA2518973A1 CA002518973A CA2518973A CA2518973A1 CA 2518973 A1 CA2518973 A1 CA 2518973A1 CA 002518973 A CA002518973 A CA 002518973A CA 2518973 A CA2518973 A CA 2518973A CA 2518973 A1 CA2518973 A1 CA 2518973A1
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P35/00—Antineoplastic agents
- A61P35/02—Antineoplastic agents specific for leukemia
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H1/00—Processes for the preparation of sugar derivatives
- C07H1/06—Separation; Purification
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H19/00—Compounds containing a hetero ring sharing one ring hetero atom with a saccharide radical; Nucleosides; Mononucleotides; Anhydro-derivatives thereof
- C07H19/02—Compounds containing a hetero ring sharing one ring hetero atom with a saccharide radical; Nucleosides; Mononucleotides; Anhydro-derivatives thereof sharing nitrogen
- C07H19/04—Heterocyclic radicals containing only nitrogen atoms as ring hetero atom
- C07H19/12—Triazine radicals
Abstract
The invention includes methods for isolating crystalline Form I of 5-azacytidine substantially free of other forms, wherein 5-azacytidine is represented by the formula: The invention also includes pharmaceutical compositions comprising Form I of 5-azacytidine.
Description
s METHODS FOR ISOLATING CRYSTALLINE FORM I OF
Field 0f the Invention The invention relates to the isolation of crystalline polymorphic Form I of 5-azacytidine (also known as azacitidine and 4-amino-1-[3-D-ribofuranosyl-S-triazin-2(11-one). s-azacytidine may be used in the treatment of disease, including the treatment of myelodysplastic syndromes (MDS).
l~~clg~~~0uaad ~f the ~nventi~n Polymorphs exist as two or more crystalline phases that have different arrangements 1 s and/or different conformations of the molecule in a crystal lattice. When a solvent molecules) is contained within the crystal lattice the resulting crystal is called a pseudopolymorph, or solvate. If the solvent molecules) within the crystal structure is a water molecule, then the pseudopolymorph/solvate is called a hydrate. The polymorphic and pseudopolymorphic solids display different physical properties, including those due to packing, and various thermodynamic, spectroscopic, interfacial and mechanical properties (See H.
Brittain, Polymorphism in Pharmaceutical Solids, Marcel Dekker, New Yorlc, NY, 1999, pp.
1-2).
Polymorphic and pseudopolymorphic forms of the drug substance (also lazown as the "active pharmaceutical ingredient" (API)), as administered by itself or formulated as a drug product (also known as the final or finished dosage form, or as the pharmaceutical composition) are well lalown and may affect, for example, the solubility, stability, flowability, fractability, and compressibility of drug substances and the safety and efficacy of drug products, (see, e.g., Krlapman, K Modern Drug Discoveries, March 2000: 53).
s-Azacytidine (also known as azacitidine and 4-amino-1-(3-D-ribofuranosyl-S-triazin-2(lI~-one; Nation Service Center designation NSC-10216; CAS Registry Number 320-67-2) has undergone NCI-sponsored trials for the treatment of myelodysplastic syndromes (MDS).
See I~ornblith et al., J. Glin. ~ncol. 20(10): 2441-2452 (2002) and Silverman et al., J. Clin.
~ncol. 20(10): 2429-2440 (2002). s-azacytidine may be defined as having a formula of ~8H12N4~5~ a molecular weight of 244.20 and a structure of In the United States Patent Application Serial No. 10/390,57 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety, eight different polymorphic and pseudopolymorphic forms of 5-azacytidine (Forms I-VIII), in addition to an amozphous form, are described. Forms I-VIII each have characteristic X-Ray Powder Diffraction (XRPD) patterns and are easily distinguished from one another using XRPD.
5-azacytidine drug substance used in the previous clinical trials has typically been synthesized from 5-azacytosine and 1,2,3,5,-tetra-O-acetyl-(3-D-ribofuranose by the method presented in Example 1. The last step of this method is a recrystallization of the crude synthesis product from a methanol/DMSO co-solvent system. Specifically, the crude synthesis product is dissolved in DMSO (preheated to about 90°G), and then methanol is added to the DMSO solution. The product is collected by vacuLUn filtration and allowed to air dry.
In In the United States Patent Application Serial No. 10/390,57 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety, it is demonstrated that this prior art method for the recrystallization of the crude synthesis product does not control for the polymorphic forms of 5-azacytidine. Specifically, the prior art recrystallization procedure produces either Form I substantially free of other forms, or a Form I/II mixed phase i. e. a solid material in which 5-azacytidine is present in a mixed phase of both polymorphic Form I and polymorphic Form II. Thus, the prior art procedures do not allow one to reliably target Form I as the single polymorphic form in the drug substance. The present invention provides methods that allow one to recrystallize 5-azacytidine as polymorphic Form I robustly and reproducibly.
_2_ Summary of the Invention The present invention provides methods for robustly and reproducibly isolating azacytidine as polymorphic Form I substantially free of other forms. The methods involve recrystallizing dissolved 5-azacytidine from a primaa-y solvent/co-solvent mixture and then collecting the resultant crystals. The invention also provides pharmaceutical compositions comprising Form I of 5-azacytidine together wltll a pharmaceutically acceptable excipient, diluent, or carrier.
Detailed Descrit~tion of the preferred embodiments Pol~rphic Form I of 5-azac, idine Form I of 5-azacytidine is described in United States Patent Application Serial No.
10/390,578 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety. Table 1 provides the most prominent 20 angles, d-spacing and relative intensities for Form I observed using X-Ray Powder Diffraction (XRPD) performed according the method of Example 4:
2~An 1e () d spaciv~g (~) Relative hctensity 12.182 7.260 39.1 13.024 6.792 44.1 14.399 6.146 31.5 16.470 5.378 27.1 18.627 4.760 16.0 19.049 4.655 35.9 20.182 4.396 37.0 21.329 4.162 12.4 23.033 3.858 100.0 23.872 3.724 28.0 26.863 3.316 10.8 27.135 3.284 51.5 29.277 3.048 25.6 29.591 3.016 11.5 30.369 2.941 10.8 32.072 2.788 13.4 Table 1: 5-azacytidine Form I - the most prominent 20 angles, d-spacing and relative intensities (Cu Ka radiation) Isolation of Polymorahic Fornz I of 5-azacytidine b Recrystallization Form I of 5-azacytidine may be reproducibly isolated substantially free of other forms by recrystallizing dissolved 5-azacytidine and collecting the resultant crystals.
Specifically, 5-azacytidine is first dissolved completely in at least one suitable primary solvent, preferably a polar solvent, more preferably a polar aprotic solvent. Suitable polar aprotic solvents include, but are not limited to, dimethylformamide (DMF), dimethylacetamide (DMA), dimethylsulfoxide (DMSO), and N-methylpyrrolidinone (NMP). The most preferred polar aprotic solvent is DMSO. Mixtures of two or more primary solvents are also contemplated for dissolving the 5-azacytidine, for example a mixture of DMSO and DMF
The 5-azacytidine used to form the solution may be synthesized by any procedure known in the art; an exemplary prior art synthesis scheme is provided in Example 1.
Any polymorphic or pseudopolymorphic forms) of 5-azacytidine, including mixed phases, may be used to form the solution. Amorphous 5-azacytidine may also be used to form the solution. It is preferred, but not required, that the primary solvent is preheated to an elevated temperature in order to ensure that the 5-azacytidine is dissolved completely. An especially preferred primary solvent is dimethyl sulfoxide, (DMSO), most preferably preheated to a temperature in the range of about 40°C to about 90°C.
Following solvation of the 5-azacytidine in the primary solvent, at least one co-solvent is added to the solution of 5-azacytidine. Suitable co-solvents include CZ-CS
alcohols (which term hereinafter refers to C2-CS alcohols that are independently: branched or unbranched, substituted or unsubstituted), aliphatic lcetones (which term her einafter refers to aliphatic lcetones that are indepedently: branched or unbranched, substituted or unsubstituted), and alkyl cyanides (which term hereinafter refers to alkyl cyanides that are independently: branched or unbranched, substituted or unsubstituted). Preferred Ca-CS alcohols, aliphatic lcetones, and allcyl cyanides, along with other suitable solvents, are listed below as Class 2 (solvents to be limited) and Class 3 (solvents of low toxic potential) per the International Conference on Harmonization's (ICH) Guideline for Residual Solvents, July 1997). The use of mixtures of two or more of any of the aforementioned co-solvents is also included within the scope of the invention.
Field 0f the Invention The invention relates to the isolation of crystalline polymorphic Form I of 5-azacytidine (also known as azacitidine and 4-amino-1-[3-D-ribofuranosyl-S-triazin-2(11-one). s-azacytidine may be used in the treatment of disease, including the treatment of myelodysplastic syndromes (MDS).
l~~clg~~~0uaad ~f the ~nventi~n Polymorphs exist as two or more crystalline phases that have different arrangements 1 s and/or different conformations of the molecule in a crystal lattice. When a solvent molecules) is contained within the crystal lattice the resulting crystal is called a pseudopolymorph, or solvate. If the solvent molecules) within the crystal structure is a water molecule, then the pseudopolymorph/solvate is called a hydrate. The polymorphic and pseudopolymorphic solids display different physical properties, including those due to packing, and various thermodynamic, spectroscopic, interfacial and mechanical properties (See H.
Brittain, Polymorphism in Pharmaceutical Solids, Marcel Dekker, New Yorlc, NY, 1999, pp.
1-2).
Polymorphic and pseudopolymorphic forms of the drug substance (also lazown as the "active pharmaceutical ingredient" (API)), as administered by itself or formulated as a drug product (also known as the final or finished dosage form, or as the pharmaceutical composition) are well lalown and may affect, for example, the solubility, stability, flowability, fractability, and compressibility of drug substances and the safety and efficacy of drug products, (see, e.g., Krlapman, K Modern Drug Discoveries, March 2000: 53).
s-Azacytidine (also known as azacitidine and 4-amino-1-(3-D-ribofuranosyl-S-triazin-2(lI~-one; Nation Service Center designation NSC-10216; CAS Registry Number 320-67-2) has undergone NCI-sponsored trials for the treatment of myelodysplastic syndromes (MDS).
See I~ornblith et al., J. Glin. ~ncol. 20(10): 2441-2452 (2002) and Silverman et al., J. Clin.
~ncol. 20(10): 2429-2440 (2002). s-azacytidine may be defined as having a formula of ~8H12N4~5~ a molecular weight of 244.20 and a structure of In the United States Patent Application Serial No. 10/390,57 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety, eight different polymorphic and pseudopolymorphic forms of 5-azacytidine (Forms I-VIII), in addition to an amozphous form, are described. Forms I-VIII each have characteristic X-Ray Powder Diffraction (XRPD) patterns and are easily distinguished from one another using XRPD.
5-azacytidine drug substance used in the previous clinical trials has typically been synthesized from 5-azacytosine and 1,2,3,5,-tetra-O-acetyl-(3-D-ribofuranose by the method presented in Example 1. The last step of this method is a recrystallization of the crude synthesis product from a methanol/DMSO co-solvent system. Specifically, the crude synthesis product is dissolved in DMSO (preheated to about 90°G), and then methanol is added to the DMSO solution. The product is collected by vacuLUn filtration and allowed to air dry.
In In the United States Patent Application Serial No. 10/390,57 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety, it is demonstrated that this prior art method for the recrystallization of the crude synthesis product does not control for the polymorphic forms of 5-azacytidine. Specifically, the prior art recrystallization procedure produces either Form I substantially free of other forms, or a Form I/II mixed phase i. e. a solid material in which 5-azacytidine is present in a mixed phase of both polymorphic Form I and polymorphic Form II. Thus, the prior art procedures do not allow one to reliably target Form I as the single polymorphic form in the drug substance. The present invention provides methods that allow one to recrystallize 5-azacytidine as polymorphic Form I robustly and reproducibly.
_2_ Summary of the Invention The present invention provides methods for robustly and reproducibly isolating azacytidine as polymorphic Form I substantially free of other forms. The methods involve recrystallizing dissolved 5-azacytidine from a primaa-y solvent/co-solvent mixture and then collecting the resultant crystals. The invention also provides pharmaceutical compositions comprising Form I of 5-azacytidine together wltll a pharmaceutically acceptable excipient, diluent, or carrier.
Detailed Descrit~tion of the preferred embodiments Pol~rphic Form I of 5-azac, idine Form I of 5-azacytidine is described in United States Patent Application Serial No.
10/390,578 entitled "Forms of 5-azacytidine," filed March 17, 2003 and incorporated herein by reference in its entirety. Table 1 provides the most prominent 20 angles, d-spacing and relative intensities for Form I observed using X-Ray Powder Diffraction (XRPD) performed according the method of Example 4:
2~An 1e () d spaciv~g (~) Relative hctensity 12.182 7.260 39.1 13.024 6.792 44.1 14.399 6.146 31.5 16.470 5.378 27.1 18.627 4.760 16.0 19.049 4.655 35.9 20.182 4.396 37.0 21.329 4.162 12.4 23.033 3.858 100.0 23.872 3.724 28.0 26.863 3.316 10.8 27.135 3.284 51.5 29.277 3.048 25.6 29.591 3.016 11.5 30.369 2.941 10.8 32.072 2.788 13.4 Table 1: 5-azacytidine Form I - the most prominent 20 angles, d-spacing and relative intensities (Cu Ka radiation) Isolation of Polymorahic Fornz I of 5-azacytidine b Recrystallization Form I of 5-azacytidine may be reproducibly isolated substantially free of other forms by recrystallizing dissolved 5-azacytidine and collecting the resultant crystals.
Specifically, 5-azacytidine is first dissolved completely in at least one suitable primary solvent, preferably a polar solvent, more preferably a polar aprotic solvent. Suitable polar aprotic solvents include, but are not limited to, dimethylformamide (DMF), dimethylacetamide (DMA), dimethylsulfoxide (DMSO), and N-methylpyrrolidinone (NMP). The most preferred polar aprotic solvent is DMSO. Mixtures of two or more primary solvents are also contemplated for dissolving the 5-azacytidine, for example a mixture of DMSO and DMF
The 5-azacytidine used to form the solution may be synthesized by any procedure known in the art; an exemplary prior art synthesis scheme is provided in Example 1.
Any polymorphic or pseudopolymorphic forms) of 5-azacytidine, including mixed phases, may be used to form the solution. Amorphous 5-azacytidine may also be used to form the solution. It is preferred, but not required, that the primary solvent is preheated to an elevated temperature in order to ensure that the 5-azacytidine is dissolved completely. An especially preferred primary solvent is dimethyl sulfoxide, (DMSO), most preferably preheated to a temperature in the range of about 40°C to about 90°C.
Following solvation of the 5-azacytidine in the primary solvent, at least one co-solvent is added to the solution of 5-azacytidine. Suitable co-solvents include CZ-CS
alcohols (which term hereinafter refers to C2-CS alcohols that are independently: branched or unbranched, substituted or unsubstituted), aliphatic lcetones (which term her einafter refers to aliphatic lcetones that are indepedently: branched or unbranched, substituted or unsubstituted), and alkyl cyanides (which term hereinafter refers to alkyl cyanides that are independently: branched or unbranched, substituted or unsubstituted). Preferred Ca-CS alcohols, aliphatic lcetones, and allcyl cyanides, along with other suitable solvents, are listed below as Class 2 (solvents to be limited) and Class 3 (solvents of low toxic potential) per the International Conference on Harmonization's (ICH) Guideline for Residual Solvents, July 1997). The use of mixtures of two or more of any of the aforementioned co-solvents is also included within the scope of the invention.
Class 2 Acetonitrile Chlorobenzene Cyclohexane 1,2-~1C1110TOethelle Dichloromethane 1,2-Dimethoxyethane N,N-Dimethylformamide N,N-I~imethylacetamide 1,4-IJioxane 2-Ethoxyethanol Ethyleneglycol Formamide 2-Methoxyethanol Methylbutyl ketone Methylcyclohexane Nitromethane Pyridine Sulfolane Tetralin 1,1,2-Trichloroethene Class 3 1-Butanol 1-Pentanol 1-Propanol 2-Butanol 2-Methyl-1-propanol 2-Propanol (isopropyl alcohol) 3-Methyl-1-butanol 3 5 Acetone Anisole Butyl acetate Cumene Ethanol Ethyl acetate Ethyl ether Ethyl formats Isobutyl acetate Isopropyl acetate Methyl acetate Methylethyl ketone Methylisobutyl lcetone Propyl acetate teat-Butylmethyl ether Tetrahydrofuran It is preferred, but not required, that the co-solvents are preheated before mixing with the primary solvent, preferably to a temperature below the temperature at which a substantial portion of the co-solvent would boil, most preferably to about 50°C. It is also preferred, but not required, that the co-solvent(s) is added gradually to the primary solvent(s).
Following mixing, the primary solvent(s)/co-solvents) mixture is then equilibrated at different temperatures in order to promote either a slow recrystallization or a fast recrystallization of Form I of 5-azacytidine, as described below.
By slow recrystallization is meant that the co-solvent/DMSO solution is allowed to equilibrate at a temperature in the range from about 0°C to about 40°C, preferably in the range of about 15°C to about 30°C, and most preferably at about ambient temperature. Slow recrystallization of Form I of 5-azacytidine is preferably performed using C2-CS alcohols, aliphatic lcetones, or alkyl cyanides as the co-solvent. More preferably, slow recrystallization is performed with Class 3 C2-CS alcohols, Class 3 aliphatic lcetones, or acetonitrile (Class 2).
The most preferred Class 3 C2-CS alchohols are ethanol, isopropyl alcohol, and 1-propanol, and the most preferred Class 3 aliphatic ketone is methylethyl lcetone.
By fast recrystallization is meant that the co-solvent solution is allowed to equilibrate at a temperature of below 0°C, preferably below about -10°C, and most preferably at about -20°C.
Following mixing, the primary solvent(s)/co-solvents) mixture is then equilibrated at different temperatures in order to promote either a slow recrystallization or a fast recrystallization of Form I of 5-azacytidine, as described below.
By slow recrystallization is meant that the co-solvent/DMSO solution is allowed to equilibrate at a temperature in the range from about 0°C to about 40°C, preferably in the range of about 15°C to about 30°C, and most preferably at about ambient temperature. Slow recrystallization of Form I of 5-azacytidine is preferably performed using C2-CS alcohols, aliphatic lcetones, or alkyl cyanides as the co-solvent. More preferably, slow recrystallization is performed with Class 3 C2-CS alcohols, Class 3 aliphatic lcetones, or acetonitrile (Class 2).
The most preferred Class 3 C2-CS alchohols are ethanol, isopropyl alcohol, and 1-propanol, and the most preferred Class 3 aliphatic ketone is methylethyl lcetone.
By fast recrystallization is meant that the co-solvent solution is allowed to equilibrate at a temperature of below 0°C, preferably below about -10°C, and most preferably at about -20°C.
Fast recrystallization of Form I of 5-azacytidine is preferably performed with a C3 - CS alcohol (which term hereinafter refers to C3-CS alcohols which are independently:
branched or unbranched, substituted or unsubstituted) or an alkyl cyanide as the co-solvent. More preferably the C3 - C5 alcohol is a Class 3 solvent, and the alkyl cyanide is acetontrile. The most preferred Class 3 C3-C5 alcohols are is~propyl alcohol (2-propanol) and 1-propanol.
Non-limiting examples ofprotocols for the recrystallization of Fonn I
according to the methods described herein are provided in Examples 2 (slow recrystallization with DMSO as the primary solvent and ethanol, isopropyl alcohol, acetonitrile, or methylethyl lcetone as the co-solvent) and 3 (fast recrystallization with DMSO as the primary solvent, and isopropyl alcohol or acetonitrile as the co-solvent) below.
Following recrystallization, the Form I of 5-azacytidine crystals may be isolated from the co-solvent mixture by any suitable method known in the art. Preferably, the Form I crystals are isolated using vacuum filtration through a suitable filter medium or by centrifugation.
Using the novel methods provided herein, it is possible for the first time to target Form I of 5-azacytidine as the drug substance reproducibly and robustly. In particular, isopropyl alcohol and acetonitrile reliably produce Form I independent of cooling rate (either slow recrystallization or fast recrystallization) and are preferred as the recrystallization co-solvents to recover Form I. Most preferably, Form I is isolated using isopropyl alcohol as the co-solvent since isopropyl alcohol carries a Class 3 risk classification (solvent of low toxic potential), whereas acetonitrile carries a Class 2 risk classification (solvent to be limited). The use of the DMSO/isopropyl alcohol system allows Form I of 5-azacytidine to be reliably recovered for the first time from solvents of low toxic potential without requiring control over the rate of recrystallation. In the most preferred embodiment, Form I of 5-azacytidine may be recovered simply by dissolving 5-azacytidine in DMSO (preferably heated to a temperature in the range of about 40°C to about 90°C prior to the addition of 5-azacytidine), adding isopropyl alcohol, and allowing the resulting solvent mixture to equilibrate at about ambient temperature.
In some embodiments of the invention, Form I of 5-azacytidine may be recovered from a primary solvent(s)/co-solvents) mixture by "seeding" with a small amount of Form I of 5-azacytidine either prior to, or during, the addition of the co-solvent(s). By seeding with Form 7_ I, it is possible to expand the list of suitable co-solvents and co-solvent classes beyond those listed above. For example, it is known that recrystallization from the DMSO/methanol system produces either Form I, or a Form I/II mixed phase (see Example 1). If a small amount of Fonn I is added to the solution of 5-azacytidine in DMS~ prior to addition of the methanol co-solvent, or is added during the addition of the methanol co-solvent, then Form I of 5-azacytidine may be reliably isolated.
Ey allowing the isolation of a single polymorphic fornl, one slcilled in the art will appreciate that the present invention allows for the first time the production of 5-azacytidine drug substance with uniform and consistent properties from batch to batch, which properties include but are not limited to solubility and dissolution rate. In W rn, this allows one to provide 5-azacytidine drug product (see below) which also has uniform and consistent properties from batch to batch.
Pharmaceutical Formulations For the most effective administration of drug substance of the present invention, it is preferred to prepare a pharmaceutical formulation (also known as the "drug product" or "pharmaceutical composition") preferably in unit dose form, comprising one or more of the 5-azacytidine polymorphs of the present invention and one or more pharmaceutically acceptable carrier, diluent, or excipient. Most preferably, Form I 5-azacytidine prepared according to the methods provided herein is used to prepare the pharmaceutical formulation.
Such pharmaceutical formulation may, without being limited by the teachings set forth herein, include a solid form of the present invention which is blended with at least one pharmaceutically acceptable excipient, diluted by an excipient or enclosed within such a carrier that can be in the form of a capsule, sachet, tablet, buccal, lozenge, paper, or other container. When the excipient serves as a diluent, it may be a solid, semi-solid, or lieluid material which acts as a vehicle, carrier, or medium fox the 5-azacytidine polymorph(s). Thus, the formulations can be in the fomn of tablets, pills, powders, elixirs, suspensions, emulsions, solutions, syrups, capsules (such as, for example, soft and hard gelatin capsules), suppositories, sterile injectable solutions, and sterile packaged powders.
Examples of suitable excipients include, but are not limited to, starches, gum arabic, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and -g_ methyl cellulose. The formulations can additionally include lubricating agents such as, for example, talc, magnesium stearate and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propyl-hydroxybenzoates;
sweetening agents; or flavoring agents. Polyols, buffers, and inert fillers may also be used.
E:vamples of polyols include, but are not limited to: mannitol, sorbitol, xylitol, sucrose, maltose, glucose, lactose, dextrose, and the like. Suitable buffers encompass, but are not limited tog phosphate, citrate, tax-trate, succinate, and the lilce. ~ther inert fillers which may be used encompass those which are known in the art and are useful in the manufacture of various dosage forms. If desired, the solid pharmaceutical compositions may include other components such as bulling agents and/or granulating agents, and the like. The compositions of the invention can be formulated s~ as to provide quiclc, sustained, controlled, or delayed release of the drug substance after administration to the patient by employing procedures well known in the ant.
In certain embodiments of the invention, the 5-azacytidine polymorph(s) may made into the form of dosage units for oral administration. The 5-azacytidine polymorph(s) may be mixed with a solid, pulverant carrier such as, for example, lactose, saccharose, sorbitol, mannitol, starch, amylopectin, cellulose derivatives or gelatin, as well as with an antifriction agent such as for example, magnesium stearate, calcium stearate, and polyethylene glycol waxes. The mixture is then pressed into tablets or filled into capsules. If coated tablets, capsules, or pulvules are desired, such tablets, capsules, or pulvules may be coated with a concentrated solution of sugar, which may contain gum arabic, gelatin, talc, titanium dioxide, or with a lacquer dissolved in the volatile organic solvent or mixture of solvents. To this coating, various dyes may be added in order to distinguish among tablets with different active compounds or with different amounts of the active compound present.
Soft gelatin capsules may be prepared in which capsules contain a mixture of the 5-azacytidine polymorph(s) and vegetable oil or non-aqueous, water miscible materials such as, for example, polyethylene glycol and the like. Hard gelatin capsules may contain granules or powder of the 5-azacytidine polymorph in combination with a solid, pulverulent carrier, such as, for example, lactose, saccharose, sorbitol, mannitol, potato starch, corn starch, arnylopectin, cellulose derivatives, or gelatin.
Tablets for oral use are typically prepared in the following manner, although other techniques may be employed. The solid substances are gently ground or sieved to a desired particle size, and a binding agent is homogenized and suspended in a suitable solvent. The 5-azacytidine polymorph(s) and auxiliary agents are mixed with the binding agent solution. The avsulting mixture is moisten ed to form a uniform suspension. The moistening typically causes the particles to aggregate slightly, and the resulting mass is gently pressed through a stainless steel sieve having a desired size. The layers of the mixture are then dried in controlled drying units for a pre-determined length of time to achieve a desired particle size and consistency.
The granules of the dried mixture are gently sieved to remove amy powder. To this mixture, disintegrating, anti-friction, and anti-adhesive agents are added. Finally, the mixture is pressed into tablets using a machine with the appropriate punches and dies to obtain the desired tablet size.
In the event that the above formulations are to be used for parenteral administration, such a formulation typically comprises sterile, aqueous and non-aqueous injection solutions comprising one or more 5-azacytidine polymorphs for which preparations are preferably isotonic with the blood of the intended recipient. These preparations rnay contain anti-oxidants, buffers, bacteriostats, and solute; which render the formulation isotonic with the blood of the intended recipient. Aqueous and non-aqueous suspensions may include suspending agents and thickening agents. The formulations may be present in unit-dose or mufti-dose containers, for example, sealed ampules and vials. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules, and tablets of the kind previously described.
Liquid preparations for oral administration are prepared in the form of solutions, syxups, or suspensions with the latter two forms containing, for example, 5-azacytidine polymorph(s), sugar, and a mixture of ethanol, water, glycerol, and propylene glycol. If desired, such liquid preparations contain coloring agents, flavoring agents, and saccharin.
Thickening agents such as carboxymethylcellulose may also be used.
As such, the pharmaceutical formulations of the present invention are preferably prepared in a unit dosage form, each dosage unit containing from about 5 mg to about 200 mg, more usually about 100 mg of the 5-azacytidine polymorph(s). In liquid form, dosage unit contains from about 5 to about 200 mg, more usually about 100 mg of the 5-azacytidine polymorph(s). The teen "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects/patients or other mammals, each unit containing a predetermined quantity of the 5-azacytidine polymorph calculated to produce the desired therapeutic effect, in association with preferably, at least one pharmaceutically acceptable carrier, diluent, or excipient.
The following examples are provided for illustrative purposes only, and are not to be construed as limiting the scope of the claims in any way.
Examples Example 1 Prior Art Procedure for Synthesis and Recrystallization of 5-azacytidine Drug Substance 5-azacytidine may be synthesized using commercially available 5-azacytosine and 1,2,3,5-tetra-O-acetyl-(3-D-ribofuranose (RTA) according to the following pathway:
NNSf(CH3)3 HN
S
GH
( . ~ J
~( ~)s)z HO N (NHZ)=SOq> Heat (HsC)aS~Q N
NHSi(CH3)3 Ac0 OAc N ~ IN + 4 (1) SnClq, GH3CN
1I~ H HI (2) NaOC-H3, C-H' (H3C)3Si0"NJ H H
OAc OAc c2) c3) The crude synthesis product is dissolved in DMSO (preheated to about 90°C), and then methanol is added to the DMSO solution. The co-solvent mixture is equilibrated at approximately -20°C to allow 5-azacytidine crystal formation. The product is collected by vacuum filtration and allowed to air dry.
Example 2 Form I of 5-azacytidine: Slow Recrvstallization of 5-azacytidine from Co-Solvent S, stems Approximately 250 mg of 5-azacytidine was dissolved with approximately 5 ml of dimethyl sulfoxide (DMSO), preheated to approximately 90 °C, in separate 100-mL beakers.
The solids were allowed to dissolve to a clear solution. Approximately 45 mL
of ethanol, isopropyl alcohol, acetonitrile, or methyl ethyl ketone co-solvent, preheated to approximately 50 °C, was added to the solution and the resultant solution was mixed.
The solution was covered and allowed to equilibrate at ambient conditions. The product was collected by vacuum filtration using a Buchner funnel.
Example 3 Form I of 5-azacytidine: Fast Recrystallization of 5-azacytidine from Co-Solvent Systems Approximately 250 mg of 5-azacytidine was dissolved with approximately 5 mL of DMS~D, preheated to approximately 90 °C, in separate 100-ml bealbers.
The solids were allowed to dissolve to a clear solution. Approximately 45 mL of isopropyl alcohol or acetonitrile co-solvent, preheated to approximately 50 °C, was added to the solution and the resultant solution was mixed. The solution was covered and placed in a freezer to equilibrate at approximately -20°C to allow crystal formation. Solutions were removed from the freezer after crystal formation. The product was collected by vacuum filtration using a l~uchner funnel.
Example 4 X-Ray Powder Diffraction of Recrystallized 5-azac idine X-ray powder diffraction (XRPD) patterns for each sample were obtained on a Scintag XDS 2000 or a Scintag X2 0/0 diffractometer operating with copper radiation at 45 kV and 40 mA using a I~evex Psi Pettier-cooled silicon detector or a Thermo ARL Pettier-cooled solid state detector. Source slits of 2 or 4 mm and detector slits of 0.5 or 0.3 mm were used for data collection. Recrystallized material was gently milled for approximately one minute using an agate mortar and pestle. Samples were placed in a stainless steel or silicon sample holder and leveled using a glass microscope slide. Powder diffraction patterns of the samples were obtained from 2 to 42° 20 at 1 °/minute. Calibration of the XZ
diffractometer is verified annually using a silicon powder standard.
XRPD performed according to this method revealed that the Form I of 5-azacytidine was isolated in Example 2 by slow recrystallization using either ethanol, isopropyl alcohol, acetonitrile, or methyl ethyl ketone as the co-solvent, and in Example 3 by fast recrystallization using isopropyl alcohol or acetonitrile as the co-solvent.
The results indicate that Form I of 5-azacytidine may be reliably recovered from the DMS~/isopropyl alcohol and DMS~/acetonitrile solvent systems without control of the rate of recrystallization.
branched or unbranched, substituted or unsubstituted) or an alkyl cyanide as the co-solvent. More preferably the C3 - C5 alcohol is a Class 3 solvent, and the alkyl cyanide is acetontrile. The most preferred Class 3 C3-C5 alcohols are is~propyl alcohol (2-propanol) and 1-propanol.
Non-limiting examples ofprotocols for the recrystallization of Fonn I
according to the methods described herein are provided in Examples 2 (slow recrystallization with DMSO as the primary solvent and ethanol, isopropyl alcohol, acetonitrile, or methylethyl lcetone as the co-solvent) and 3 (fast recrystallization with DMSO as the primary solvent, and isopropyl alcohol or acetonitrile as the co-solvent) below.
Following recrystallization, the Form I of 5-azacytidine crystals may be isolated from the co-solvent mixture by any suitable method known in the art. Preferably, the Form I crystals are isolated using vacuum filtration through a suitable filter medium or by centrifugation.
Using the novel methods provided herein, it is possible for the first time to target Form I of 5-azacytidine as the drug substance reproducibly and robustly. In particular, isopropyl alcohol and acetonitrile reliably produce Form I independent of cooling rate (either slow recrystallization or fast recrystallization) and are preferred as the recrystallization co-solvents to recover Form I. Most preferably, Form I is isolated using isopropyl alcohol as the co-solvent since isopropyl alcohol carries a Class 3 risk classification (solvent of low toxic potential), whereas acetonitrile carries a Class 2 risk classification (solvent to be limited). The use of the DMSO/isopropyl alcohol system allows Form I of 5-azacytidine to be reliably recovered for the first time from solvents of low toxic potential without requiring control over the rate of recrystallation. In the most preferred embodiment, Form I of 5-azacytidine may be recovered simply by dissolving 5-azacytidine in DMSO (preferably heated to a temperature in the range of about 40°C to about 90°C prior to the addition of 5-azacytidine), adding isopropyl alcohol, and allowing the resulting solvent mixture to equilibrate at about ambient temperature.
In some embodiments of the invention, Form I of 5-azacytidine may be recovered from a primary solvent(s)/co-solvents) mixture by "seeding" with a small amount of Form I of 5-azacytidine either prior to, or during, the addition of the co-solvent(s). By seeding with Form 7_ I, it is possible to expand the list of suitable co-solvents and co-solvent classes beyond those listed above. For example, it is known that recrystallization from the DMSO/methanol system produces either Form I, or a Form I/II mixed phase (see Example 1). If a small amount of Fonn I is added to the solution of 5-azacytidine in DMS~ prior to addition of the methanol co-solvent, or is added during the addition of the methanol co-solvent, then Form I of 5-azacytidine may be reliably isolated.
Ey allowing the isolation of a single polymorphic fornl, one slcilled in the art will appreciate that the present invention allows for the first time the production of 5-azacytidine drug substance with uniform and consistent properties from batch to batch, which properties include but are not limited to solubility and dissolution rate. In W rn, this allows one to provide 5-azacytidine drug product (see below) which also has uniform and consistent properties from batch to batch.
Pharmaceutical Formulations For the most effective administration of drug substance of the present invention, it is preferred to prepare a pharmaceutical formulation (also known as the "drug product" or "pharmaceutical composition") preferably in unit dose form, comprising one or more of the 5-azacytidine polymorphs of the present invention and one or more pharmaceutically acceptable carrier, diluent, or excipient. Most preferably, Form I 5-azacytidine prepared according to the methods provided herein is used to prepare the pharmaceutical formulation.
Such pharmaceutical formulation may, without being limited by the teachings set forth herein, include a solid form of the present invention which is blended with at least one pharmaceutically acceptable excipient, diluted by an excipient or enclosed within such a carrier that can be in the form of a capsule, sachet, tablet, buccal, lozenge, paper, or other container. When the excipient serves as a diluent, it may be a solid, semi-solid, or lieluid material which acts as a vehicle, carrier, or medium fox the 5-azacytidine polymorph(s). Thus, the formulations can be in the fomn of tablets, pills, powders, elixirs, suspensions, emulsions, solutions, syrups, capsules (such as, for example, soft and hard gelatin capsules), suppositories, sterile injectable solutions, and sterile packaged powders.
Examples of suitable excipients include, but are not limited to, starches, gum arabic, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and -g_ methyl cellulose. The formulations can additionally include lubricating agents such as, for example, talc, magnesium stearate and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propyl-hydroxybenzoates;
sweetening agents; or flavoring agents. Polyols, buffers, and inert fillers may also be used.
E:vamples of polyols include, but are not limited to: mannitol, sorbitol, xylitol, sucrose, maltose, glucose, lactose, dextrose, and the like. Suitable buffers encompass, but are not limited tog phosphate, citrate, tax-trate, succinate, and the lilce. ~ther inert fillers which may be used encompass those which are known in the art and are useful in the manufacture of various dosage forms. If desired, the solid pharmaceutical compositions may include other components such as bulling agents and/or granulating agents, and the like. The compositions of the invention can be formulated s~ as to provide quiclc, sustained, controlled, or delayed release of the drug substance after administration to the patient by employing procedures well known in the ant.
In certain embodiments of the invention, the 5-azacytidine polymorph(s) may made into the form of dosage units for oral administration. The 5-azacytidine polymorph(s) may be mixed with a solid, pulverant carrier such as, for example, lactose, saccharose, sorbitol, mannitol, starch, amylopectin, cellulose derivatives or gelatin, as well as with an antifriction agent such as for example, magnesium stearate, calcium stearate, and polyethylene glycol waxes. The mixture is then pressed into tablets or filled into capsules. If coated tablets, capsules, or pulvules are desired, such tablets, capsules, or pulvules may be coated with a concentrated solution of sugar, which may contain gum arabic, gelatin, talc, titanium dioxide, or with a lacquer dissolved in the volatile organic solvent or mixture of solvents. To this coating, various dyes may be added in order to distinguish among tablets with different active compounds or with different amounts of the active compound present.
Soft gelatin capsules may be prepared in which capsules contain a mixture of the 5-azacytidine polymorph(s) and vegetable oil or non-aqueous, water miscible materials such as, for example, polyethylene glycol and the like. Hard gelatin capsules may contain granules or powder of the 5-azacytidine polymorph in combination with a solid, pulverulent carrier, such as, for example, lactose, saccharose, sorbitol, mannitol, potato starch, corn starch, arnylopectin, cellulose derivatives, or gelatin.
Tablets for oral use are typically prepared in the following manner, although other techniques may be employed. The solid substances are gently ground or sieved to a desired particle size, and a binding agent is homogenized and suspended in a suitable solvent. The 5-azacytidine polymorph(s) and auxiliary agents are mixed with the binding agent solution. The avsulting mixture is moisten ed to form a uniform suspension. The moistening typically causes the particles to aggregate slightly, and the resulting mass is gently pressed through a stainless steel sieve having a desired size. The layers of the mixture are then dried in controlled drying units for a pre-determined length of time to achieve a desired particle size and consistency.
The granules of the dried mixture are gently sieved to remove amy powder. To this mixture, disintegrating, anti-friction, and anti-adhesive agents are added. Finally, the mixture is pressed into tablets using a machine with the appropriate punches and dies to obtain the desired tablet size.
In the event that the above formulations are to be used for parenteral administration, such a formulation typically comprises sterile, aqueous and non-aqueous injection solutions comprising one or more 5-azacytidine polymorphs for which preparations are preferably isotonic with the blood of the intended recipient. These preparations rnay contain anti-oxidants, buffers, bacteriostats, and solute; which render the formulation isotonic with the blood of the intended recipient. Aqueous and non-aqueous suspensions may include suspending agents and thickening agents. The formulations may be present in unit-dose or mufti-dose containers, for example, sealed ampules and vials. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules, and tablets of the kind previously described.
Liquid preparations for oral administration are prepared in the form of solutions, syxups, or suspensions with the latter two forms containing, for example, 5-azacytidine polymorph(s), sugar, and a mixture of ethanol, water, glycerol, and propylene glycol. If desired, such liquid preparations contain coloring agents, flavoring agents, and saccharin.
Thickening agents such as carboxymethylcellulose may also be used.
As such, the pharmaceutical formulations of the present invention are preferably prepared in a unit dosage form, each dosage unit containing from about 5 mg to about 200 mg, more usually about 100 mg of the 5-azacytidine polymorph(s). In liquid form, dosage unit contains from about 5 to about 200 mg, more usually about 100 mg of the 5-azacytidine polymorph(s). The teen "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects/patients or other mammals, each unit containing a predetermined quantity of the 5-azacytidine polymorph calculated to produce the desired therapeutic effect, in association with preferably, at least one pharmaceutically acceptable carrier, diluent, or excipient.
The following examples are provided for illustrative purposes only, and are not to be construed as limiting the scope of the claims in any way.
Examples Example 1 Prior Art Procedure for Synthesis and Recrystallization of 5-azacytidine Drug Substance 5-azacytidine may be synthesized using commercially available 5-azacytosine and 1,2,3,5-tetra-O-acetyl-(3-D-ribofuranose (RTA) according to the following pathway:
NNSf(CH3)3 HN
S
GH
( . ~ J
~( ~)s)z HO N (NHZ)=SOq> Heat (HsC)aS~Q N
NHSi(CH3)3 Ac0 OAc N ~ IN + 4 (1) SnClq, GH3CN
1I~ H HI (2) NaOC-H3, C-H' (H3C)3Si0"NJ H H
OAc OAc c2) c3) The crude synthesis product is dissolved in DMSO (preheated to about 90°C), and then methanol is added to the DMSO solution. The co-solvent mixture is equilibrated at approximately -20°C to allow 5-azacytidine crystal formation. The product is collected by vacuum filtration and allowed to air dry.
Example 2 Form I of 5-azacytidine: Slow Recrvstallization of 5-azacytidine from Co-Solvent S, stems Approximately 250 mg of 5-azacytidine was dissolved with approximately 5 ml of dimethyl sulfoxide (DMSO), preheated to approximately 90 °C, in separate 100-mL beakers.
The solids were allowed to dissolve to a clear solution. Approximately 45 mL
of ethanol, isopropyl alcohol, acetonitrile, or methyl ethyl ketone co-solvent, preheated to approximately 50 °C, was added to the solution and the resultant solution was mixed.
The solution was covered and allowed to equilibrate at ambient conditions. The product was collected by vacuum filtration using a Buchner funnel.
Example 3 Form I of 5-azacytidine: Fast Recrystallization of 5-azacytidine from Co-Solvent Systems Approximately 250 mg of 5-azacytidine was dissolved with approximately 5 mL of DMS~D, preheated to approximately 90 °C, in separate 100-ml bealbers.
The solids were allowed to dissolve to a clear solution. Approximately 45 mL of isopropyl alcohol or acetonitrile co-solvent, preheated to approximately 50 °C, was added to the solution and the resultant solution was mixed. The solution was covered and placed in a freezer to equilibrate at approximately -20°C to allow crystal formation. Solutions were removed from the freezer after crystal formation. The product was collected by vacuum filtration using a l~uchner funnel.
Example 4 X-Ray Powder Diffraction of Recrystallized 5-azac idine X-ray powder diffraction (XRPD) patterns for each sample were obtained on a Scintag XDS 2000 or a Scintag X2 0/0 diffractometer operating with copper radiation at 45 kV and 40 mA using a I~evex Psi Pettier-cooled silicon detector or a Thermo ARL Pettier-cooled solid state detector. Source slits of 2 or 4 mm and detector slits of 0.5 or 0.3 mm were used for data collection. Recrystallized material was gently milled for approximately one minute using an agate mortar and pestle. Samples were placed in a stainless steel or silicon sample holder and leveled using a glass microscope slide. Powder diffraction patterns of the samples were obtained from 2 to 42° 20 at 1 °/minute. Calibration of the XZ
diffractometer is verified annually using a silicon powder standard.
XRPD performed according to this method revealed that the Form I of 5-azacytidine was isolated in Example 2 by slow recrystallization using either ethanol, isopropyl alcohol, acetonitrile, or methyl ethyl ketone as the co-solvent, and in Example 3 by fast recrystallization using isopropyl alcohol or acetonitrile as the co-solvent.
The results indicate that Form I of 5-azacytidine may be reliably recovered from the DMS~/isopropyl alcohol and DMS~/acetonitrile solvent systems without control of the rate of recrystallization.
Claims (39)
1. A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of:
1,1,2-Trichloroethene 1,2-Dichloroethene 1,2-Dimethoxyethane 1,4-Dioxane 1-Butanol 1-Pentanol 1-Propanol
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of:
1,1,2-Trichloroethene 1,2-Dichloroethene 1,2-Dimethoxyethane 1,4-Dioxane 1-Butanol 1-Pentanol 1-Propanol
2-Butanol 2-Ethoxyethanol 2-Methoxyethanol 2-Methyl-1-propanol 2-Propanol (isopropyl alcohol)
3-Methyl-1-butanol Acetone Acetonitrile Anisole Butyl acetate Chlorobenzene Cumene Cyclohexane Dichloromethane Ethanol Ethyl acetate Ethyl ether Ethyl formate Ethyleneglycol Formamide Isobutyl acetate Isopropyl acetate Methyl acetate Methylbutyl ketone Methylcyclohexane Methylethyl ketone Methylisobutyl ketone N,N-Dimethylacetamide N,N-Dimethylformamide Nitromethane Propyl acetate Pyridine Sulfolane tert-Butylmethyl ether Tetrahydrofuran, and Tetralin by cooling said solvent mixture from a temperature selected to allow said 5-azacytidine to dissolve completely to about ambient temperature; and isolating the recrystallized 5-azacytidine.
2. The method of claim 1 wherein said primary solvent is a polar solvent.
3. The method of claim 2 wherein said polar solvent is a polar aprotic solvent.
2. The method of claim 1 wherein said primary solvent is a polar solvent.
3. The method of claim 2 wherein said polar solvent is a polar aprotic solvent.
4. The method of claim 3 wherein said polar aprotic solvent is selected from the group consisting of dimethylsulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidinone.
5. The method of claim 4 wherein said polar aprotic solvent is dimethylsulfoxide.
6. The method of claim 1 wherein said co-solvent is acetonitrile.
7. The method of claim 1 wherein said co-solvent is ethanol.
8. The method of claim 1 wherein said co-solvent is methylethyl ketone.
9. The method of claim 1 wherein said co-solvent is 2-propanol (isopropyl alcohol).
10. The method of claim 1 wherein said co-solvent is 1-propanol.
11. A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of C2-C5 alcohols, aliphatic ketones, and alkyl cyanides, by cooling said solvent mixture from a temperature selected to allow said 5-azacytidine to dissolve completely to about ambient temperature;
and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of C2-C5 alcohols, aliphatic ketones, and alkyl cyanides, by cooling said solvent mixture from a temperature selected to allow said 5-azacytidine to dissolve completely to about ambient temperature;
and isolating the recrystallized 5-azacytidine.
12. The method of claim 11 wherein said primary solvent is a polar solvent.
13. The method of claim 12 wherein said polar solvent is a polar aprotic solvent.
14. The method of claim 13 wherein said polar aprotic solvent is selected from the group consisting of dimethylsulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidinone.
15. The method of claim 14 wherein said polar aprotic solvent is dimethylsulfoxide.
16. The method of claim 11 wherein said co-solvent is acetonitrile.
17. The method of claim 11 wherein said co-solvent is ethanol.
18. The method of claim 11 wherein said co-solvent is methylethyl ketone.
19. The method of claim 11 wherein said co-solvent is 2-propanol (isopropyl alcohol).
20. The method of claim 11 wherein said co-solvent is 1-propanol.
21. ~A method for isolating crystalline Form I 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of:
1,1,2-Trichloroethene 1,2-Dichloroethene 1,2-Dimethoxyethane 1,4-Dioxane 1-Butanol 1-Pentanol 1-Propanol 2-Butanol 2-Ethoxyethanol 2-Methoxyethanol 2-Methyl-1-propanol 2-Propanol 3-Methyl-1-butanol Acetone Acetonitrile Anisole Butyl acetate Chlorobenzene Cumene Cyclohexane~
Dichloromethane Ethyl acetate Ethyl ether Ethyl formate Ethyleneglycol Formamide Isobutyl acetate Isopropyl acetate Methyl acetate Methylbutyl ketone Methylcyclohexane Methylisobutyl ketone N,N-Dimethylacetamide N,N-Dimethylformamide Nitromethane Propyl acetate Pyridine Sulfolane tert-Butylmethyl ether Tetrahydrofuran, and Tetralin by cooling said solution from a temperature selected to allow said 5-azacytidine to dissolve completely to about -20°C ; and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of:
1,1,2-Trichloroethene 1,2-Dichloroethene 1,2-Dimethoxyethane 1,4-Dioxane 1-Butanol 1-Pentanol 1-Propanol 2-Butanol 2-Ethoxyethanol 2-Methoxyethanol 2-Methyl-1-propanol 2-Propanol 3-Methyl-1-butanol Acetone Acetonitrile Anisole Butyl acetate Chlorobenzene Cumene Cyclohexane~
Dichloromethane Ethyl acetate Ethyl ether Ethyl formate Ethyleneglycol Formamide Isobutyl acetate Isopropyl acetate Methyl acetate Methylbutyl ketone Methylcyclohexane Methylisobutyl ketone N,N-Dimethylacetamide N,N-Dimethylformamide Nitromethane Propyl acetate Pyridine Sulfolane tert-Butylmethyl ether Tetrahydrofuran, and Tetralin by cooling said solution from a temperature selected to allow said 5-azacytidine to dissolve completely to about -20°C ; and isolating the recrystallized 5-azacytidine.
22. ~The method of claim 21 wherein said primary solvent is a polar solvent.
23. ~The method of claim 22 wherein said polar solvent is a polar aprotic solvent.
24. ~The method of claim 23 wherein said polar aprotic solvent is selected from the group consisting of dimethylsulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidinone.
25. ~The method of claim 24 wherein said polar aprotic solvent is dimethylsulfoxide.
26. ~The method of claim 21 wherein said co-solvent is acetonitrile.
27. ~The method of claim 21 wherein said co-solvent is 2-propanol (isopropyl alcohol).
28. ~The method of claim 21 wherein said co-solvent is 1-propanol.
29. A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of C3 -C5 alcohols and alkyl cyanides by cooling said solution from a temperature selected to allow said 5-azacytidine to dissolve completely to about -20°C; and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising at least one primary solvent and at least one co-solvent selected from the group consisting of C3 -C5 alcohols and alkyl cyanides by cooling said solution from a temperature selected to allow said 5-azacytidine to dissolve completely to about -20°C; and isolating the recrystallized 5-azacytidine.
30. The method of claim 29 wherein said primary solvent is a polar solvent.
31. The method of claim 30 wherein said polar solvent is a polar aprotic solvent.
32. The method of claim 31 wherein said polar aprotic solvent is selected from the group consisting of dimethylsulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidinone.
33. The method of claim 32 wherein said polar aprotic solvent is dimethylsulfoxide.
34. The method of claim 29 wherein said co-solvent is acetonitrile.
35. The method of claim 29 wherein said co-solvent is 2-propanol (isopropyl alcohol).
36. The method of claim 29 wherein said co-solvent is 1-propanol.
37. ~A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and isopropyl alcohol; and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and isopropyl alcohol; and isolating the recrystallized 5-azacytidine.
38. ~A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and 1-propanol; and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and 1-propanol; and isolating the recrystallized 5-azacytidine.
39. ~A method for isolating crystalline Form I of 5-azacytidine substantially free of other forms, the method comprising:
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and methanol by seeding said solvent mixture with Form I of 5-azacytidine; and isolating the recrystallized 5-azacytidine.
recrystallizing 5-azacytidine from a solvent mixture comprising dimethylsulfoxide and methanol by seeding said solvent mixture with Form I of 5-azacytidine; and isolating the recrystallized 5-azacytidine.
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| PCT/US2004/007896 WO2004082822A2 (en) | 2003-03-17 | 2004-03-16 | Methods for isolating crystalline form i of 5-azacytidine |
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| US6943249B2 (en) | 2003-03-17 | 2005-09-13 | Ash Stevens, Inc. | Methods for isolating crystalline Form I of 5-azacytidine |
| US6887855B2 (en) * | 2003-03-17 | 2005-05-03 | Pharmion Corporation | Forms of 5-azacytidine |
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| EP2644614A3 (en) | 2007-01-11 | 2014-02-26 | IVAX Pharmaceuticals s.r.o. | Solid state forms of 5-azacytidine and processes for preparation thereof |
| US20110288042A1 (en) * | 2007-08-02 | 2011-11-24 | Chemagis Ltd. | Stable highly pure azacitidine and preparation methods therefor |
| NZ583824A (en) * | 2007-09-26 | 2012-06-29 | Sinai School Medicine | Azacytidine analogues and uses thereof |
| US20100311683A1 (en) * | 2007-11-01 | 2010-12-09 | Beach C L | Cytidine analogs for treatment of myelodysplastic syndromes |
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