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1. WO2008105808 - FORMULATIONS OF RADIOPROTECTIVE α, β UNSATURATED ARYL SULFONES

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FORMULATIONS OF RADIOPROTECTIVE
α, β UNSATURATED ARYL SULFONES

FIELD OF THE INVENTION
The invention relates to solution and suspension formulations for effective pharmacological delivery of cytoprotective agents, e.g., at least one α, β unsaturated aryl sulfone, for the protection and/or treatment of cells and tissues from/of the toxicity of ionizing radiation.

BACKGROUND OF THE INVENTION
While anti-radiation suits or other protective gear may be effective at reducing radiation exposure, such gear is expensive, unwieldy, and generally not available to public. Moreover, radioprotective gear will not protect normal tissue adjacent a tumor from stray radiation exposure during radiotherapy. Pharmaceutical radioprotectants offer a cost-efficient, effective and easily available alternative to radioprotective gear. However, previous attempts at radioprotection of normal cells with pharmaceutical compositions have not been entirely successful. For example, cytokines directed at mobilizing the peripheral blood progenitor cells confer a myeloprotective effect when given prior to radiation (Neta et ah, Semin. Radiat. Oncol. 6:306-320, 1996), but do not confer systemic protection. Other chemical radioprotectors administered alone or in combination with biologic response modifiers have shown minor protective effects in mice, but application of these compounds to large mammals was less successful, and it was questioned whether chemical radioprotection was of any value (Maisin, J.R., Bacq and Alexander Award Lecture. "Chemical radioprotection: past, present, and future prospects", Int J. Radiat Biol. 73:443-50, 1998). Pharmaceutical radiation sensitizers, which are known to preferentially enhance the effects of radiation in cancerous tissues, are clearly unsuited for the general systemic protection of normal tissues from exposure to ionizing radiation.

What is needed, therefore, is a practical means to protect subjects from the toxicity of radiation, wherein the subjects are either scheduled to incur or are at risk for incurring, or have incurred, exposure to ionizing radiation.

SUMMARY OF THE INVENTION
Exemplary pharmaceutical compositions of the present invention, for example, are aqueous solutions and comprise between about 20 mg/ml to about 100 mg/ml of at least one α, β unsaturated aryl sulfone (e.g., the compound ON.1210.Na ((E)-4-Carboxystyryl-4-chlorobenzylsulfone sodium salt (Ci6Hi2ClNaO4S))), a cosolvent in an amount between about 25% and about 90% w/v (e.g., about 50% PEG 400), wherein the composition is buffered and exists within the range of about pH 7.0 to about pHIO (e.g., 0.2M Tris-EDTA, pH about 8.5).
Further embodiments of pharmaceutical compositions of the present invention, for example, are aqueous suspensions and comprise between about 10 mg/ml to about 250 mg/ml of the at least one α, β unsaturated aryl sulfone, at least one hydrophilic wetting agent having an HLB value between about 8 and about 14 (e.g., Tween 80) in an amount between about 0.1% and about 5% w/v, a component known in the art to effect proper isotonicity (e.g., NaCl), wherein the composition is buffered and exists within the range of about pH 7.0 to about pHIO (e.g., 0.2M Tris-EDTA, pH about 8.5).
The present invention is also directed to alternate pharmaceutical compositions for administration for reducing toxic effects of ionizing radiation in a subject, comprising an effective amount of at least one radioprotective α, β unsaturated aryl sulfone, and at least one component selected from the group consisting of a) at least one water soluble polymer in an amount between about 0.5% and about 90% w/v, b) at least one chemically modified cyclodextrin in an amount between about 20% and about 60% w/v, and c) DMA in an amount between about 10% and about 50% w/v.
Certain embodiments of pharmaceutical compositions described herein comprise between about 0.1 mg/ml to about 250 mg/ml of at least one
radioprotective α, β unsaturated aryl sulfone, and at least one component selected from the group consisting of a) at least one chemically modified cyclodextrin selected from the group consisting of 2-hydroxypropyl-beta-cyclodextrin, 2-hydroxypropyl-gamma-cyclodextrin, and hydroxyethyl-beta-cyclodextrin in an amount between about 20% and about 60% w/v, b) a water soluble polymer selected from the group consisting of povidone in an amount between about 0.5% and about 20% w/v and PEG in an amount between about 25% and about 90% w/v, and c) DMA in an amount between about 10% and about 50% w/v, wherein the composition has a pH within the range of about 7.0 to about 10.

BRIEF DESCRIPTION OF THE FIGURES

FIG. IA and IB show the effect of 5 Gy and 10 Gy of ionizing radiation, respectively, on the viability of DU 145 prostate tumor cells in the presence or absence of (E)-4-fluorostyryl-4-chlorobenzylsulfone.
FIG.2 A and 2B show the effect of 5 Gy and 10 Gy of ionizing radiation, respectively, on the viability of DU 145 prostate tumor cells in the presence or absence of (E)-4-carboxystyryl-4-chlorobenzylsulfone.
FIG.3A and 3B show the effect of 10 Gy ionizing radiation on the viability of DU145 prostate tumor cells treated post-irradiation, respectively, with (E)-4-fluorostyryl-4-chlorobenzylsulfone and (E)-4-carboxystyryl-4-chlorobenzylsulfone. FIG.4 is a plot of average body weight (grams) vs. time(days) for C57B6/J mice given 4 mg/kg (E)-4-fluorostyryl-4-chlorobenzylsulfone every other day for 18 days.
FIG.5 is a Kaplan Meyer survival plot of C57B6/J mice pre-treated with (E)-4-carboxystyryl-4-chlorobenzylsulfone at 18 and 6 hrs before receiving 8 Gy of ionizing radiation.
FIG.6 is a Kaplan Meyer survival plot of C57B6/J mice treated with (E)-4-carboxystyryl-4-chlorobenzylsulfone after receiving 8 Gy of ionizing radiation.
FIG.7 shows the structure of the sodium salt of 4-chlorobenzyl-4-carboxystyryl sulfone (ON.1210.Na).
FIG.8 shows pH solubility profiles of ON.1210.Na at ambient temperature.

DETAILED DESCRIPTION OF THE INVENTION
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs. All publications and patents referred to herein are incorporated by reference. The entireties of the disclosures of U.S. Patent Nos. 6,656,973 and 6,667,346 are particularly incorporated herein by reference.
The major biological effects of radiation exposure are the destruction of bone marrow cells, gastrointestinal (GI) damage, lung pneumonitis, and central nervous system (CNS) damage. The long-term effects of radiation exposure include an increase in cancer rates. It has been estimated that the exposure of 100 rems
(roentgen equivalent man: a measurement used to quantify the amount of radiation that would produce harmful biological effects) would produce ARS symptoms. Exposure levels above 300 rems would result in the death of approximately 50% of the exposed population.
The α, β-unsaturated aryl sulfones, in particular benzyl styryl sulfones, provide significant and selective systemic protection of normal cells from radiation-induced damage in animals. When used in radiotherapy techniques, these compounds also exhibit independent toxicity to cancer cells. Compositions and formulations of α,β unsaturated aryl sulfones described herein protect normal cells and tissues from the effects of acute and chronic exposure to ionizing radiation. The α,β unsaturated aryl sulfones are also operationally cytotoxic in tumor cells.
Compositions described herein are intended for prophylactic use, for example, to enhance survival in personnel who are in imminent danger of exposure to life-threatening levels of x-ray or gamma radiation, and/or to enhance survival in personnel who have just received life-threatening levels of xray or gamma radiation. In animal efficacy studies, pre-treatment with ON.01210.Na, for example, by the intravenous, sub-cutaneous or intraperitoneal route resulted in protection of mice from a lethal dose of ionizing radiation.
Subjects may be exposed to ionizing radiation when undergoing therapeutic irradiation for the treatment of proliferative disorders. Such disorders include cancerous and non-cancer proliferative disorders. Formulations described herein are effective in protecting normal cells during therapeutic irradiation of a broad range of tumor types, including but not limited to the following: breast, prostate, ovarian, lung, colorectal, brain (i.e., glioma) and renal. The compositions are also effective against leukemic cells, for example. The compositions are useful in protecting normal cells during therapeutic irradiation of abnormal tissues in non-cancer proliferative disorders, including but not limited to hemangiomatosis in new born, secondary progressive multiple sclerosis, chronic progressive myelodegenerative disease, neurofibromatosis, ganglioneuromatosis, keloid formation, Paget's Disease of the bone, fibrocystic disease of the breast, Peronies and Duputren's fibrosis, restenosis and cirrhosis.
Therapeutic ionizing radiation may be administered to a subject on any schedule and in any dose consistent with the prescribed course of treatment, as long as the α,β unsaturated aryl sulfone radioprotectant compound is administered prior to the radiation. The course of treatment differs from subject to subject, and those of ordinary skill in the art can readily determine the appropriate dose and schedule of therapeutic radiation in a given clinical situation. Compositions of α,β unsaturated aryl sulfones described herein should be administered far enough in advance of the therapeutic radiation such that the compound is able to reach the normal cells of the subject in sufficient concentration to exert a radioprotective effect on the normal cells. At least one α,β unsaturated aryl sulfone may be administered as much as about 24 hours, preferably no more than about 18 hours, prior to administration of the radiation. In one embodiment, an α,β unsaturated aryl sulfone formulation is administered at least about 6 - 12 hours before administration of the therapeutic radiation. Most preferably, the α,β unsaturated aryl sulfone is administered once at about 18 hours and again at about 6 hours before the radiation exposure. One or more α,β unsaturated aryl sulfones may be administered simultaneously, or different α,β unsaturated aryl sulfones may be administered at different times during the treatment.
Preferably, an about 24 hour period separates administration of α,β unsaturated aryl sulfone and the therapeutic radiation. More preferably, the administration of α,β unsaturated aryl sulfone and the therapeutic radiation is separated by about 6 to 18 hours. This strategy will yield significant reduction in radiation-induced side effects without affecting the anticancer activity of the therapeutic radiation.
An acute dose of ionizing radiation which may cause remediable radiation damage includes a localized or whole body dose, for example, between about 10,000 millirem (0.1 Gy) and about 1,000,000 millirem (10 Gy) in 24 hours or less, preferably between about 25,000 millirem (0.25 Gy) and about 200,000 (2 Gy) in 24 hours or less, and more preferably between about 100,000 millirem (1 Gy) and about 150,000 millirem (1.5 Gy) in 24 hours or less.
A chronic dose of ionizing radiation which may cause remediable radiation damage includes a whole body dose of about 100 millirem (.001 Gy) to about 10,000 millirem (0.1 Gy), preferably a dose between about 1000 millirem (.01 Gy) and about 5000 millirem (.05 Gy) over a period greater than 24 hours, or a localized dose of 15,000 millirem (0.15 Gy) to 50,000 millirem (0.5 Gy) over a period greater than 24 hours.
In the event of a terrorist attack releasing lethal amounts of radiation, radioprotective compositions described herein should provide protection when administered just after, e.g., up to about four hours after, exposure.

I. EXAMPLE STRUCTURAL GENUS
By "α,β unsaturated aryl sulfone" as used herein is meant a chemical compound containing one or more α,β unsaturated aryl sulfone groups:
^-O2S-HC=HC-Q2
α β
wherein Q2 is substituted or unsubstituted aryl, and the hydrogen atoms attached to the α and β carbons are optionally replaced by other chemical groups.
By "substituted" means that an atom or group of atoms has replaced hydrogen as the substituent attached to a ring atom. The degree of substitution in a ring system may be mono-, di-, tri- or higher substitution.
The term "aryl" employed alone or in combination with other terms, means, unless otherwise stated, a carbocyclic aromatic system containing one or more rings (typically one, two or three rings) wherein such rings may be attached together in a pendent manner or may be fused. Examples include phenyl; anthracyl; and naphthyl, particularly 1-naphthyl and 2-naphthyl. The aforementioned listing of aryl moieties is intended to be representative, not limiting. It is understood that the term "aryl" is not limited to ring systems with six members.
The term "heteroaryl" by itself or as part of another substituent means, unless otherwise stated, an unsubstituted or substituted, stable, mono- or multicyclic heterocyclic aromatic ring system which consists of carbon atoms and from one to four heteroatoms selected from the group consisting of N, O, and S, and wherein the nitrogen and sulfur heteroatoms may be optionally oxidized, and the nitrogen atom may be optionally quaternized. The heterocyclic system may be attached, unless otherwise stated, at any heteroatom or carbon atom which affords a stable structure.

Examples of such heteroaryls include benzimidazolyl, particularly 2-benzimidazolyl; benzofuryl, particularly 3-, 4-, 5-, 6- and 7-benzofuryl; 2-benzothiazolyl and 5-benzothiazolyl; benzothienyl, particularly 3-, 4-, 5-, 6-, and 7-benzothienyl; 4-(2-benzyloxazolyl); furyl, particularly 2- and 3-furyl; isoquinolyl, particularly 1- and 5-isoquinolyl; isoxazolyl, particularly 3-, 4- and 5-isoxazolyl; imidazolyl, particularly 2-, -4 and 5-imidazolyl; indolyl, particularly 3-, 4-, 5-, 6-and 7-indolyl; oxazolyl, particularly 2-, 4- and 5-oxazolyl; purinyl; pyrrolyl, particularly 2-pyrrolyl, 3-pyrrolyl; pyrazolyl, particularly 3- and 5-pyrazolyl;
pyrazinyl, particularly 2-pyrazinyl; pyridazinyl, particularly 3- and 4-pyridazinyl; pyridyl, particularly 2-, 3- and 4-pyridyl; pyrimidinyl, particularly 2- and 4-pyrimidyl; quinoxalinyl, particularly 2- and 5-quinoxalinyl; quinolinyl, particularly 2- and 3-quinolinyl; 5-tetrazolyl; 2-thiazolyl; particularly 2-thiazolyl, 4-thiazolyl and 5-thiazolyl; thienyl, particularly 2- and 3-thienyl; and 3-(l,2,4-triazolyl). The aforementioned listing of heteroaryl moieties is intended to be representative, not limiting.
According to one embodiment, the α,β unsaturated aryl sulfone group is a styryl sulfone group:

wherein the hydrogen atoms attached to the α and β carbons are optionally replaced by other chemical groups, and the phenyl ring is optionally substituted.
By "styryl sulfone" or "styryl sulfone compound" or "styryl sulfone therapeutic" as used herein is meant a chemical compound containing one or more such styryl sulfone groups.
The α,β unsaturated aryl sulfone radioprotective compounds are
characterized by cis-trans isomerism resulting from the presence of a double bond. Stearic relations around a double bond are designated as "Z" or "E". Both configurations are included in the scope of "α,β unsaturated aryl sulfone":



Z configuration
E configuration
According to one embodiment, the α,β unsaturated aryl sulfone compound is a compound of the formula I:

O
Il
Q1- (CH2JrT-S-CH=CH-Q2 ,
O
wherein:
n is one or zero;
Qi and Q2 are, same or different, are substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.
Preferably, n in formula I is one, that is, the compounds comprise α,β unsaturated benzylsulfones, e.g. styryl benzylsulfones.
In one preferred embodiment according to formula I, Qi and/or Q2 are selected from substituted and unsubstituted heteroaryl; for example, (E)-3-furanethenyl-2,4-dichlorobenzylsulfone.

In another preferred embodiment according to formula 1, Qi and Q2 are selected from substituted and unsubstituted phenyl.
Preferred compounds where Qi and Q2 are selected from substituted and unsubstituted phenyl comprise compounds of the formula II:
' o
Qi-CH2S=O Il
CH=CH
<J2a
wherein:
Qia and Q2a are independently selected from the group consisting of phenyl and mono-, di-, tri-, tetra- and penta-substituted phenyl where the substituents, which may be the same or different, are independently selected from the group consisting of hydrogen, halogen, C1-C8 alkyl, C1-C8 alkoxy, nitro, cyano, carboxy, hydroxy, phosphonato, amino, sulfamyl, acetoxy, dimethylamino(C2-C6 alkoxy), C1-C6 trifluoroalkoxy and trifluoromethyl.
In one embodiment, compounds of formula II are at least di-substituted on at least one ring, that is, at least two substituents on at least one ring are other than hydrogen. In another embodiment, compounds of formula II are at least
trisubstituted on at least one ring, that is, at least three substituents on at least one ring are other than hydrogen.
In one embodiment, the radioprotective compound has the formula III:


wherein Ri, R2, R3 and R4 are independently selected from the group consisting of hydrogen, halogen, C1-C8 alkyl, C1-C8 alkoxy, nitro, cyano, carboxy, hydroxy phosphonato, amino, sulfamyl, acetoxy, dimethylamino(C2-C6 alkoxy), C1-C6 trifluoroalkoxy and trifluoromethyl.
According to a particularly preferred embodiment of the invention, the radioprotective compound is according to formula III, and Ri and R2 are independently selected from the group consisting of hydrogen, halogen, cyano, and trifluoromethyl; and R3 and R4 are independently selected from the group consisting of hydrogen and halogen.
According to one sub-embodiment of formula III, the radioprotective α,β unsaturated aryl sulfone compound is a compound of the formula Ilia, wherein R2 and R4 are other than hydrogen:



Preferred compounds according to formula Ilia having the E-configuration include, but are not limited to, (E)-4-fluorostyryl-4-chlorobenzylsulfone; (E)-4-chlorostyryl-4-chlorobenzylsulfone; (E)-2-chloro-4-fluorostyryl-4-chlorobenzylsulfone; (E)-4-carboxystyryl-4-chlorobenzyl sulfone; (E)-4-fluorostyryl-2,4-dichlorobenzylsulfone; (E)-4-fluorostyryl-4-bromobenzylsulfone; (E)-4-chlorostyryl-4-bromobenzylsulfone; (E)-4-bromostyryl-4-chlorobenzylsulfone; (E)-4-fluorostyryl-4-trifluoromethylbenzylsulfone; (E)-4-fluorostyryl-3,4-dichlorobenzylsulfone; (E)-4-fluorostyryl-4-cyanobenzylsulfone; (E)-2,4-dichloro-4-chlorobenzylsulfone; (E)-4-fluorostyryl-4-chlorophenylsulfone and (E)-4-chlorostyryl-2,4-dichlorobenzylsulfone.
According to another embodiment, compounds of formula Ilia have the Z configuration wherein Ri and R3 are hydrogen, and R2 and R4 are selected from the group consisting of 4-halogen. Such compounds include, for example, (Z)-4-chlorostyryl-4-chlorobenzylsulfone; (Z)-4-chlorostyryl-4-fluorobenzylsulfone; (Z)-4-fluorostyryl-4-chlorobenzylsulfone; (Z)-4-bromostyryl-4-chlorobenzylsulfone; and (Z)-4-bromostyryl-4-fluorobenzylsulfone.
According to another embodiment, the radioprotective α,β unsaturated aryl sulfone compound is a compound of the formula IV:

IV

wherein
Ri, R2, R3, and R4 are independently selected from the group consisting of hydrogen, halogen, C 1-8 alkyl, C 1-8 alkoxy, nitro, cyano, carboxy, hydroxy, and trifluoromethyl.
In one embodiment, Ri in formula IV is selected from the group consisting of hydrogen, chlorine, fluorine and bromine; and R2, R3 and R4 are hydrogen. A preferred compound of formula IV is (Z)-styryl-(E)-2-methoxy-4-ethoxystyrylsulfone.
According to yet another embodiment, the radioprotective α,β unsaturated aryl sulfone compound is a compound of the formula V:
Cb o
I Il v
c Q5

wherein
Q3, Q4 and Q5 are independently selected from the group consisting of phenyl and mono-, di-, tri-, tetra- and penta-substituted phenyl where the substituents, which may be the same or different, are independently selected from the group consisting of halogen, C1-C8 alkyl, C1-C8 alkoxy, nitro, cyano, carboxy, hydroxy, phosphonato, amino, sulfamyl, acetoxy, dimethylamino(C2-C6 alkoxy), C1-C6 trifluoroalkoxy and trifluoromethyl.
According to one sub-embodiment of formula V, the radioprotective α,β unsaturated aryl sulfone compound is a compound of the formula Va:



wherein
Ri and R2 are independently selected from the group consisting of hydrogen, halogen, C1-C8 alkyl, C 1-8 alkoxy, nitro, cyano, carboxyl, hydroxyl, and trifluoromethyl; and R3 is selected from the group consisting of unsubstituted phenyl, mono-substituted phenyl and di-substituted phenyl, the substituents on the phenyl ring being independently selected from the group consisting of halogen and C 1-8 alkyl.

Preferably, Ri in formula Va is selected from the group consisting of fluorine and bromine; R2 is hydrogen; and R3 is selected from the group consisting of 2-chlorophenyl, 4-chlorophenyl, 4-fluorophenyl, and 2-nitrophenyl.
A preferred radioprotective styryl sulfone according to formula Va is the compound wherein Ri is fluorine, R2 is hydrogen and R3 is phenyl, that is, the compound 2-(phenylsulfonyl)- 1 -phenyl-3-(4-fluorophenyl)-2-propen- 1 -one.
By "dimethylamino(C2-C6 alkoxy)" is meant (CH3)2N(CH2)nO- wherein n is from 2 to 6. Preferably, n is 2 or 3. Most preferably, n is 2, that is, the group is the dimethylaminoethoxy group, that is, (CH3^NCH2CH2O-.
By "phosphonato" is meant the group -PO(OH)2.
By "sulfamyl" is meant the group -SO2NH2.
Where a substituent on an aryl nucleus is an alkoxy group, the carbon chain may be branched or straight, with straight being preferred. Preferably, the alkoxy groups comprise C1-C6 alkoxy, more preferably C1-C4 alkoxy, most preferably methoxy.
(E)-α,β unsaturated aryl sulfones may be prepared by Knoevenagel condensation of aromatic aldehydes with benzylsulfonyl acetic acids or arylsulfonyl acetic acids. The procedure is described by Reddy et al, Acta. Chim. Hung.
115:269-71 (1984); Reddy et al, Sulfur Letters 13:83-90 (1991); Reddy et al, Synthesis No. 4, 322-23 (1984); and Reddy et al, Sulfur Letters 7:43-48 (1987), the entire disclosures of which are incorporated herein by reference. See, particularly, the entire disclosures of U.S. Patent Nos. 6,656,973 and 6,667,346.
The α,β unsaturated aryl sulfones may take the form or pharmaceutically acceptable salts. The term "pharmaceutically acceptable salts" embraces salts commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically-acceptable.

Table 1: Example Compounds




In one exemplary emobodiment, α,β unsaturated aryl sulfone formula Ia:


wherein Qi and Q2 are, same or different, are substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl illustrated by Table 2 below.



Table 3



Polymorphs of all compounds disclosed and contemplated herein are intended to be within the scope of the claims appended hereto.

II. EXAMPLE SPECIES
An exemplary species of a radioprotective α,β unsaturated arylsulfone is ON.1210.Na. ON.1210.Na is a derivative of chlorobenzylsulfone. This and related compounds are described herein as exhibiting valuable prophylactic properties which mitigate the effects of accidental and intentional exposure to life-threatening levels of irradiation. Hence, a systematic development of this and related compounds is described with the objective of developing a shelf stable formulations.

Table 4 describes the general physical properties of ON.1210.Na. The example compound is a sodium salt of (E)-4-Carboxystyryl-4-chlorobenzylsulfone.

Table 4: Physical Properties of ON.1210.Na


The compound ON 01210.Na appears to form at least one polymorph. X-ray diffraction pattern, for example, of precipitated ON 01210.Na is different from that of the originally synthesized compound. Polymorphs of ON 01210.Na are intended to be within the scope of the claims appended hereto.
Treatment of normal human fibroblasts with ON 01210.Na, for example, prior to exposure to cytotoxic levels of ionizing radiation provides dose-dependent radio-protection.
The physio-chemical properties of ON.1210.Na, as an example drug substance, was determined in order to evaluate appropriate formulation approaches for development of a safe, reliable and effective parenteral formulation of these compounds. This includes microscopic studies, partition coefficient, pKa, pH solubility studies, pH stability studies under accelerated conditions, solid state characterization of the drug substance, and solid state stability of drug substance under accelerated conditions. See, section IV, infra. This example compound has a low octanol:water partition coefficient (1.28-2.87). The equilibrium solubility of the drug at pH 4.0, 5.0, 6.0, 7.4, 8.0, 9.0 was 0.000154, 0.0379, 0.715, 11.09, 16.81, 23.3 mg/mL, respectively. The pKa calculated from pH-solubility studies was 2.85 ± 0.6. The pH-stability profile of the drug indicated better stability at neutral and biological pH but degradation was rapid under acidic conditions. The degradation followed a pseudo-first-order rate. The accelerated solid-state stability study of the bulk drug substance showed no evidence of degradation. This drug is quite stable in an aqueous environment at biological pH. Therefore, it can be formulated as a shelf stable parenteral formulation. The aqueous solubility of the drug as the free acid is low and can be significantly enhanced by increase in pH, co-solvents and
complexation.

III. FORMULATIONS OF RADIOPROTECTANT α, β UNSATURATED
ARYL SULFONES
Although compositions described and contempated herein are not so limited, due to the oral, for example, bioavailability of the compounds upon administration, a preferred route of administration of the compositions described herein include, for example, parenteral administration. Parenteral administration includes intravenous, intramuscular, intraarterial, intraperitoneal, intravaginal, intravesical (e.g., into the bladder), intradermal, topical or subcutaneous administration. The α,β unsaturated aryl sulfone may be administered in the form of a pharmaceutical composition comprising one or more α,β unsaturated aryl sulfones in combination with a pharmaceutically acceptable carrier. The α,β unsaturated aryl sulfone in such formulations may comprise from 0.1 to 99.99 weight percent. By "pharmaceutically acceptable carrier" is meant any carrier, diluent or excipient which is compatible with the other ingredients of the formulation and is not deleterious to the subject.
The specific dose and schedule of α,β unsaturated aryl sulfone to obtain the radioprotective benefit will, of course, be determined by the particular
circumstances of the individual patient including, the size, weight, age and sex of the patient, the nature and stage of the disease being treated, the aggressiveness of the disease, and the route of administration, and the specific toxicity of the radiation. For example, a daily dosage of from about 0.01 to about 150 mg/kg/day may be utilized, more preferably from about 0.05 to about 50 mg/kg/day. Particularly preferred are doses from about 1.0 to about 10.0 mg/kg/day, for example, a dose of about 7.0 mg/kg/day. The dose may be given over multiple administrations, for example, two administrations of 3.5 mg/kg. Higher or lower doses are also contemplated.
For parenteral administration, the α,β unsaturated aryl sulfones may be mixed with a suitable carrier or diluent such as water, an oil, saline solution, aqueous dextrose (glucose) and related sugar solutions, cyclodextrins or a glycol such as propylene glycol or polyethylene glycol as described infra. Solutions for parenteral administration preferably contain a pharmaceutically acceptable, water soluble salt of the α,β unsaturated aryl sulfone. Stabilizing agents, antioxidizing agents, chelating agents, and preservatives, for example, may also be added.
Suitable antioxidizing agents include sulfite, ascorbic acid, citric acid and its salts, and sodium EDTA as a chelator, for example. Suitable preservatives include benzalkonium chloride, methyl- or propyl-paraben, and chlorbutanol.
Shelf-stable pharmaceutical compositions which comprise effective amount of at least one radioprotective α, β unsaturated aryl sulfone compound are described herein. The term "effective amount" of at least one radioprotective α, β unsaturated aryl sulfone compound, for example, as used herein refers to an amount of compound, after dilution as described infra, that is effective to mitigate, reduce or eliminate toxicity associated with radiation in normal cells of the subject and/or to impart a direct cytotoxic effect to abnormally proliferating cells in the subject. As used with respect to bone marrow purging, "effective amount of the radioprotective α,β unsaturated aryl sulfone compound" refers to an amount of at least one α,β unsaturated aryl sulfone effective to reduce or eliminate the toxicity associated with radiation in bone marrow removed from a subject and/or to impart a direct cytotoxic effect to malignant cells in the bone marrow removed from the subject. Each α,β unsaturated arylsulfone is administered, for example, in a concentration of about 0.25 micromolar to about 100 micromolar; preferably, from about 1.0 to about 50 micromolar; more preferably from about 2.0 to about 25 micromolar. Particularly preferred concentrations for administration are, for example, about 0.5, 1.0 and 2.5 micromolar and about 5, 10 and 20 micromolar. Higher or lower concentrations may also be used depending upon factors well known in the art.

The formulations described and claimed herein are generally intended for parenteral administration. Compositions of the present invention are generally formulated with active ingredient, e.g., one or more compounds described herein, in a concentrated form for storage and handling prior to dilution with suitable parenteral diluent prior to infusion. Preferred shelf-stable compositions of the present invention, for dilution prior to administration, generally comprise between about 10 mg/ml to about 150 mg/ml of at least one α, β unsaturated aryl sulfone.
A single dosage is generally within the range of about 1 ml to about 5 ml of any of the compositions described herein. Individual 3 ml dosages of compositions described herein are contemplated, for example. The dosages may be packaged, for example, in 5 ml vials. Compositions of the present invention may, for example, be diluted with about 7 parts diluent (7:1) prior to administration. However, the dilution factor and the diluent employed depend on the concentration of drug in the formulation. Compositions of the present invention, however, may be diluted with anywhere, for example, within the range of about 2 volumes of suitable parenteral diluent prior to infusion to about 12 volumes of suitable parenteral diluent, prior to administration.
Compositions of the present invention may be diluted, for example, for parenteral administration and should have a pH within the range of about 6.5 to about 10.0. Preferably the final diluted product for parenteral administration should have a pH within the range of about 7.0 to about 9.5 A diluted product pH of about 7.0 to about 8.0 is preferredThe osmolarity of the diluted formulation for parenteraladministration should be approximately within the range of about 200 to about 400 mθsm/kg. Preferred osmolarity of the diluted formulation for administration should be approximately within the range of about 270 to about 330 mOsm/kg. A preferred osmolarity of the diluted formulation for administration should be approximately 300 mOsm/kg.
Compositions described herein, unless specified otherwise, are preferrably aqueous-based; however, ethanol, for example, is also a preferred base-component of the formulations described herein.

Preferred compositions of the present invention comprise between about 5mg/ml to about 200 mg/ml of at least one α, β unsaturated aryl sulfone in an aqueous, for example, solution or suspension.

SOLUTIONS
Example compositions of the present invention comprise between about 20 mg/ml to about 150 mg/ml (e.g., about 25mg/ml, 50mg/ml, 75 mg/ml, 100 mg/ml, 125mg/ml, 150mg/ml) of at least one α, β unsaturated aryl sulfone (e.g., (E)-4-carboxystyryl-4-chlorobenzylsulfone sodium salt (ON.1210.Na)); wherein the composition exhibits a pH within the range of about 7 to about 10. A preferred pH, for example, is between about 8 and about 9, for example. About 8.5 is an example preferred pH (between about 8.4 and about 8.6). A pH between about 8.3 and about 8.7 is preferred, for example). A preferred buffer is Tris-EDTA, for example, which provides a good physiological buffering capacity at the pH of administration.
Exemplary compositions of the present invention described herein exhibit a final concentration of about 0.1M Tris and 0.0 IMEDTA. However, the Tris
concentration may be within a range of about 0.005 M to about 0.5 M (or about 0.005M to about 0.5M "Tris-EDTA", for example) to suit the conditions for administration. Any buffer known in the art to be suitable for for injectable formulations may be employed in these compositions of the present invention. Suitable buffering agents, for example, include phosphate buffers, for example, trisodium orthophosphate, disodium hydrogen phosphate, sodium bicarbonate, as well as sodium citrate, potassium citrate, N-methylglucamine, L(+) lysine, glycine and L(+) arginine provide good buffering capacity between about pH 7 - 9.5, for example.
An example solution composition of the present invention comprises an effective amount of at least one radioprotective α, β unsaturated aryl sulfone compound in a formulation which comprises between about lOmg/ml to about 100mg/ml of the compound (e.g., ON.1210.Na); at least one buffer selected from the group consisting of Tris-EDTA, sodium bicarbonate, sodium citrate, N-methylglucamine, L(+) lysine, glycine, L(+) arginine , and phosphate; a water- soluble cosolvent within the range of about 20% w/v to about 60% w/v; and, wherein the composition has a pH within the range of about 8 to about 9. An example composition of the present invention of this type comprises Tris-EDTA buffer within the range of about 0.005M-0.5M; PEG within the range of about 40% w/v to about 60% w/v; and, wherein the composition has a pH within the range of about 8.3 to about 8.7 A preferred example of this type comprises Tris-EDTA buffer within the range of about 0.1M to about 0.3M (e.g., 0.2M); PEG 400 within the range of about 40% w/v to about 60% w/v (e.g., 50% w/v); and, wherein the composition has a pH within the range of about 8.3 to about 8.7 (e.g., between about 8.4 and about 8.6).
An example composition of the present invention comprises about 20mg/mr to about 60mg/ml of the compound (ON.1210.Na); Tris-EDTA buffer within the range of about 0.15M to about 0.25M; PEG 400 within the range of about 45% w/v to about 55% w/v; and, wherein the composition has a pH within the range of about 8.4 to about 8.6, and the compound is substantially stable in the composition at about 250C for at least about 120 days.
Formulations described herein are preferred which have a pH within a range of about 7.5 to about 9.2. High pH, e.g., about 8.5, is preferred. Compositions are preferred that comprise between about 0.5% and about 90% of at least one cosolvent, e.g. at least about 10%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, and at least about 90%. The term "cosolvent", as used herein, includes but is not limited to water soluble excipients known in the art including polyethylene glycol (PEG) (e.g., PEG 400), polypropylene glycol, polyglycerol, DMA, propylene glycol, glycerol, ethanol, sorbitol, and isopropyl alcohol.
A preferred solution formulation of the present invention comprises Tris-EDTA buffer composed of Tris within the range of about 0.005M to about 0.5M and EDTA within the range of about 0.0005M to about 0.05M ; PEG within the range of about 40% w/v to about 60% w/v; and, wherein the composition has a pH within the range of about 8.3 to about 8.7. An exemplary composition comprises between about 20mg/ml to about 60mg/ml of the compound (ON.1210.Na); Tris-EDTA composed of Tris within the range of about 0.15M to about 0.25M and EDTA within the range of about 0.015M to about 0.025M; PEG 400 within the range of about 45% w/v to about 55% w/v; and, wherein the composition has a pH within the range of about 8.4 to about 8.6, and the compound is substantially stable in the
composition at about 250C for at least about 120 days.

SUSPENSIONS
Suspension formulations described herein are aqueous compositions wherein a portion of the drug is in solution while a remaining portion is in solid phase in the composition. The concentration of drug in the solution phase of the suspension depends on the final pH of the suspension. Higher the pH; higher will be the concentration of drug in the solution phase. At pH of about 8.5, the drug in the solution phase is at concentration of about 1 mg/ml. However, that concentration can be easily manipulated by the use of hydrophilic wetting agent in the suspension. For example: with reference to a solution formulation containing 0.2M TRIS-EDTA pH8.5 which has a drug concentration of 25 mg/ml, if Tween 80 is added, for example, to a concentration of about 1% and the drug concentration is increased beyond 50 mg/ml then we would have a suspension. In other words, we can easily manipulate the drug concentration in the solution phase from 0.1 mg/ml to about 50 mg/ml, for example.
The present invention is accordingly directed to compositions for administration for reducing toxic effects of ionizing radiation in a subject, comprising an effective amount of at least one radioprotective α, β unsaturated aryl sulfone, and a) at least one hydrophilic wetting agent, e.g., a biocompatible surfactant known in the art which can be injected subcutaneously, having an HLB value between about 6 to about 17, (e.g., within the range of about 8 to aboutl4), b) a biological buffer known in the art which effects a pH between about 4.5 and about 10, and c) a component known in the art to effect the isotonicity of the formulation. One aspect of the present invention, for example, include compositions which comprise a viscosity-adjusting agent (a suspending agent), biocompatible and suitable for parenteral administration, in the range of about from 0.1 to about 5%. This concentration can be easily adjusted by one of ordinary skill in the art using the host of cosolvents described herein.
Suspension compositions described herein generally comprise at least one radioprotective α, β unsaturated aryl sulfone at a concentration of about 3mg/ml to about 500mg/ml. Preferred compositions described herein comprise at least one radioprotective α, β unsaturated aryl sulfone at a concentration of about 10mg/ml to about 250mg/ml. Other preferred compositions described herein comprise at least one radioprotective α, β unsaturated aryl sulfone at a concentration of about

10mg/ml to about 250mg/ml. Example embodiments of suspension compositions described herein comprise between about 25 mg/ml to about 75 mg/ml of at least one radioprotective α, β unsaturated aryl sulfone. An example suspension embodiment comprises about 50 mg/ml of at least one radioprotective α, β unsaturated aryl sulfone.
Preferred example pharmaceutical compositions of the present invention comprise between about 20 mg/ml to about 100 mg/ml, e.g., 25mg/ml, 50mg/ml, 75mg/ml, lOOmg/ml, of the compound ON.1210.Na ((E)-4-Carboxystyryl-4-chlorobenzylsulfone, sodium salt (Ci6Hi2ClNaO4S)).
Tween 80, for example, may be used in the formulation as a wetting agent.

However, any other pharmaceutically acceptable hydrophilic wetting agent may be employed in compositions of the present invention. Particularly preferred is any surfactant with an HLB value between 8 - 14. Preferred surfactants are
biocompatable surfactants well known in the art which can be injected
subcutaneously, including but not limited to Tween 20, Tween 40, Tween 60, and the like well known in the art. A more complete list of these type components is described infra. The amount of Tween 80, for example, could vary in compositions described herein from 0.01 to 5%. A preferred concentration is about 1%.
Hydrophilic wetting agents include Sorbitan monopalmitate (Span 40), Sorbitan monolaurate (Span 20), Polyoxyethylene sorbitan tristearate, (Tween 65),
Polyoxyethylene sorbitan trioleate, (Tween 85), Polyethylene glycol 400, Polysorbate 60, NF, (Tween 60), Polyoxyethylene monostearate, Polysorbate 80, NF, (Tween 80), Polysorbate 40, NF, (Tween 40), Polysorbate 20, NF, (Tween 20). The pH of formulations described herein are generally between about 4.5 to about 10. The preferred pH is between about 7.0 and about 10. The proper selection of specific formulation pH depends on the tolerability at the local site of injection and the desired maximum plasma concentration (higher the pH - the greater is the Cmax). A preferred pH, for example, is between about 8 and about 9, for example. About 8.5 is an example preferred pH (between about 8.4 and about 8.6). A pH between about 8.3 and about 8.7 is preferred, for example.
An exemplary suspension pharmaceutical composition, for administration for reducing toxic effects of ionizing radiation in a subject, comprises an effective amount of at least one radioprotective α, β unsaturated aryl sulfone and at least one at least one hydrophilic wetting agent having an HLB value between about 6 and about 17 in an amount between about 0.5% w/v and about 60% w/v, an agent to effect isotonicity; and, wherein the composition exhibits a pH between about 7.5 and about 9.5.
A preferred buffer is phosphate , e.g., potassium phosphate, KH2PO4, for example, which provides a good buffering capacity at the pH of administration. However, any suitable biological buffer may be used, for example, glycine, Tris-glycine, phosphate buffers, which preferably provides good buffering capacity between about pH 7 - 9.5, for example.
Another exemplary suspension formulation of the present invention comprises between about 20mg/ml to about 150mg/ml of at least one radioprotective α, β unsaturated aryl sulfone and at least one hydrophilic wetting agent in an amount between about 1% w/v and about 50% w/v selected from the group consisting of Sorbitan monopalmitate (Span 40), Sorbitan monolaurate (Span 20),
Polyoxyethylene sorbitan tristearate, (Tween 65), Polyoxyethylene sorbitan trioleate, (Tween 85), Polyethylene glycol 400, Polysorbate 60, NF, (Tween 60), Polyoxyethylene monostearate, Polysorbate 80, NF, (Tween 80), Polysorbate 40, NF, (Tween 40), Polysorbate 20, NF, (Tween 20) , an agent to effect isotonicity selected from the group consisting of NaCl and manitol; and, a buffer selected from the group consisting of potassium phosphate, trisodium orthophosphate, disodium hydrogen phosphate, sodium bicarbonate, as well as sodium citrate, potassium citrate, N-methylglucamine, L(+) lysine, glycine and L(+) arginine wherein the composition exhibits a pH between about 7.5 and about 9.5.
The isotonicity of the formulation vehicle is preferably adjusted by sodium chloride. However, mannitol could also be used or potassium chloride, for example. Indeed, any suitable pharmaceutical agent known in the art as a proper excipient in the industry may be used to adjust the isotonicity of compositions described herein. The viscosity of the formulation, for example, may be adjusted using a suitable suspending agent, for example carboxy methyl cellulose or any of the similar excipients well known in the art. See, e.g., Handbook of Pharmaceutical Excipients, for example. The suspending agent will be biocompatible and suitable for parenteral administration. The concentration of the suspending agent could vary from 0.1 to 5%. The preferred amount is in the range of about 1%.
Another example embodiment of a suspension formulation comprises the sodium salt of (E)-4-carboxystyryl-4-chlorobenzylsulfone (ON.1210.Na) in an amount between about 20mg/ml and about 75mg/ml, the buffer is potassium phosphate, the isotonicity agent is NaCl, and the hydrophilic wetting agent is tween 80 in an amount of about 1% w/v; and, wherein the composition exhibits a pH between about 8 and about 8.6.
Further identified and disclosed herein is the fact that the half life of α, β unsaturated aryl sulfones, ON.1210.Na, for example, increases significantly when the route of administration is changed to intramuscular (in contrast to intravenous), and increases even further upon subcutaneous administration. When, ON.1210.Na, for example, is administered as a suspension described herein the half life of the drug is on the order of 30-40 hours depending on the specific formulation and its viscosity. This dramatic increase in half-life translates to prolonged exposure to drug over a period of 72 hours and beyond. This increase is possible because of an apparent low dissolution rate of drug from the site of administration.

ALTERNATE ELEMENTS FOR CURRENT FORMULATIONS
The term "water soluble polymer", as used herein, for use in alternate formulations of the present invention includes but is not limited to water soluble polymer excipients known in the art including poly-oxyethylene, poly-oxyethylene-poly-oxypropylene copolymer, polyvinylalcohol, polyvinylpyrrolidone (PVP)

(Povidone (soluble homopolymer of N-vinyl-2-pyrrolidone)), polyvinylpyridine N-oxide, copolymer of vinylpyridine N-oxide and vinylpyridine, and the like, as well as derivatives thereof, and combinations thereof. Poly-oxyethylene and/or poly-oxyethylene-poly-oxypropylene copolymers are example water-soluble polymers for use in alternate formulations of the present invention. Poloxamer 407 (e.g., Pluronic F 127, Lμtrol® micro 127). for example, and/or Poloxamer 188 (e.g., Pluronic F 68, Lμtrol® micro 68) are poly-oxyethylene-poly-oxypropylene copolymers that can be used independently or in combination in formulations of the present invention. BASF Corporation, Mount Olive, NJ.
Polyethylene glycols (PEGs) are preferred water soluble polymers. Low molecular weight liquid polyethylene glycols, for example, PEG 300, PEG 400, PEG 600, and PEG 800, are preferred water soluble polymers that can be used independently or in combination with each other, for example, in formulations of the present invention. Particularly preferred are PEG 300, PEG 400, and PEG 600. Lutrol® E 300. Lutrol® E 400 and Lutrol® E 600. for example, are commercially available from BASF Corporation, Mount Olive, NJ. PEG 400 (Polyethylene glycol 400, Macrogol 400, PEG 400, Poly(oxy- 1 ,2-ethanediyl),alpha-hydro-omega-hydroxy- (CAS No: 25322-68-3)), e.g., Lutrol® E 400. is preferred. Example water soluble polymers selected from the group consisting essentially of PEG 300, PEG 400, PEG 600, and PEG 800 are preferred. Although not specifically listed here PEG products substantially the same, otherwise within this characteristic range of PEG entities, may be employed in compositions of the present invention.
Low molecular weight povidone grades (CAS No: 9003-39-8), Kollidon® 12 PF and Kollidon® 17 PF. for example, form a soluble complex between the compounds and povidone. Both products are available as pyrogen-free powders, suitable for use in injectables, from BASF Corporation, Mount Olive, NJ.

Kollidon® 12 PF, Kollidon® 17 PF, Kollidon® 25, Kollidon® 30, and Kollidon® 90 F are preferred examples of povidone. Compositions of the present invention are exemplified herein that comprise Povidone K 90, for example, at concentrations of about 1% to about 5% in water. These compositions are further contemplated, for example, that comprise Povidone K 90, for example, at concentrations of about 0.5% to about 10% in water. Low molecular weight Povidones, for example, may be employed at much higher concentrations in compositions of the present invention, e.g., between about 5% by weight and about 40%. A preferred range is between about 5% to about 20% by weight, depending on the viscosity of the formulation.
Chemically Modified Cyclodextrins are example components of
compositions described herein. Cyclodextrin drug compositions described herein are easily diluted, for example, eliminating the need for elaborate mixing procedures. Chemically modified cyclodextrin, hydroxypropyl-b-cyclodextrin, for example, formulations are preferred for parenteral administration due to the ability to of the cyclodextrins to solubilize and stabilize the compounds described herein as well as the superior safety profile exhibited by the chemically modified
cyclodextrins. The use of cyclodextrins referred to herein can reduce dosing volume and in situ irritation resulting from high pH, for example, other solvents, or any direct chemical irritancy due to the compounds otherwise described herein.
Many different chemical moieties may be introduced into the Cyclodextrin molecule by reaction with the hydroxyl groups lining the upper and lower ridges of the toroid; for example, hydroxypropyl, carboxymethyl, and acetyl. Since each Cyclodextrin hydroxyl groups differs in its chemical reactivity, reaction processes produces an amorphous mixture of thousands of positional and optical isomers. Preferred examples of chemically modified cyclodextrins as components of formulations of the present invention include, but are not limited to, 2-hydroxypropyl-beta-Cyclodextrin, 2-hydroxypropyl-gamma-Cyclodextrin, and hydroxyethyl-beta-Cyclodextrin. Cyclodextrin molecules (alpha, beta, or gamma) can have up to 3(n) substituents, where n is the number of glucopyranose units of the Cyclodextrin molecule. This is referred to as the degree of substitution (DS).

The DS refers to substituents other than hydrogen; substituents may be all of one kind or mixed. Non-integer degrees of substitution occur as weighted averages are used to describe substitutional variability. See, e.g., Volume 3 (cyclodextrins) of the 11 Volume Collection "Comprehensive Supramolecular Chemistry", available through Elsevier Science Inc., 660 White Plains road, Tarrytown, N. Y., 10591-5153 USA. See, also, Pitha, Josef, U.S. Patent No. 4,727,064, Pharmaceutical
Preparations Containing Cyclodextrin Derivatives; Muller, B. W., U.S. Patent No. 4,764,604, Derivatives of Gamma Cyclodextrins; Yoshida, A., et al., (1988) Int. Pharm, Vol. 46, p. 217: Pharmaceutical Evaluation Of Hydroxy Alkyl Ethers OfB-Cyclodextrins; Muller, B. W., (1986). J. Pharm Sci. 75, No 6, June 1986:
Hydroxypropyl-B-Cyclodextrin Derivatives: Influence Of Average Degree Of Substitution On Complexing Ability And Surface Activity; Irie, T., et ah, (1988) Pharm Res., No 11, p. 713: Amorphous Water- Soluble Cyclodextrin Derivatives: 2-hydroxy ethyl, 3-hydroxypropyl, 2-hyroxyisobutyl, and carboxamidomethyl derivatives of B-cyclodextrin.
Hydroxypropyl-B-Cyclodextrin (hydroxypropyl cyclodextrin) (HPCD) is itself very soluble in water (greater than 500 mg/ml at room temperature). Dr. Joseph Pitha of the NIH has experimentally evaluated many of the uses of this cyclodextrin derivative and found that it can be conveniently applied to cell cultures and membrane preparations. It is also observed that HPCD is non-toxic after IP and IV administration to different rodent species. The maximum human dose of HPCD given parenterally was approximately 500 mg/kg iv given continuously as a 5 percent aqueous solution to one individual for four days; no adverse clinical effects were reported. Pitha, Josef, et al, (1988) Life Sciences. 43, No 6, 493-502: Drug Solubilizers To Aid Pharmacologists: Amorphous Cyclodextrin Derivatives.
Compounds described herein may be formulated in compositions which generally comprise an effective amount of at least one α, β unsaturated aryl sulfone, water, and at least one chemically modified cyclodextrin. Embodiments of formulations of the present invention are preferred which comprise about 5% to about 90% w/v chemically modified cyclodextrin(s) and have a pH within the range of about 6.8 to about 9.6. Formulations described herein are preferred which have a pH within a range of about 7.6 to about 9.2. High pH, e.g., about 8 to about 9, or higher, is preferred. Particularly preferred compositions for the present invention comprise about 20% to about 60% w/v chemically modified cyclodextrin(s).
Example compositions for the present invention comprise about 30% to about 50% w/v chemically modified cyclodextrin(s). An example composition of the present invention comprises at least one chemically modified cyclodextrin selected from the group consisting of 2-hydroxypropyl-beta-Cyclodextrin, 2-hydroxypropyl-gamma-Cyclodextrin, and hydroxyethyl-beta-Cyclodextrin, preferably in an amount of about 30% to about 50% w/v, an effective amount of at least one α, β unsaturated aryl sulfone, e.g., (E)-4-carboxystyryl-4-chlorobenzylsulfone sodium salt (ON.1210.Na), and water. 2-hydroxypropyl-beta-Cyclodextrin, (Hydroxypropyl-B-Cyclodextrin) (hydroxypropyl cyclodextrin) (HPCD) is a preferred chemically modified cyclodextrin for use in compositions of the present invention. Shelf-stable aqueous compositions for the present invention, for dilution prior to parenteral administration for the protection of normal cells from toxicity of ionizing radiation or to mitigate the effects of accidental/intentional exposure to life-threatening levels of irradiation, comprise, for example, an effective amount of at least one α, β unsaturated aryl sulfone, and about 35% to about 45% (e.g., about 40% w/v) w/v chemically modified cyclodextrin.
Preferred shelf-stable compositions of the present invention, for dilution prior to administration, comprise between about 10 mg/ml to about 100 mg/ml of at least one α, β unsaturated aryl sulfone. Particularly preferred compositions of the present invention comprise between about 20 mg/ml to about 80 mg/ml of at least one α, β unsaturated aryl sulfone. Example compositions of the present invention comprise between about 20 mg/ml to about 75 mg/ml (e.g., about 25mg/ml , 50mg/ml, 75mg/ml) of at least one α, β unsaturated aryl sulfone (e.g., (E)-4-carboxystyryl-4-chlorobenzylsulfone sodium salt (ON.1210.Na)); and, wherein the composition has a pH within the range of about 7.5 to about 9 (e.g., about 8.5).
Preferred formulations described and claimed herein have significantly increased the solubility of radioprotective α, β unsaturated aryl sulfones,
ON.1210.Na, for example, to allow concentrated formulations of the present invention, wherein upon dilution, the drug is physically stable for at least about 24 hours.

IV. FORMULATION STUDIES
ON.1210.Na, a sodium salt of a chlorobenzylsulphone, is an example of an efficacious radiation protectant drug. ON.1210.Na is particularly shown to protect during life-threatening levels of radiation exposure. Described herein are shelf stable parenteral formulations of this and related compounds for therapeutic administration to patients.
A stability indicating HPLC assay is used during the preformulation studies.

Preformulation studies include determination of microscopic and macroscopic properties, partition coefficient, pKa, pH-solubility, pH-stability, solid-state characterization and solid-state stability. XRD and thermal analyses re used to characterize the solid and solid-state stability. The solid-state stability as well as the pH stability of the drug is carried out at 750C.
Microscopic and XRD data reveals that the drug is crystalline having an irregular plate like crystals. The drug has a low octanol:water partition coefficient (1.28-2.87). The equilibrium solubility of the drug at pH 4.0, 5.0, 6.0, 7.4, 8.0, 9.0 is 0.000154, 0.0379, 0.715, 11.09, 16.81, 23.3 mg/mL, respectively. The pKa calculated from a pH-solubility study is 2.85 ± 0.6. The pH-stability profile of the drug indicats better stability at neutral and biological pH but degradation is rapid under acidic condition. The degradation followed a first-order rate. The accelerated solid-state stability of the bulk drug substance shows no evidence of degradation.
The solubility of the drug can be significantly increased with increase in pH.

Also, the stability of the drug can be enhanced by buffering the aqueous solutions around pH 7. The drug is quite stable in an aqueous environment rendering itself for the development of a shelf stable formulation.



Table 6: Effect of Dilution on Solubility in different ON.1210.Na Formulations



A study was conducted to develop and validate a stability indicating sensitive HPLC assay for ON.1210.Na for preformulation and formulation
development. The isocratic system uses a mobile phase consisting of
Acetonitrile:0.1% Trifluoroacetic acid in water (60:40 v:v) at a flow rate of 1 mL/min. A C- 18 Gemini column (250 x 4.6 mm) is used and effluents are monitored at a 254 nm. Forced degradation is carried out by exposing ON.1210.Na to 0.1N HCl, 0.1N NaOH and 3% (v/v) hydrogen peroxide. The validation parameters include linearity, specificity, sensitivity, precision and accuracy.
Standard curves are linear in the concentration range of 0-500 μg/mL. The retention times of the drug and several degradation products were well within seven minutes. The Relative Standard Deviation (RSD) values for the within-day and day-to-day precision range from 0.4 to 2.5 % and 2.2 to 4.4 %, respectively. The RSD for accuracy measurement ranges from 0.85 to 1.7%. The critical level, the detection level and the determination level for this assay are 2.86 ± 0.67 μg/mL, 5.69 ± 0.67 μg/mL and 15.6 ± 1.79 μg/mL, respectively.
A sensitive and stability indicating HPLC method is developed and validated for ON.1210.Na. The force degradation, preformulation and formulation studies demonstrate the suitability of this method.
The first step in this process is the development of a stability indicating

HPLC assay. The next phase is the validation of the assay. This HPLC assay is able to support preformulation, formulation development, and the stability studies of the bulk drug and formulated ON.1210.Na, for example.

Stability of the ON.1210.Na (solid)
A solid drug sample (ONl 210), after autoclaving in a crimped vial, is also evaluated for any degradation using the developed HPLC method. The sample, after autoclaving, is used to make a standard solution of 400 μg/mL and injected onto HPLC. The results indicate no reduction in the Area Under the Curve (AUC) of the parent peak, and also no additional peaks are detected. Based on this observation, it seems that the bulk drug ON.1210.Na is stable under the autoclaving conditions.

Solid-State Stability of ON.1210.Na
The stability of ON.1210.Na in the solid state is determined by exposing the drug at 75°C over a prolonged time. The sample is crimped in a 10 mL injection vial and kept at the above temperature. The sample is collected after 15 days and one month and reconstituted with diluting solution and its concentration is
determined by HPLC. Appearance of any additional peak in the chromatogram is also noted. A control sample is represented by ON.1210.Na not exposed to 750C and reconstituted to a known concentration with diluting solution. The results of this study are depicted in Table 7.

Table 7: Solid-State Stability of ON.1210.Na at 750C



The solid state stability data shows that there is a slight increase in potency of the

10 compound as a function of time at 750C. This is probably due to the loss of moisture present in the sample. This was confirmed by determining the moisture content of the bulk ON.1210.Na. The result shows that there is about 14.5% of moisture in the sample which equates to 3 moles of water per mole of ON.1210.Na. The
chromatograms showed no evidence of degradation of the sample.
15
Thermal Analyses
A differential scanning calorimeter (DSC) (model DSC-50, Shimadzu,
Kyoto, Japan) and a thermogravimetric analyzer (TGA) (model TGA-50, Shimadzu, Kyoto, Japan) are connected to a thermal analysis operating system (TA-50WS,

20 Shimadzu, Kyoto, Japan). The heat of fusion is calibrated using indium (purity
99.99%; mp 156.4; ΔH 6.8 mcal/mg). The sample to be analyzed (5-10 mg) by
DSC is crimped nonhermetically in an aluminum pan and heated from 30 to 4000C at a rate of 10°C/min under a stream of nitrogen (flow rate of 20 rnL/min). For the thermogravimetric analysis (TGA), approximately 10 mg of the sample is weighed

25 into aluminum pans and heated from 30 to 4000C at a heating rate of 10°C/min under nitrogen purge. The DSC thermogram indicates two thermal events: (i) an endothermic peak at 500C possible due to desolvation or dehydration. This is further supported by the TGA thermogram which also indicates a weight loss exactly at the same temperature range, and (ii) the exothermic peak at 36O0C probably due to the melting of the drug with decomposition.

Powder X-Ray Diffraction Studies
The samples free acid (ON.1210), the salt (ON.1210.Na) and the precipitated sample from filtered saturated ON.1210.Na solution kept at refrigerated condition are analyzed using Siemens powder X Ray diffractometer under ambient conditions. The scan range (2Θ) is from 5° to 40° (Step scan, step size of 0.05°, with a dwell time of 1 second).

Table 8: Peak Search Report for ON.1210 Acid
Peak Search Report (21 Peaks, Max P/N = 6.7)
PEAK: 11-pts/Parabolic Filter, Threshold^ 3.0, Cutoff=0.1%, BG=3/1.0, Peak- Top=Summit


Table 9: Peak Search Report for ON.1210 Na (13 Peaks, Max P/N = 10.6)

PEAK: 11-pts/Parabolic Filter, Threshold^ .0, Cutoff=0.1%, BG=3/1.0, Peak- Top=Summit



Figure clearly shows that the sodium salt of ON.1210 is a crystalline material.

Characterization of Precipitate
The sodium salt has a tendency to form a supersaturated solution in water, Upon storage, the solution starts showing some precipitate. The precipitate is isolated, dried and characterized by HPLC, DSC, TGA and XRPD.
The precipitate is dissolved in acetonitrile water mixture and analyzed by HPLC. The precipitate elutes at the same time as the standard of ON.1210.Na suggesting that the precipitate is of ON.1210.
The precipitate is further characterized by DSC. A thermogram of the precipitate does not show the transition around 5O0C as is seen with the ON.1210.Na standard. However, it does show the same melting / decomposition around 36O0C.

The precipitate is further characterized by XRPD. The diffractogram shows most of the peaks that are observed with ON.1210.Na except the one observed at 8.815.

Table 10: Peak search report of precipitated sample
Peak Search Report (6 Peaks, Max P/N = 10.9)
PEAK: 11-pts/Parabolic Filter, Threshold=3.0, Cutoff=0.1%, BG=3/1.0, Peak- Top=Summit


In conclusion, this drug, e.g., ON.1210.Na, is surprisingly demonstrated to be quite stable in an aqueous environment at biological pH. Therefore, it can be formulated as an efficacious shelf stable parenteral formulation. We have further discovered that the aqueous solubility of the drug is low and can be enhanced by increased pH, cosolvents and, by formation of inclusion complex.
Related compounds include, but are not limited to (E)-4-fluorostyryl-4- chlorobenzylsulfone; (E)4-chlorostyryl-4-chlorobenzylsulfone; (E)-2-chloro-4- fluorostyryl-4-chlorobenzylsulfone; (E)-4-carboxystyryl-4-chlorobenzyl sulfone; (E)-4-fluorostyryl-2,4-dichlorobenzylsulfone; (E)-4-fluorostyryl-4- bromobenzylsulfone; (E)-4-chlorostyryl-4-bromobenzylsulfone; (E)-4-bromostyryl- 4-chlorobenzylsulfone; (E)-4-fluorostyryl-4-trifluoromethylbenzylsulfone; (E)-4- fluorostyryl-3,4-dichlorobenzylsulfone; (E)-4-fluorostyryl-4-cyanobenzylsulfone; (E)-2,4-dichloro-4-chlorobenzylsulfone; and (E)-4-chlorostyryl-2,4- dichlorobenzylsulfone.
Related compounds include, but are not limited to (Z)-4-chlorostyryl-4- chlorobenzylsulfone; (Z)-4-chlorostyryl-4-fluorobenzylsulfone; (Z)-4-fluorostyryl- 4-chlorobenzylsulfone; (Z)-4-bromostyryl-4-chlorobenzylsulfone; and (Z)-4- bromostyryl-4-fluorobenzylsulfone.
All related compounds disclosed, contemplated, or exemplified in U.S. Patent No.6,656,973, including but not limited to synthesis examples 1-219, are herein incorporated by reference.

EXAMPLES
EXAMPLE I
Preparation of ON.1210.Na salt
4-Chlorobenzyl-4-carboxystyryl sulfone (ON 01210) (49 g; 0.145 mol) was taken in a one-liter conical flask and 500 ml of distilled water was added. Sodium hydroxide solution (16 ml: 10 M stock) ( 0.150 mol.) was added to the conical flask. The contents of the flask were then boiled with stirring till ON.01210 was completely dissolved. The solution was then cooled to room temperature and shining crystals separated were filtered through a fluted filter paper. The crystalline material was dried under vacuum to yield (48 g) (92% yield) of pure ON.1210.Na.

EXAMPLE II
Radioprotective Effects of α,β-Unsaturated Arylsulfones on Cultured
Normal Cells
The radioprotective effects of the compounds in Table 11 below on cultured normal cells were evaluated as follows.
HFL- 1 cells, which are normal diploid lung fibroblasts, were plated into 24 well dishes at a cell density of 3000 cells per 10 mm2 in DMEM completed with 10% fetal bovine serum and antibiotics. The test compounds listed in Table 11 were added to the cells 24 hours later in select concentrations from 2.5 to 20 micromolar, inclusive, using DMSO as a solvent. Control cells were treated with DMSO alone. The cells were exposed to the test compound or DMSO for 24 hrs. The cells were then irradiated with either 10 Gy (gray) or 15 Gy of ionizing radiation (IR) using a J.L. Shepherd Mark I, Model 30-1 Irradiator equipped with 137cesium as a source.
After irradiation, the medium on the test and control cells was removed and replaced with fresh growth medium without the test compounds or DMSO. The irradiated cells were incubated for 96 hours and duplicate wells were trypsinized and replated onto 100 mm2 tissue culture dishes. The replated cells were grown under normal conditions with one change of fresh medium for 3 weeks. The number of colonies from each 100 mm2 culture dish, which represents the number of surviving cells, was determined by staining the dishes as described below.

To visualize and count the colonies derived from the clonal outgrowth of individual radioprotected cells, the medium was removed and the plates were washed one time with room temperature phosphate buffered saline. The cells were stained with a 1 :10 diluted Modified Giemsa staining solution (Sigma) for 20 minutes. The stain was removed, and the plates were washed with tap water. The plates were air dried, the number of colonies from each plate were counted and the average from duplicate plates was determined.
The results are presented in Table 11. A "+" indicates radioprotective activity of between 2- and 4.5-fold at the concentrations tested. Fold protection was determined by dividing the average number of colonies from the test plates by the average number of colonies on the control plates.

Table 11: Radioprotection by α,β-Unsaturated Arylsulfones


EXAMPLE III
Protection of Mice from Radiation Toxicity by Pre-Treatment With (E)- 4-Carboxystyryl-4-ChlorobenzylsuIfone
C57 black mice age 10-12 weeks (Taconic) were divided into two treatment groups of 10 mice each. One group, designated the "200x2" group, received intraperitoneal injections of 200 micrograms (E)-4-carboxystyryl-4-chlorobenzylsulfone dissolved in DMSO (a 10 mg/Kg dose, based on 20 g mice) 18 and 6 hours before irradiation with 8 Gy gamma radiation. The other group, designated "500x2," received intraperitoneal injections of 500 micrograms (E)-4-carboxystyryl-4-chlorobenzylsulfone dissolved in DMSO (a 25 mg/Kg dose, based on 20 g mice) 18 and 6 hours before irradiation with 8 Gy gamma radiation. A control group of 16 animals received 8 Gy gamma radiation alone. Mortality of control and experimental groups was assessed for 40 days after irradiation, and the results are shown in FIG.5.
By day 20 post-irradiation, the control mice exhibited a maximum mortality rate of 80%; the 8 Gy dose of gamma radiation is thus considered an LDgo dose. By contrast, only about 50% of the "200x2" group and about 30% of the "500x2" mice were dead at day 20 after receiving the LD80 radiation dose. By day 40, a maximum mortality rate of approximately 60% was reached in the "200x2" group, and a maximum mortality rate of approximately 50% was reached in the "500x2" group. These data show that radiation toxicity in mice is significantly reduced by pre-treatment with (E)-4-carboxystyryl-4-chlorobenzylsulfone.

EXAMPLE IV
Radioprotective Effect of (E)-4-Carboxystyryl-4-chlorobenzylsulfone in

Mice When Given After Radiation Exposure
C57 B6/J mice age 10-12 weeks (Taconic) were divided into two treatment groups of 10 and 9 mice, respectively. One group, designated the "200x2" group, received intraperitoneal injections of 200 micrograms (E)-4-carboxystyryl-4-chlorobenzylsulfone dissolved in DMSO (a 10 mg/Kg dose, assuming 20 g mice) 18 and 6 hours before irradiation with 8 Gy gamma radiation. The other group, designated "200 Post," received an intraperitoneal injection of 200 micrograms (E)- 4-carboxystyryl-4-chlorobenzylsulfone dissolved in DMSO (a 10 mg/Kg dose, based on 20 g mice) 15 minutes after irradiation with 8 Gy gamma radiation. A control group of 16 animals received 8 Gy gamma radiation alone. Mortality of control and experimental groups was assessed for 40 days after irradiation, and the results are shown in FIG.6.
FIG.6 shows that treatment of mice with (E)-4-carboxystyryl-4-chlorobenzylsulfone after irradiation resulted in significant delay in radiation-induced mortality as compared with the control animals. While the radioprotection afforded by post-irradiation treatment is not as great as seen with pre-irradiation treatment, (E)-4-carboxystyryl-4-chlorobenzylsulfone is nonetheless effective in mitigating the effects of radiation toxicity after the subject has received the radiation dose.

EXAMPLE V
Formulation of 25mg/ml ON.1210.Na ((E)-4-Carboxystyryl-4- chlorobenzylsulfone sodium salt

12.114 g Tromethamine (0.1M) and 2.9224 g EDTA (0.01 M) are in 0.5 L deionized water. To that solution 500 ml of PEG 400 is added and stirred constantly till the pH is equilibrated. The pH of the final solution is adjusted using either HCl / NaOH to 7.8.
To the above vehicle enough ON01210 Na is added to obtain the final concentration of 25 mg/ml. The pH of the formulation is adjusted with either HCl or NaOH to obtain the final pH of 8.5.

EXAMPLE VI
The formulation prepared in example V was monitored for its physical stability. The physical stability of the formulation was compared with a similar formulation prepared in water, and that prepared using phosphate buffer.5
(All formulations are 1 : 1 w/buffer: PEG400 (see, e.g., Example V)) Table 12

EXAMPLE VII
Example Suspension Formulation
IL 50mg/mL ON.1210.Na suspension

13.609g KH2PO4
8.766g NaCl
10mL Tween 80
50g ONl 210.Na
and qs to IL with D.I. water.

The suspension is then mixed by stirring and pH is adjusted to 8.2 and stirred overnight. The pH is checked the following day (it decreases overnight) and is readjusted to ph8.2. Continue this process untill the pH stabilizes.

All publications and patents referred to herein are incorporated by reference.

Various modifications and variations of the described subject matter will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it should be understood that the invention as claimed should not be unduly limited to these embodiments. Indeed, various modifications for carrying out the invention are obvious to those skilled in the art and are intended to be within the scope of the following claims.