US 20020019417 A1
This invention relates to methods of preventing, treating or lessening verity of gout by administration of PARP inhibitors.
1. A method for treating gout in an animal comprising the step of administering an effective amount of a PARP inhibitor compound to said animal.
2. The method of
3. The method of
4. A method of preventing urate crystal-induced neutrophil recruitment in a mammal comprising administering a PARP inhibitor to said mammal.
 The present invention relates to methods of treating gout with inhibitors of the nuclear enzyme poly(adenosine 5′-diphospho-ribose) polymerase [“poly(ADP-ribose) polymerase” or “PARP”, which is also referred to as ADPRT (NAD:protein (ADP-ribosyl transferase (polymersing)) and PARS (poly(ADP-ribose) synthetase) and provides compounds and compositions containing the disclosed compounds for use in the disclosed method.
 Reviews of PARP as well as the effects of inhibiting the same may be found, for example, in PCT/US98/18184, PCT/US98/18226, PCT/US98/18187, PCT/US98/18195, PCT/US98/18196, PCT/US98/18188, PCT/US98/18189, PCT/US98/18185, PCT/US98/18186, the entire contents of each of which are hereby incorporated by reference.
 Deposition of crystals of monosodium urate (MSU crystals) in the joint articular space is the etiological cause of inflammatory pathologies such as gout and pseudogout. Clinically, these inflammatory diseases are associated with oedema and erythema of the joints with consequently severe pain. A strong infiltration of leucocytes in the intraarticular and periarticular space leading to: 1) acute, episodic articular and periarticular inflammation, and 2) chronic articular changes, are also characteristic of this pathology. It has long been clear that neutrophils are the predominant d cell type recovered from these inflammatory joints (Dieppe et al., (1979). Synovial fluid crystals. Q. J. Med. XLVIII: 533-553; Terkletaub, (1991). Monocyte-derived neutrophil chemotactic factor/interleukin-8 is a potential mediator of crystal-induced inflammation. Arth. Rheum. 34: 894-903.). A better understanding of the inflammatory processes elicited by MSU crystals, and the fact that there is a clear relationship between these crystals and gouty arthritis, has prompted the characterisation of experimental models of crystal-induced inflammation. Examples of models where crystal challenge has led to cell recruitment into specific cavities, are canine joints (Phelps & McCarty, 1966, Ann Int. Med. 9: 115-125), rat pleurisy (Deporter et al., 1979, Br. J. Pharmacol. 65: 163-165; Sedgwick et al., 1985, Agents Actions 17: 209-213), and utilisation of a pre-formed rat air-pouch (Brookes et al., 1987). The latter experimental system has shown that neutrophil accumulation was related to generation of chemoattractants such as LTB4, which was subsequently inhibited by colchicine (Brooks et al., 1987, Br. J. Pharmacol. 90: 413-419).
 Neutrophils have been shown to be activated by MSU crystals, releasing an array of mediators that may be, in part, responsible for the local and systemic inflammatory manifestations found in crystal-induced joint disorders. The crystals interact with neutrophils leading to the release of lysomal enzymes (Hoffstein et al., 1975, Arth. Rheum. 18: 153-165), release of oxygen derived free radicals (Sirnchowitz et al., 1982, Arth. Rheum. 25: 181-188; Abramson et al., 1982, Arthr Rheum. 25: 174-180), induction of phospholipase A2 (PLA2) in leucocytes (Bomalaski et al., 1990, J. Immunol. 145: 3391-3397), and activation of synthesis of 5-lipoxygenase products (Poubelle et al., 1987, Biochem. Biophys. Res. Commun. 149: 649-657).
 In vitro, MSU crystals have been shown to release the cytokine interleukin-1β (IL-1β) from human neutrophils, adding this stimulus to a list of others that also release this cytokine, such as zymosan, LPS, phorbol esters, granulocyte macrophage-colony stimulating hormone (GM-CSF) and TNF-alpha. Furthermore it has also been shown that human monocytes and synoviocytes can synthesise and release various cytokines such as IL-6 and IL-8 (Guerne et al., 1989, Arth. Rheum. 32: 1443-1452; Terkeltaub et al., 1991, Arth. Rheum. 34: 894-903). In addition, colchicine selectively inhibits MSU crystal- and TNF-═induced release of IL-1β. (Roberge et al., 1994, J. Immunol. 152: 5485-5494).
 In experimental models of gout the synthesis of a CXC chemokine selective for neutrophils, such as IL-8, has also been observed, but not that of a CC chemokine monocyte chemoattractant protein-1 (MCP-1) (Hachicha et al., 1995, J. Exp. Med. 182: 2019-2025). These results suggest that production of IL-8 and abolition of the release of MCP-1, will lead to an event where, theoretically there will be a recruitment of neutrophils but not mononuclear cells. This hypothesis is in accordance with the pathological state of gout and pseudogout, where the predominant inflammatory cell is the neutrophil (Hachicha et al., 1995). In addition MSU crystal activation of mononuclear phagocytes, which are normally found in the joint space, also induces secretion of IL-8 (Terkeltaub et al., 1991). The importance of IL-8 in this pathology has been shown in synovial fluids of patients with acute gouty arthritis where it occurs in elevated amounts (Terkeltaub et al., 1991; di Giovine et al., 1991, J. Clin. Invest. 87: 1375-1381). The use of a neutralising antibody against IL-8 has been shown significantly to attenuate the crystal induced joint swelling at 12 h and neutrophil infiltration into arthritic joints at 12 and 24 h in a rabbit model (Nishimura et al., 1997, J. Leukoc. Biol. 62: 444-449).
 These studies demonstrate the importance of both the emigrating neutrophil and the chemokine IL-8, as well as the release of this and other cytokines from resident cells such as the synoviocytes, macrophages and mast cells in treating gout. Since neutrophils are not present or are extremely rare in normal synovial fluid, enhanced neutrophil-endothelial adhesion is necessary for gout to occur (Terkeltaub, 1996, In. Koopman, W. J. editor. Arthritis and allied conditions: a textbook of rheumatology. Baltimore: Williams and Wilkins: pp. 2085-2102, and Terkeltaub, 1992, In Inflammation. Basic Principles and Clinical Correlates, ed. by J. I.Gallin, I. M. Goldstein and R. Snyderman, pp 977-981, Raven Press, New York). IL-1β and TNF-alpha may be critical in mediating the rapid up-regulation of the major endothelial ligand for neutrophils. For instance rapid and prolonged expression of E-selectin in response to injection of urate crystals has been demonstrated in pig skin (Chapman et al., 1996, Br. J. Rheumatol. 35: 323-334). The release of cytokines, chemokines and products of the arachidonic acid cascade system lead to the recruitment of neutrophils in this pathology, and inhibition of these leads to an attenuation of the pathology.
 The following gout model was used to test a PARP inhibitor according to the present invention.
 Male outbread Swiss albino mice (20-22 g body weight) were purchased from Banton and Kingsman (T.O. strain; Hull, Humberside) and maintained on a standard chow pellet diet with tap water ad libitum and a 12:00 h light/dark cycle. All animals were housed for 1 week prior to experimentation to allow body weight to reach 28-30 g.
 1, 11b-dihydrobenzopyrano[4,3,2-de ] isoquinolin-1-one was dissolved in 100% DMSO at room temperature at a concentration of 45 mg in 2 ml. The compound was then injected into the peritoneal cavity, so as each mouse received a single dose corresponding to 45 mg/2 ml/kg (e.g. 60 μl for a mouse of 30 g). Control mice received DMSO at 2 ml/kg i.p. A third group of mice which were left untreated were added to control for potential effects of the vehicle. The study involved therefore, the following three groups: group A, untreated mice, n=6, group B, DMSO-treated mice, n=8, and group C, mice treated with 1,11b-dihydrobenzopyrano[4,3,2-de ]isoquinolin-1-one, n=8
 MSU crystal-induced neutrophil recruitment was tested as follows. In all cases, mice were treated 1 h after the treatment noted above, with MSU crystals. A homogenous suspension of MSU crystals was obtained by a 30 min rotation. Peritonitis was induced by injection of 3 mg MSU crystals in 0.5 ml PBS (0.1 M, pH 7.4), and the recruitment of neutrophils into the cavity evaluated at the 6 h time point (Getting et al., 1997, J. Pharmacol. Exp. Ther. 283: 123-130). Animals were then euthanised by CO2 exposure and the peritoneal cavity washed with 3 ml of PBS supplemented with 3 mM EDTA and 25 U/ml heparin.
 An aliquot (100 μl) of the lavage fluid was then diluted 1:10 in Turk's solution (0.01% crystal violet in 3% acetic acid). The samples were then vortexed and 10 μl of the stained cell solution were placed in a Neubauer haematocymometer and neutrophils numbers counted using a light microscope (Olympus B061). Cell-free supernatants have been prepared by centrifugation and stored for potential future analysis.
 Data are shown for single mice, and also shown as mean ± S.E. of (n) mice per group. Statistical differences were determined by ANOVA, plus Bonferroni test. A P value<0.05 was taken as significant.
 TABLE I reports the number of neutrophils as measured 6 h post-MSU crystal injection in the three experimental groups.
 TABLE II illustrates these data as mean ± S.E. It can be seen that DMSO produced a modest not significant increase in cell migration (+7%). In contrast, the exemplary compound of the present invention , at the dose of 45 mg/kg, significantly reduced cell influx, with a calculated 55% of inhibition vs. the vehicle group.
 The above results demonstrate the ability of a PARP inhibitor to prevent neutrophil recruitment in response to MSU crystal-induced, or urate crystal-induced, activation, within the present invention.
 The present invention therefore, provides a method of preventing, treating and/or lessening the severity of leukocyte, specifically neutrophil, recruitment in response to urate crystals and, more generally, provides a method of preventing, treating and/or lessening the severity of gout.
 Compounds useful in the present invention include PARP inhibitors disclosed and methods of making the same in any of PCT/US98/18184, PCT/US98/18226, PCT/US98/18187, PCT/US98/18195, PCT/US98/18196, PCT/US98/18188, PCT/US98/18189, PCT/US98/18185, PCT/US98/18186, and U.S. application Nos. 08/922520, 09/079513, 09/145179, 09/079508, 09/145166, 09/079507, 09/145177, 09/145180, 09/079509, 09/079510, 09/145184, 09/079511, 09/145185, 08/922548, 09/145181, 09/147502, 09/219843, 08/922575, 09/079512, 09/145176, 09/079514, 09/145178, 09/224293, 09/224294 and 09/387767, the entire contents of each of which are hereby incorporated by reference.
 Further PARP inhibitor compounds which will be useful in the methods of the present invention include compounds of the following general formula shown below and derivatives thereof, with specific exemplary compounds (the entire contents of each noted reference is hereby incorporated by reference for specific compounds and methods of making the same):
 Benzamide and substituted benzamide (as described, for example, in U.S. Pat. No. 5,587,384)
 specific examples include:
 Benzoxazole-4-carboxamide (as described, for example, in EP 0879820)
 specific examples include:
 2-phenylbenzoxazole-4-carboxamide (NU1051),
 2-(4-methoxyphenyl) benzoxazole-4-carboxamide (NU1054), and
 2-methylbenzoxazole-4-carboxamide (NU1056).
 Quinazolin-4-[3H]one (as described, for example, in EP 0897915)
 specific examples include:
 8-hydroxy-2-phenylquinazolin-4-[3H]one, and
 3,4-Dihydro-1(2H)-isoquinolinone and 1(2H)-isoquinolinone (as described, for example, in U.S. Pat. No.5,177,075)
 specific examples include:
 3,4-Dihydro-1(2H) -isoquinolinone,
 5-(Acetyloxy)-3,4-dihydro-1(2H) -isoquinolinone and
 1,6-Naphthyridine-5(6H)-one(as described, for example, in U.S. Pat. No. 5,391,554)
 specific examples include:
 7-Methyl-1,6-Naphthyridine-5(6H)-one and
 5 7,8-Dihydro-1,6-Naphthyridine-5(6H)-one.
 6(5H)phenanthridinone (as described in the above-identified applications)
 specific examples include:
 2-amino-10-hydroxy-6(5H)phenanthridinone and those shown below.
 8-Carbamoylnaphthalenecarboxylic acid derivatives (as described in the above-identified applications) and specific examples provided below.
 Specific examples of these derivatives include the following:
 [de]-fused isoquinolin-1-one (as described in the above-identified applications) and specific examples provided below
 The following are specific examples of these derivatives:
 Lactam fused xanthene (as described in the above-identified applications) and specific examples provided below (wherein, for example Y may be CH, CH2 or N)
 Substituted xanthene lactam (as described in the above-identified applications) and specific examples provided below
 Further specific examples of useful inhibitors include:
 5-amino-3,4-dihydro-1(2H)-isoquinolinone and its monohydrochloride salt,
 5-ethyl-3, 4-dihydro-1(2H)-isoquinolinone,
 3,4-dihydro-5-(dimethylamino)-1(2H)-isoquinolinone and its hydrochloride salt,
 3,4-dihydro-5-[2-(1-piperidinyl) ethoxy-]1(2H)-isoquinolinone,
 phthalhydrazide (1,4-dioxo-1,2,3,4-tetrahydrophthalazine, also known as 2,3-dihydro-1,4-phthalazinedione),
 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol),
 1,11b-dihydrobenzopyrano[4,3,2-de ]isoquinolin-1-one,
 N-hydroxynaphthalimide sodium salt, and
 the pharmacologically acceptable base or acid addition salts thereof.
 Other compounds useful in the present invention include compounds of the following formula:
 wherein Z is any of the following:
 Further compounds useful in the present invention include the following, with reference to the following structure:
 Also included as useful compounds in the present methods are the pharmaceutically acceptable salts, hydrates, esters, solvates, prodrugs, metabolites, and stereoisomers of the compounds and derivatives described herein.
 The methods of the present invention may be administered to a mammal, such as a human, locally and/or systemically. The compounds of the present invention may be administered, for example, parenterally, either by intermittent or continuous intravenous administration, by either a single dose or a series of divided doses. Compounds of the invention may be used in combination or sequentially. The compound of the invention can be administered by intermittent or continuous administration via implantation of a biocompatible, biodegradable polymeric matrix delivery system containing a compound described herein, or via a subdural pump inserted to administer the compound directly to the site of gout symptoms. Alternatively, a compound of the present invention may be administered topically, through a patch or other transdermal delivery system to the site of gout symptoms.
 Preferably, the compounds of the invention exhibit an IC50 for inhibiting PARP in vitro, as measured by the methods described herein, of about 20 μM or less, preferably less than about 10 μM, more preferably less than about 1 μM, or less than 0.1 μM, most preferably less than about 0.01 μM
 The compounds of-the invention are useful in a free base form, in the form of pharmaceutically acceptable salts, pharmaceutically acceptable hydrates, pharmaceutically acceptable esters, pharmaceutically acceptable solvates, pharmaceutically acceptable prodrugs, pharmaceutically acceptable metabolites, and in the form of pharmaceutically acceptable stereoisomers. These forms are all within the scope of the invention. In practice, the use of these forms amounts to use of the neutral compound.
 “Pharmaceutically acceptable salt”, “hydrate”, “ester” or “solvate” refers to a salt, hydrate, ester, or solvate of the inventive compounds which possesses the desired pharmacological activity and which is neither biologically nor otherwise undesirable. Organic acids can be used to produce salts, hydrates, esters, or solvates such as acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, p-toluenesulfonate, bisulfate, sulfamate, sulfate, naphthylate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentane-propionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, hemisulfate heptanoate, hexanoate, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, tosylate and undecanoate. Inorganic acids can be used to produce salts, hydrates, esters, or solvates such as hydrochloride, hydrobromide, hydroiodide, and thiocyanate.
 Examples of suitable base salts, hydrates, esters, or solvates include hydroxides, carbonates, and bicarbonates of ammonia, alkali metal salts such as sodium, lithium and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, aluminum salts, and zinc salts.
 Salts, hydrates, esters, or solvates may also be formed with organic bases. Organic bases suitable for the formation of pharmaceutically acceptable base addition salts, hydrates, esters, or solvates of the compounds of the present invention include those that are non-toxic and strong enough to form such salts, hydrates, esters, or solvates. For purposes of illustration, the class of such organic bases may include mono-, di-, and trialkylamines, such as methylamine, dimethylamine, triethylamine and dicyclohexylamine; mono-, di- or trihydroxyalkylamines, such as mono-, di-, and triethanolamine; amino acids, such as arginine and lysine; guanidine; N-methyl-glucosamine; N-methyl-glucamine; L-glutamine; N-methyl-piperazine; morpholine; ethylenediamine; N-benzyl-phenethylamine; (trihydroxy-methyl)aminoethane; and the like. See, for example, “Pharmaceutical Salts,” J. Pharm. Sci., 66:1, 1-19 (1977). Accordingly, basic nitrogen-containing groups can be quaternized with agents including: lower alkyl halides such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates such as dimethyl, diethyl, dibutyl and diamyl sulfates; long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides; and aralkyl halides such as benzyl and phenethyl bromides.
 The acid addition salts, hydrates, esters, or solvates of the basic compounds may be prepared either by dissolving the free base of a PARP inhibitor of the present invention in an aqueous or an aqueous alcohol solution or other suitable solvent containing the appropriate acid or base, and isolating the salt by evaporating the solution. Alternatively, the free base of the PARP inhibitor of the present invention can be reacted with an acid, as well as reacting the PARP inhibitor having an acid group thereon with a base, such that the reactions are in an organic solvent, in which case the salt separates directly or can be obtained by concentrating the solution.
 “Pharmaceutically acceptable prodrug” refers to a derivative of the inventive compounds which undergoes biotransformation prior to exhibiting its pharmacological effect(s). The prodrug is formulated with the objective(s) of improved chemical stability, improved patient acceptance and compliance, improved bioavailability, prolonged duration of action, improved organ selectivity, improved formulation (e.g., increased hydrosolubility), and/or decreased side effects (e.g., toxicity). The prodrug can be readily prepared from the inventive compounds using methods known in the art, such as those described by Burger's Medicinal Chemistry and Drug Chemistry, Fifth Ed., Vol. 1, pp. 172-178, 949-982 (1995). For example, the inventive compounds can be transformed into prodrugs by converting one or more of the hydroxy or carboxy groups into esters.
 “Pharmaceutically acceptable metabolite” refers to drugs that have undergone a metabolic transformation. After entry into the body, most drugs are substrates for chemical reactions that may change their physical properties and biologic effects. These metabolic conversions, which usually affect the polarity of the compound, alter the way in which drugs are distributed in and excreted from the body. However, in some cases, metabolism of a drug is required for therapeutic effect. For example, anticancer drugs of the antimetabolite class must be converted to their active forms after they have been transported into a cancer cell. Since most drugs undergo metabolic transformation of some kind, the biochemical reactions that play a role in drug metabolism may be numerous and diverse. The main site of drug metabolism is the liver, although other tissues may also participate.
 The term “treating” refers to:
 (i) preventing a disease, disorder or condition from occurring in an animal that may be predisposed to the disease, disorder and/or condition, but has not yet been diagnosed as having it;
 (ii) inhibiting the disease, disorder or condition, i.e., arresting its development; and
 (iii) relieving the disease, disorder or condition, i.e., causing regression of the disease, disorder and/or condition.
 A feature characteristic of many of these transformations is that the metabolic products are more polar than the parent drugs, although a polar drug does sometimes yield a less polar product. Substances with high lipid/water partition coefficients, which pass easily across membranes, also diffuse back readily from tubular urine through the renal tubular cells into the plasma. Thus, such substances tend to have a low renal clearance and a long persistence in the body. If a drug is metabolized to a more polar compound, one with a lower partition coefficient, its tubular reabsorption will be greatly reduced. Moreover, the specific secretory mechanisms for anions and cations in the proximal renal tubules and in the parenchymal liver cells operate upon highly polar substances.
 As a specific example, phenacetin (acetophenetidin) and acetanilide are both mild analgesic and antipyretic agents, but are each transformed within the body to a more polar and more effective metabolite, p-hydroxyacetanilid (acetaminophen), which is widely used today. When a dose of acetanilid is given to a person, the successive metabolites peak and decay in the plasma sequentially. During the first hour, acetanilid is the principal plasma component. In the second hour, as the acetanilid level falls, the metabolite acetaminophen concentration reaches a peak. Finally, after a few hours, the principal plasma component is a further metabolite that is inert and can be excreted from the body. Thus, the plasma concentrations of one or more metabolites, as well as the drug itself, can be pharmacologically important.
 The reactions involved in drug metabolism are often classified into two groups, as shown in the Table II. Phase I (or functionalization) reactions generally consist of (1) oxidative and reductive reactions that alter and create new functional groups and (2) hydrolytic reactions that cleave esters and amides to release masked functional groups. These changes are usually in the direction of increased polarity.
 Phase II reactions are conjugation reactions in which the drug, or often a metabolite of the drug, is coupled to an endogenous substrate, such as glucuronic acid, acetic acid, or sulfuric acid.
 The compounds of the present invention exhibit pharmacological activity and are, therefore, useful as pharmaceuticals. In particular, the compounds exhibit central nervous and cardiac vesicular system activity. It is understood that tautomeric forms, when possible, are included in the invention.
 Many of the PARP inhibitors are known and, thus, can be synthesized by known methods from starting materials that are known, may be available commercially, or may be prepared by methods used to prepare corresponding compounds in the literature. See, for example, Suto et al., “Dihydroiso-quinolinones: The Design and Synthesis of a New Series of Potent Inhibitors of Poly(ADP-ribose) Polymerase”, Anticancer Drug Des., 6:107-17 (1991), which discloses processes for synthesizing a number of different PARP inhibitors. Further processes for synthesizing compounds useful in the methods of the present invention are described in the above-noted international and U.S. patent applications.
 Typically, the PARP inhibitors used in the composition of the invention will have an IC50 for inhibiting poly(ADP-ribose) polymerase in vitro of about 20 μM or less, preferably less than about 10 μM, more preferably less than about 1 μM, or preferably less than about 0.1 μM, most preferably less than about 0.01 μM.
 The compounds of the present invention may be useful in the free base form, in the form of base salts where possible, and in the form of addition salts, as well as in the free acid form. All these forms are within the scope of this invention. In practice, use of the salt form amounts to use of the base form. Pharmaceutically acceptable salts within the scope of this invention are those derived from mineral acids such as hydrochloric acid and sulfuric acid; and organic acids such as ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and the like, giving the hydrochloride, sulfonate, ethanesulfonate, benzenesulfonate, p-toluene-sulfonate, and the like respectively, or those derived from bases such as suitable organic and inorganic bases. Examples of pharmaceutically acceptable base addition salts with compounds of the present invention include organic bases which are nontoxic and strong enough to form such salts. These organic bases and the use thereof are readily understood by those skilled in the art. Merely for the purpose of illustration, such organic bases may include mono-, di-, and trialkylamines, such as methylamine, diethylamine and triethylamine; mono-, di-, or trihydroxyalkylamines such as mono-, di-, and triethanolamine; amino acids such as arginine, and lysine; guanidine; N-methylglucosamine; N-methylgiucamine; L-glutamine; N-methylpiperazine; morpholine; ethylenedianane; N-benzylphenethylamine; tris(hydroxymethyl)antinoethane; and the like.
 The acid addition salts of the basic compounds may he prepared by dissolving the free base of the compounds of the present invention in aqueous or aqueous alcohol solution or other suitable solvents containing the appropriate acid or base and isolating the salt by evaporating the solution, or by reacting the free base of a compound of the present invention with an acid as well as reacting a compound of the present invention having an acid group thereon with a base such that the reactions are in an organic solvent, in which case the salt separates directly or can be obtained by concentration of the solution.
 The compounds of this invention contain one or more asymmetric carbon atoms. Therefore, the invention includes the individual stereoisomers and mixtures thereof as well as the racemic compounds. The individual isomers may be prepared or isolated by methods known in the art.
 The term “pharmaceutically acceptable carrier” as used herein refers to any carrier, diluent, excipient, suspending agent, lubricating agent, adjuvant, vehicle, delivery system, emulsifier, disintegrant, absorbent, preservative, surfactant, colorant, flavorant, or sweetener.
 For these purposes, the composition of the invention may be administered orally, parenterally, by inhalation spray, adsorption, absorption, topically, rectally, nasally, bucally, vaginally, intraventricularly, via an implanted reservoir in dosage formulations containing conventional non-toxic pharmaceutically-acceptable carriers, or by any other convenient dosage form. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal, and intracranial injection or infusion techniques.
 When administered parenterally, the composition will normally be in a unit dosage, sterile injectable form (solution, suspension or emulsion) which is preferably isotonic with the blood of the recipient with a pharmaceutically acceptable carrier. Examples of such sterile injectable forms are sterile injectable aqueous or oleaginous suspensions. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable forms may also be sterile injectable solutions or suspensions in non-toxic parenterally-acceptable diluents or solvents, for example, as solutions in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, saline, Ringer's solution, dextrose solution, isotonic sodium chloride solution, and Hanks' solution. In addition, sterile, fixed oils are conventionally employed as solvents or suspending mediums. For this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides, corn, cottonseed, peanut, and sesame oil. Fatty acids such as ethyl oleate, isopropyl myristate, and oleic acid and its glyceride derivatives, including olive oil and castor oil, especially in their polyoxyethylated versions, are useful in the preparation of injectables. These oil solutions or suspensions may also contain long-chain alcohol diluents or dispersants.
 Sterile saline is a preferred carrier, and the compounds are often sufficiently water soluble to be made up as a solution for all foreseeable needs. The carrier may contain minor amounts of additives, such as substances that enhance solubility, isotonicity, and chemical stability, e.g., anti-oxidants, buffers and preservatives.
 Formulations suitable for nasal or buccal administration (such as self-propelling powder dispensing formulations) may comprise about 0.1% to about 5% w/w, for example 1% w/w of active ingredient. The formulations for human medical use of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredient(s).
 When administered orally, the composition will usually be formulated into unit dosage forms such as tablets, cachets, powder, granules, beads, chewable lozenges, capsules, liquids, aqueous suspensions or solutions, or similar dosage forms, using conventional equipment and techniques known in the art. Such formulations typically include a solid, semisolid, or liquid carrier. Exemplary carriers include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, mineral oil, cocoa butter, oil of theobroma, alginates, tragacanth, gelatin, syrup, methyl cellulose, polyoxyethylene sorbitan monolaurate, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate, and the like.
 The composition of the invention is preferably administered as a capsule or tablet containing a single or divided dose of the inhibitor. Preferably, the composition is administered as a sterile solution, suspension, or emulsion, in a single or divided dose. Tablets may contain carriers such as lactose and corn starch, and/or lubricating agents such as magnesium stearate. Capsules may contain diluents including lactose and dried corn starch.
 A tablet may be made by compressing or molding the active ingredient optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, surface active, or dispersing agent. Molded tablets may be made by molding in a suitable machine, a mixture of the powdered active ingredient and a suitable carrier moistened with an inert liquid diluent.
 The compounds of this invention may also be administered rectally in the form of suppositories. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at room temperature, but liquid at rectal temperature, and, therefore, will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax, and polyethylene glycols.
 Compositions and methods of the invention also may utilize controlled release technology. Thus, for example, the inventive compounds may be incorporated into a hydrophobic polymer matrix for controlled release over a period of days. The composition of the invention may then be molded into a solid implant, or externally applied patch, suitable for providing efficacious concentrations of the PARP inhibitors over a prolonged period of time without the need for frequent re-dosing. Such controlled release films are well known to the art. Particularly preferred are transdermal delivery systems. Other examples of polymers commonly employed for this purpose that may be used in the present invention include nondegradable ethylene-vinyl acetate copolymer an degradable lactic acid-glycolic acid copolymers which may be used externally or internally. Certain hydrogels such as poly(hydroxyethylmethacrylate) or poly(vinylalcohol) also may be useful, but for shorter release cycles than the other polymer release systems, such as those mentioned above.
 In a preferred embodiment, the carrier is a solid biodegradable polymer or mixture of biodegradable polymers with appropriate time release characteristics and release kinetics. The composition of the invention may then be molded into a solid implant suitable for providing efficacious concentrations of the compounds of the invention over a prolonged period of time without the need for frequent re-dosing. The composition of the present invention can be incorporated into the biodegradable polymer or polymer mixture in any suitable manner known to one of ordinary skill in the art and may form a homogeneous matrix with the biodegradable polymer, or may be encapsulated in some way within the polymer, or may be molded into a solid implant.
 In one embodiment, the biodegradable polymer or polymer mixture is used to form a soft “depot” containing the pharmaceutical composition of the present invention that can be administered as a flowable liquid, for example, by injection, but which remains sufficiently viscous to maintain the pharmaceutical composition within the localized area around the injection site. The degradation time of the depot so formed can be varied from several days to a few years, depending upon the polymer selected and its molecular weight. By using a polymer composition in injectable form, even the need to make an incision may be eliminated. In any event, a flexible or flowable delivery “depot” will adjust to the shape of the space it occupies with the body with a minimum of trauma to surrounding tissues. The pharmaceutical composition of the present invention is used in amounts that are therapeutically effective, and may depend upon the desired release profile, the concentration of the pharmaceutical composition required for the sensitizing effect, and the length of time that the pharmaceutical composition has to be released for treatment.
 The PARP inhibitors are used in the composition in amounts that are therapeutically effective. The compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, welling, or emulsifying agents, solution promoters, salts for regulating the osmotic pressure, and/or buffers. In addition, they may also contain other therapeutically valuable substances. The compositions are prepared according to conventional mixing, granulating, or coating methods, and contain about 0.1 to 75% by weight, preferably about 1 to 50% by weight, of the active ingredient.
 Doses of the compounds preferably include pharmaceutical dosage units comprising an efficacious quantity of active compound. By an efficacious quantity is meant a quantity sufficient to inhibit PARP and derive its beneficial effects through administration of one or more of the pharmaceutical dosage units. Preferably, the dose is sufficient to prevent or reduce the effects of vascular stroke or other neurodegenerative diseases.
 For medical use, the amount required of the active ingredient to achieve a therapeutic effect will vary with the particular compound, the route of administration, the mammal under treatment, and the particular disorder or disease being treated. A suitable systematic dose of a compound of the present invention or a pharmacologically acceptable salt thereof for a mammal suffering from, or likely to suffer from, any of condition as described hereinbefore is in the range of about 0.1 mg/kg to about 100 mg/kg of the active ingredient compound, the most preferred dosage being about 1 to about 10 mg/kg.
 It is understood, however, that a specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the severity of the particular disease being treated and form of administration.
 It is understood that the ordinarily skilled physician or veterinarian will readily determine and prescribe the effective amount of the compound for prophylactic or therapeutic treatment of the condition for which treatment is administered. In so proceeding, the physician or veterinarian could employ an intravenous bolus followed by an intravenous infusion and repeated administrations, parenterally or orally, as considered appropriate. While it is possible for an active ingredient to be administered alone, it is preferable to present it as a formulation.
 When preparing dosage form incorporating the compositions of the invention, the compounds may also be blended with conventional excipients such as binders, including gelatin, pregelatinized starch, and the like; lubricants, such as hydrogenated vegetable oil, stearic acid, and the like; diluents, such as lactose, mannose, and sucrose; disintegrants, such as carboxymethylcellulose and sodium starch glycolate; suspending agents, such as povidone, polyvinyl alcohol, and the like; absorbants, such as silicon dioxide; preservatives, such as methylparaben, propylparaben, and sodium benzoate; surfactants, such as sodium lauryl sulfate, polysorbate 80, and the like; colorants such as F.D.& C. dyes and lakes; flavorants; and sweeteners.
 The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims. All references cited herein are incorporated in their entirety by reference herein.