MXPA01006436A - Triazineone compounds for treating diseases due to sarcosystis, neospora and toxoplasma - Google Patents

Abstract

Disclosed herein are methods of treating therapeutically, or metaphylactically infectedanimals susceptible to, or infected animal suffering from parasitic neurologic or abortigenic diseases due to i(Sarcocystis), i(Neospora) or i(Toxoplasma) that are treatable with triazineone compounds by administering thereto a pharmaceutically effective amount of the compound, including a single high dose therapeutic treatment.

Description

COMPOUNDS OF TRIAZINONE FOR THE TREATMENT OF DISEASES DUE TO SARCOSYSTIS, NEOSPORA AND TOXOPLASMA BACKGROUND OF THE INVENTION Field of the Invention: The present invention relates to triazine compounds for the treatment of animals infected with parasites that cause abortive or neurological diseases. More specifically, the present invention relates to triazinone compounds which are useful in the treatment of parasitic protozoa such as coccidia which cause abortive or neurological diseases. Brief Description of the Prior Art: Triazinone compounds such as triazindiones, for example, the compounds of diclazuril, and triazintriones, for example, toltrazuril compounds, have been used in the treatment and protection of various mammals, insects and fish diseases caused by a wide range of pro-tozoos. See U.S. Patents: 4,933,341; 4,935,423; 5,114,938; 5,141,938; 5,188,832; 5,196,562; 5,526,631 and 5,464,837. Protozoa sensitive to these compounds infect birds, mammals and insects and manifest themselves as diarrhea, exhaustion, nausea and vomiting. Generally, the mode of action of the triazinones is to attack the intermediate phases of the parasite found in the cells of the digestive tract and the intestinal walls, causing the endoplasmic reticulum, the perinuclear space and the mitochondria of the parasite to swell. This significantly alters the capacity for nuclear divisions causing the sizontes ("shizonts") and the micro-gamontes ("microgamonts") to become scarce forming only a few merozoites and microgametes respectively. It is stated that the final result is the loss of capacity of these last phases of the parasites to cross new mammalian cells, effectively stopping the replication of the parasite in the host. Of particular interest here are certain protozoa suspected of causing neurological and / or abortive animal diseases since the 1970s. It has been experienced that successful isolation and cultivation in vi tro of any of these protozoa is difficult. For example, successful isolation from the brain or cerebro-spinal fluid was not achieved until the late 1980s. Once it was determined that the neurological diseases could be caused by certain parasites that infected the brain and that the abortive diseases could be produced by certain parasites that infected the fetuses, it became imperative the need for effective anti-parasitic drugs that could cross the blood-brain barrier and the placental barrier without producing harmful side effects. Many of the drugs known in the art that can cross the blood-brain barrier and / or the placental barrier to effectively treat parasitic brain infections have such harmful side effects that they can not be used without great risk. Therefore, effective drugs have not been approved to date that provide an effective treatment for such neurological or abortive diseases. The following is a brief description of parasitic diseases. Equine Protozoal Myeloencephalitis (EPM) is a neurological disease of horses, with a predilection for young horses subjected to exertion (for example, thoroughbred racehorses and thoroughbred horses), and for that reason it is a disease with a significant monetary impact for the equine industry. EPM, first recognized as a disease in the 1970s, was cultured from a horse with EPM and named Sarcocystis neurona in 1991. In 1997, a Neospora spp., Now named Neospora hugesi, was isolated. from the brain of a horse with EPM. Consequently, it has now been proposed that EPM may be caused by this newly recognized organism only, by Sarcocystis neuron alone or by the combination of the two. The EPM gives rise, most frequently, asymmetric incoordination (ataxia), weakness and spasticity. The disease can simulate almost any neurological situation. It may appear as a long or chronic situation. The chronic form is often insidious at the beginning, difficult to diagnose until the end of the course of the disease, and may lead to death. In the most benign cases, the only clinical sign may be poorly defined pelvic limb weakness or lower respiratory noise. In the most serious cases, horses are unable to swallow or stand. Now it has been known that in the most severe cases, the parasite, for example, S. neurona infects the brain and produces significant damage in it. The clinical signs of MPS are caused by neuronal damage (brain and spinal cord) directly through parasites as well as brain damage resulting from the infiltration of inflamed cells, edema and neuronal death associated with merozoites and merons in the system. central nervous system (CNS). Currently, no effective treatment or prophylaxis has been approved for EPM control. The combination of drugs for human trimethoprim-sulfonamide has been used. However, the treatment is expensive and requires an extensive number of repeated doses. Toxoplasma gondii has been known for some time from another cocci-diane parasite, and it was first isolated from the in-testes and muscle tissues of cats. The definitive host for this parasite is the cat that can host the organism for long periods of time dispersing oocytes to other animals including cattle, sheep, pigs and humans. The infection of sheep, cattle and humans has been associated with abortion and congenitally acquired disorders, which mainly affect the central nervous system. It has also recently been associated with abortion and malformations in kittens born to infected females that had been seronegative before infection during gestation. Non-feline hosts, such as cattle, sheep, pigs and humans, do not produce oocysts but develop and may suffer from muscle and brain invasion by tachyzoites and bradyzoites that produce the clinical signs of the disease - neurological symptoms and abortion with fetal defects. It has been reported that 60% of cats are serologically positive to T. gondii. Once, again, no treatment or prophylaxis for toxo-plasmosis has been approved. Yet another coccidian parasite, Neospora caninum, produces both neurological and abortive disease in animals. It was first isolated from dogs in 1988. Initially it was confused with Toxoplasma gondii. The disease caused by this parasite occurs more severely in puppies infected with the placenta and is characterized by progressive ascending paralysis in puppies, particularly in the hind limbs.; Polymyositis and hepatitis can also occur. More recently, this disease has been recognized as a leading cause of miscarriage and defects of neurologically associated limbs in newborn calves. Microscopic lesions of nonsuppurative encephalitis and myocarditis can be seen in aborted fetuses, in the brain, spinal cord and heart. Recently it has been identified that a definitive host for Neospora caninum is the dog. To date, no treatment or prophylaxis has been approved for either Neospora caninum of dogs or bovines or for Neospora hugesi of horses. References in the known art, including the references cited above, do not suggest or teach the use of triazinone compounds such as toltrazuril or toltrazuril sulfone (recently renamed "ponazuril") for the treatment of animals infected with coccidia or, more specifically, of the Sarcocystidae family that cause abortive or neurological diseases without producing intolerable side effects. There is, therefore, the need for an improved and safe treatment for animals affected with parasitic diseases that manifest as neurological and abortive diseases.

SUMMARY OF THE INVENTION According to the foregoing, the present invention encompasses a method of therapeutic treatment of a sick animal suffering from a neurological or abortifacient parasitic disease that is capable of being treated with a triazinone compound, with the proviso that when the disease is Sarcocystis neuron the compound is not diclazuril or toltrazuril. The method comprises administering to the animal a pharmaceutically effective amount of the compound. The term "pharmaceutically effective amount" as used herein means that the amount of triazinone to be administered is high enough to inhibit the growth in vivo or in vi tro of the parasite protozoa, typically coccidia which produce neurological diseases and / or abortions. The pharmaceutically effective amount controls the parasites in the infected tissues and consequently leads to an improvement in the health of the animal.

In addition, the present invention encompasses a method for metaphylactically treating an animal infected with a parasite that can produce a neurological or abortive disease, which is susceptible to being treated with a triazinone compound. The metaphylactic treatment comprises administering to the animal the triazinone compound using a metaphylactically effective regimen. By the term "metaphylactically effective regimen" is meant the administration of patterned intermittent doses of the triazinone compounds over a prolonged period of time until said animal overcomes the invasion of parasites by, for example, developing a response immune protective or other way to get rid of the parasite. Typically, the regimen is such that it can effectively control the parasites and avoid the clinical signs of the disease. Metaphylactically effective doses may also be administered for a prolonged period of up to five years or the life span of the animal, especially in the case where the parasite is difficult to control. For the metaphylactic treatment, the triazinone compounds preferred are the triazintriones, which include but are limited to toltrazuril and ponazuril. Also, the present invention encompasses a treatment of animals with a high single dose. This method comprises administering to the animals a single high dose of a pharmaceutically effective amount of the triazinone compound to the sick animal suffering from a parasitic neurological or abortive disease that is capable of being treated with a triazinone. By the term "single high dose" is meant an amount that is administered only once. This amount is significantly higher than the amount of the dose used in the therapeutic or metaphylactic treatment; It is effective in controlling the parasites that cause the disease, and as such will not result in harmful effects such as toxicity. The single high dose of triazinone is consistently greater than 10 mg / kg. This and other aspects of the invention are described more fully hereinafter.

DETAILED DESCRIPTION OF THE INVENTION As indicated above, the present invention relates to a method of treating an infected or diseased animal suffering from a parasitic disease manifested as a neuralgic or abortive disease that is capable of being treated with a triazinone compound, comprising the administration thereto of a pharmaceutically effective amount of said compound. Illustrative examples, but not limiting, of animals can be equines, cattle, cats, dogs, pigs, sheep, birds, insects and humans. The parasites that infect or cause the disease are coccidia of the family Sarcocystidae, which can manifest as neurological or abortive diseases. Illustrative, but not limiting, examples can be selected from the same group as Sarcocystis spp., Neospora spp, and Toxoplasma spp. Sarcocystidae are typically selected from the group consisting of S. neurona, N. hugesi, N. caninum and T. gondii. Infections or protozoa diseases include, but are not limited to, EPM, Neosporosis, and Toxoplasmosis. In the practice of the invention, the treatment of infections or parasitic diseases caused by the protozoa described herein results in the alleviation of the symptoms of neurological and abortive diseases. Generally, symptoms include weakness, ataxia, paralysis, miscarriage, weak newborns and other related disorders. For therapeutic treatment, the regimen may be once a day, two or more times a day, once every other day or even once a week, depending on factors such as the severity of the disease and the type of parasite. producer of the disease. In some cases, however, the treatment regimen may last indefinitely, sometimes for the rest of the animal's life. For example, in the case of infection of an animal with a more resistant strain of the parasite, the treatment may be extended for longer periods of time until the symptoms of the disease have been eliminated. Typically, the duration of the treatment is from about 28 days to 90 days and preferably from about 28 to 60 days. The most preferred treatment is once a day for approximately 28 days. For the metaphylactic treatment, the infected animals are treated to protect them against the clinical manifestations of the diseases. This treatment eventually results in the acquisition of the animal's ability to control the parasite, for example, by establishing an effective immune response to impart protection against future infections, without the need for additional administration of the triazinone compounds. . The metaphylactic activity, according to the invention, refers to the use of the triazinone compounds in a regimen of intermittent treatment prescribed (metaphylactically effective regimen) to control the protozoa, which may have infected the animal, since the previous treatment. Consequently, the metaphylactically effective regimen is administered to reduce the ability of parasites to cause disease by, for example, killing or reducing them in number. In essence, the metaphylactically effective regimen may be administered two or more times, typically from about once a month until the animal's life is completed or until an inherent elimination mechanism is developed, for example, an effective immune response, within the animal for protect it from future infections. The latter may occur after 5 years or less. As can be appreciated, the metaphylactic treatment is based on the recognition that when the animals are infected with the protozoa described herein, they do not show clinical signs such as neurological signs or abortion until a significant time has elapsed (for example, 2-6 months after the infection). In contrast, enteric protozoan infections manifest themselves shortly after infection. In accordance with this invention, the metaphylactic treatment prevents the parasite from establishing itself and causing a clinical disease. The treatment regimen is performed on an intermittent schedule approximately once a month, once every two months, or once every two weeks. For therapeutic and metaphylactic treatments, an equivalent dose of about 1.0 to 100 mg / kg, preferably about 1.0 to 25 mg / kg and more preferably about 2.5 to 10 mg / kg may be employed. The upper part of the interval will be required in particularly resistant cases (for example, when an animal is infected with a resistant strain). The level of dosage required and the duration of the treatment are within the point of view of a common expert in the field. A pre-fermented treatment regimen for horses with EPM or bovine with Neosporosis is approximately 1, 0 to 25 mg / Kg, and a more preferred range is approximately 2.5 to 10 mg / kg of triazintrione every 28 days. For the single high dose treatment, the triazinone is administered in pharmaceutically effective amounts that are greater than 10 mg / Kg and up to about 100 mg / Kg. It is a distinctive feature of the invention that the compounds of this invention can be non-toxic, thus they can be administered at high dosage levels. The advantage of administration at the high dose lies in the fact that repeated doses are not required. For the high single dose treatment, it has been found that ponazuril is safe and effective at doses as high as 100 mg / kg body weight. Unlike the compounds of the related art, triazinone compounds that are equivalent to ponazuril are preferred since they do not cause harmful side effects if administered at very high dosage levels. Without being bound by any particular theory of the invention, it is believed that the unexpected success of the treatments described herein results from the ability of the triazinone compounds to cross the blood-brain barrier or the placental barrier. It is believed that the compounds of this invention readily cross the blood-brain barrier and, also, are able to cross the placenta and kill protozoa in the brain and cerebro-spinal fluid / spinal cord. It has further been found that compounds of this class are non-toxic and non-mutagenic even at the high doses necessary for the high single dose treatment regimen described herein. Until now, there were no readily available, cost-effective drugs available to treat and effectively protect against these diseases without producing unacceptable side effects such as toxicity or mutagenicity in animals. The following is a description of the triazinone compounds, particularly, but not limited to, the toltrazuryl compounds. This description and the claimed invention also encompass other triazine compounds which are useful in the same way as toltrazuril compounds. The toltrazuryl compounds useful herein are of the formula (1): wherein R 1 represents haloalkylthio, haloalkylsulfinyl or haloalkylsulfonyl, R 2 represents hydrogen, alkyl, alkoxy, alkoxyalkyl, alkylmercapto, halogen, haloalkyl or an optionally substituted sulfamoyl radical, such as dialkyl sulfamoyl, R 3 and R 4 may be the same or different and represent hydrogen, alkyl, alkenyl or alkynyl and X is O or S, and their physiologically acceptable salts. Additionally, it has been found that, in particular, the following compounds of formula la and their physiologically acceptable salts may be useful here: wherein R1 represents haloalkyl (C1-C4) -thio, haloalkyl (C-C) -sulfinyl or haloalkyl (C? -C4) -sulfonyl, R11 represents hydrogen, (C -? - C4) alkyl, (C? -C), halogen, alkoxy (Ci-C.) Alkyl (C? -C), alkyl (C? -C) -mercapto, dialkyl (C? -C4) aminosulfonyl or haloalkyl (C? -c4) and R111 and RIV may be the same or different and represent hydrogen, (C1-C4) alkyl or (C2-C4) alkenyl and X is O or S. Finally, it has been found that (a) 1- (4-phenoxy-phenyl) -1,3,5-triazines of formula I are obtained when the compounds of formula II (II) in which R1, R2, R3 and X have the meanings indicated above, are reacted with a substituted carbonyl isocyanate of formula III wherein R 5 represents a halogen atom, an alkoxy group or an aryloxy group, and substituted 1,3,5-triazine derivatives, formed during this process, of formula IV wherein R1, R2, R3 and X have the meanings indicated above, are optionally isolated and optionally reacted with a compound of formula V A Z (V) wherein A represents alkyl, alkenyl or alkynyl and Z represents halogen; or that (b) the 1- (4-phenoxy-phenyl) -1,3,5-triazine derivatives of general formula I are obtained when the compounds of formula II, in which R 1, R 2, R 3 and X have the meanings indicated above, are reacted with bis (chlorocarbonyl) -amines of formula VI COCÍ _ / R -N COCÍ (VI) wherein R6 represents alkyl, optionally in the presence of acid acceptors or that (c) in order to obtain the compounds of formula I in which the substituents R2, R3 and R4 as well as X have the meanings indicated above and R1 represents halogenoalkylsulfinyl or haloalkylsulfonyl, the compounds of formula wherein R 2, R 3 and R 4 have the meaning given above and R 1 'represents haloalkylthio, are reacted with the appropriate amount of a suitable oxidizing agent. If N- [3-chloro-4- (4'-trifluoromethylthio-phenoxy) -phenyl] -N1-methyl-urea and the chlorocarbon isocyanate are used in process variant (a), the course of the reaction can be represented by the following equation: If N- [3-ethoxy-4- (4'-trifluoromethylthio-phenoxy) -phenyl] -thiourea and N-methyl-bis- (chlorocarbonyl) amine are used as starting materials in process variant (b) , the course of the reaction can be represented by the following equation: The compounds of general formula I, obtained according to the process variant (a) or (b), in which Rx = haloalkylthio and X = O can be oxidized according to variant (c) of the process to the corresponding derivatives of haloalkylsulfinyl or haloalkylsulfonyl. If hydrogen peroxide is used as an oxidizing agent, the course of the reaction can be represented by the following equation: In the formulas I, II, IV, V, VI and VII, alkyl as defined in R2, R3, R4, R6 or A is straight or branched chain alkyl with preferably 1 to 6, in particular 1 to 4, atoms of carbon. Examples that may be mentioned are methyl, ethyl, n- and i-propyl and optionally substituted n-, i- and t-butyl. In formulas I, II, IV, V and VII, alkenyl as defined in R3, R4 or A is straight or branched chain alkenyl with preferably 2 to 6, in particular 2 to 4, carbon atoms. Examples, which may be mentioned, are optionally substituted ethenyl, propen-1-yl, propen-2-yl and buten-3-yl. In formulas I, II, IV, V and VII, alkynyl as defined in R3, R4 or A is straight chain or branched alkynyl with preferably 2 to 6, in particular 2 to 4, carbon atoms. Examples that may be mentioned are optionally substituted ethinyl, pro-pin-1-yl, propin-2-yl and butin-3-yl. In the formulas I, II, III, IV and VII, alkoxy as defined in R2 or R5 is straight or branched chain alkoxy with preferably 1 to 6, in particular 1 to 4, carbon atoms. Examples that may be mentioned are optionally substituted methoxy, ethoxy, n- and i-propoxy and n- and i-butoxy. In the formulas I, II, III, IV, V and VII, halogen as defined in R2, R5 or Z is preferably fluorine, chlorine, bromine and iodine, especially chlorine and bromine. In the formulas I, II, IV and VII, haloalkylthio as defined in R 1 is haloalkylthio preferably with 1 to 4, in particular 1 or 2, carbon atoms and preferably 1 to 5, in particular 1 to 3, atoms of identical or different halogen atoms, the halogen atoms are preferably fluorine, chlorine and bromine, especially fluorine and chlorine. Examples which may be mentioned are trifluoromethylthio, chloro-di-fluomethylthio, bromomethylthio, 2,2,2-trifluoroethylthio and penta-fluorethylthio. In formulas I, II and IV, haloalkylsulfinyl as defined in R 1 is haloalkylsulfinyl with preferably 1 to 4, in particular 1 or 2, carbon atoms and preferably 1 to 5, in particular 1 to 3, identical halogen atoms or different, the halogen atoms are preferably fluorine, chlorine and bromine, especially fluorine and chlorine. Examples that may be mentioned are trifluoromethyl sulfuryl, chloro-di-fluoro-methyl sulfuryl, bromomethylsulfinyl, 2,2,2-trifluoromethyl-sulfinyl and pentafluorethylsulfinyl.

In the formulas I, II and IV, halogenoalkylsulfonyl as defined in R 1 is halogenoalkylsulfonyl with preferably 1 to 4, in particular 1 or 2, carbon atoms and preferably 1 to 5, in particular 1 to 3, identical halogen atoms or different, the halogen atoms are preferably fluorine, chlorine and bromine, especially fluorine and chlorine. Examples which may be mentioned are trifluoromethylsulfonyl, chloro-di-fluomethylsulphonyl, bromomethyl-sulfonyl, 2,2,2-trifluoromethylsulfonyl and pentafluoroethylsulphonyl. In formulas I, II and IV, optionally substituted sulfamoyl as defined in R2 is preferably one of the following radicals: S02NH2, S02NH-CH3, S02N (CH3) 2, S02NH-C2H5, S02-N (C2H5) 2, / \ NH SO, Nsí N -CH, \ / In the formulas III, aryloxy as defined in R5 is preferably carbocyclic monocyclic aryloxy or carbocyclic bicyclic aryloxy, particularly phenoxy. In the formulas III, R5 aryloxy is preferably phenoxy. Most of the substituted ureas or thioureas of the formula II which are useful as starting products were not known until now, but can be easily prepared by methods that are themselves known, by (a) either reacting 4- aminodiphenyl ethers substituted with the corresponding isocyanates or substituted isothiocyanates in an inert solvent at temperatures between 0 ° C and 100 ° C, or, by changing the sequence, (b) reacting ammonia or substituted amines and the corresponding isocyanate or 4-isothiocyanate -diphenyl ethers substituted with one another under the same conditions, or by (c) subjecting 4-hydroxyphenyl-ureas or substituted thioureas to a condensation reaction with activated halogenaromatic compounds in aprotic solvents, such as dimethylsulfoxide, dimethylformamide or hexamethylphosphoric triamide, in the presence of bases, such as sodium hydride, potassium hydroxide, potassium carbonate zam, a temperatures between 20 ° C and 150 ° C. When the amount of solvent is chosen appropriately, the reaction products generally crystallize upon cooling the solution. Literature for the alternative preparation of ureas from amines and isocyanates is: Methoden der Org. Chemie (Methods of Organic Chemistry) (Houben-Weyl), IV edition, Volume VIII, pages 157-158. Some of the bis- (chlorocarbonyl) amines of the general formula VI which can be used according to the invention in process (b) are already known (check the article in Synthesis 1970, pages 542-543) and, if not yet known, can be prepared analogously from cyclic diacidylsulfides and chlorination in inert organic solvents, preferably in carbon tetrachloride. Possible diluents for the reaction of ureas or thioureas of formula II with the carbonyl isocyanates of formula III (process variant (a)) and with the bis (chlorocarbonyl) -amines of formula VI (process variant (b)) as well as for the reaction of the 1,3,5-triazine derivatives of the formula IV with compounds of the formula A-Z, are all organic solvents that are inert in these reactions. These include, in addition to the pyridine, preferably, aromatic hydrocarbons, such as benzene, toluene and xylene, halogenated aromatic hydrocarbons, such as chlorobenzene and dichlorobenzene, and ethers, such as tetrahydrofuran and dioxane. The hydrochloric acid that can be formed during the reaction, is released as a gas or can be taken up by organic or inorganic acid acceptors. Acid acceptors include, preferably, tertiary organic bases, such as trialkylamines, for example, triethylamine, N-hetero mono- or bi-cyclic aromatic amines, such as pyridine aza-cycloalkylamines which are mono- or bi-cyclic, such as diazabicyclononene, diazabicycloundecene and many others, or inorganic bases, such as alkali metal carbonates, oxides or hydroxides or as carbonates, oxides or hydroxides of alkaline earth metal. The reaction temperatures for the reaction steps mentioned above may vary within a wide range. In general, the reaction is carried out between about 0 ° C and about 150 ° C, preferably between about 20 ° C and about 100 ° C. In the reaction steps mentioned above, the reaction can be carried out under normal pressure or under elevated pressure. In general, the reaction is carried out under normal pressure. The possible oxidizing agents for the conversion, according to the variant (c) of the process of the tri-fluoromethylthio compounds of the general formula 1, in which Y represents oxygen, in the corresponding sulfinyl or sulfonyl compounds are, appropriately: H202 / glacial acetic acid, H202 / acetic anhydride, H202 / methanol; peracids, such as, for example, m-chloroperbenzoic acid and chromic acid; potassium permanganate; sodium periodate, cherry-colored ammonium nitrate; and nitric acid. A resulting compound can be converted into a corresponding addition salt, for example by reacting it with an inorganic or organic base. In the practice of the invention, the triazinone compound can be formulated in any convenient manner in compositions or formulations for administration to animals. Formulations suitable for oral administration, which is preferred herein, may be suspensions, tablets, capsules, gels, pastes, pills, or preparations in the form of powders, granules or pellets. The preferred formulation for oral administration is in the form of a paste or a food additive. Other modes of administration that may be employed include parenteral, topical, intramuscular, and in -tropucosal or other routes known to those skilled in the art. Topical administration in the form of a spray is also preferred. Typically, they are employed in pharmaceutically acceptable carrier and auxiliary formulations. Examples thereof may be thickening agents selected from the group consisting of: Carbopol, inorganic thickeners such as silicates, bentonites or colloidal silica and organic thickeners such as fatty alcohols or fatty acid esters, and the wetting agent is selected from the group consisting of -tylene glycol and sodium lauryl sulfate being the Carbopols, more specifically, Carbopol 974P, the most preferred thickening agent here for the formulation of the paste. The preservatives selected from the group consisting of parabens, alcohols and aldehydes can also be used here. These can be liquid, solid or gaseous materials, which on the other hand are inert or medically acceptable and are compatible with the active ingredients. Surprisingly, the pastes of the present invention are effective for the release of triazinones, particularly toltrazuril, and ponazuril to cross the blood-brain barrier or the placental barrier and attack the parasites that have already invaded the brain or infected the fetus. pregnant animals. At the level of convenience, a description is provided here of a specific embodiment of the preferred pastes herein and how they are prepared. A preferred paste according to the present invention contains a micronized suspension of triazinetrione (for example, ponazuril), propylene glycol, a thickening agent such as Carbopol, preservatives such as methylparaben and propylparaben, and water. It can be made by combining water, typically, purified water and propylene glycol, heating the combination to about 70 ° C, and adding the preservatives at this temperature. The resulting mixture is cooled to room temperature after which Carbopol is added, preferably in the form of Carbopol 974P. Finally, triazinetrione is added. After complete mixing, the pH is adjusted to about 6.0 with sodium hydroxide. The most preferable pulp includes 15% w / w ponazuril, 20% w / w propylene glycol, 0.5% w / w Carbopol 974P, 0.14% w / w methylparaben, 0.02% w / w of propylparaben, 0.1% w / w of sodium hydroxide, the remainder being purified water. Edulcorants including dextrose, sucrose, lactose, fructose, sorbitol, xylitol, artificial sweeteners and molasses can be added to improve taste. Additionally, yeast or liver flavor may be added for the same purpose. The invention is further described by the following illustrative but not limiting examples. EXAMPLES EXAMPLE 1; A pharmacokinetic study was conducted in horses comparing the blood levels of toltrazuril, ponazuril and toltrazuril sulfoxide at different times after a single dose of toltrazuril. All horses received a single dose of 10 mg / kg, which was administered orally as a suspension. Blood samples were collected at the time of treatment (0) and at 0, 25, 0.5, 1, 2, 4, 6, 12, 24, 48 and 72 hours after the treatment. The results of the sampling are listed in Table 1. It was surprising to note that the horses that had received toltrazuril showed relatively high levels of ponazuril in their serum. Additionally, significant levels of toltrazuril sulfoxide were found in the bloodstream. This was indicative that ponazuril alone could produce acceptable blood levels that were seen to pass the blood-brain barrier, a characteristic required to treat neurological diseases such as those caused by Sarcocystis neuron, Toxoplasma gondii, Neospora caninum and Neospora heu. -Dried.

TABLE 1 Pharmacokinetics of a single dose of toltrazuril in horses D Compound meconcentration in m / 1 of blood dido 0 0.25 0.5 1 2 4 A toltrazuril 0.027 0.733 2.863 4.511 3.119 toltrazuril - < 0.01 0, 077 0.070 0.159 0.142 ponazuril sulfoxide 0.010 0.089.0.088 0.171 0.110 B toltrazuril 0.061 0.393 2.617 4.296 6.820 toltrazuril- < 0.01 0.025 0.047 0.083 0.157 ponazuril sulfoxide < 0.01 0.029 0.036 0.040 0.050 C toltrazuril 0.061 0.560 3,286 5,788 9,079 toltrazuril - < 0.01 0.024 0.041 0.097 0.218 ponazuril sulfoxide < 0.01 0.013 0.019 0.026 0.032 D-toltrazuril 0.017 0.295 3,286 2,165 3,328 toltrazuril- < 0.01 0.027 0.039 0.058 0.100 ponazuril sulfoxide < 0.01 0.011 0.021 0.024 0.029 E toltrazuril < 0.01-0.039 1, 146 3.175 8.410 toltrazuril- < 0.01 < 0.01 0.021 0.064 0.194 ponazuril sulfoxide < 0, 01 < 0.01 0.017.0.015.0.044 F toltrazuril 0,110 0,428 1,741-8,144 toltrazuril- < 0.01 0.026 0.044-0.183 ponazuril sulfoxide < 0.01 0.012 < 0.01 - 0.041 EXAMPLE 2: Ponazuril, l-methyl-3- [4-p- [trifluoromethyl) sulfonylphenoxy] m-tolyl] -s-triazin-2,4,6,6 (1H, 3H, 5H) -trione, a representative triazinetrione, was formulated , in paste for administration to horses. The components listed in Table 2 were used in the preparation of formulations as follows. Table 2 Components of the horse paste of ponazuril The formulations were prepared using process (A) and (B) as follows. The first process (A) comprised: 1) Mix a portion of the water with propylene glycol; 2) add preservatives (methylparaben and propylparaben; 3) slowly add Carbopol 974P until a uniform suspension is prepared; 4) add ponazuril in micronized form; 5) adding the sodium hydroxide to bring the suspension to a pH of about 6.0; and 6) add the rest of the water to CS for the volume. The final suspension was in the form of a paste, which could be orally dispensed to a horse. The second process (B) comprised: 1) Mix a portion of the water with propylene glycol; 2) heat up to 70 ° C; 3) add preservatives (methylparaben and propylparaben) while maintaining the solution at 70 ° C; 4) cool the solution to room temperature; 5) slowly add Carbopol 974P until a uniform suspension was prepared; 6) add ponazuril in micronized form; 7) add the sodium hydroxide and bring the suspension to a pH of about 6.0; and add the rest of the water to CS for the volume. The final suspension was also in the form of a paste, which could be orally dispensed to a horse. The resulting pastes were administered to horses and found to be acceptable to the palate and well accepted. EXAMPLE 3: Ponazuril, l-methyl-3- [4-p- [trifluoromethyl] -sulfonylphenoxy] -m-tolyl] -s-triazin-2,4,6 (1H, 3H, 5H) -trione was tested, a representative triazintrione, in terms of its ability to treat horses that already showed signs of Equine Protozoal Mieloencephalitis (EPM). The compound was formulated in paste form using 15% ponazuril as the active ingredient (ai) as described in EXAMPLE 1. It was administered to horses already diagnosed with EPM once a day for 28 days at a dosing rate between 2, 5 mg / kg and 10 mg / kg. The clinical cases of EPM that arose naturally were well characterized by symptoms and laboratory diagnosis. The diagnosis used for the incorporation of EPM-positive horses in this trial was as follows: confirmed asymmetric neurological deficit as determined by a standard neurological examination, including radiography, indicative of EPM; Positive Western blot for Sarcocystis neuron IgG; red blood cell content below 500 cells / mL; CSF indices - total protein < 90, IgG index > 0.3, quotient AQ < 2.2. The additional requirements were that the horses did not suffer from other diseases other than EPM. Therefore, they had to meet the following criteria: negative CSF (< 1: 4) for EHV-1; normal serum values for vitamin E (2.0 μg / mL); absence of attack disorders; absence of behavior disorders. The horses diagnosed were assigned to groups at random. The horses of Group 1 received the pulp formulation daily at a dosage value of 5 mg / Kg while the horses of Group 2 received the pulp formulation daily at a dosage value of 10 mg / Kg. The treatment dose was based on body weight. The horses were evaluated during a period of 90 days (approximately 60 days after the interruption of the treatment) in order to determine that the treatment was effective. The response to treatment was scored using the following system: 1) 0 = complete-clinically normal success with a negative CSF; 2) 1 = barely detectable deficit in the normal gait mode; 3) 2 = deficit easily detectable and exaggerated by the support, rotation, deviation, pressure of the flank on the jaw and elongation of the neck; 4) 3 = very noticeable deficit when walking, facial twisting, pressure of the flank or elongation of the neck; 5) 4 = stumbles, stumbles and falls spontaneously; 6) 5 = recumbent, unable to get up. An improvement of one (1) unit in the score was considered a significant improvement. The results of this study are shown in Table 3. The total (100%) of the horses in the 10 mg / Kg group treated for 28 days showed a significant improvement in the clinical score at day 90 after the start of the study. ponazuril treatment (day 0). Eight of nine (88.9%) horses treated with the 5 mg / kg dose showed an acceptable improvement. When all the points are added for each group, for each day of treatment, the total score is obtained. The improvement in the total scores shown by, both, Group 1 and Group 2 horses is roughly equivalent. It is concluded that ponazuril is effective for the active treatment of EPM in horses, either at doses of 5 mg / kg or 10 mg / kg. TABLE 3: Response of horses infected with EPM to treatment with toltrazuril sulfone EXAMPLE 4: In order to determine the scope of protection provided by ponazuril, an in vitro assay was carried out. The following strains of parasites were evaluated for their sensitivity to this compound: SN3 strain of Sarcocystis neuron; SF1 strain of Sarcocystis falcatula; RH strain of Toxoplasma gondii; and the NC-1 strain of Neospora caninum. Ponazuril was tested at 2 concentrations (1 μg / mL and 10 μg / mL). Bovine turbinate (BT) cells were used for all in vi tro studies. Cells were grown to confluence in 25 cm2 flasks in RMPI 1640 medium supplemented with 10% v / v fetal bovine serum (FBS), 100 units of penicillin (G / mL), 100 mg of streptomycin / mL and 5 × 10 ~ 2 mM of 2-mercaptoethanoi. After the confluence of the cells was achieved, the cells were maintained in the same medium with reduced FBS (2% v / v). The cell cultures were incubated at 37 ° C in a humidified atmosphere containing 5% carbon dioxide and 95% air. For the growth of the parasites, BT cell tumors were infected with parasites and examined with an inverted microscope for the development of lesions (cytopathic effect, "CPE") or the presence of many extracellular merozoites. Once the lesions were observed, or many extracellular parasites were present, the monolayer was scraped with the tip of a 5 mL pipette and 1 to 3 drops of fluid containing the merozoites were transferred to two fresh BT cell flasks. . The merozoites of S. neurona and S. falcatula were transferred in this way every 5 to 10 days while the tachizoites of T. gondii and N. caninum were transferred every 3 to 4 days. The test used to determine the effectiveness of ponazuril was the "Microtiter Monolayer Disruption Assay" (MMDA). This test was used to determine if the parasites or compound were toxic to BT cells. Flat bottom 96-well microtiter plates were inoculated with BT cells and the resulting monolayers were used to determine the effects of toltrazuril and ponazuril on the production of merozoites as measured by CPE (plaque formation). Monolayers were inoculated with parasites (S. neurona or S. falcatula up to a count of 50,000 / well, T. gondii to a level of 10,000 / well, and N. caninum to 20,000 / well. All wells were inoculated with the test compound 2 hours after infection. Potions with the untreated or infected monolayer served as controls for the parasite and BT cells treated with the uninfected agent served as toxicity controls. Each treatment was examined in replicates of 6. Each potion was visually monitored daily and the assay stopped when 90-100% of the untreated merozoite infected cells had been lysed (90-100% CPE). All wells of the plates were rinsed with phosphate buffered saline (PBS) and fixed in 100% methanol for 5 minutes after which they were stained with crystal violet solution. The areas of induced destruction of the merozoites or the BT cells killed due to toxicity did not capture the crystal violet. An ELISA plate reader was used to quantify the incorporation of crystal violet and these data were used to determine the concentration of ponazuril that inhibits 50% destruction (In-hibitoria5 concentration or CI5o) - The data showing the inhibition are presented in the Table 4. It is observed that an amount as small as 1 μg / mL of ponazuril provides 100% inhibition of cell destruction produced by N. caninum, T. gondii and S. falcatula while 10 μg / mL of ponazuril was required. to produce 100% inhibition of cell destruction by S. neurona. This indicates that triazinones such as toltrazuril and ponazuril would be effective for the treatment of diseases caused by coccidia which are known to be associated with the syndromes of neurological and abortive diseases including diseases caused by S. neurona, N. caninum, N. hugesi and T. gondii. Additionally, ponazuril was not toxic to BT cells. TABLE 4: ponazuril in vi tro data EXAMPLE 5: This experiment was carried out in order to determine if triazinones such as toltrazuril could pass the blood-brain barrier. Normal horses were divided into three groups of three horses per group. The horses of Group 1 received toltrazuril administered orally as a 5% suspension at a dosage level of 2.5 mg / Kg. The horses of Group 2 received toltrazuril administered orally as a 5% suspension at a dosage level of 5.0 mg / Kg. The horses of Group 3 received toltrazuril administered orally as a 5% suspension at a dosage level of 7.5 mg / Kg. The doses were repeated daily for 10 days. Blood samples were taken at 48, 96 and 240 hours and the concentration of toltrazuril, toltrazuril sulphoxide and ponazuril was measured in the skin. Ten days after the start of treatment (day 10), a sample of cerebrospinal fluid was extracted from each horse and, again, the concentrations of toltrazuril, toltrazuril sulphoxide and ponazuril were measured in these samples. The concentrations ^ of toltrazuril, toltrazuril sulphoxide and ponazuril in serum and cerebrospinal fluid are given in TABLES 5a and 5b. The concentration of ponazuril in the blood and cerebrospinal fluid after treatment of the horses with toltrazuril was significant, whereas the concentration of ponazuril in the cerebrospinal fluid after treatment of the horses with toltrazuril was essentially equivalent to the concentration of toltrazuril itself . This is evidence that both toltrazuril and ponazuril cross effectively the blood-brain barrier and that ponazuril crosses this barrier more effectively than toltrazuril. The data suggest for an expert in the field that triazinones can also cross effectively the placental barrier.

TABLE 5a Drug levels in horses after repeated doses of toltrazuril TABLE 5b Drug levels in horses after repeated doses of ponazuril Although the invention has been described in detail in the foregoing for purposes of illustration, it is understood that such detail is only for that purpose and that variations may be made therein by those skilled in the art without departing from the spirit and scope of the invention except in what may be limited by the claims.

Claims (25)

Claims

1. A method for therapeutically treating a sick animal suffering from an abortifacient or parasitic neurological disease that is susceptible to being treated with a triazinone compound, comprising administering to the animal a pharmaceutically effective amount of the compound, with the proviso that when the disease Sarcocystis neuron is the compound is not diclazuril or toltrazuril.

2. The method of Claim 1 wherein the parasitic disease is caused by coccidia.

3. The method of Claim 2 wherein the coccidium is a member of the Sarcocystidae family.

4. The method of Claim 3 wherein the member of the Sarcocystidae family is selected from the group consisting of Sarcocystis, Neospora and a Toxoplasma.

5. The method of Claim 4 wherein the Sarcocystis is selected from the group consisting of Sarcocystis spp, the Neospora is selected from the group consisting of Neospora spp and the Toxoplasma is selected from the group consisting of Toxoplasma spp.

6. The method of Claim 5 wherein Sarcocystis spp is Sarcocystis neuron, Neospora spp is Neospora caninum or Neospora hugesi and Toxoplasma spp is Toxoplasma gondii.

1 . The method of Claim 4 wherein the Sarcocystis is Sarcocystis neuron causing Equine Pro-tozoal Myeloencephalitis.

8. The method of Claim 4 where the Neospora is Neospora caninum causing Bovine or Canine Neosporosis.

9. The method of Claim 4 wherein the Toxoplasma is Toxoplasma gondii.

10. A method of metaphylactic treatment of animals infected with a parasite that is a causative agent of an abortive or neurological disease that is susceptible to being treated with a triazinone compound, which comprises administering thereto a metaphylactically effective regimen of said triazinone.

11. The method of Claim 1 or Claim 10 wherein the triazinone compound is selected from the group consisting of toltrazuril, ponazuril and diclazuril.

12. The method of Claim 1 or Claim 10 wherein the triazinone compound is ponazuril.

13. The method of Claim 1 or Claim 10 wherein the triazinone compound is administered in two or more repeated doses.

14. The method of Claim 13 wherein the repeated doses are administered in an amount between 1.0 and 100 mg / kg.

15. The method of Claim 10 wherein the triazinone compound is administered until the animal has developed a protective immunity.

16. The method of Claim 1 or Claim 10 wherein the triazinone is administered in an amount between 2.5 mg / kg and 10 mg / kg.

17. The method of Claim 16 wherein the triazinone is toltrazuril or ponazuril.

18. The method of Claim 1 wherein the triazinone compound is administered in a single high dose of more than 10 mg / kg.

19. The method of Claim 8 wherein the triazinone compound is administered in a regimen of repeated periodic doses until an immunological protection is established.

20. The method of Claim 1 wherein the triazinone compound is administered at a rate of 2.5 mg / kg to 10 mg / kg daily for a period of 28 days.

21. A therapeutic composition comprising (a) a triazinone compound in a pharmaceutically effective amount to treat a sick animal that is susceptible to it (b) a carrier, and (c) optionally, an auxiliary agent.

22. The composition of Claim 18 which is in the form of paste.

23. A method for treating equine protozoan myeloencephalitis (EPM) which comprises administering to an equine, suspected of having EPM, a therapeutically effective amount of one or more triazindiones.

The method of Claim 23 wherein the triazine-dione is diclazuril.

25. The method of Claim 23 where the equine is a horse.