Triazineone compounds for treating diseases due to Sarcocystis, Neospora and Toxoplasma

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

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to triazineone compounds for treating animals
 infected with parasites that cause abortigenic or neurologic diseases.
 More specifically, the present invention relates the triazineone compounds
 that are useful in treating parasitic protozoa such as coccidia that cause
 abortigenic or neurologic diseases.
 2. Brief Description of the Prior Art
 Triazineone compounds such as triazinediones, e.g., diclazuril compounds,
 and triazinetriones, e.g., toltrazuril compounds have been used in
 treating and protecting various mammals, insects and fish from diseases
 caused by a broad range of protozoa. See U.S. Pat. Nos.; 4,933,341;
 4,935,423; 5,114,938; 5,141,938; 5,188,832, 5,196,562, 5,256,631 and
 5,464,837. Protozoa sensitive to these compounds infect birds, mammals and
 insects and manifest as diarrhea, wasting, nausea and vomiting. Generally,
 the mode of action of the triazineones is to attack the intermediate
 parasite stages found in the gut and intestinal wall cells, causing the
 endoplasmic reticulum, the perinuclear space and the mitochondria of the
 parasite to swell. This purportedly disturbs the ability for nuclear
 divisions causing the shizonts and microgamonts to remain small forming
 only a few merozoites and microgametes respectively. The end result is
 reported to be the loss of the ability of these latter stages of the
 parasites to penetrate new mammalian cells, effectively halting the
 replication of the parasite in the host.
 Of particular concern here are certain protozoa suspected of causing
 neurologic and/or abortigenic diseases of animals since the 1970's.
 Successful isolation and in vitro cultivation of some of these protozoa
 proved to be difficult. For example successful isolation from the brain or
 cerebral spinal fluid were not accomplished until the late 1980s. Once it
 was determined that neurologic diseases could be produced by certain
 parasites infecting the brain and abortigenic diseases could be produced
 by certain parasites infecting the fetus, the need for effective
 anti-parasite drugs which could cross the blood-brain and the placental
 barrier without producing deleterious side effects became imperative. Many
 of the art-known drugs that can to cross the blood-brain barrier and/or
 the placental barrier to effectively treat parasitic infections of the
 brain have detrimental side effects such that they cannot be used without
 great risk. As such, there have been no effective drugs approved to date
 which provide an effective treatment for such neurologic or abortigenic
 diseases. The following is a brief description of the parasitic diseases.
 Equine Protozal Myoencephalitis (EPM) is a neurologic disease of horses,
 with a predilection for young horses undergoing stress (e.g., thoroughbred
 race horses and purebred performance horses), and is thus a disease with
 significant monetary impact for the horse industry. EPM, first recognized
 as a disease in the 1970's, was cultured from a horse with EPM and given
 the name Sarcocystis neurona until 1991. In 1997, a Neospora spp., now
 named Neospora hugesi, was isolated from the brain of a horse with EPM.
 Accordingly, it is now proposed that EPM may be caused by this newly
 recognized organism alone, by Sarcocystis neurona alone or the combination
 of the two. EPM most often results in asymmetric incoordination (ataxia),
 weakness, and spasticity. The disease can mimic almost any neurologic
 condition. It can occur as a peracute or chronic condition. The chronic
 form is often insidious at onset, difficult to diagnose until late in the
 course of the disease, and can result in death. In the mildest cases, the
 only clinical sign may be ill-defined pelvic limb lameness or a minor
 respiratory noise. In the most severe cases, horses are unable to swallow
 or stand. It is now known that in the most severe cases, the parasite,
 e.g., S. neurona infects the brain and produces significant damage
 therein. The clinical signs of EPM are caused by direct neuronal (brain
 and spinal cord) damage by the parasites as well as brain damage resulting
 from infiltration of inflammatory cells, edema, and neuronal death
 associated with merozoites and meronts in the central nervous system
 (CNS). Currently, there is no approved effective treatment or prophylaxis
 for the control of EPM. The human drug trimethoprim-sulfonamide
 combination has been used. However, treatment is expensive and requires an
 extensive number of repeated doses.
 Another coccidian parasite, Toxoplasma gondii, has been known for some time
 and was first isolated from the intestines and muscle tissue of cats. The
 definitive host for this parasite is the cat that can harbor the organism
 for long periods of time spreading oocysts to other animals including
 bovines, ovines swine and humans. Infection of sheep, cattle and humans
 has been associated with abortion and congenitally acquired disorders,
 which primarily affect the central nervous system. It has also recently
 been associated with abortion and malformation in kittens born to infected
 queens that had been seronegative prior to infection during pregnancy.
 Non-feline hosts such as bovines, ovines swine and humans do not produce
 oocysts but develop and may suffer from invasion of muscle and brain by
 tachyzoites and bradyzoites which produce the clinical signs of
 disease--neurological symptoms and abortion with fetal defects. It has
 been reported that 60% of cats are serologically positive to T. gondii.
 Once again, there is no approved treatment or prophylactic for
 toxoplasmosis.
 Yet another coccidia parasite, Neospora caninum, produces both a neurologic
 and abortigenic disease in animals. It was first isolated from dogs in
 1988, and was previously confused with Toxoplasma gondii. The disease
 caused by this parasite occurs most severely in transplacentally infected
 puppies and is characterized by progressive ascending paralysis in the
 puppies, particularly of the hind limbs; polymyositis and hepatitis may
 also occur. This disease has more recently been recognized as a major
 cause of abortion and neurologically-associated limb defects in newborn
 calves. Microscopic lesions of non-suppurative encephalitis and
 myocarditis in aborted fetuses may be seen in the brain, spinal cord and
 heart. A definitive host for Neospora caninum has recently been identified
 to be the dog. At this time there is no approved treatment or prophylaxis
 for either Neospora caninum of dogs or bovines or Neospora hugesi of
 horses.
 Art-known references, including the above-cited references do not suggest
 or teach the use of triazineone compounds such as Toltrazuril or
 Toltrazuril Sulfone (recently renamed "Ponazuril") in treating animals
 infected with coccidia or, more specifically, of the family Sarcocystidae
 causing abortigenic or neurologic diseases without causing intolerable
 side effects. There is, therefore, a need for an improved and safe
 treatment for animals afflicted with parasitic diseases manifesting as
 neurologic or abortigenic diseases.
 SUMMARY OF THE INVENTION
 In accordance with the foregoing, the present invention encompasses a
 method of therapeutically treating a diseased animal suffering from a
 parasitic neurologic or abortigenic disease that is susceptible to being
 treated with a triazineone compound. The method comprises administering to
 the animal, a pharmaceutically effective amount of the compound. The term
 "harmaceutically-effective amount" as used herein means that the amount of
 triazineone being administered is high enough to inhibit the in vivo or in
 vitro growth of the parasitic protozoa, typically coccidia that produce
 neurological disease and/or abortions. The pharmaceutically-effective
 amount controls the parasites in the infected tissues and consequently
 lead to an improvement in the animal's health.
 Further, the present invention encompasses a method of metaphylactically
 treating an animal infected with a parasite that can cause a neurologic or
 abortigenic disease, that is susceptible to being treated with a
 triazineone compound. The metapylactic treatment comprises administering
 to the animal, the triazineone compound using a
 metaphylactically-effective regimen. By the term
 "metaphylactically-effective regimen" is meant administering scheduled
 intermittent doses of triazineone compounds for a prolonged period until
 said animal overcomes the invading parasites by, say, developing a
 protective immune response or otherwise clearing the parasite. Typically,
 the regimen is such as would effectively control the parasites and prevent
 clinical signs of disease. The metaphylactically-effective dose can also
 be administered for a prolonged period up to five years or the lifetime of
 the animal, especially in an instance when the parasite is difficult to
 control. For the metaphylactic treatment, the preferred triazineone
 compounds are triazinetriones, which include but are not limited to
 Toltrazuril, and Ponazruil.
 Also, the present invention encompasses a single high dose treatment of the
 animals. This method comprises administering to the animals a single high
 dose of a pharmaceutically effective amount of the triazineone compound to
 a diseased animal suffering from a parasitic neurologic or abortigenic
 disease that is susceptible to being treated with a triazineone. By the
 term "single high dose" is meant an amount that is administered only once.
 This amount is significantly higher than the dose amount employed in the
 therapeutic or metapylactic treatment; is effective in controlling the
 disease-causing parasites, and as such would not result in detrimental
 effects such as toxicity. The single high dose of triazineone is
 accordingly greater than 10 mg/Kg. This and other aspects of the invention
 are described more fully hereunder.
 DETAILED DESCRIPTION OF THE INVENTION
 As set forth above, the present invention relates to a method of treating a
 infected or diseased animal suffering from a parasitic disease that
 manifests as neurologic or abortigenic disease that is susceptible to
 being treated with a triazineone compound, comprising, administering
 thereto a pharmaceutically effective amount of said compound. Illustrative
 but non-limiting examples of the animals can be equines, bovines, felines,
 canines, swine, ovines, birds, insects and humans. The parasites infecting
 or causing disease are coccidia of the Family Sarcocystidae that can
 manifest as neurologic or abortigenic diseases. Illustrative but
 non-limiting examples thereof can be selected from the group consisting of
 Sarcocystis spp., Neospora spp. and Toxoplasma spp. The Sarcocystidae are
 typically selected from the group consisting of S. neurona, N. hugesi, N.
 caninum and T. gondii. The protozoan infections or diseases include but
 are not limited to EPM, Neosporosis, and Toxoplasmosis.
 In the practice of the invention, treatment of the parasitic infections or
 diseases caused by the protozoa described herein results in the
 alleviation of the symptoms of the neurologic and abortigenic diseases.
 Generally, the symptoms include lameness, ataxia, paralysis, abortion,
 weak newborns and other related disorders. For therapeutic treatment, the
 regimen can be once a day, two or more times a day, once every other day
 or even once per week, depending on factors such as the severity of the
 disease and the type of disease-producing parasite. In some cases,
 however, the treatment regimen can last indefinitely, sometimes for the
 remaining life of the animal. For example, in the case of infection of an
 animal with a more resistant strain of parasite, the treatment can be
 extended for longer periods of time until the signs of disease are
 eliminated. Typically the duration of treatment is from about 28 days to
 90 days and preferably from about 28 to 60 days. The most preferred
 treatment is once, daily for about 28 days.
 For the metaphylactic treatment, infected animals are treated to protect
 them against clinical manifestation of diseases. This treatment eventually
 results in the animals' acquisition of the ability to control the
 parasite, say, by the establishing an effective immune response to impart
 protection against future infections, without a need for further
 administration of triazineone compounds. The metaphylactic activity, in
 accordance with the invention, refers to the use of the triazineone
 compounds on a scheduled intermittent treatment regimen
 (metaphyl-actically-effective regimen) to control the protozoa, which may
 have infected the animal, since the previous treatment. Accordingly, the
 metaphylactically-effective regimen is administered to reduce the ability
 of the parasites to cause disease by, say, killing them or reducing them
 in number. In essence, the metaphylactically effective regimen can be
 administered two or more times, typically from about once per month, up to
 over the lifetime of the animal or until an inherent clearance mechanism,
 e.g., an effective immune response develops within the animal to protect
 it from future infections. The latter can occur within 5 years or less. As
 would be realized, the metaphylactic treatment is based on the recognition
 that when animals are infected with the protozoa described herein, they do
 not demonstrate clinical signs such as neurological signs or abortion
 until a significant time has passed (e.g., 2-6 months post infection). In
 contrast, the 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 on an intermittent schedule of
 about once per month, once per two months or once per two weeks.
 For the therapeutic and metaphylactic treatments one can employ a dose
 equivalent of about between 1.0 and 100 mg/Kg, preferably about 1.0 to
 25mg/Kg and more preferably about 2.5 to 10mg/Kg. The high range would be
 required in particularly resistant cases (e.g. when an animal is infected
 with a resistant strain). The required dose level and duration of
 treatment are within the purview of one of ordinary skill in the art. A
 preferred treatment regimen for horses with EPM or bovines with
 Neosporosis is about 1.0 to 25 mg/Kg, and a more preferred range is about
 2.5 to 10 mg/Kg of triazinetrione every 28 days.
 For the single high dose treatment the triazineone is administered in
 pharmaceutically effective amounts that are greater than 10 mg/Kg and up
 to about 100 mg/Kg. It is a distinct feature of the invention the
 compounds of this invention can be non-toxic, thus they can be
 administrated at high dose levels. The advantage of the high dose
 administration resides in the fact repeated doses are not required. For
 the single high dose treatment, Ponazuril has been found to be both safe
 and effective at doses as high as 100 mg/Kg body weight. Unlike
 art-related compounds, the triazineone compounds which are equivalent to
 Ponazuril are preferred in that they do not cause detrimental side effects
 if administered at very high dose levels.
 Without being bound to any particular theory of the invention, it believed
 that the unexpected success of the treatments described herein results
 from the ability of the triazineone compounds to cross the blood-brain
 barrier or placental barrier. It is believed that the compounds of this
 invention easily cross the blood-brain barrier and, also, are able to
 penetrate the placenta and kill the protozoa in situ in the brain and
 cerebral spinal fluid/spinal cord. It has been a further been found that
 the compounds of this class are non-toxic and non-mutagenic even at the
 high doses necessary for the single high dose treatment regimen described
 herein.
 Heretofore, no cost-effective, easily administered drugs have been
 available for effectively treating and protecting against these diseases
 without producing unacceptable side effects such as toxicity or
 mutagenicity in animals. The following is a description of the triazineone
 compounds with particularity but without limitation to Toltrazuril
 compounds. This disclosure and the claimed invention also encompass other
 triazineone compounds that are useful in the manner of the Toltrazuril
 compounds. The Toltrazuril compounds useful herein are of formula (1):
 ##STR1##
 in which
 R.sup.1 represents halogenoalkylthio, halogenoalkyl-sulphinyl or
 halogenoalkylsulphonyl,
 R.sup.2 represents hydrogen, alkyl, alkoxy, alkoxyalkyl, alkylmercapto,
 halogen, halogenoalkyl or an optionally substituted sulphamoyl, such as
 dialkyl sulphamoyl, radical,
 R.sup.3 and R.sup.4 can be identical or different and represent hydrogen,
 alkyl, alkenyl or alkinyl and X is 0 or S, and their physiologically
 acceptable salts.
 Furthermore, it as been found that, in particular, the following compounds
 of the formula la and their physiologically acceptable salts have, can be
 useful herein:
 ##STR2##
 in which
 R.sup.I represents halogenoalkyl(C.sub.1 -C.sub.4)-thio,
 halogenoalkyl(C.sub.1 -C.sub.4 )-sulphinyl or halogenoalkyl(C.sub.1
 -C.sub.4)-sulphonyl,
 R.sup.II represents hydrogen, alkyl (C.sub.1 -C.sub.4), alkoxy (C.sub.1
 -C.sub.4),halogen, alkoxy(C.sub.1 -C.sub.4)alkyl(C.sub.1 -C.sub.4), alkyl
 (C.sub.1 -C.sub.4)-mercapto, dialkyl (C.sub.1 -C.sub.4)aminosulphonyl or
 halogenoalkyl (C.sub.1 -C.sub.4) and
 R.sup.III and R.sup.IV can be identical or different and represent
 hydrogen, alkyl (C.sub.1 -C.sub.4) or alkenyl (C.sub.2 -C.sub.4) and X is
 0 or S. and X is 0 or S. Finally, it has been found that
 (a) 1-(4-phenoxy-phenyl)-1,3,5-triazines of the formula I are obtained when
 compounds of the formula II
 ##STR3##
 in which
 R.sup.1, R.sup.2, R.sup.3 and X have the meaning indicated above, are
 reacted with a substituted carbonyl isocyanate of the formula III
 ##STR4##
 in which
 R.sup.5 represents a halogen atom, an alkoxy group or an aryloxy group, and
 the substituted 1,3,5-triazine derivatives, formed during this procedure,
 of the formula IV
 ##STR5##
 in which
 R.sup.1, R.sup.2, R.sup.3 and X have the meaning indicated above, are
 optionally isolated and optionally reacted with a compound of the formula
 V
EQU A--Z (V)
 wherein
 A represents alkyl, alkenyl or alkinyl and
 Z represents halogen; or that
 (b) 1-(4-phenoxy-phenyl)-1 ,3,5-triazine derivatives of the general formula
 I are obtained when compounds of the formula II, in which R.sup.1,
 R.sup.2, R.sup.3 and X have the meaning indicated above, are reacted with
 bis-(chlorocarbonyl)-amines of the formula VI
 ##STR6##
 in which
 R.sup.6 represents alkyl, optionally in the presence of acid acceptors or
 that
 (c) in order to obtain compounds of the formula I in which the substituents
 R.sup.2, R.sup.3 and R.sup.4 as well as X have the meaning indicated above
 and R.sup.1 represents halogenoalkylsulphinyl or halogenoalkylsulphonyl,
 compounds of the formula
 ##STR7##
 in which
 R.sup.2, R.sup.3 and R.sup.4 have, the meaning indicated above and R.sup.1
 represents halogenalkylthio, are reacted with the appropriate amount of a
 suitable oxidizing agent..
 If N-[3-chloro-4-(4'-trifluoromethylthio-phenoxy)-phenyl]-N'-methyl-urea
 and chlorocarbonyl isocyanate are used in process variant (a), the course
 of the reaction can be represented by the following equation:
 ##STR8##
 If N-[3-ethoxy-4-(4'-trifluoromethylthio-phenoxy)-phenyl]-thiourea and
 N-methyl-bis-(chlorocarbonyl) amine are used as the starting materials in
 process variant (b), the course of the reaction can be represented by the
 following equation:
 ##STR9##
 The compounds of the general formula 1, obtained according to process
 variant (a) or (b), in which R.sub.1.dbd.halogenoalkylthio and X.dbd.0 can
 be oxidized according to process variant (c) to the corresponding
 halogeno-alkylsulphinyl or halogenoalkylsulphonyl derivatives. If hydrogen
 peroxide is used as the oxidizing agent, the course of the reaction can be
 represented by the following equation:
 ##STR10##
 In the formulae I, II, IV, V, VI and VII, alkyl as defined in R.sup.2,
 R.sup.3, R.sup.4, R.sup.6 or A is straight-chain or branched alkyl with
 preferably 1 to 6, in particular 1 to 4, carbon atoms. Examples that may
 be mentioned are optionally substituted methyl, ethyl, n- and i-propyl and
 n-, i- and t-butyl.
 In the formulae I, II, IV, V and VlI, alkenyl as defined in R.sup.3,
 R.sup.4 or A is straight-chain or branched 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 the formulae I, II, IV, V and VII, alkinyl as defined in R.sup.3,
 R.sup.4 or A is straight-chain or branched alkinyl with preferably 2 to 6,
 in particular 2 to 4, carbon atoms. Examples which may be mentioned are
 optionally sub- stituted ethinyl, propen-1-yl, propin-2-yl and butin-3-yl.
 In the formulae I, II, III, IV and VII, alkoxy as defined in R.sup.2 or
 R.sup.5 is straight-chain or branched alkoxy with preferably 1 to 6, in
 particular 1 to 4, carbon atoms. Examples which may be mentioned are
 optionally substituted methoxy, ethoxy, n- and i-propoxy and n- and
 i-butoxy.
 In the formulae I, II, III, IV, V and VII, halogen as defined in R.sup.2,
 R.sup.5 or Z is preferably fluorine, chlorine, bromine and iodine,
 especially chlorine and bromine.
 In the formulae I, II, IV and VII, halogenoalkylthio as defined in R.sup.1
 is halogenoalkylthio preferably 1 to 4, in particular 1 or 2, carbon atoms
 preferably 1 to 5, in particular 1 to 3, identical or different halogen
 atoms, halogen atoms preferably being fluorine, chlorine and bromine,
 especially fluorine and chlorine. Examples which may be mentioned are
 trifluoro-methylthio, chloro-di-fluoromethylthio, bromomethylthio,
 2,2,2-tri-fluoroethylthio and pentafluoroethylthio.
 In the formulae I, II and IV, halogenoalkylsulphinyl as defined in R.sup.1
 is halogenoalkylsulphinyl with preferably 1 to 4, in particular 1 or 2,
 carbon atoms and preferably 1 to 5, in particular 1 to 3, identical or
 different halogen atoms, halogen atoms preferably being fluorine, chlorine
 and bromine, especially fluorine and chlorine. Examples which may be
 mentioned are trifluoromethylsulphuryl, chloro-di-fluoromethylsulphuryl,
 bromomethylsulphinyl, 2,2,2-trifluoroethylsulphinyl and
 pentafluoroethyl-sulphinyl.
 In the formulae I, II and IV, halogenoalkylsulphonyl as defined in R.sup.1
 is halogenoalkylsulphonyl with preferably 1 to 4, in particular 1 or 2,
 carbon atoms and preferably 1 to 5, in particular 1 to 3, identical or
 different halogen atoms, halogen atoms preferably being fluorine, chlorine
 and bromine, especially fluorine and chlorine. Examples which may be
 mentioned are trifluoromethylsulphonyl, chloro-di-fluoromethylsulphonyl,
 bromomethyl-sulphonyl, 2,2,2-trifluoroethylsulphonyl and
 pentafluoro-ethylsulphonyl.
 In the formulae I, II, and IV, optionally substituted sulphamoyl as defined
 in R2 is preferably one of the following radicals:
 ##STR11##
 In the formulae III, aryloxy as defined in R.sup.5 is preferably monocyclic
 carbocyclic aryloxy or bicyclic carbocyclic aryloxy, particularly phenoxy.
 In the formulae III, aryloxy R.sup.5 is preferably phenoxy.
 Most of the substituted ureas or thioureas of the formula II which are used
 as starting materials have not been known hitherto, but they can be easily
 prepared by methods which are in themselves known by (a) either reacting
 substituted 4-aminodiphenyl ethers with the corresponding substituted
 isocyanates or isothiocyanates in an inert solvent at temperatures between
 0.degree. C. and 100.degree. C., or, reversing the sequence, (b) reacting
 ammonia or substituted amines and the corresponding substituted isocyanato
 or 4-isothiocyanato-diphenyl ethers with one another under the same
 conditions, or by (c) subjecting substituted 4-hydroxyphenyl-ureas or
 -thioureas to a condensation reaction with activated halogenoaromatic
 compounds in aprotic solvents, such as dimethylsulphoxide,
 dirnethylform-arnide or hexamethylphosphoric acid triamide, in the
 presence of bases, such as sodium hydride, potassium hydroxide, potassium
 carbonate z.a.m., at temperatures between 20.degree. C. and 150.degree. C.
 When the amount of solvent is appropriately chosen, the reaction products
 generally crystallize out on cooling the solution. Literature for the
 alternate preparation of ureas from amines and isocyanates is: Methoden
 der Org. Chemie (Methods of Organic Chemistry) (Houben-Weyl), IVth
 edition, Volume VIII, page 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
 (compare the article in Synthesis 1970, page 542-543) and, if they are not
 yet known, they can be prepared in an analogous manner from cyclic
 diacyldisulphides and chlorination in inert organic solvents, preferably
 in carbon tetrachloride.
 Possible diluents for the reaction of the ureas or thioureas of the formula
 II both with carbonyl isocyanates of the formula III (process variant a)
 and with bis(chlorocarbonyl)-amines of the 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 the organic solvents
 which 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 tetrahydrofurane and dioxane.
 The hydrochloric acid which may form during the reaction escapes as a gas
 or can be bonded by organic or inorganic acid acceptors. The 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-cyclo alkyl amines 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 alkaline earth metal carbonates, oxides or hydroxides.
 The reaction temperatures for the above-mentioned reaction stages can be
 varied within a wide range. In general, the reaction is carried out
 between about 0.degree. C. and about 150.degree. C., preferably between
 about 20.degree. C. and about 100.degree. C.
 In the above-mentioned reaction stages, the reaction can be carried out
 under normal pressure or under elevated pressure. In general, the reaction
 is carried out under normal pressure.
 Possible oxidizing agents for the conversion, according to process variant
 (c) of the trifluoromethylthio compounds of the general formula 1, in
 which Y represents oxygen, into the corresponding sulphinyl or sulphonyl
 compounds are, appropriately: H.sub.2 O.sub.2 /glacial acetic acid;
 H.sub.2 O.sub.2 /acetic anhydride; H.sub.2 O.sub.2 /methanol; peracids,
 such as, for example, m-chloroperbenzoic acid, and chromic acid; potassium
 permanganate; sodium periodate, cerise 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 triazineone compound can be
 formulated in any convenient manner into compositions or formulations for
 administration to animals. Formulations suitable for oral administration,
 which is preferred herein, can be suspensions, tablets, capsules, gels,
 pastes, boluses, or preparations in the form of powders, granules, or
 pellets. The preferred orally administered formulation is in the form of a
 paste or a feed additive. Other modes of administration that can be
 employed include parenteral, topical, intramuscular, and intramucosal or
 by other routes known to those skilled in the art. Topical administration
 in the form of a pour-on is also preferred.
 Typically, pharmaceutically acceptable carriers and auxiliaries are
 employed in the formulations. Examples thereof can be a 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 polyethylene glycol and sodium lauryl sulfate
 with Carbopols, more specifically, Carbopol 974P being the most preferred
 thickening agent for the paste formulation preferred herein. Also employed
 herein can be preservatives selected from the group consisting of
 parabens, alcohols and aldehydes. These may be liquid, solid, or gaseous
 materials, which are otherwise inert or medically acceptable and are
 compatible with the active ingredients.
 Surprisingly, the pastes of the present invention are effective in
 delivering the triazineones, particularly Toltrazuril, and Ponazuril to
 cross the blood-brain or placenta barrier and attack the parasites which
 have already invaded the brain or infected the fetus of a pregnant
 animals. As a matter convenience, there is provided herein a description
 of a specific embodiment of the preferred pastes and how it is prepared. A
 preferred paste, according to the present invention contains a micronized
 suspension of the triazinetrione (e.g., 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.degree. C., and adding the preservatives, at this temperature. The
 resulting mixture is cooled to room temperature after which Carbopol,
 preferably in the form of Carbopol 974P, is added. Finally the
 triazinetrione is added. After complete mixing, the pH is adjusted to
 approximately 6.0 with sodium hydroxide. The most preferable paste
 includes 15% w/w Ponazuril, 20% wiw Propylene Glycol, 0.5% w/w Carbopol
 974P, 0.14% w/w Methylparaben, 0.02% w/w Propylparaben, 0.1% w/w sodium
 hydroxide with the remainder being purified water. Sweeteners including
 dextrose, sucrose, lactose, fructose, sorbitol, xylitol, artificial
 sweeteners and molasses may be added to improve palatability.
 Additionally, yeast or liver flavoring may be added for the same purpose.
 The invention is further described by following illustrative but non-
 limiting examples.

EXAMPLES
 EXAMPLE 1
 A pharmacokinetic study was conducted in horses comparing blood levels of
 Toltrazuril, Ponazuril and Toltrazuril Sulfoxide at various times post 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 drawn at
 the time of treatment (0) and at 0.25, 0.5, 1, 2, 4, 6, 12, 24, 48 and 72
 hours post treatment. Results of the sampling are listed in Table 1. It
 was surprising to note that horses receiving Toltrazuril demonstrated
 relatively high levels of Ponazuril in their serum. Additionally,
 significant levels of Toltrazuril sulfoxide were found in the bloodstream.
 This was an indication that Ponazuril, alone, would produce acceptable
 blood levels that are envisioned to pass the blood-brain barrier, a
 characteristic required to treat neurological diseases such as those
 caused by Sarcocystis neurona, Toxoplasma gondii, Neospora caninum and
 Neospora heugesi.
 TABLE 1
 Pharmacokinetics of a Single Dose of Toltrazuril in Horses
 D Compound Measured
 Concentration in mg/l of Blood
 0 0.25 0.5 1 2 4
 A Toltrazuril 0.027 0.773 2.863 4.511
 3.119
 Toltrazuril-Sulfoxide &lt;0.01 0.077 0.070 0.159
 0.142
 Ponazuril 0.010 0.089 0.088 0.171
 0.110
 B Toltrazuril 0.061 0.393 2.617 4.296
 6.820
 Toltrazuril Sulfoxide &lt;0.01 0.025 0.047 0.083
 0.157
 Ponazuril &lt;0.01 0.029 0.036 0.040 0.050
 C Toltrazuril 0.061 0.560 3.286 5.788
 9.079
 Toltrazuril Sulfoxide &lt;0.01 0.024 0.041 0.097
 0.218
 Ponazuril &lt;0.01 0.013 0.019 0.026 0.032
 D Toltrazuril 0.017 0.295 3.286 2.165
 3.328
 Toltrazuril Sulfoxide &lt;0.01 0.027 0.039 0.058
 0.100
 Ponazuril &lt;0.01 0.011 0.021 0.024 0.029
 E Toltrazuril &lt;0.01 0.039 1.146 3.175 8.410
 Toltrazuril Sulfoxide &lt;0.01 &lt;0.01 0.021 0.064 0.194
 Ponazuril &lt;0.01 &lt;0.01 0.017 0.015 0.044
 F Toltrazuril 0.110 0.428 1.741 -- 8.144
 Toltrazuril Sulfoxide &lt;0.01 0.026 0.044 -- 0.183
 Ponazuril &lt;0.01 0.012 &lt;0.01 -- 0.041
 Concentration in mg/l of Blood
 6 12 24 48 72
 A Toltrazuril 5.149 5.066 6.434 7.607 6.653
 Toltrazuril-Sulfoxide 0.167 0.230 0.407 0.732 0.592
 Ponazuril 0.108 0.170 0.324 1.622 1.933
 B Toltrazuril 11.474 11.670 11.690 6.677 5.058
 Toltrazuril Sulfoxide 0.320 0.451 0.566 0.454 0.346
 Ponazuril 0.131 0.254 0.255 0.831 0.880
 C Toltrazuril 14.202 13.751 -- 9.758 7.633
 Toltrazuril Sulfoxide 0.280 0.436 -- 0.477 0.377
 Ponazuril 0.061 0.135 -- 0.540 0.642
 D Toltrazuril 3.816 10.544 7.236 8.234 --
 Toltrazuril Sulfoxide 0.133 0.668 0.461 0.749 --
 Ponazuril 0.030 1.651 0.315 0.986 --
 E Toltrazuril 11.335 12.032 8.694 6.869 --
 Toltrazuril Sulfoxide 0.259 0.430 0.481 0.741 --
 Ponazuril 0.074 0.268 0.231 0.501 --
 F Toltrazuril 10.966 6.660 10.224 7.096 --
 Toltrazuril Sulfoxide 0.245 0.453 0.633 0.642 --
 Ponazuril 0.061 0.725 0.192 0.532 --
 EXAMPLE 2
 Ponazuril,
 1-methyl-3-[4-p-[trifluoromethyl)sulfonylphenoxy]-m-tolyl]-s-triazine-2,4,
 6 (1 H,3H,5H)-trione, a representative Triazinetrione, was formulated into
 a paste for administration to horses. The components listed in Table 2
 were used in preparing formulations as follows.
 TABLE 2
 Components of Ponazuril Horse Paste
 Theoretical Actual Amount
 Ingredient Amount % w/w
 Ponazuril - Micronized 22.5 Kg 15.0
 Propylene Glycol 30.0 Kg 20.0
 Carbopol 974P 0.750 Kg 0.5
 Methylparaben, NF 0.210 Kg 0.14
 Propylparaben, NF 0.030 Kg 0.02
 Sodium Hydroxide, NF 0.150 Kg 0.10
 Purified Water 96.365 Kg 64.24
 The formulations were prepared using process (A) and (B) as follows. The
 first process (A) comprised: 1) Mixing a portion of the water with the
 Propylene Glycol; 2) adding the preservatives (Methylparaben and
 Propylparaben; 3) slowly adding the Carbopol 974P until an even suspension
 was prepared; 4) adding the Ponazuril in a micronized form; 5) adding the
 Sodium Hydroxide to bring the suspension to a pH of approximately 6.0; and
 6) adding the remainder of the water to QS to volume. The final suspension
 was in the form of a paste, which can be delivered orally to a horse.
 The second process (B) comprised: 1) Mixing a portion of the water with the
 Propylene Glycol; 2) heating to 70.degree. C.; 3) adding the preservatives
 (Methylparaben and Propylparaben while holding the solution at 70.degree.
 C.; 4) cooling the solution to room temperature; 5) slowly adding the
 Carbopol 974P until an even suspension was prepared; 6) adding the
 Ponazuril in a micronized form; 7) adding the Sodium Hydroxide to bring
 the suspension to a pH of approximately 6.0; and 8) adding the remainder
 of the water to QS to volume. The final suspension was also in the form of
 a paste, which can be delivered orally to a horse.
 The resulting pastes were administered to horses and found to be palatable
 and well accepted.
 EXAMPLE 3
 Ponazuril,
 1-methyl-3-[4-p-[trifluoromethyl)sulfonylphenoxy]-m-tolyl]-s-triazine-2,4,
 6 (1 H,3H,5H)-trione, a representative Triazinetrione, was tested for its
 ability to treat horses already demonstrating signs of Equine Protozoal
 Myoencephalitis (EPM). The compound was formulated into a paste using
 Ponazuril as a 15% active ingredient (a.i.) as described in EXAMPLE 1. It
 was administered to horses already diagnosed with EPM once a day for 28
 days at a dose rate between 2.5 mg/Kg and 10 mg/Kg.
 Naturally occurring clinical cases of EPM were well characterized by
 signalment and laboratory diagnosis. The diagnosis used for incorporation
 of EPM-positive horses into this trial was as follows: Confirmed
 asymmetrical neurological deficit as determined by a standardized
 neurological examination, to include radiography, indicative of EPM;
 Positive Western Blot for Sarcocystis neurona IgG; Red Blood Cell count
 below 500 cells/mL; CSF indices--Total Protein &lt;90, IgG index &gt;0.3. AQ
 quotient &lt;2.2.
 Additional requirements were that the horses were not suffering from
 diseases other than EPM. Therefore, they had to meet the following
 criteria: Negative CSF (&lt;1:4) for EHV-1; Normal serum values for Vitamin E
 (.2.0 .mu.g/mL); Lack of seizure disorders; Lack of behavior disorders.
 Diagnosed horses were randomly assigned to groups. Group 1 horses received
 the paste formulation daily at a dose rate of 5mg/Kg whereas Group 2
 horses received the paste formulation daily at a dose rate of 10 mg/Kg.
 The treatment dose was based on body weight. The horses were evaluated for
 a period of 90 days (approximately 60 days after discontinuation of
 treatment) in order to determine that treatment was indeed effective. The
 response to treatment was scored using the following system: 1) 0=complete
 success-clinically normal with a negative CSF; 2) 1=Deficit just detected
 at a normal gait; 3) 2=Deficit easily detected and exaggerated by backing,
 turning, swaying, jaw loin pressure and neck extension; 4) 3=Deficit very
 prominent on walking, Facial turning, loin pressure or neck extension; 5)
 4=Stumbling, tripping and falling down spontaneously; 6) 5=Recumbent,
 unable to rise. An improvement of one (1) unit in the score was considered
 a significant improvement.
 Results of this study are shown in Table 3. All (100%) of the horses in the
 10 mg/Kg group which were treated for 28 days showed a significant
 improvement in clinical score by day 90 post start of treatment with
 Ponazuril (day 0). Eight of nine (88.9%) horses treated with the 5mg/Kg
 dose demonstrated acceptable improvement. When adding all of the scores
 for each group for each treatment day, a total score is obtained. The
 improvement in total scores demonstrated by both Group 1 and Group 2
 horses is approximately equivalent. It is thus concluded that Ponazuril at
 either a 5mg/Kg or 10 mg/Kg is effective for the active treatment of EPM
 in horses.
 TABLE 3
 Response of EPM-Infected Horses to Treatment with
 Toltrazuril Sulfone
 Horse 5 mg/Kg Dose 10 mg/Kg Dose
 ID Day 0 Day 28 Day 90 Day 0 Day 28 Day 90
 A 2 1 2
 B 2 1 1
 C 4 2 1
 D 3 2 0
 E 2 2 1
 F 3 2 0
 G 2 1 1
 H 2 2 1
 I 2 1 0
 J 2 0 0
 K 3 0 0
 L 2 3 3
 M 2 2 0
 N 2 2 0
 O 3 3 2
 TOTAL 17 13 6 19 15 4
 EXAMPLE 4
 In order to determine the scope of protection provided by Ponazuril, in
 vitro testing was conducted. The following strains of parasites were
 evaluated for their sensitivity to this compound: Strain SN3 of
 Sarcocystis neurona; strain SF1 of Sarcocystis falcatula; strain RH of
 Toxoplasma gondii; and the NC-1 strain of Neospora caninum. Ponazuril was
 tested at concentrations (1 .mu.g/mL and 10 .mu.g/mL).
 Bovine turbinate (BT) cells were used for all in vitro studies. Cells were
 grown to confluency in 25 cm.sup.2 flasks in RMPI 1640 media supplemented
 with 10% v/v fetal bovine serum (FBS), 100 Units penicillin (G/mL), 100 mg
 streptomycin/mL and 5.times.10.sup.-2 mM 2-mercpatoethanol. After cell
 confluence was obtained, cells were maintained in the same media with
 reduced FBS (2% v/v). Cell cultures were incubated at 37.degree. C. in a
 humidified atmosphere containing 5% carbon dioxide and 95% air.
 For growth of parasites, BT cell monolayers 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 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 the merozoite-containing fluid was transferred to two
 flasks of fresh BT cells. Merozoites of S. neurona and S. falcatula were
 passaged in this manner every 5 to 10 days while the tachyzoites of T.
 gondii and N. caninum were passaged every 3 to 4 days.
 The assay used to determine the effectiveness of Ponazuril was the
 Microtiter Monolayer Disruption Assay (MMDA). This assay was used to
 determine if the parasites or compound were toxic for BT cells. Flat
 bottomed 96-well microtiter plates were inoculated with BT cells and the
 resulting monolayers were used to determine the effects of Toltrazuril and
 Ponazuril on merozoite production as measured by CPE (plaque formation).
 Monolayers were inoculated with parasites (S. neurona or S. falcatula at a
 count of 50,000/well, T. gondii at a level of 10,000/well, and N. caninum
 at 20,000/well. All wells were inoculated with the test compound 2 hours
 after infection. Untreated and uninfected monolayer wells served as
 parasite controls and uninfected agent treated BT cells served as toxicity
 controls. Each treatment was examined in replicates of 6. Each well was
 visually monitored daily and the assay was stopped when 90-100% of the
 untreated merozoite infected cells had lysed (90-100% CPE). All wells of
 the plates were rinsed in Phosphate Buffered Saline (PBS) and fixed in
 100% methanol for 5 minutes after which they were stained in crystal
 violet solution. Areas of merozoite induced destruction or BT cell death
 due to toxicity do not take up the crystal violet. An ELISA plate reader
 was used to quantitate the crystal violet incorporation and these data
 were used to determine the concentration of Ponazuril that inhibits
 destruction by 50% (Inhibitory Concentration.sub.5 or IC.sub.50 ). The
 data demonstrating inhibition are presented in Table 4. It is noted that
 as little as 1 Hg/mL of Ponazuril provided 100% inhibition of cell
 destruction produced by N. caninum, T. gondii and S. falcatula whereas 10
 .mu.g/mL of Ponazuril was required to produce 100% inhibition of cell
 destruction by S. neurona . This indicates that triazineones such as
 Toltrazuril and Ponazuril would be efficacious for treatment of diseases
 caused by the Coccidia known to associated with neurological and
 abortigenic disease syndromes including diseases caused by S. neurona, N.
 caninum, N. hugesi and T. gondii. Additionally, Ponazuril was not toxic to
 the BT cells.
 TABLE 4
 In vitro Data on Ponazuril
 Organism Percent Inhibition of Cell Destruction
 0.1 .mu.g/mL 1 .mu.g/mL 5.0 .mu.g/mL 10 .mu.g/mL
 Sarcocystis 0 40 90 100
 neurona
 Sarcocystis 61 100 100 100
 falcatula
 0.001 .mu.g/mL 0.01 .mu.g/mL 0.1 .mu.g/mL 1.0 .mu.g/mL
 Neospora caninum 3 13 100 100
 NC-1
 Toxoplasma gondii 11 16 100 100
 EXAMPLE 5
 This experiment was conducted in order to determine whether triazineones
 such as Toltrazuril can pass the blood-brain barrier. Normal horses were
 divided into three groups of three horses per group. Group 1 horses
 received Toltrazuril administered orally as a 5% suspension at a dose
 level of 2.5 mg/Kg. Group 2 horses received Toltrazuril administered
 orally as a 5% suspension at a dose level of 5.0 mg/Kg. Group 3 horses
 received Toltrazuril administered orally as a 5% suspension at a dose
 level of 7.5 mg/Kg. The dosing was repeated daily for 10 days. Blood
 samples were drawn at 48, 96 and 240 hours and the concentration of
 Toltrazuril, Toltrazuril sulfoxide and Ponazuril in the serum was
 measured. Ten days after the start of the treatment (Day 10), a sample of
 cerebral spinal fluid was removed from each horse and the concentrations
 of Toltrazuril, Toltrazuril Sulfoxide and Ponazuril were again measured in
 these samples. The concentrations of Toltrazuril, Toltrazuril Sulfoxide
 and Ponazuril in the serum and cerebral spinal fluid are reported in
 TABLES 5a and 5b. Concentration of Ponazuril in the blood and cerebral
 spinal fluid after treatment of horses with Toltrazuril was significant,
 in that the concentration of Ponazruil in the cerebral spinal fluid after
 treatment of horses with Toltrazuril was essentially equivalent to the
 concentration of Toltrazuril itself. This is evidence that both
 Toltrazuril and Ponazuril effectively cross the blood-brain barrier and
 that Ponazuril crosses this barrier more effectively than does
 Toltrazuril. The data would suggest to one skilled in the art that the
 triazineones can also effectively cross the placental barrier.
 TABLE 5a
 Drug Levels after Repeated Doses of Toltrazuril in Horses
 Horse 10 Day Dose Toltrazuril Level Cerebral Spinal
 ID (mg/Kg) 48 Hrs 96 Hrs 240 Hrs Fluid - Day 10
 1 2.5 4.49 9.85 15.29 0.23
 2 2.5 4.0 9.09 9.60 0.06
 3 2.5 11.6 13.1 15.21 0.15
 4 5.0 7.28 14.17 24.92 0.19
 5 5.0 9.18 14.03 16.54 0.12
 6 5.0 9.26 18.19 17.59 0.26
 7 7.5 N/A 27.74 30.08 0.50
 8 7.5 9.90 19.55 24.15 0.21
 9 7.5 10.46 18.47 23.53 0.45
 AVG 2.5 mg/Kg Dose 6.70 10.68 13.37 0.15
 AVG 5.0 mg/Kg 8.57 15.46 19.68 0.19
 Dose
 AVG 7.5 mg/Kg 21.92 25.95 0.39
 Dose 10.18
 TABLE 5b
 Drug Levels after Repeated Doses of Toltrazuril in Horses
 Horse 10 Day Dose Toltrazuril Level Cerebral Spinal
 ID (mg/Kg) 48 Hrs 96 Hrs 240 Hrs Fluid - Day 10
 1 2.5 0.29 0.99 2.61 0.09
 2 2.5 0.24 1.15 2.36 0.07
 3 2.5 3.70 3.13 4.04 0.11
 4 5.0 0.48 2.09 5.44 0.12
 5 5.0 0.63 2.03 2.03 0.14
 6 5.0 0.48 2.66 5.61 0.21
 7 7.5 6.35 2.69 6.31 0.23
 8 7.5 0.78 2.89 6.37 0.17
 9 7.5 0.52 3.09 7.06 0.27
 AVG 2.5 mg/Kg 1.41 1.76 3.00 0.09
 Dose
 AVG 5.0 mg/Kg 0.53 2.26 5.02 0.16
 Dose
 AVG 7.5 mg/Kg 2.55 2.89 6.58 0.22
 Dose
 Although the invention has been described in detail in the foregoing for
 the purpose of illustration, it is to be understood that such detail is
 solely for that purpose and that variations can be made therein by those
 skilled in the art without departing from the spirit and scope of the
 invention except as it may be limited by the claims.