EP1318795A2 - Anthelmintics for preventing parasitic infections in humans and animals - Google Patents

Abstract

The invention relates to agents containing specific active ingredients that act as repellents and to their use for preventing humans or animals from being infected with parasitic flatworms (platyhelminths).

Description

Anthelmintics to prevent parasitic infections in humans and animals IN

The present invention relates to compositions comprising certain active substances suitable as repellents and their use for reducing the infection of humans or animals with the infection stages of parasitic flatworms (platinum helminths). The agents are used on the skin against such stages of flatworms, so-called cercariae, which can penetrate through the skin into the host body.

Several types of platinum mints cause serious illnesses in humans and animals. In tropical countries, infections with Schistosoma species in particular lead to chronic suffering and often to death. Important pathogens are Schistosoma mansoni, Schistosoma haematobium and Schistosoma japonicum.

The local population, tourists, humanitarian aid workers and military personnel are affected. When humans are infected, the infectious cercariae, which are in the water of open water, can penetrate the body through the skin.

Also problematic in countries with a temperate climate is the infestation of people with cercariae of various types of the genera Trichobilharzia and Ornithobilharzia, which can penetrate the skin and cause dermatitis. Such infections occur during leisure activities on inland waters or sea coasts as well as during activities in fishing, pond management or

Field irrigation. Generally, in many situations of daily life, the skin is in contact with u. Contaminated / infected water may be unavoidable.

However, pretreatment of the skin according to the invention with substances having an anti-inflammatory effect can protect the pathogens from penetrating. Some compounds have been tested in the past for their suitability for preventing infections with such parasites. However, the substances previously described for the purposes of the invention are toxic if they enter the body through the skin or after oral ingestion:

For example, Hexachlorophene has a killing effect on cercariae from Schistosoma mansoni (Fripp, P.J. and Armstrong, F.L., The efficacy of hexachlorophene skin cleanser as a cercariae repellent. South African Med. J. 47: 1973, 526-527). Because of health risks, especially liver damage, hexachlorophene cannot be applied to the skin in humans. It is toxic at

Contact with skin and if swallowed may cause birth defects and may be carcinogenic [Commission of the European Communities, Directive 93/72 / EEC of 1 September. 1993, Appendix Vol. I and II (EU Hazardous Substances Ordinance) with additions up to 1999, Official Journal of EUL258A, 36th year, Oct. 16, 1993, additions up to 1997].

Niclosamide acts against the penetration of cercariae [Bruce, J.I. et al. (1992) Efficacy of niclosamide as a potential topical antipenetrant (TAP) against cercariae of Schistosoma mansoni in monkeys. Mem. Inst. Oswaldo Cruz 87:28 1-289.] Is toxicologically unsafe because it can cause inheritable genetic damage (Registry of Toxic Effects of Chemical Substances, National Institute of Occupational Safety and Health). Use on the skin when exposed to water is prohibited by its environmentally hazardous properties, since niclosamide is highly water-endangering [Federal Environment Agency (ed.) Catalog of water-endangering substances. LTwS no. May 12, 1996 with ongoing additions,

Berlin 1996]. Therefore, no commercial use against cercariae has occurred in humans.

N, N-Diethyl-m-toluamide (DEET) acts on cercariae from Schistosoma mansoni [Salafsky, B. et al. Evaluation of N, N-diethyl-m-toluamide (DEET) as a topical agent for preventing skin penetration by cercariae of Schistosoma mansoni. At the. J. Trop. Med. Hyg. 58: 1998, 828-834). However, DEET has some unfavorable properties.

The effect of the ant-helminthics described so far against infectious stages of plathelminths has so far only been tested on cercariae of the species Schistosoma mansoni, so that the effectiveness of these agents against other types of worms has not yet been demonstrated.

It has now surprisingly been found that the agents according to the invention are suitable for providing effective protection against infections for humans and animals

Plathelminths, especially Schistosoma haematobium, Schistosoma japonicum, Trichobilharzia spp. and Ornithobilharzia spp., but also Echinostoma spp. et al to offer.

The invention accordingly relates to

1. Agent for defense against helminthic parasites, characterized by a content of at least one compound of the formula (I)

in which

R ^{1 represents} hydrogen or an optionally substituted alkyl, alkenyl or alkynyl radical,

R ² and R ^{5 are} identical or different and stand for optionally substituted alkyl, alkenyl or alkynyl radicals and R ³ and R ^{5 represent} hydrogen, optionally substituted alkyl, aralkyl or aryl or together with the atom to which they are attached form an optionally substituted, monocyclic ring.

2. Agent for defense against helminthic parasites according to item 1, characterized in that in the formula (I)

R ^{1 represents} hydrogen, (C _r C ₁₀ ) - alkyl, (C ₂ -C ₁₀ ) -A - kmyl,

R ² and R ^{5 are the} same or different and stand for (CI -CJO) - alkyl, (C2-C10) - alkenyl or (C -Cιo) alkynyl and

R ³ and R ^{4 are} hydrogen, (Cj-Cio) - alkyl, in each case in the aryl part optionally mono- to triple, identical or differently substituted aryl or aralkyl each having 6 to 10 carbon atoms in the aryl part and optionally 1 to 4 carbon atoms in the alkyl part , the aryl substituents in each case being suitable: halogen, in each case straight-chain or branched (Ci-C ^ alkyl, (Ci-C ^ haloalkyl, (-C-C4) haloalkoxy and (C ₁ -C) halo - alkylthio or together with the atom to which they are attached represent cycloalkyl having 3 to 7 carbon atoms.

3. Means for repelling henhenic parasites according to item 1, characterized in that in formula (I)

R ^{1 represents} hydrogen, (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ alkynyl,

R ^{2 represents} (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl, R ³ and R ^{4 are} hydrogen, (C ₁ -C ₅ ) alkyl, each in the phenyl part optionally mono- to trisubstituted, identically or differently substituted, phenyl or phenylalkyl with optionally 1 or 2 carbon atoms in the alkyl part, the following being suitable as phenyl substituents: Fluorine, chlorine, bromine, (-C-C ₂ ) - alkyl, (Cι-C ₂ ) ~

Haloalkyl, (CC ^ -haloalkoxy, (Cj-C ₂ ) -haloalkylthio or together with the atom to which they are attached are cycloalkyl having 3 to 6 carbon atoms and

R ^{5 is} (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl.

4. Means for repelling helminthic parasites according to item 1, characterized in that in the formula (I)

R ^{l is} hydrogen, (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) -

Alkynyl,

R ^{2 represents} (C ₁ -C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl,

R ³ and R ^{4 are} hydrogen, (C ₁ -C ₅ ) -alkyl, each in the phenyl part optionally mono- to trisubstituted, identically or differently, substituted phenyl, benzyl, phenethyl, the substituents in each case being: fluorine, chlorine, bromine, methyl , Ethyl, trifluoromethyl, trifluoromethoxy, trifluoromethylthio or together with the atom to which they are attached stand for cyclopropyl, cyclopentyl, cyclohexyl and

R ^{5 represents} (C _r C ₁₀ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl.

5. Agent for defense against helminthic parasites according to item 1, characterized in that in the formula (I) R ^{1 represents} hydrogen, (C _r C ₅ ) -alkyl or (C ₂ -C ₅ ) -alkenyl,

R ^{2 represents} (C _r C ₅ ) alkyl or (C ₂ -C ₅ ) alkenyl,

R ³ and R ^{4 represent} hydrogen, (C _r C ₅ ) alkyl, or together with the atom to which they are attached, stand for cyclopropyl and

R ^{5 stands} for (-C ₅ ) alkyl or (C ₂ -C ₅ ) alkenyl.

6. A method of repelling helminthic parasites, characterized in that compounds of the general formula (I) are used.

7. Use of compounds of general formula (I) for defense against helminthic parasites.

8. A process for the preparation of agents for defense against helminthic parasites, characterized in that compounds of the general formula (I) are mixed with extenders and / or surface-active agents.

The compound of the formula is particularly suitable for use in the agents according to the invention

The compounds of formula (I) and their preparation are known from DE OS 38 20 528. The active substances contained in the agents according to the invention have already been used specifically for use as repellants on the skin against insects and ticks.

A major advantage of using the compounds according to the invention is their high skin, plant and environmental compatibility and the generally low toxicity of these compounds.

It is also desirable to be protected against mosquitoes when they are outdoors, which on the one hand are perceived as annoying and on the other hand, the mosquitoes with their bites can transmit diseases such as malaria, various viruses, filaria and parasites, especially in the tropics. The agents according to the invention now enable simultaneous prevention against infections with platinum helminths and protection against mosquitoes with one agent. This avoids the need to use two different, possibly incompatible agents on the skin at the same time.

In addition to the active ingredients, the agents according to the invention can also contain all customary auxiliaries and additives which are used in formulations for topical application.

The active ingredients are used directly or in the form of suitable preparations dermally or with the aid of shaped articles containing active ingredients, e.g. Strips, plates, ribbons, collars, ear tags, limb ribbons, marking devices.

The dermal application takes place, for example, in the form of bathing, dipping, dipping), spraying (spraying), pouring on (pour-on or spot-on), washing, shampooing, watering, powdering. Suitable preparations are:

Solutions or concentrates for administration after dilution, solutions for

Skin use, infusion formulations, gels;

Emulsions and suspensions for dermal use and semi-solid preparations;

Formulations in which the active ingredient is processed in an ointment base or in an oil in water or water in oil emulsion base;

Solid preparations such as powders, shaped articles containing active ingredients.

Solutions for use on the skin are dripped on, spread on, rubbed in, sprayed on, sprayed on or applied by dipping (dipping), bathing or washing.

The solutions are prepared by dissolving the active ingredient in a suitable solvent and possibly adding additives such as solubilizers, acids, bases, buffer salts, antioxidants, preservatives.

The following may be mentioned as solvents: physiologically compatible solvents such as water, alcohols such as ethanol, butanol, benzyl alcohol, glycerol, hydrocarbons, propylene glycol, polyethylene glycols, N-methylpyrrolidone, and mixtures thereof.

The active ingredients can optionally also be dissolved in physiologically compatible vegetable or synthetic oils.

The following may be mentioned as solubilizers: solvents which require the active ingredient to be dissolved in the main solvent or prevent it from precipitating. Examples are polyvinyl pyrrolidone, polyoxyethylated castor oil, polyoxyethylated sorbitan esters. Preservatives are: benzyl alcohol, trichlorobutanol, p-hydroxybenzoic acid ester, n-butanol.

It may be advantageous to add thickeners when preparing the solutions. Thickeners are: inorganic thickeners such as bentonites, colloidal silica, aluminum monostearate, organic thickeners such as cellulose derivatives, polyvinyl alcohols and their copolymers, acrylates and methacrylates.

Gels that are applied or spread on the skin are produced by adding enough thickening agent to solutions that have been prepared as described above to produce a clear mass with an ointment-like consistency. The thickeners specified above are used as thickeners.

Pour-on formulations are poured or sprayed onto limited areas of the skin, the active ingredient being distributed over the surface of the body.

Pour-on formulations are prepared by dissolving, suspending or emulsifying the active ingredient in suitable skin-compatible solvents or solvent mixtures. If necessary, further auxiliaries such as dyes, antioxidants, light stabilizers and adhesives are added.

The following may be mentioned as solvents: water, alkanols, glycols, polyethylene glycols, polypropylene glycols, glycerol, aromatic alcohols such as benzyl alcohol, phenylethanol, phenoxyethanol, esters such as ethyl acetate, butyl acetate, benzylbenzoate, ethers such as alkylene glycol alkyl ethers such as dipropylene glycol monomethyl ether, diethylene glycol, monobutyl glycol, monobutyl glycol Methyl ethyl ketone, aromatic and / or aliphatic hydrocarbons, vegetable or synthetic oils, DMF, dimethyl acetamide, N-methyl pyrrolidone, 2-dimethyl-4-oxy-methylene-l, 3-dioxolane. Dyes are all dyes approved for use on animals, which can be dissolved or suspended.

Excipients are also spreading oils such as isopropyl myristate, dipropylene glycol pelargonate, silicone oils, fatty acid esters, triglycerides, fatty alcohols.

Antioxidants are sulfites or metabisulfites such as potassium metabisulfite, ascorbic acid, butylated hydroxytoluene, butylated hydroxyanisole, tocopherol.

Light stabilizers are e.g. Substances from the class of benzophenones or

Novantisol acid.

Adhesives are e.g. Cellulose derivatives, starch derivatives, polyacrylates, natural polymers such as alginates, gelatin. Emulsions are either water in oil or oil in water.

They are produced by dissolving the active ingredient either in the hydrophobic or in the hydrophilic phase and homogenizing it with the solvent of the other phase with the aid of suitable emulsifiers and, if necessary, other auxiliary substances such as dyes, absorption-promoting substances, preservatives, antioxidants, light stabilizers, viscosity-increasing substances ,

The following may be mentioned as the hydrophobic phase (oils): paraffin oils, silicone oils, natural vegetable oils such as sesame oil, almond oil, castor oil, synthetic triglycerides such as caprylic / capric acid biglyceride, triglyceride mixture with vegetable fatty acids of chain length

C ₈ . ₁₂ or other specially selected natural fatty acids, partial glyceride mixtures of saturated or unsaturated fatty acids, which may also contain hydroxyl groups, mono- and diglycerides of C ₈ / CIO fatty acids.

Fatty acid esters such as ethyl stearate, di-n-butyryl adipate, lauric acid hexyl ester,

Dipropylene glycol pelargonate, ester of a branched fatty acid of medium chain length with saturated fatty alcohols of chain length Cι ₆ -C _18, isopropyl myristate, isopropyl palmitate, caprylic / Caprinsäureester of saturated fatty alcohols of chain length _{C12 -C18,} isopropyl stearate, decyl oleate, ethyl oleate, ethyl lactate, waxy fatty acid ester such as dibutyl phthalate, adipic acid diisopropyl ester, related to the latter Ester mixtures including fatty alcohols such as

Isotridecyl alcohol, 2-octyldodecanol, cetylstearyl alcohol, oleyl alcohol.

Fatty acids such as Oleic acid and its mixtures.

The following can be mentioned as the hydrophilic phase:

Water, alcohols such as e.g. Propylene glycol, glycerin, sorbitol and their mixtures.

The following may be mentioned as emulsifiers: nonionic surfactants, e.g. polyoxyethylated castor oil, polyoxyethylated sorbitan monooleate, sorbitan monostearate, glycerol monostearate, polyoxyethyl stearate, alkylphenol polyglycol ether;

ampholytic surfactants such as di-Na-N-lauryl-β-iminodipropionate or lecithin;

anionic surfactants, such as sodium lauryl sulfate, fatty alcohol ether sulfates, mono / dialkyl polyglycol ether orthophosphoric acid ester monoemanolamine salt; cationic surfactants such as cetyltrimemylammonium chloride.

The following may be mentioned as further auxiliaries: viscosity-increasing substances and substances stabilizing the emulsion, such as carboxymethyl cellulose, methyl cellulose and other cellulose and starch derivatives, polyacrylates, alginates, gelatin, gum arabic, polyvinyl pyrrone, polyvinyl alcohol, copolymers of methyl vinyl ether and maleic anhydride, polyethylene glycols, waxes , colloidal silica or mixtures of the listed substances.

Suspensions are prepared by adding the active ingredient in a carrier liquid, if necessary with the addition of other auxiliaries such as wetting agents, dyes, Suspending substances, preservatives, antioxidants, light stabilizers suspended.

All homogeneous solvents and solvent mixtures are mentioned as carrier liquids.

The surfactants specified above may be mentioned as wetting agents (dispersants).

Further additives mentioned are those mentioned above.

Semi-solid preparations for dermal administration differ from the suspensions and emulsions described above only in their higher viscosity.

To prepare solid preparations, the active ingredient is mixed with suitable carriers, if appropriate with the addition of auxiliaries, and brought into the desired shape.

All physiologically compatible solid inert substances may be mentioned as carriers. Inorganic and organic substances serve as such. Inorganic substances are e.g. Common salt, carbonates such as calcium carbonate, hydrogen carbonates, u-minium oxides,

Silicas, clays, precipitated or colloidal silicon dioxide, phosphates.

Excipients are preservatives, antioxidants, dyes, which have already been listed above.

Other suitable auxiliaries are lubricants and lubricants such as Magnesium stearate, stearic acid, talc, bentonite.

Furthermore, it is desirable that such a protective agent also after prolonged contact with water, for example when swimming, washing clothes or

Fishing, still shows a sufficient protective effect. For this purpose, the Agents according to the invention also contain water-repellent or waterproof substances.

Suitable waterproof substances have previously been used in sunscreens to protect the user against the UN radiation from the sun (e.g.

US 55 18712 and US 4810489). The aim was to maintain the sun protection even when the user was swimming or sweating profusely, etc. Sun protection agents containing such water-resistant or water-repellent substances and insect repellents are already known (US 5716602). However, no agents containing anthelmintics have yet been described.

Accordingly, waterproof substances can also be contained in the agent according to the invention. These can be fat-soluble, water-insoluble substances as well as compounds that increase the adhesion of the agent to the skin.

Skin protection products could contain, for example, 1 to 50% by weight of a polymer such as polyynylpyrrolidones, polyacrylates, silicones, etc. as water-resistant components.

The agents for topical use can be used as a spray, solution, cream, ointment or layer- or film-forming agent, according to the methods known for the production of cosmetics (Schrader, K. (1979) basics and formulations of the cosmetics. Dr. Alfred Hüthig Verlag, Heidelberg).

For use, the formulations according to the invention are applied to the skin uniformly and without gaps in a consumer-appropriate amount.

The agents according to the invention are of course also suitable for use on animals in order to prevent infection of the animals with parasites of these genera. The funds can be used in pets, such as dogs and cats

Livestock, such as cattle, sheep, etc. When using the agents according to the invention, 0.03 to 1 mg, preferably 0.03 to 0.1 mg and particularly preferably 0.04 to 0.06 mg of the active ingredient are generally applied per square centimeter of skin. This provides prophylactic protection against skin-penetrating worms and their pre-stages.

The active ingredient must be applied repeatedly during a longer stay in the water.

The agents according to the invention are illustrated by the following examples without restricting them however.

Biological example:

Efficacy against Schistosoma mansoni cercariae

[500 μl / 1 final concentration of the active ingredients]

For infection, snails (Biomphalaria glabrata) were incubated with 8 miracidia in 10 ml of water overnight. Cercariae were obtained about 6 to 9 weeks after infection by irradiating the snails kept in the dark with light and collecting the cercariae after they had swarmed out within 2 hours.

Sufficient water containing cercariae (1 or 2 ml, see below) was added to the test batches so that each batch contained about 100 to 150 cercariae.

5 μl of active ingredient were thoroughly mixed with 25 μl of PEG300. Then was

9 ml of aquarium water added and the mixture shaken vigorously. After (delayed) addition of 1 ml of cercariae, the survival of the cercariae was observed with the stereo magnifier. The following classification was used to classify the effectiveness of the active compounds: 0 = no effect over the entire test period of 120 minutes; 1 = weak effect

(Cercariae show a greatly reduced mobility); 2 = good effect (cercariae are only slightly mobile and curved); 3 = full effectiveness (cercariae are completely motionless)

In this test, the effect of the compound of the following formula

rated with 1.

Claims

Patentansprfiche

1. Agent for defense against hen-hhenic parasites, characterized by a content of at least one compound of the formula (I)

in which

R ^{1 represents} hydrogen or an optionally substituted alkyl, alkenyl or alkynyl radical,

R ² and R ^{5 are} identical or different and stand for optionally substituted alkyl, alkenyl or alkynyl radicals and

R ³ and R ^{5 are} hydrogen, optionally substituted alkyl, aralkyl or

Aryl stand or together with the atom to which they are attached form an optionally substituted, monocyclic ring.

2. Agent for repelling hen-hhenic parasites according to claim 1, characterized in that in the formula (I)

R ^{1 represents} hydrogen, (C _r C ₁₀ ) -A] alkyl, (C ₂ -C ₁₀ ) -alkynyl,

R ² and R ^{5 are the} same or different and are for (Cι-Cιo) alkyl, (C ₂ -Cιo) -

Alkenyl or (C ₂ -Cι ₀ ) alkynyl and

R ³ and R ⁴ for hydrogen, (Cj-Cι ₀ ) alkyl, each in the aryl part optionally mono- to triple, the same or differently substituted aryl or aralkyl each having 6 to 10 carbon atoms in the aryl part and optionally 1 to 4 carbon atoms in the alkyl part, the aryl substituents in each case being suitable: halogen, in each case straight-chain or branched (C1-C4) alkyl, (-C-C) haloalkyl, and (-C-C4) haloalkylthio or together with the atom to which they are attached are cycloalkyl having 3 to 7 carbon atoms.

3. Means for repelling helminthic parasites according to spoke, characterized in that in the formula (I)

R ^{1 represents} hydrogen, (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl,

R2 represents (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl,

R ³ and R ^{4 are} hydrogen, (C 1 -C 5) -alkyl, each in the phenyl part optionally mono- to trisubstituted, identically or differently substituted, phenyl or phenylalkyl with optionally 1 or 2 carbon atoms in the alkyl part, the following being suitable as phenyl substituents: Fluorine, chlorine, bromine, (-C-C ₂ ) - alkyl, (Cj-C ₂ ) - haloalkyl, (C ₁ -C ₂ ) -haloalkoxy, (Cι-C) -haloalkylthio or together with the atom to which they are cycloalkyl having 3 to 6 carbon atoms and

R ^{5 is} (C _r C ₁₀ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl.

Protection against helminthic parasites according to claim 1, characterized in that in the formula (I) R ^{1 represents} hydrogen, (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl,

R ^{2 represents} (C _r C ₅ ) alkyl, (C ₂ -C ₅ ) alkenyl or (C ₂ -C ₅ ) alkynyl,

R ³ and R ⁴ for hydrogen, (-C-C5) alkyl, each in the phenyl part optionally mono- to triple, identical or differently substituted phenyl, benzyl, phenethyl, the substituents in each case being: fluorine, chlorine, bromine, methyl, ethyl , Trifluoromethyl, trifluoromethoxy, trifluoromethylthio or together with the atom to which they are attached stand for cyclopropyl, cyclopentyl, cyclohexyl and

R5 represents (Ct-CtoVAlkyl, (C ₂ -C ₅ ) -alkenyl or (C ₂ -C ₅ ) -alkynyl.

5. Agent for defense against helminthic parasites according to claim 1, characterized in that in the formula (I)

R ^{1 represents} hydrogen, (C _r C ₅ ) -alkyl or (C ₂ -C ₅ ) -alkenyl,

R ^{2 represents} (C _r C ₅ ) alkyl or (C ₂ -C ₅ ) alkenyl,

R ³ and R ^{4 represent} hydrogen, (C1-C5) - alkyl, or together with the atom to which they are attached stand for cyclopropyl and

R ^{5 represents} (C _r C ₅ ) alkyl or (C ₂ -C ₅ ) alkenyl.

6. A method of repelling helminthic parasites, characterized in that compounds of the general formula (I) are used.

7. Use of compounds of general formula (I) for defense against helminthic parasites.

8. A process for the preparation of agents for defense against helminthic parasites, characterized in that compounds of the general formula (I) are mixed with extenders and / or surface-active agents.