EP1309320A2

EP1309320A2 - Anthelminthic agents for the prevention of parasitic infections in humans and animals ii

Info

Publication number: EP1309320A2
Application number: EP01945311A
Authority: EP
Inventors: Achim Harder; Georg Von Samson-Himmelstjerna; Bernd-Wieland Krüger; Heinz Mehlhorn; Jürgen Schmidt
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 2000-07-06
Filing date: 2001-06-25
Publication date: 2003-05-14
Also published as: PL359596A1; US20040014813A1; DE10032879A1; CA2413581A1; CN1440280A; KR20030017542A; BR0112369A; AU2001267565A1; WO2002002087A3; HUP0301298A3; WO2002002087A2; HUP0301298A2; ZA200300055B; JP2004501959A

Abstract

The invention relates to agents containing particular active ingredients which can be used as repellents, and the use thereof to prevent humans or animals being infected by the stages of infection of parasitic flatworms (platyhelminths). Said active ingredients are cyclic or acyclic amides.

Description

Anthelmintics to prevent parasitic infections in humans and animals II

The present invention relates to compositions containing certain active substances suitable as repellents and their use for preventing infection of humans or animals with the infection stages of parasitic flatworms (plathelminths). 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 plathelminths cause serious human and animal diseases. 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 japomcum. The local population, tourists, humanitarian aid workers and military personnel are affected. When humans are infected, the infectious cercariae, which are found in open water, can penetrate the body through the skin.

The infestation of is also problematic in countries with a temperate climate

People with cercariae of various types of the genera Trichobilharzia and Ornithobilharzia, who can dig into the skin and cause dermatitis. Such infections occur during leisure activities on inland waterways or sea coasts, as well as during activities in fishing, pond management or field irrigation. Generally, in many situations of everyday life, the contact is

Skin with u. U. contaminated / infected water inevitable.

A pretreatment of the skin according to the invention with anthelmintic substances can, however, protect against the penetration of the pathogens.

Some compounds have been tested in the past for their suitability for preventing infections with such parasites. So far for the However, substances described according to 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 Schistosomas 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 poisonous in contact with the skin and if swallowed, may cause malformations 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 apotential 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). Application on the skin after exposure in

Water is forbidden due to 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 to date.

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 effects of the anthelmintics described so far against infectious stages of plathelminths have 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 been demonstrated.

It has now surprisingly been found that the agents according to the invention are suitable for providing effective protection for humans and animals against infections with plathelminths, in particular Schistosoma haematobium, Schistosoma japonicum, Trichobilharzia spp. and Omithobilharzia 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

Y represents hydrogen, optionally substituted alkyl or the radical O-X,

X represents hydrogen, COR ¹¹ , COOR12, Rl3,

R ^{1 represents} an optionally substituted alkyl, alkenyl, cycloalkyl or cycloalkenyl radical, R ² , R ¹¹ , R ¹² and R ^{13 are} identical or different and represent optionally substituted alkyl or alkenyl radicals,

R ³ to R ^{10 are the} same or different and represent hydrogen or optionally substituted alkenyl radicals and where R ² and R ³ together with the atoms to which they are bonded can also form an optionally substituted monocyclic ring and

n and m are the same or different and denote 0 or 1, with the proviso that X is not hydrogen or R ¹³ if n and m are 0.

2. Means for defense against helminthic parasites according to item 1, characterized by a content of at least one compound of the formula (I) in which

Y represents hydrogen, Ci-C _ö alkyl or the radical OX,

X represents hydrogen, COR ¹ * or R ¹³ ,

R ¹ for C ₃ -C ₇ cycloalkyl, C ₃ -C ₇ cycloalkenyl, C ₁ -C ₂ alkyl-C ₃ -C ₇ cycloalkyl, CrC ₂ alkyl-C ₃ -C cycloalkenyl, where the cycloalkyl or

Cycloalkenyl rings of the aforementioned radicals are optionally substituted up to three times by C 1-6 alkyl or by a C 1 -C 6 -dialkylene bridge or

R ^{1 represents} C _r C ₇ alkyl or C ₃ -C ₇ alkenyl,

R ² , R ¹¹ , R ^{13 are the} same or different and represent Ci-Cό- alkyl, R ³ to R ^{6 are the} same or different and represent hydrogen or C 1 -C 6 -alkyl, where R ² and R ³ together with the atoms to which they are attached can form a 5- or 6-membered monocyclic ring and

n for 1 and

m stands for 0.

3. A method for combating parasitic helminths, characterized in that compounds of the formula (I) according to item 1 are allowed to act on helminths and / or their habitat.

4. Use of compounds of the formula (I) according to item 1 for controlling parasitic helminths.

5. A process for the preparation of agents for defense against helminthic parasites, characterized in that compounds of the formula (I) according to item 1 are mixed with extenders and / or surface-active agents.

According to a preferred embodiment in formula (I) the substituent Y is hydrogen or -Ce-alkyl, such as. B. methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, iso-butyl or tert-butyl, pentyl or hexyl. In this case, R ¹ preferably represents C ₃ -C ₇ cycloalkyl, C ₃ -C ₇ cycloalkenyl, C ₁ -C ₂ alkyl-C ₃ -C ₇ cycloalkyl, C ₁ -C ₂ alkyl- C ₃ -C ₇ cycloalkenyl, the cycloalkyl or cycloalkenyl rings of the abovementioned radicals optionally being substituted up to three times by C 1 -C 6 -alkyl or by a C ₁ -C ₆ -dialkylene bridge.

According to a further embodiment, compounds of the formula (I) in which are suitable for use in the agents according to the invention Y stands for the rest OX,

X represents hydrogen, COR ¹ COOR ¹² , R ^l3 ,

R ^{1 represents} optionally substituted alkyl or alkenyl radicals,

R ² , R ¹¹ , R ¹² and R ^{13 are} identical or different and represent optionally substituted alkyl or alkenyl radicals,

R ³ to R ^{10 are the} same or different and represent hydrogen or optionally substituted alkenyl radicals, and where R ² and R ³ together with the atoms to which they are attached can also form an optionally substituted monocyclic ring and

n and m are the same or different and represent 0 or 1, with the proviso that X is not hydrogen or R ¹³ if n and m are 0.

Compounds of the formula (I) in which

X represents hydrogen, COR ¹¹ or R ¹³ ,

R ^{1 represents} Ci-C-alkyl or C ₃ -C ₇ -alkenyl,

R ² , R ⁿ , R ^{13 are the} same or different and are C ₃ -C ₆ alkyl,

R ³ to R ^{6 are the} same or different and stand for hydrogen or Ci- - alkyl, where R ² and R ³ together with the atoms to which they are attached can form a 5- or 6-membered monocyclic ring and n for 1 and

m stands for 0.

In these compounds, R ² and R ³ very particularly preferably form, together with the atoms to which they are attached, a 5- or 6-membered monocyclic ring, in particular a piperazine ring.

Of these, the compounds of the formula (Ia) are particularly suitable.

embedded image in which

X represents hydrogen, COR ¹¹ , COOR ¹² , R ¹³ , where R ¹ \ R ¹² and R ^{13 are the} same or different and for optionally substituted alkyl or alkenyl radicals, in particular for hydrogen or CrGrAlkyl, such as. B.

Methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, iso-butyl or teri-

Butyl, stand and

R ^{1 represents} C _r C ₆ alkyl or C ₃ -C ₆ alkenyl.

In particular, the following compounds of the formula (I) or (Ia)

mentioned as particularly suitable for use in the agents according to the invention.

The compounds of formula (I) and (la) and their preparation are known from DE OS 37 08 033.

The following compound of the formula (I) is also suitable for use according to the invention

This compound is known and commercially available.

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 is 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 straps, marking devices.

The dermal application happens e.g. in the form of bathing, diving (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 use on the skin, infusion formulations, gels;

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

Formuherungen 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, glycerin, hydrocarbons, propylene glycol, polyethylene glycols, N-methyl-pyrrolidone, 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, dimethylacetamide, N-methylpyrrolidone, 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 novantisolic acid.

Adhesives are, for example, 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, with the aid of suitable emulsifiers and, if appropriate, other auxiliaries such as dyes, absorption-promoting substances,

Preservatives, antioxidants, light stabilizers, viscosity-increasing substances, homogenized with the solvent of the other phase.

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 /

Caprinsäurebiglycerid, triglyceride mixture with vegetable fatty acids of chain length _C8-12 or other natural fatty acids, Partialglycerid- specially selected mixtures of saturated or unsaturated fatty acids possibly also containing hydroxyl groups, mono- and diglycerides of the Cs / C o _t-fatty acids.

Fatty acid esters such as ethyl stearate, di-n-butyryl adipate, lauric acid hexyl ester, dipropylene glycol pelargonate, esters of a branched fatty acid of medium chain length with saturated fatty alcohols of chain length C ₆ -C ₁₈ , isopropyl myristate, isopropyl palmitate, caprylic / capric alcohol esters of saturated fatty alcohol Chain length C ₁₂ -C ₁₈ , isopropyl stearate, oleic acid oleyl ester, oleic acid decyl ester, ethyl oleate, lactic acid ethyl ester, waxy fatty acid esters such as dibutyl phthalate, adipic acid diisopropyl ester, the latter related ester mixtures including fatty alcohols such as isotride-cyl alcohol, 2-octyl alcohol, 2-octyl alcohol, 2-octyl alcohol doleyl alcohol.

Fatty acids such as Oleic acid and its mixtures.

The following can be mentioned as the hydrophilic phase:

Water, alcohols such as propylene glycol, glycerin, sorbitol and their mixtures. The following may be mentioned as emulsifiers: nonionic surfactants, for example polyoxyethylated castor oil, polyoxyethylene 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 monoethanolamine salt; cationic surfactants such as cetyltrimethylammonium chloride.

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

Suspensions are produced by suspending the active ingredient in a carrier liquid, optionally with the addition of other auxiliary substances such as wetting agents, dyes, absorption-promoting substances, preservatives, antioxidants, light stabilizers.

All homogeneous solvents and solvent mixtures may be 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. Table salt, carbonates such as calcium carbonate, hydrogen carbonates, aluminum 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 still has a sufficient protective effect even after prolonged contact with water, for example when swimming, washing clothes or fishing. For this purpose, the agents according to the invention can also contain water-repellent or water-resistant substances.

Suitable waterproof substances have previously been used in sunscreens which are intended to protect the user against the UV radiation from the sun (for example US 55 18712 and US 4810489). The aim was to maintain sun protection even when the user was swimming or sweating profusely, etc. Sunscreen compositions containing such water-resistant or water-repellent substances and insect repellents are already known (US5716602). However, no agents containing anthelmintics have yet been described.

Accordingly, waterproof substances can also be used in the invention Means be included. 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, 1-50% 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) fundamentals and formulations of cosmetics.

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 agents can be used in pet animals such as dogs and cats and in farm animals such as cattle, pigs, sheep and the like. a. be applied.

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 or their pre-stages. The active ingredient must be applied repeatedly during a longer stay in the water.

The compositions according to the invention are illustrated by the following examples, but without restricting them. 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 each 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 9 ml of aquarium water was added and the mixture was 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 have a greatly reduced mobility); 2 = good effect (cercariae are only slightly mobile and curved); 3 = full effectiveness (cercariae are completely motionless)

Evaluation for various compounds according to the invention: Connection rating

Claims

claims

in which

Y represents hydrogen, optionally substituted alkyl or the radical O-X,

X represents hydrogen, COR ¹ COOR ¹² , R ¹³ ,

R ^{1 represents} an optionally substituted alkyl, alkenyl, cycloalkyl or cycloalkenyl radical,

2. Means for defense against helminthic parasites according to claim 1, characterized in that they contain at least one compound of the formula (I) in which

Y represents hydrogen, d-Ce-alkyl or the radical O-X,

X represents hydrogen, COR ¹ 1 or R ¹³ ,

R ¹ for C ₃ -C ₇ cycloalkyl, C ₃ -C ₇ cycloalkenyl, C ₁ -C ₂ alkyl-C ₃ -C ₇ cycloalkyl, C] -C alkyl-C ₃ -C cycloalkenyl , where the cycloalkyl or

Cycloalkenyl rings of the above radicals are optionally substituted up to three times by Ci-Cg-alkyl or by a Ci-Cg-dialkylene bridge or

R ^{1 represents} C _r C ₇ alkyl or C ₃ -C ₇ alkenyl,

R ² , R ¹¹ , R ^{13 are the} same or different and represent C 1 -C 6 -alkyl,

R ³ to R ^{6 are} identical or different and represent hydrogen or Cj-Cg-alkyl, where R ² and R ³ together with the atoms to which they are attached can form a 5- or 6-membered monocyclic ring and

n for 1 and

m stands for 0.

3. A method for combating parasitic helminths, characterized in that compounds of the formula (I) according to Claim 1 are allowed to act on helminths and / or their habitat.

4. Use of compounds of formula (I) according to claim 1 for combating parasitic helminths.

5. A process for the preparation of agents for defense against helminthic parasites, characterized in that compounds of the formula (I) according to Claim 1 are mixed with extenders and / or surface-active agents.