Method and composition for the control of arthropods

Abstract

The present invention relates to the use of certain siloxanes and mixtures thereof in the control of arthropods such as insects and arachnids, and in particular ectoparasites, such as head lice.

1 . Use of a composition comprising as active ingredient at least one siloxane, other than solely a linear allyl or aryl siloxane having a viscosity less than 20,000 centistokes, for the control of arthropods.  
     
     
         2 . Use according to  claim 1  wherein the siloxane is selected from: 
 (i) a linear siloxane, other than solely a linear alkyl or aryl siloxane having a viscosity less than 20,000 centistokes;  
 (ii) a branched siloxane;  
 (iii) a cyclic siloxane; and  
 (iv) a silicone copolymer.  
 
     
     
         3 . Use according to  claim 1  or  claim 2  wherein the siloxane is a linear or branched siloxane of the general formula (1):  
       
         
           
           
               
               
           
         
       
       where n is from 1 to about 15,000, preferably from 20-7000, and substituents R are independently chosen from one or more of linear, branched or cyclic alkyl groups containing 1 to 20 carbon atoms, aryl substituents such as phenyl, naphthyl, substituted phenyl or substituted naphthyl, a siloxane chain so as to give a branched silicone, hydrogen, or vinyl groups, and wherein substituents R may also contain further functional groups attached to carbon selected from one or more of alkenyl, alkynyl, carboxyl, hydroxy, acrylate, ester, ether, alkoxy, halogen, cyano, mercapto, carbohydrate, amino, quaternary ammonium, sulphonic acid and thiosulfate groups and/or a terminal R group may represent OH.  
     
     
         4 . Use according to  claim 1  or  claim 2  wherein the siloxane is a cyclic siloxane of general formula (VI)  
       
         
           
           
               
               
           
         
       
       wherein R is as defined above and p is from 3 to 10.  
     
     
         5 . Use according to  claim 1  or  claim 2  wherein the siloxane is a siloxane copolymer of general formula (VIII):  
       
         
           
           
               
               
           
         
       
       wherein n is from 1 to 15,000, m is chosen such that m+n equal up to 15,000, R is as defined above and x is chosen, depending on n and m, so as to give a copolymer with a molecular weight in the range of 1000-30,000 and a non-siloxane content of between 25 and 90%.  
     
     
         6 . Use according to any of  claims 1  to  5  wherein said composition comprises a non-volatile siloxane and a volatile siloxane.  
     
     
         7 . Use according to  claim 6  wherein the composition comprises from 85 to 99.9% by volume of the volatile silicone and from 0.1 to 15% by volume of the non-volatile silicone.  
     
     
         8 . Use according to  claim 7  wherein the volatile silicone comprises 97.5 to 95.5% and the non-volatile silicone comprises 2.5 to 4.5% of the formulation.  
     
     
         9 . Use according to  claim 6  wherein the non-volatile siloxane has a viscosity in the range 50-350 centistokes and comprises more than 50% of the formulation.  
     
     
         10 . Use according to any of  claims 6  to  9  wherein the non-volatile siloxane is a dimethicone or a dimethiconol.  
     
     
         11 . Use according to any of  claims 6  to  9  wherein the volatile siloxane is a cyclomethicone.  
     
     
         12 . Use according to  claim 11  wherein the cyclomethicone is cyclopentasiloxane or a mixture of cyclopentasiloxane and cyclohexasiloxane.  
     
     
         13 . Use according to any of  claims 1  to  12  wherein the arthropod is an insect or arachnid.  
     
     
         14 . Use according to  claim 13  wherein the insect is an ectoparasite.  
     
     
         15 . Use of a siloxane derivative selected from 
 (i) a linear siloxane, other than solely a linear allyl or aryl siloxane having a viscosity less than 20,000 centistokes;    (ii) a branched siloxane;    (iii) a cyclic siloxane; and    (iv) a silicone copolymer;    in the manufacture of a medicament for the control of ectoparasites.    
     
     
         16 . Use according to  claim 14  or  claim 15  wherein the ectoparasite is of the order Anoplura.  
     
     
         17 . Use according to  claim 16  wherein the species is  Pediculus humanus.    
     
     
         18 . A method of controlling arthropods which comprises applying to said arthropod a siloxane derivative selected from: 
 (i) a linear siloxane, other than solely a linear alkyl or aryl siloxane having a viscosity less than 20,000 centistokes;    (ii) a branched siloxane;    (iii) a cyclic siloxane; and    (iv) a silicone copolymer.    
     
     
         19 . A siloxane composition comprising a cyclomethicone, in admixture with dimethiconol, wherein the cyclomethicone comprises 96.5-97.5 by volume and the dimethiconol comprises 2.5-3.5% by volume.