Higher alcohol toxicants effective against insects
This is a continuation of application Ser. No. 802,014, filed May 31, 1977 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     There are only a relatively few pediculicides which are commercially available today. The most popular pediculicidal toxicants are Lindane (gamma benzene hexachloride), Malathion [(S-1,2-dicarbethoxyethyl)-0,0-dimethyl phosphorodithioate], synergized pyrethrins and Cuprex (a combination of tetrahydronapthalene, copper oleate and acetone, the acetone not asserted to be active). Because of increased concern about the overall safety of some of the known ectoparasitic toxicants, the search for new, safe and effective pediculicides has intensified recently. 
     In addition to killing insects, a good ectoparasiticide should also destroy ova to avoid a resurgence of the infestation. Surviving ova may hatch days or weeks after the initial treatment. Lacking ovicidal activity, a pediculicide safe to the host usually must be re-applied until control is achieved. 
     It has now been found that those higher alcohols which have a logarithm of their partition coefficient between n-octanol and water of at least 0.61 exhibit pediculicidal and/or ovicidal activity. These alcohols are known materials and have been incorporated into many pharmaceutical and costmetic preparations. For example, cetyl alcohol constitutes 15% of a published hair groom gel and 61% of a floating bath oil, and lauryl or isocetyl or dodecyl alcohol constitute about 30% of a mineral oil gel. Cetyl alcohol and lauryl alcohol are also listed under the United States Food &amp; Drug Administration&#39;s approved Synthetic Flavor Substituents and Adjuvants list (Z1 CFR 1.1.1164). Cetyl alcohol has been used in compositions applied to the skin (U.S. Pat. Nos. 3,226,295 and 3,943,234) and lauryl alcohol derivatives have been used in parasiticides (U.S. Pat. No. 2,030,093). 
     It is the object of this invention to provide new, safe and effective toxicants for lice and their ova, and mites. This and other objects of the invention will become apparent to those skilled in the art from the following detailed description. 
     SUMMARY OF THE INVENTION 
     This invention relates to ectoparasiticidal toxicants and a method of controlling ectoparasites. More particularly, the invention relates to the use of certain higher alcohols as toxicants for lice and/or their ova and to toxicant compositions containing such higher alcohols. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The toxicants of the instant invention are monohydric alcohols, ROH, in which R is a substituted or unsubstituted alkyl group. The substituting moieties can be aryl, aryloxy halogen or the like. The R groups generally contain at least 4 carbon atoms and the maximum number of carbon atoms is not restricted but is generally 24 or less. It has been found that in order that the alcohols exhibit satisfactory pendiculicidal and/or ovicidal activity, the logarithm of the partition coefficient (hereinafter log P) for the compound between n-octanol and water must be at least 0.61. Log P values can be obtained by consulting Leo et al, Chemical Review, 71, 525 (1971) or calculated by the method therein described. When pediculicidal activity is desired, it is preferred that the alcohols be unsubstituted alkyl alcohols having log P values of 1.16-7.13. When ovicidal activity is desired, it is preferred that the alcohols have log P values of 1.1-7.13 and preferably are alkyl alcohols having log P values of 2.3-5.13. Accordingly, when both pediculicidal and ovicidal activity is desired, it is preferred to employ an unsubstituted alkyl alcohol having log P values of 2.13-5.1. 
     Typical of the monohydric alcohols which can be employed in this invention are n-butanol, sec-butanol, iso-butanol (but not tert-butanol), iso-pentanol, n-pentanol, n-hexanol, n-octanol, n-decanol, n-dodecanol, hexadecyl alcohol, oleyl alcohol, benzyl alcohol, 2-phenoxyethanol, cyclohexanol, 4-chlorobutanol, 2-phenylethanol, and the like. 
     One or more of the toxic alcohols of the present invention can be incorporated into an active toxicant composition which can be in the form of a liquid, powder, lotion, cream, gel, aerosol spray, or foam as the result of formulation with inert pharmaceutically acceptable carriers by procedures well known in the art. Any pharmaceutically acceptable carrier, whether aqueous or not aqueous, which is inert to the active ingredient can be employed. By inert is meant that the carrier does not have a substantial detrimental effect on the pediculicidal or ovicidal toxicant activity of the active ingredient. 
     The active alcohol is incorporated into the toxicant composition used to treat the substrate (human or animal) in need of such treatment, believed to be in need of such treatment, or desired to be prophylactically protected in an effective toxicant amount. By such amount is meant the amount which will cause at least 75% of the ectoparasites exposed in the two minute immersion tests described below to die within 24 hours in the case of lice and within 2 weeks in the case of the ova. The minimum concentration of alcohol in the composition required to provide an effective toxic amount varies considerably depending on the particular alcohol, the particular inert pharmaceutically acceptable carrier being employed and any other ingredients which are present. Thus, in one case a 10% concentration may suffice, while in other cases, concentrations as high as 30 to 40% may be required to obtain an effective toxic dose. The alcohols can also be employed as an adjuvant toxicant in a preparation which otherwise exhibits pediculicidal and/or ovicidal activity. In such preparations, the term &#34;effective toxic dose&#34; means that amount which will increase the mortality rate by about 20% in the standard immersion test. 
     The two minute immersion test referred to above is carried out as follows: 
     Pediculicidal activity: A 50 ml beaker is filled with tap water and allowed to come to room temperature (about 24° C.). Ten young adult male and ten young adult female lice (Pediculus humanus corporis) of the same age group and from the same stock colony are placed on a 2×2 cm coarse mesh patch. The sample to be tested, maintained at room temperature, is shaken until homogeneous and placed into a 50 ml beaker. The mesh patch is placed into the sample immediately after pouring, allowed to submerge, and after two minutes is removed and immediately plunged into the beaker containing the tap water. The patch is vigorously agitated every ten seconds and after one minute the patch is removed and placed on paper toweling. The lice are then transferred to a 4×4 cm black corduroy cloth patch and this point of time is considered zero hours. Thereafter, the corduroy patch is placed in a petri dish which is covered and stored in a 30° C. holding chamber. 
     Ovicidal activity: 15 adult, 5 to 10 day old, female lice (Pediculus humanus corporis) are placed on a 2×2 cm nylon mesh patch which is placed in a petri dish, covered and maintained in an incubator at 30° C. for 24 hours. The adult lice are then removed and the number of plump, viable eggs and shriveled, non-fertile eggs on the patch are recorded. The sample to be tested, maintained at room temperature, is shaken until homogeneous and poured into a 50 ml beaker. Immediately after the pouring, the mesh patch is placed into the beaker, allowed to submerge, and after two minutes is removed and immediately plunged into a 50 ml beaker containing tap water at room temperature (about 24° C.). The patch is vigorously agitated every ten seconds and after one minute, the patch is removed and placed on paper toweling for one minute. The patch is then placed in a petri dish which is covered and stored in the 30° C. incubator. Fourteen days following treatment, the number of hatched eggs and the number of shriveled or unhatched eggs is noted. 
     In both the pediculicidal and ovicidal two minute immersion tests, controls are run in identical manners to that described with room temperature (24° C.) tap water substituted for the sample to be tested. The results of the tests reported are net results. 
     In the following tables 1 and 2, the results of pediculicidal and ovicidal testing, respectively, for various alcohols of this invention and other alcohols are set forth. The alcohols were tested in undiluted form (100% alcohol), as a 25% solution in water, and in a solution containing 15% of the alcohol, 25% isopropanol and 60% aqueous (&#34;15/25/60&#34;). The results are set forth in terms of percent mortality. 
     
                       TABLE 1                                                     
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            Pediculicidal Rating                                          
                  100%       25%                                          
Alcohol   Log P   Alcohol    Solution                                     
                                    15/25/60                              
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Methanol  -0.66   0          0      0                                     
Ethanol   -0.32   45         0      0                                     
iso-Propanol                                                              
          -0.12*  65         0      0                                     
n-Propanol                                                                
          0.34    70         0      0                                     
tert-Butanol                                                              
          0.37    80         0      0                                     
sec-Butanol                                                               
          0.61    95         0      35                                    
iso-Butanol                                                               
          0.65    95         40     0                                     
n-Butanol 0.88    100        20     0                                     
Benzyl Alcohol                                                            
          1.10    90         0      5                                     
iso-Pentanol                                                              
          1.16    100        55     80                                    
2-Phenoxy-                                                                
ethanol   1.16    100        5      5                                     
Cyclohexanol                                                              
          1.23    100        0      20                                    
4-Chloro-                                                                 
butanol   1.27*   100        0      20                                    
2-Phenyl-                                                                 
ethanol   1.36    100        0      80                                    
n-Pentanol                                                                
          1.40    100        10     75                                    
n-Hexanol 2.03    100        5      85                                    
n-Octanol 3.15    100        10     85                                    
n-Decanol 4.15*   100        20     95                                    
n-Dodecanol                                                               
          5.13    100        10     100                                   
Hexadecyl                                                                 
Alcohol   ≦7.13*                                                   
                  100        40     90                                    
Oleyl Alcohol                                                             
          7.47*   100        0      40                                    
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                       TABLE II                                                    
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              Ovicidal Rating                                             
                    100%     25%                                          
Alcohol     Log P   Alcohol  Solution                                     
                                    15/25/60                              
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Methanol    -0.66   4        27     0                                     
Ethanol     -0.32   4        7      13                                    
iso-Propanol                                                              
            -0.12*  1        0      --                                    
n-Propanol  0.34    27       23     --                                    
tert-Butanol                                                              
            0.37    16       17     0                                     
sec-Butanol 0.61    10       46     32                                    
iso-Butanol 0.65    0        58     2                                     
N--Butanol  0.88    48       17     2                                     
Benzyl Alcohol                                                            
            1.10    100      100    29                                    
iso-Pentanol                                                              
            1.16    100      52     0                                     
2-Phenoxyethanol                                                          
            1.16    100      100    100                                   
Cyclohexanol                                                              
            1.23    100      0      57                                    
4-Chlorobutanol                                                           
            1.27*   100      100    100                                   
2-Phenylethanol                                                           
            1.36    100      100    34                                    
n-Pentanol  1.40    100      67     35                                    
n-Hexanol   2.03    100      100    100                                   
n-Octanol   3.15    100      100    100                                   
n-Decanol   4.15*   100      100    100                                   
n-Dodecanol 5.13    100      100    100                                   
Hexadecyl Alcohol                                                         
            ≦7.13*                                                 
                    100      75     29                                    
Oleyl Alcohol                                                             
            7.47*   84       0      20                                    
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     The miticidal activity of the instant toxicants was determined as follows. Into a one cubic foot chamber, held at room temperature, is placed a covered microscope depression slide containing ten adult mixed sex mites, Psoroptes equi var. cuniculi. The slide is positioned at a distance of ten inches horizontally and four inches below the activator of a mechanical spray device and uncovered. The mechanical pump spray device delivers 50 micrograms of sample per depression of the activator. The sample to be tested, maintained at room temperature, is shaken until homogenous and placed in the mechanical pump spray device. The primed activator is depressed twice, releasing 100 micrograms of spray mist into the closed chamber. The mist is allowed to settle and the slide containing the mites is removed and covered. This point of time is considered zero hours. The covered slide is then held at room temperature for 24 hours. Microscopic observations are noted at 0, 1, 3, and 24 hours post treatment. Controls are run in an identical manner as that described using water or the diluting agent, and net mortality results are reported. 
     
                       TABLE III                                                   
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               Miticidal Rating                                           
                                 50% Solution in                          
Alcohol      log P   100% Alcohol                                         
                                 Isopropanol                              
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iso-Propanol -0.12*  0           --                                       
sec-Butanol  0.61    50          --                                       
n-Butanol    0.88    100         --                                       
Benzyl Alcohol                                                            
             1.10    100         --                                       
Cyclohexanol 1.23    --          100                                      
2-Phenylethanol                                                           
             1.36    100         --                                       
n-Pentanol   1.40    100         --                                       
n-Hexanol    2.03    100         --                                       
Hexadecyl Alcohol                                                         
             ≦7.13*                                                
                     --          100                                      
Oleyl Alcohol                                                             
             7.47*   30          --                                       
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     The log P values set forth in the foregoing tables I, II and III are those set forth in the aforementioned Leo et al article except for the values starred which were calculated using standard methods. The log P value for hexadecyl alcohol is a calculated value and the actual figure is dependent on the degree of branching of the alkyl moiety. 
     As noted above, various end use formulations can be prepared. Some typical formulations are set forth below and the amounts recited are percentages by weight: 
     
         ______________________________________                                    
Clear colorless liquid suitable for mechanical spray                      
application or inunction                                                  
Isopropyl alcohol     65                                                  
Hexadecyl alcohol     15                                                  
Water                 20                                                  
Clear shampoo                                                             
Isopropyl alcohol     25                                                  
n-Dodecanol           15                                                  
Triethanolamine lauryl sulfate                                            
                      20                                                  
Water                 40                                                  
Lotion                                                                    
Isopropyl alcohol     25                                                  
Hexadecyl alcohol     15                                                  
Carboxypolymethylene  0.1                                                 
Triethanolamine       0.1                                                 
Water                 59.8                                                
Cream                                                                     
Isopropyl alcohol     25.0                                                
Isopentanol           15.0                                                
Glyceryl monostearat  22.5                                                
Sorbitan monostearate 1.5                                                 
Polysorbate 60        3.5                                                 
Xanthan gum           0.2                                                 
Water                 32.3                                                
Quick Breaking Aerosol Foam                                               
Mono and diglycerides from the                                            
glycerides of edible fats                                                 
                      8                                                   
n-Octanol             15                                                  
Isopropanol           25                                                  
Glycerine             3                                                   
Isobutane             8                                                   
Water                 41                                                  
Powder                                                                    
4-Chlorobutanol       10                                                  
Talc                  90                                                  
Stick                                                                     
Sodium stearate       8.0                                                 
Sorbitol              3.5                                                 
Isopropanol           25.0                                                
Ethanol               39.0                                                
n-Decanol             15.0                                                
Water                 9.5                                                 
Gel                                                                       
Carboxypolymethylene  1.5                                                 
Isopropyl alcohol     25.0                                                
4-Chlorobutanol       10.0                                                
Polysorbate 80        4.0                                                 
Triethanolamine       3.0                                                 
Water                 56.5                                                
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     Various changes and modifications can be made in the instant invention without departing from the spirit and scope thereof. The various embodiments set forth herein were for the purpose of further illustrating the invention and were not intended to limit it. Throughout this specification and claims, all parts and percentages have been by weight and all temperatures in degrees Centigrade unless otherwise indicated.