Treatment for ectoparasites

#The present invention relates generally to the removal of ectoparasites from the bodies of humans and animals, and more particularly to a topical treatment to facilitate such removal.

#Ectoparasite infestation of humans and animals is a serious health problem throughout the world. Of particular importance as a public health issue is pediculosis, or infestations with lice, which are pervasive among children and can quickly be spread in a school setting. A very common parasite is Pediculus humanus var capitis, the common head louse, although there are other important parasites, including Pthirus pubis (the pubic louse) and Pediculus humanus var corporis (the body louse). Infestations are frequently accompanied by itching and skin damage. Infections and other adverse conditions may occur when the skin is scratched in an attempt to relieve the itching. Further, lice are known to be capable of transmitting serious diseases, including trench fever, relapsing fever and typhus.

#Pediculosis is most frequently treated by applying pesticidal compositions, such as lotions or shampoos, to the affected body areas, such as the hair, and then exhaustively combing with a fine-tooth comb made especially for the purpose of removing nits. Commercially available preparations may include as their active ingredients pyrethrins, piperonyl butoxide, malathion, lindane or permethrins, many of which unfortunately have neurotoxic properties, are readily absorbed through the skin and therefore can establish undesirable systemic concentrations. It is perceived that the effectiveness of pesticides has recently diminished, as the parasites appear to continually become more resistant to their action. The resistance may be aggravated by small amounts of residual pesticide on the treated areas, following the procedure. This resistance also contributes to an increased opportunity for toxic systemic exposure to the active ingredients, since the preparations must be applied repeatedly to obtain an eradication of the infestation. Further, the pesticides do not usually kill the parasite's eggs that may be present on a host, so the tedious mechanical removal techniques must also be used.

#Cream and lotion compositions for ectoparasite removal which generate heat upon contact with water are prepared by combining the following components:

#No. Ingredient Wt. Percent 1 Sodium aluminosilicate 35 Triethylene glycol 48 Sodium lauryl sulfate 16 PEG-180 1 2 Sodium aluminosilicate 65 PEG-4 17 Triethylene glycol 18 3 Sodium aluminosilicate 40 Fumed silica 0.5 Cetyl alcohol 0.2 Dimethicone 1 PEG-400 58.1 Polyvinylpyrrolidone 0.1 Stearic acid 0.1 4 Potassium aluminosilicate 40 Fumed silica 0.5 Cetyl alcohol 0.2 Dimethicone 1 PEG-400 58.1 Polyvinylpyrrolidone 0.1 Stearic acid 0.1 5 Potassium aluminosilicate 45 Heavy mineral oil 12 Propylene glycol 12 Glycerin 2 Polysorbate 80 10 Glyceryl stearate + PEG-100 stearate* 2 Sorbitan laurate 10 Methyl gluceth-20 5 Dimethicone 2 6 Potassium aluminosilicate 40 PEG-400 25.3 PEG-600 25.6 Polyvinylpyrrolidone 0.1 Dimethicone 1 Cetyl alcohol 0.3 Stearic alcohol 0.3 Polysorbate 20 5 Fumed silica 0.2 Benzoic acid 2 Methylparaben 0.13 Propylparaben 0.07 *Arlacel ™ 165, sold by Uniquema, New Castle, Delaware U.S.A.

#Composition 6 is prepared as follows: (1) the PEG-400 is heated to about 60° C. and stirred while the polyvinylpyrollidone is slowly sprinkled onto the liquid surface, then stirring is continued until a solution has been formed; (2) in a separate vessel, the PEG-600, cetyl alcohol and stearic acid are stirred and heated to about 60° C. to form a solution; (3) the solution of step 1 is added to the solution of step 2 with thoroughly stirring, while maintaining the temperature about 60° C.;(4) the benzoic acid, methylparaben and propylparaben are sequentially added with continued stirring and maintenance of the 60° C. temperature condition, each component being completely dissolved before the next is added; (5) with continued stirring and temperature maintenance, the dimethicone, polysorbate 20 and fumed silica are added; and (6) the potassium aluminosilicate is added, heating is discontinued, and stirring is continued to assure a uniform dispersion as the mixture cools to ambient temperature.