Topical Avermectin Formulations and Methods For Elimination and Prophylaxis of Susceptible and Treatment Resistant Strains of Head Lice

Abstract

An avermectin-based topical formulation is disclosed which is useful for prevention and treatment of head lice ( Pediculus humanus capitis ). This topical formulation may be formulated as a shampoo-condition which comprises an effective amount of avermectin, solubilizers, suspending agents, preservatives, nonionic surfactants, humectants, a silicone compound, and water. Also disclosed are methods of using the topical formulations disclosed within this specification to treat either a susceptible or treatment-resistant strain of lice, as well as uses in the manufacture of a medicament for treating or preventing a lice infestation from a susceptible or treatment-resistant strain in a human patient.

1 .- 20 . (canceled) 
     
     
         21 . A method for the treatment or prophylaxis of a lice infestation, the method comprising:
 (a) applying to an area of a human a topical pediculicidal formulation comprising
 about 0.1% to about 2.0% by weight ivermectin, 
 a solubilizer, 
 about 20% to 30% by weight olive oil, 
 a non-ionic surfactant, and 
 about 30% to 40% by weight water; and 
   (b) maintaining the topical pediculicidal formulation on the area.   
     
     
         22 . The method of  claim 21 , wherein the topical pediculicidal formulation is maintained in (b) for from about 1 to about 60 minutes. 
     
     
         23 . The method of  claim 22 , wherein the topical pediculicidal formulation is maintained in (b) for about 10 minutes. 
     
     
         24 . The method of  claim 21 , further comprising rinsing the area with water. 
     
     
         25 . The method of  claim 21 , wherein the lice are treatment-resistant lice. 
     
     
         26 . The method of  claim 21 , wherein the lice are head lice and the area comprises hair. 
     
     
         27 . The method of  claim 26 , wherein the topical pediculicidal formulation is rubbed into the hair until saturation occurs. 
     
     
         28 . The method of  claim 26 , wherein the topical pediculicidal formulation is in the form of a shampoo-conditioner. 
     
     
         29 . The method of  claim 28 , wherein the method is repeated at least once within seven days of the initial method. 
     
     
         30 . The method of claim  1 , wherein a dose of about 1 mL to about 100 mL of the topical pediculicidal formulation is applied in (a). 
     
     
         31 . The method of  claim 21 , wherein the lice are pubic lice and the area is selected from the group consisting of the pubic area, facial hair, eyelashes, eyebrows, armpits, chest hair and the scalp. 
     
     
         32 . The method of  claim 21 , wherein the topical pediculicidal formulation comprises about 0.5% by weight ivermectin. 
     
     
         33 . The method of  claim 21 , wherein the topical pediculicidal formulation further comprises shea butter. 
     
     
         34 . The method of  claim 21 , wherein the solubilizer comprises polysorbate 80, cetyl acetate, acetylated lanolin alcohol or a combination thereof. 
     
     
         35 . The method of  claim 21 , wherein the topical pediculicidal formulation further comprising one or more paraben preservatives selected from the group consisting of methylparaben, propylparaben, ethylparaben, butylparaben, isobutylparaben, isopropylparaben, benzylparaben, sodium salts thereof, and any combination thereof. 
     
     
         36 . The method of  claim 21 , wherein the nonionic surfactant comprises oleyl alcohol, lanolin alcohol, a sorbitan tristearate or a combination thereof. 
     
     
         37 . The method of  claim 21 , wherein the topical pediculicidal formulation further comprising a conditioner selected from the group consisting of cyclomethicone, dimethicone, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, polydimethylsiloxanes, and combinations thereof. 
     
     
         38 . The method of  claim 21 , wherein the topical pediculicidal formulation is selected from the group consisting of a cream, a gel and a pomade. 
     
     
         39 . The method of  claim 21 , wherein the topical pediculicidal formulation has a rate of killing permethrin resistant SF-HL head lice that is 3.2 to 3.8 times faster than ivermectin in solution at the same weight %. 
     
     
         40 . The method of  claim 21 , wherein the topical pediculicidal formulation is indirectly ovicidal.