Topical gel formulation comprising organophosphate insecticide and preparation thereof

Abstract

The present invention provides a topical gel pharmaceutical formulation of insecticide suitable for treating an ectoparasite in a mammal, comprising: a) about 0.1-10% by weight of an insecticide; b) at least about 75% by weight of an organic solvent selected from the group consisting of a lower alkyl alcohol, a ketone, a glycol and a mixture thereof, wherein the organic solvent contains at least about 40% by weight of the lower alkyl alcohol; and c) at least one polymer selected from the group consisting of a cellulosic polymer, acrylates, methacrylates, and polyvinyl pyrrolidone. The present gel pharmaceutical formulation preferably contains malathion and optionally contains isopropyl myristate. The present invention further provides a process of preparing as well as a method of treating ectoparasites in a mammal using the same.

1 - 82 . (canceled) 
     
     
         83 . A topical gel pharmaceutical formulation of insecticide suitable for treating an ectoparasite in a mammal, comprising: a) about 0.1-10% by weight of malathion; b) at least about 75% by weight of a lower alkyl alcohol; and c) about 0.1% to about 10% of at least one cellulosic polymer, wherein the formulation is free of added water, and has a viscosity at least about 1000 cps. 
     
     
         84 . The topical gel pharmaceutical formulation of  claim 83 , wherein the viscosity is at least about 3000 cps. 
     
     
         85 . The topical gel pharmaceutical formulation of  claim 83 , wherein the viscosity is at least about 5000 cps. 
     
     
         86 . The topical gel pharmaceutical formulation of  claim 83 , wherein the viscosity is between about 2200 cps and about 5300 cps. 
     
     
         87 . The topical gel pharmaceutical formulation of  claim 83 , wherein the cellulosic polymer is selected from the group consisting of hydroxyl ethyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, methyl cellulose, carboxy methyl cellulose, sodium carboxy methyl cellulose, and ethyl cellulose. 
     
     
         88 . The topical gel pharmaceutical formulation of  claim 83 , wherein the cellulosic polymer is hydroxyl propyl cellulose. 
     
     
         89 . The topical gel pharmaceutical formulation of  claim 83 , wherein the cellulosic polymer is present in the amount of about 0.5% to about 5%. 
     
     
         90 . The topical gel pharmaceutical formulation of  claim 83 , wherein the lower alkyl alcohol is selected from ethyl alcohol and isopropyl alcohol. 
     
     
         91 . The topical gel pharmaceutical formulation of  claim 83 , comprising about 0.1% to about 5% by weight of malathion. 
     
     
         92 . The topical gel pharmaceutical formulation of  claim 83 , further comprising a fragrance. 
     
     
         93 . The topical gel pharmaceutical formulation of  claim 83 , further comprising at least one compound selected from the group consisting of terpineol, terpene, limonene, dipentene, and pine needle oil. 
     
     
         94 . The topical gel pharmaceutical formulation of  claim 93 , wherein the at least one compound is present in the amount of about 0.1% to about 30%. 
     
     
         95 . The topical gel pharmaceutical formulation of  claim 93 , wherein the at least one compound is present in the amount of about 10% to about 20%. 
     
     
         96 . The topical gel pharmaceutical formulation of  claim 83 , further comprising an antioxidant. 
     
     
         97 . The topical gel pharmaceutical formulation of  claim 96 , wherein the antioxidant is at least one compound selected from the group consisting of ascorbic acid, butylated hydroxyl anisole, butylated hydroxy toluene, propyl gallate, tartaric acid, phosphoric acid, erythrobic acid, lactic acid, sodium sulfite, sodium bisulfate, sodium metabisulfite, thioglycolic acid, cysteine hydrochloride and alpha tocopherol. 
     
     
         98 . The topical gel pharmaceutical formulation of  claim 96  wherein the antioxidant is present in the amount of about 0.025% to about 5%. 
     
     
         99 . The topical gel pharmaceutical formulation of  claim 96 , wherein the antioxidant is present in the amount of about 0.1% to about 1%. 
     
     
         100 . A topical gel pharmaceutical formulation of insecticide suitable for treating an ectoparasite in a mammal, comprising: a) about 0.1 to about 10% by weight of malathion; b) at least 75% by weight of a lower alkyl alcohol; and about 0.1% to about 10% of at least one cellulosic polymer, and wherein the formulation is essentially free of water, and has a viscosity at least about 1000 cps. 
     
     
         101 . The topical gel pharmaceutical formulation of  claim 100 , wherein the viscosity is at least about 3000 cps. 
     
     
         102 . The topical gel pharmaceutical formulation of  claim 98 , wherein the cellulosic polymer is selected from the group consisting of hydroxyl ethyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, methyl cellulose, carboxy methyl cellulose, sodium carboxy methyl cellulose, and ethyl cellulose. 
     
     
         103 . The topical gel pharmaceutical formulation of  claim 98 , wherein the cellulosic polymer is hydroxyl propyl cellulose. 
     
     
         104 . The topical gel pharmaceutical formulation of  claim 98 , further comprising at least one compound selected from the group consisting of terpineol, terpene, limonene, dipentene, and pine needle oil.