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.
