Patent ID: 6991801

Claim:
A spot-on composition consisting essentially of: a) a pharmaceutically active combination consisting of at least one macrocyclic lactone selected from the group consisting of moxidectin, doramectin, emamectin, abamectin, ivermectin, selamectin and eprinomectin and at least one compound selected from the group consisting of praziquantel, morantel and pyrantel in a topically effective amount; b) a thickening agent; and c) a liquid carrier vehicle; wherein the a liquid carrier vehicle comprises a solvent and a cosolvent wherein the solvent is selected from the group consisting of benzyl alcohol, butyl diglycol, dimethylacetamide, dimethylformamide, dimethyl isosorbide, C 8 –C 10 caprylic/capric triglycerides, dipropylene glycol n-butyl ether, ethanol, isopropanol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monomethylacetamide, dipropylene glycol monomethyl ether, liquid polyoxyethylene glycols, propylene glycol, 2-pyrrolidone, diethylene glycol monoethyl ether, ethylene glycol, diethyl phthalate, and a mixture of at least two of these solvents and the cosolvent is selected from the group consisting of methanol, ethanol, absolute ethanol, isopropanol or benzyl alcohol; and the composition further comprises a crystallization inhibitor selected from the group consisting of an anionic surfactant, a cationic surfactant, a non-ionic surfactant, an amine salt, an amphoteric surfactant, polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinyl acetate and vinylpyrrolidone, polyethylene glycols, benzyl alcohol, mannitol, glycerol, polyvidone, sorbitol, polyoxyethylenated sorbitan esters, lecithin, carboxymethylcellulose, acrylic derivatives, and a mixture of these crystallization inhibitors.