Patent ID: 6962713

Claim:
A spot-on formulation for combating parasites of an animal that consists of a parasitically effective amount of at least one ectoparasiticidal compound (A), a parasitically effective amount of at least one endectocidal parasiticide compound (B); a vehicle for localized cutaneous application to the animal, with absorption and a resultant plasma concentration of the endectocidal parasiticide; a crystallization inhibitor, and optionally at least one antioxidant, wherein: compound (A) is an ectoparasiticide of the formula; in which: R 1 is CN; R 2 is —S(O) n R 3 ; R 3 is haloalkyl; R 4 is NH 2 ; R 11 is halogen; R 13 is haloalkyl; n is an integer equal to 0, 1 or 2; X is a radical C—R 12 ; and R 12 is a halogen atom; compound (B) is a macrocycic lactoun endectocidal parasiticide selected from the group consisting of an avezmectin, ivermectin, abamectin and doramectin; the vehicle contains diethylene glycol monoethyl other and ethanol; or mixture of C 8 -C 10 caprylic/capric triglycerides, propylene giycol, diethylene glycol momoethyl ether, and ethanol or 2-propanol; the crystallization inhibitor is polyvinylpyrrolidone or a crystallization inhibitor pair consisting of polysorbate 80 and polyvinylpyrrolidone.