Patent ID: 8653128

Claim:
A dimethyl sulfoxide free (DMSO-free) topical antiparasitic composition for a domestic animal comprises: a) an antiparasitic active ingredient that is fipronil, and at least one additional antiparasitic active ingredient selected from the group consisting of acaricides, amitraz, cymiazole, insect growth regulators, pyriproxyfen, s-methoprene, avermectins, ivermectin, abamectin, eprinomectin, moxidectin, selamectin, and milbemycin; b) a glycol ether main solvent that is selected from the group consisting of diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol, PEG, and combinations thereof; c) a mono alkyl ester co-solvent having a dielectric constant of less than 10 or greater than 40 and/or a boiling point greater than 100° C., and the co-solvent comprising ethyl acetate and ethyl lactate; d) a crystallization inhibitor that is Solketal and at least one additional crystallization inhibitor/viscolizer selected from the group consisting of cellulose acetate butyrate, N-methylpyrrolidone, N,N-dimethylacetamide, Polyvinylpyrrolidone, isosorbide dimethyl ether, and propylene carbonate; and e) an antioxidant that is ascorbyl palmitate and at least one additional antioxidant selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and propyl gallate, and characterized in that the antioxidant has a percent weight per volume (% w/v) of total composition of from about 0.005% to about 2%; said composition further characterized in that the percentages of weight per volume (% w/v) of components present in the composition are as follows: total antiparasitic active ingredient from about 1% to about 20%; total crystallization inhibitor from about 1% to about 20%; total co-solvent from about 1% to about 15%; and at least one excipient and total main solvent, complement to 100%.