Patent ID: 7671034

Claim:
A premix for an animal feed that exhibits an extended shelf-life consisting essentially of: a) about 0.04 to about 0.7% (w/w) of at least one avermectin compound; b) a pharmaceutically acceptable excipient comprising: i) about 5 to about 15% (w/w) of a surfactant wherein said surfactant is selected from the group consisting of polyoxyl 40 hydrogenated castor oil, PEG-50 castor oil, PEG-60 corn glyceride, PEG-60 almond oil, PEG-40 palm kernel oil, and PEG-60 corn oil; ii) about 15 to about 25% (w/w) of a wax wherein said wax is selected from the group consisting of distilled monoglycerides, glyceryl tribehenate, glyceryl trimyristate, and hydrogenated coco-glycerides; iii) about 0.1 to about 2% (w/w) of an antioxidant wherein said antioxidant is selected from the group consisting of butylated hydroxyanisole, butylated hydroxytoluene, ascorbic acid, sodium metabisulphite, propyl gallate, sodium thiosulphate, propylene glycol, citric acid, anhydrous citric acid and a mixture thereof; iv) about 60 to about 80% (w/w) of a pharmaceutically acceptable carrier vehicle wherein said carrier vehicle is selected from the group consisting of fine ground corn cobs, crushed limestone, and dried grains; c) about 0.3 to about 1% (w/w) of an additional amount of a pharmaceutically acceptable acid stabilizer effective to decrease the acid or base catalyzed decomposition of the at least one avermectin compound, and; d) optionally, an effective amount of at least one insect growth regulating compound.