Patent ID: 7348417

Claim:
A method for purifying moxidectin, said method comprising: a) combining moxidectin with a first solvent to produce a moxidectin solution wherein said first solvent is methylcyclohexane; b) concentrating said solution at a temperature at or below about 50° C., and thereafter cooling the temperature of said moxidectin solution to a temperature within the range of about 40° to 30° C.; c) combining a second solvent with said moxidectin solution wherein said second solvent is selected from hexane, heptane, toluene, isooctane or a mixture thereof and is present in a weight ratio of 2:1 to 6:1 of second solvent to first solvent; and thereafter d) agitating the moxidectin solution while lowering the temperature to within the range of about 30 to 10° C., so as to generate moxidectin crystals from said solution; e) filtering said crystals from said moxidectin solution; and f) drying said crystals.