Moxidectin is a semi-synthetic milbemycin derived from nemadectin by selective oxidation followed by methyloximation. Moxidectin was patented in 1991 as an anthelmintic for internal parasite control. The presence of the methyloxime affords moxidectin a greater hydrophobicity and longer biological half-life compared to nemadectin. It binds selectively to parasite glutamate-gated chloride neurotransmission leading to ion channels and disrupts paralysis and death of the parasite.