Oxfendazole is a broad-spectrum benzimidazole anthelmintic. Its main use is for protecting livestock against roundworm, strongyles, and pinworms. Oxfendazole is the sulfoxide metabolite of fenbendazole. Like mebendazole, oxfendazole inhibits tubulin polymerization, disrupting microtubule assembly, impairing glucose uptake and energy metabolism in helminths and leading to immobilization and death. The compound shows preferential binding to parasitic beta-tubulin isoforms compared to mammalian tubulins, which underlies its safety margin in target species. Chemically it is a low aqueous solubility sulfoxide often formulated as oral suspensions, drenches or medicated feeds. In ruminants oxfendazole displays hepatic metabolism with enterohepatic recycling, contributing to extended plasma residence and sustained efficacy against gastrointestinal nematodes.
Typical API quality specifications target assay acceptance around 98.0 to 102.0 percent by validated HPLC methods. Related compounds and impurities monitored during manufacture and release include fenbendazole (parent or precursor), the oxfendazole sulfone, hydroxy-fenbendazole and small benzimidazole-ring degradation products. Common control limits applied in industry practice are individual related substances controlled to approximately 0.2 to 0.5 percent each and total related substances limited to about 1.0 to 2.0 percent depending on method sensitivity and regulatory expectations. Genotoxic or unspecified impurities are handled with tighter reporting and control thresholds consistent with ICH guidelines, and identification/quantification is typically performed by validated HPLC-UV or LC-MS methods.
Oxfendazole is used as a veterinary anthelmintic to control and prevent infections by nematode parasites in livestock, notably gastrointestinal roundworms, strongyles and pinworms; it is formulated for oral administration and selected for its prolonged activity in ruminant species.
Oxfendazole is not commonly approved for human therapeutic use and human safety data are limited; exposure should be managed with standard occupational hygiene and handling controls, and any human health questions should be directed to regulatory health authorities or medical professionals rather than using veterinary products for human treatment.
