CGP 20376 is a benzothiazole compound, an anthelmintic, with dual dose-dependent modulation of in vitro effects on the respiratory burst of eosinophils and antifibrillatory properties.

CGP 20376 (1 micron/ml) reduction of motility of 98-100% after 24 hours of exposure occurred at levels. After exposure for 1 h CGP 20376 immobilized 100% of the microfilariae irreversibly at a drug level of 1 microgram/ml. Whereas no significant immobilization was seen with CGP 6140 after one hour.[5]

CGP 20376 (20 mg/kg orally) had a rapid and profound reduction, but by 137 d.p.t. microfilarial skin densities were approaching pre-treatment levels. By 137 d.p.t. embryogenesis was almost completely interrupted in the CGP 20376 treated animals and the majority of remaining intrauterine microfilariae were pathologically altered.[1]