Metabolite of toltrazuril, q.v.; triazine trione antiprotozoal. Prepn: A. Haberkorn et al., DE 2718799; eidem, US 4219552 (1978, 1980 both to Bayer). Stereoselective generation by microsomes: E. Benoit et al., Biochem. Pharmacol. 46, 2337 (1993). LC/MS determn in meat and eggs: V. Hormazábal et al., J. Liq. Chromatogr. Relat. Technol. 26, 791 (2003). Activity vs Sarcocystis neurona, the causative agent of EPM: D. S. Lindsay et al., Vet. Parasitol. 92, 165 (2000); R. P. Franklin et al., ibid. 114, 123 (2003); vs Neospora canium: A. K. Darius et al., Parasitol. Res. 92, 453, 520 (2004).