Micronucleus test of mofezolac (N-22).

A micronucleus test using BDF1 male mice was conducted in order to evaluate the in vivo mutagenicity of mofezolac (N-22). N-22 was orally administered at doses of 75, 150, 300 and 600 mg/kg, with a sampling time of 24 hr. The frequency of polychromatic erythrocytes with micronuclei was 0.07-0.08% in the groups treated with N-22 and did not differ markedly from that of the vehicle control (0.13%). The present study indicates that N-22 has no in vivo mutagenic properties.