Nasal lesions induced by intranasal administration of benzaikonium chloride in rats

We investigated the lesions of nasal cavity mucous membrane caused by administration of 0.01, 0.05 and 0.10 w/v% Benzalkonium chloride (BZC) solutions in the nasal cavity of rats. No BZC-induced symptoms or nasal lesions were seen in the 0.01 w/v% BZC-treated group. On the other hand, BZC-induced symptoms such as nasal sound and rubbing the nose with forelegs were observed in the 0.05 and 0.10 w/v% BZC-treated groups. Additionally, BZC-induced lesions, including epithelial desquamation, inflammation and edema, occurred in the anterior nasal cavity in the 0.05 and 0.10 w/v% BZC-treated groups, but these lesions were confined to the dorsal meatus and the adjacent nasal septum. These results indicate that 0.01 w/v% BZC solution has no effect on the nasal cavity mucous membrane. However, 0.05 and 0.10 w/v% BZC solutions induce lesions in the nasal cavity mucous membrane due to their irritating effect.