ABSTRACT
<p><b>OBJECTIVE</b>To study the influence of intranasal medication on the structure, pathology and reversibility of the nasal mucosa to provide a basis for the feasibility of intranasal route of drug administration.</p><p><b>METHODS</b>Nasal drops of gentamicin were placed in the nasal cavity of rabbits for 3, 5, 7, 14 and 28 days. After that, the drops were stopped and drugs protecting the nasomucosa were used for one and three weeks. After being sacrificed over time, the nasomucosa of the rabbit was observed under optical and electron microscopes.</p><p><b>RESULTS</b>Damage to the nasal mucosa appeared to different extents with prolonged use of nasal drops. Within 3 - 7 days of applying the drug, damages to the nasal mucosa gradually appeared, and after two and four weeks, were most serious. After stopping the drug, the nasal mucosa was gradually restored.</p><p><b>CONCLUSION</b>Damages of drugs to the nasal mucosa could be restored. The intranasal route of drug administration would be feasible and clinically applicable.</p>