ABSTRACT
<p><b>OBJECTIVE</b>To develop a transparent, non-toxic, non-irritating anti-fogging agent with long-lasting effect for nasal endoscopy.</p><p><b>METHODS</b>The anti-fogging agent was prepared by mixing ethanol, propylene glycol, polyoxyethylene lauryl ether, sodium dodecyl sulfate, polyethylene glycol 400 and deionized water at different proportions based on an orthogonal test design. Twenty-seven test samples of the anti-fogging agents were obtained, which were colorless, transparent, and non-irritating, with a pH value of 7-8. Storz00 nasal endoscopy and its imaging system were used to test the anti-fogging time of the 27 samples, and each agent was tested for 3 times with medical Seoul iodine and 95% ethanol as control.</p><p><b>RESULTS</b>The optimal composition of the anti-fogging agent was 20% ethanol, 10% propylene glycol, 20% polyoxyethylene lauryl ether, 4% sodium dodecyl sulfate, 4% polyethylene glycol, 42% deionized water. The anti-fogging time of this agent reached 15 min, significantly longer than that of medical Seoul iodine (4 min) and 95% ethanol (18 s).</p><p><b>CONCLUSION</b>This anti-fogging agent for nasal endoscopes is colorless and safe and has a long anti-fogging time by forming a homogenous transparent membrane over the endoscopic lens.</p>