[Studies on the nasal absorption of gentamycin]

Study on drug absorptive function of nasal mucosa is a new and interesting subject bridging otorhinolaryngology and pharmacology. The authors applied 40 mg/ml gentamycin to 10 dogs at the dose of 5 mg/kg through three routes of administration, ie, intravenous, intramuscular and intranasal. The serum levels of the drug from 0 to 180 minutes after applying the drug were determined with thin-layer chromatography-scanning method and the bioavailability of three routes was counted. It was found that within 10 to 30 minutes after using gentamycin the drug concentration in the blood increased and reached a peak. The half-life period was about three hours. The bioavailability of the intranasal administration were 80.5%, and intramuscular 42%. It was indicated that the nasal mucosa possessed an excellent penetrance for gentamycin and let it be absorbed into blood stream quickly and maintain an effective level for a long time.