RESUMEN
OBJECTIVE: To optimize the formulation of ketamine hydrochloride for intranasal administration that was of effective anesthetic effect.METHODS: Using ketamine hydrochloride injection as basic preparation,various nasal absorption enhancer or viscosity modifiers(0.5%,1% and 2% azone,EDTA,carbomer,2-hydroxypropyl-?-cyclodextrin,carboxymethyl cellulose) were added to make different nasal drops.After intranasal administration,the anesthetic effect was evaluated to find the optimum formulation.The behavior of anesthetic induction period and anesthetic index were used to evaluate the anesthetic effect.RESULTS: The perfect anesthetic effect was achieved when the formulation was prepared by adding 1% azone in ketamine hydrochloride injection(at a dose of 10 mg?kg-1).The anesthetic time was long.The muscle relaxing time,eyelid reflecting disappearing time,pain disappearing time and righting reflecting disappearing time were(21.4?7.1) min,(11.4?4.6) min,(15.6?5.7) min and(12.0?4.8) min,respectively.CONCLUSIONS: Optimal formulation of ketamine hydrochloride for intranasal administration was obtained when 1% azone was added as an absorption enhancer.