Objective: To investigate the sedative and hypnotic effects and safety of oral emulsified isoflurane in rats.
Methods: Thirty healthy Sprague-Dawley (SD) rats were randomly divided into three groups. The rats in the emulsified isoflurane group were orally administered with emulsified isoflurane with the sequential method, while the rats in the normal sodium group and the intralipid group were orally administered with sodium and intralipid respectively. The rats in the emulsified isoflurane group received 2.15 mL/100 g of 8% emulsified isoflurane, a dosage calculated with an increase of a common ratio (r = 0.8) on the basis of median effective dose (ED50). Similarly, 2.15 mL/100 g of normal sodium and 2.15 mL/100 g of 30% intralipid were given to the rats in the normal sodium group and the intralipid group, respectively. The neurobehaviors of the rats were assessed, and the interval of disappearance and recovery of the righting reflex were recorded.
Results: Oral emulsified isoflurane reduced the autonomic activity time and induced the loss of righting reflex. The ED50 of the loss of righting reflex was 1.72 mL/100 g. The rats orally administered with 2.15 mL/100 g of 8% emulsified isoflurane had 90% of loss of righting reflex, with a sleeping latency of 15-20 min and up to 60 min of sleeping duration.
Conclusion: Oral emulsified isoflurane has obvious sedative and hypnotic effects.