Enhancement of the hypnotic potency of barbiturates by inclusion complexation with .BETA.-cyclodextrin.

Abstract

The 50% effective doses of 5 barbiturate-.beta.-cyclodextrin complexes on oral administration to mice were compared with those of the corresponding barbiturates. In all cases tested, the complex gave a smaller ED50 than the intact drug. ED50 of phenobarbital, which forms the most stable complex and consequently shows the greatest enhancement in solubility, was reduced most markedly by complexation. With the exception of barbital, sleep latency (the time from oral administration to loss of righting reflex) on administration of the complex to mice was shorter than that on giving an equimolar amount of the intact drug and sleeping time (the time from loss to recovery of righting reflex) was significantly increased by inclusion complexation with .beta.-cyclodextrin.