Objective       To screen and optimize the formulation of self-microemulsifying drug delivery system (SMEDDS) for honokiol.       Methods       The formulation of honokiol-SMEDDS was screened by solubility experiment

compatibility test for excipients and pseudo-ternary phase diagrams. And the best formulation was determined by the particle size and in vitro release evaluation.       Results       In the best formulation of honokiol-SMEDDS

octyl and decyl glycerate (MCT)

polyoxyethylene hydrogenated castor oil (Cremophor RH40) and diethylene glycol monoethyl ether (Transcutol P) were used as oil phase

surfactant and co-surfactant

respectively. The percentage of oil phase was 20%

K

m

of surfactant to cosurfactant was 2

the drug loading was 10%

and the average particle size was 28 nm.       C

onclusion       The honokiol-SMEDDS is prepared successfully

and the solubility of honokiol is improved significantly.