Improved oral bioavailability of myricitrin by liquid self-microemulsifying drug delivery systems

Abstract This study aimed to prepare a self-microemulsifying drug delivery system loaded with myricitrin (M-SMEDDS) to improve the low oral bioavailability of myricitrin. Prepared M-SMEDDS consisted of an oil phase (ethyl oleate), a surfactant (Cremophor EL35) and a co-surfactant (dimethyl carbinol). M-SMEDDS was characterized using the particle size, zeta potential and encapsulation efficiency, while the pharmacokinetics studies were also investigated. The prepared M-SMEDDS exhibited stable physicochemical properties with a small average droplet size (21.68 ± 0.15 nm), negative zeta potential (−23.17 ± 1.03 mV) and high encapsulation efficiency (92.73%). The in vitro release study showed that myricitrin was significantly released from M-SMEDDS compared with the free myricitrin. The relative oral bioavailability of M-SMEDDS was 2.47-fold higher than that of the free drug. These results indicated that the preparation, in vitro and in vivo studies of M-SMEDDS could obviously improve the solubility and oral bioavailability of myricitrin. This study therefore provides preliminary evidence for further clinical research and application of M-SMEDDS.