Investigation on the Preparation, Characteristics, and Controlled Release Model of Paeonol-Loaded Liposome in Carbomer Hydrogel

Paeonol is a phenolic compounce that is volatile. In order to decrease its volatility and achieve controlled release, paeonol-loaded liposome in carbomer hydrogel was prepared by coating with soybean phospholipid via ethanol injection method and then added into the carbomer hydrogel.The quality of paeonol-loaded liposome in carbomer hydrogel was evaluated by the degree of roundness, particle size distribution, zeta potential, entrapment efficiency (filtration method and chitosan neutralization method), viscosity, infrared spectrum, etc. Furthermore, the diffusion from paeonolloaded liposome in hydrogel was studied in vitro.The results showed that the average particle size of paeonol-loaded liposome was about 401 nm, the potential was -17.8 mV, and the entrapment efficiency was above 45%. The viscosity of paeonol- loaded liposome in hydrogel was 23.972×10-3 Pa*s, and the diffusion rate from paeonol-loaded liposome in hydrogel in vitro was obviously slower than that from the other paeonol preparations.The conclusions could be drawn that paeonol-loaded liposome in hydrogel was a kind of novel preparation, and its diffusion in vitro had obvious controlled-release characteristics, which further proved that it might improve the bioavailability of paeonol.