ABSTRACT
OBJECTIVE: To prepare lappaconitine(LA)-loaded microemulsion with olive oil and study its morphology, particle size, drug loading capacity, drug release behavior and rheological characteristics. METHODS: Pseudo-ternary phase diagram method was used to screen and prepare LA-loaded microemulsion with olive oil. LA release properties in vitro were investigated by dynamic dialysis method. The rheological properties of LA-loaded microemulsion with olive oil were studied using MCR 301 rheometer. RESULTS: The optimal formulation of LA-loaded microemulsion with olive oil was as follows:olive oil was the oil phase, castor oil polyoxyethylene ether-40/span-80(4:1) was the surfactant, glycerin was the cosurfactant, and Km=3. The morphology of the microemulsion particles was round or oval, and the average particle size was(91±0.55) nm. The drug-loading rate of LA in the microemulsion was 1.85%.Drug release experiments in vitro showed that the microemulsion had a sustained release effect on LA, and the drug release behavior was more suitable to be described by Higuchi equation. Rheological experiments showed that the fluid of LA-loaded microemulsion with olive oil belong to pseudoplastic fluid of non-Newtonian fluid exhibiting thixotropic and shear-thinning fluid behavior as well as certain viscoelasticity. CONCLUSION: The LA-loaded microemulsion witholive oil are successfully prepared, and the microemulsion has ideal sustained release behavior and good rheological properties. The study provides a foundation for the developmenton preparation of LA-loaded microemulsion with olive oil.