ABSTRACT
OBJECTIVE： To optimize the preparation technology of Oridonin A oral liposomes （ORI-LIP） by using supercritical fluidsolution-enhanced dispersion （SEDS） technology， and to investigate its advantage with routine liposome preparation technologies. METHODS： Using particle size as evaluation index， orthogonal design was employed to investigate the influence of pressure， temperature and flow rate on the preparation technology of ORI-LIP by SEDS. At the same time， thin film dispersion and reverse evaporation method were used to prepare ORI liposomes. The particle size， encapsulation efficiency， drug loading amount and stability （accelerated test for 6 months） were compared among 3 methods. Moreover， the difference in dissolution behavior in vitro of ORI crude drug and 3 kinds of liposomes was evaluated. RESULTS： The optimized preparation condition of ORI liposomes by SEDS included temperature of 50 ℃， pressure of 18 MPa， flow rate of 1 mL/min. Compared with thin film dispersion and reverse evaporation method， the liposomes prepared by the SEDS method exhibited smaller particle size [（147.4±4.8）nm]， better encapsulation efficiency （67.8％）， drug-loading amount （7.8％） and stability （particle size increased slightly， encapsulation efficiency decreased only by 4.4％）. Results of in vitro dissolution test showed that compared with crude drug， release rate of each liposome was slow and persistent， and the cumulative release rate was higher. The accumulative release rate of ORI-LIP prepared by SEDS could achieve to 67.2％， and reached to dissolution equilibrium at 24 h. CONCLUSIONS： ORI-LIP prepared by SEDS has smaller particle size， higher encapsulation efficiency， drug loading amount and stability， which can improve the in vitro release of ORI. Compared with conventional methods， SEDS technology has certain advantages.