ABSTRACT
OBJECTIVE: To prepare palmatine-loaded flexible nano-liposomes (PFNL) and study their pharmaceutical properties, in order to lay the foundation for the industral application. METHODS: The flexible nano-liposomes were prepared by thin-film homogenization method with propyleneglycol (PG) as softening agent. The entrapment rate of palmatine was evaluated by protamine aggregation method and HPLC. The effects of concentrations of phosphatidylcholine (PSC), cholesterol (CH), and PG on the entrapment efficiency of palmatine were also investigated. The pharmaceutical properties of PFNL were evaluated by TEM, PCS and CLSM. The deformation of PFNL was determined by its relative rate of permeating the microporous filter membrane. The coagulation rate constant (K) was measured by constant temperature conductivity method. The side-by-side diffusion cells and pig vaginal mucosa were used to investigate the characteristics of the release of palmatine from PFNL in vitro, and the effects of PFNL on the expression of cytokines (SLPI, LF and SP-D) were investigated and compared with classic liposomes and lotion of palmatine. RESULTS: The palmatine entrapment efficiency was (78 ±2.13)% when the PFNL were prepared with PSC (3%), CH (0.02%), and PG (20%). The prepared nano flexible liposomes had a closed spherical or elliptical shape and appeared as multi-lamellar vesicles under the TEM and CLSM. The calculated mean size was (185 ±19) nm, and the Zeta potential was (-53 ±2.27) mV. The deformation of PFNL was (79 ± 5.75)%. The coagulation rate constant (K) of PFNL was always lower than that of traditional palmatine- loaded liposomes. The accumulated permeation amount of palmatine from the PFNL at 6.0 h was 1.53 and 2.86 folds of those of classic liposomes and lotion, respectively. Moreover, the expressions of cytokines (SLPI, LF and SP-D) in female SD rats after being treated with PFNL, PCL and PL were similar to that of the control group. CONCLUSION: The prepared PFNL have high encapsulation efficiency, good stability and safety, and greatly increase the vaginal mucosa permeability of palmatine. Flexible nano-liposomes may be a useful drug delivery carrier for the gynecological application of palmatine.