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AIM To prepare D-α-tocopherol polyethylene glycol 1000 succinate (TPGS)-modified artesunate liposomes and to investigate the in vitro anti-tumor activity.METHODS The liposomes prepared by thin-film dispersion method were characterized by transmission electron microscopy and particle size analyzer,and the encapsulation efficiency was determined by ultrafiltration centrifugation.The liposomes' cytotoxicity to human hepatoma HepG2 cells was evaluated by MTT method.RESULTS The average particle size,PDI,Zeta potential,encapsulation efficiency,drug loading of the liposomes were 126.7 nm,0.182,-10.1 mV,78.8％ and 18.38％,respectively.The liposomes displayed a significant inhibition on HepG2 cells with the IC50 value of 0.034 μmol/mL.CONCLUSION Compared with non-TPGS-modified artesunate liposomes,the TPGS-modified artesunate liposomes prepared by this method afford smaller vesicle size,better stability and higher encapsulation efficiency with stronger in vitro anti-tumor activity.
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Objective: To prepare and optimize the prescription of colchicine ethosomes containing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and to investigate its feasibility as a carrier for transdermal drug delivery. Methods: The colchicine ethosomes containing TPGS were prepared by the injection-sonication method. And the encapsulation efficiency (EE) was determined by minicolumn centrifugation method. The prescription of ethosomes was optimized by uniform design with EE as the evaluation index, and the physicochemical properties of the optimized ethosomes were investigated. Characterization of the vesicles was based on particle size, Zeta potential, entrapment efficiency, and transmission electron microscopy (TEM). The transdermal permeation characteristics of ethosomes, colchicine 30% ethanol solution, and colchicine ethosomes containing TPGS were compared by using Franz diffusion cells. Results: The optimized formulation was as follows: The contents of soybean phospholipid and TPGS were 350 and 50 mg, respectively. In addition, the concentration of ethanol was 36.44%. The average EE, particle size, polydispersity index, and Zeta potential were (74.71 ± 2.18)%, (89.6 ± 3.5) nm, 0.201 ± 0.008, and (-34.6 ± 2.7) mV, respectively. The in vitro experiment showed that the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes were (64.49 ± 5.61) μg/cm2, (2.84 ± 0.23) μg/(cm2∙h), (128.22 ± 11.64) μg/cm2, and the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes containing TPGS were (91.36 ± 7.11) μg/cm2, (4.73 ± 0.38) μg/(cm2∙h), and (182.84 ± 14.37) μg/cm2, respectively, which was significantly higher than those in ethosomes. Conclusion: The colchicine ethosomes containing TPGS show high EE and obviously enhance the percutaneous absorption of colchicine, which might be a potential carrier for transdermal drug delivery.
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OBJECTIVE: To study the oral absorption of paclitaxel-loaded mixed micelles made of D-α-tocopherol polyethylene glycol 1000 succinate(TPGS) and sodium cholate(NaC) in rats. METHODS: Paclitaxel-loaded mixed micelles were prepared by film dispersion method. The Zeta potential and diameter distribution of TPGS/NaC mixed micelles were measured using laser size scattering determinator. The morphology of micelles was observed by transmission electron microscope. Dialysis method was used to evaluate the release behavior of drug-loaded micelles in vitro. The absorption kinetics was obtained by in situ perfusion method in rats. RESULTS: Most of the mixed micelles were spherical with an average diameter of 24.2 nm and the Zeta potential was -7.84 mV. Compared to the bulk drug, the apparent absorption rate constant (Ka)of paclitaxel-loaded mixed micelles was increased significantly. CONCLUSION: TPGS/NaC mixed micelles can improve the oral absorption of paclitaxel and increase its oral bioavailability.