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Objective To obtain the intestines absorption of TPGS-CS/PTX polymeric micelles in rats, a drug-loaded micelle system was established by a kind of amphiphilic copolymer, D-α-tocopherol polyethylene glycol 1000 succinate-chitosan (TPGS-CS) was prepared by grafting D-α-tocopherol polyethyleneglycol 1000 succinate (TPGS) as the donor of the micelle hydrophobic group on chitosan (CS) as bioadhesive material, and loading paclitaxel as model drug. Methods TPGS was activated by its hydroxy-terminal carboxylation with succinic anhydride (SA) and 4-dimethylaminopyridine (DMAP). The TPGS-CS copolymer was prepared by the amidation of free amino groups on CS. The chemical structure of the TPGS-CS grafted copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR) and Nuclear magnetic resonance spectroscopy (NMR). The polymer micelle loading paclitaxel was selected as model drug and TPGS-CS/PTX was prepared by ultrasonic emulsification method. The encapsulation efficacy (EE) and drug loading (DL) were determined by high performance liquid chromatography (HPLC). The particle size, Zeta potential, and size distribution of the micelle system were measured by dynamic light scattering (DLS). The surface morphology of the micelles was investigated by Transmission electron microscopy (TEM). The in vivo intestines absorption rate (Ka) of paclitaxel-loaded TPGS-CS micelle was calculated in rats. Results The results of FT-IR and 1H NMR indicated that the copolymer (TPGS-CS) was synthesized. The TEM result showed that the formed particles were uniform in shape without aggregation. The Ka of TPGS-CS/PTX was 20 percent higher in comparison to the reference preparation, it indicated that this polymeric micelles could increase bioavailability. Conclusion The proposed TPGS-CS copolymer was successfully synthesized in this experiment, and the drug-loaded micelles prepared by ultrasonic emulsification exhibited good characteristics compared with the reference preparation, the Ka of paclitaxel was increased to some extent to promote oral absorption of the drug.
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Objective: To prepare GEN-VES-TPGS nano-micelles and improve the oral bioavailability of genistein (GEN). Methods: GEN-VES-TPGS nano-micelles, made by film hydration, were evaluated with particle size, entrapment efficiency, and drug-loading as indexes. Single factor experiment was used to optimize the formulation and productive technology, including dosages of TPGS, VES, GEN, hydration volume, temperature, and time. Morphology of nano-micelles, release rate in vitro, and pharmacokinetics in rat were investigated. Results: The results showed GEN-VES-TPGS nano-micelles presented with good clarity, appropriate particle diameter (43.50 ± 1.65) nm, negative charge, when the dosages of TPGS, VES, GEN were 200, 30, and 6 mg, respectively. Meanwhile, a condition of 15 mL, 50 ℃ at 3 h to hydrate was necessary to prepare. In this setting, the encapsulation efficiency of the nano-micelles was (98.99 ± 0.69)% and drug-loading rate was (2.57 ± 0.04)%. The pharmacokinetic results in rats showed the oral bioavailability of GEN-VES-TPGS nano-micelles was 162.96% of the GEN APIs. Conclusion: The prepared GEN-VES-TPGS nano-micelles have small particle size and good stability, and increase the oral bioavailability of GEN evidently.
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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 investigate the effect of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) on the inhibition of proliferation of breast cancer cells MCF-7 by baohuoside I. Methods: The cytotoxicity of baohuoside I to MCF-7 cells was determined by MTT assay, the cellular uptake of baohuoside I was detected by fluorescence microscopy, and the intracellular baohuoside I was determined by HPLC. Results: The effect of baohuoside I on the inhibition of MCF-7 cell proliferation was enhanced in the presence of TPGS, especially on lower concentration. The uptake rates of MCF-7 within 2 h were 29.51%, 38.12%, and 40.37%, when the proportions of baohuosaide I and TPGS were 1:1, 1:2, and 1:4, respectively. The ratios were increased by 27.92%, 65.24%, and 74.99% compared with those using baohuoside I only. Conclusion: TPGS can increase the uptake rate of baohuoside I in MCF-7 cells and enhance the inhibition of MCF-7 cell proliferation.
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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.