ABSTRACT
Objective To prepare F7 thermosensitive liposome and evaluate its physicochemical properties, then investigate its cytotoxicity against tumor cells in vitro. Methods The F7 thermosensitive liposome was prepared by the pH gradient active drug loading method using dipalmitoyl phosphatidylcholine myristoyl lyso-phosphocholine and 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy (polyethylene glycol)-2000 as membrane materials. The encapsulation efficiency and drug loading were determined for the F7 thermosensitive liposome by HPLC. The phase transition temperature of F7 thermosensitive liposome was investigated by differential scanning calorimetry;the liposome morphology was observed by atomic force microscopy;the drug release of liposome was examined by dialysis;and the particle size and zeta potential were measured through Malvern particle size analyzer. The cytotoxicity of F7 and F7 thermosensitive liposome was determined by the MTT method, and the freeze-drying process was optimized using the designexpert software. Results The encapsulation efficiency of F7 thermosensitive liposomes was (97.56±0.22) ％, and the drug loading ratio was (1.51±0.01) ％. The phase transition temperature of F7 thermosensitive liposome was 39.9℃, the zeta potential was (-15.10±0.85) mV, the particle size was (86.94±1.21) nm, and the poly disperse coefficient was 0.17±0.01. Compared with the F7 injection, the F7 thermosensitive liposomes showed a stronger, dose-dependent inhibitory effect on the growth of lung cancer H1299 and breast cancer MCF-7 cells. The freeze-dried powder of liposomes dissolved well with the encapsulation efficiency of 95％ and the particle size of approximately 130 nm. Conclusion The F7 thermosensitive liposome prepared by the pH gradient active drug loading method has high encapsulation efficiency and good stability. The preparation method is simple and feasible for further development of the F7 preparation.
ABSTRACT
OBJECTIVE: To establish a rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) method for quantification of vincristine sulfate (VCR) in dog plasma and to study the pharmacokinetics of vincristine sulfate thermosensitive liposomes (VSTL) in dogs. METHODS: The plasma was extracted with terl-butyl methyl ether (TBME). VCR and IS(vinblastine sulfate) were separated on an Agela Venusil XBP C18(2.1 mm × 30 mm, 3.0 μm) with a mobile phase gradient at a flow rate of 0.4 mL · min-1. The injection volume was 10 μL. An Agilent 6460A QQQ triple-quadrople mass spectrometer equipped with an electros-pray ionization(ESI) source was used as detector and was operated in positive ion mode. Multiple-reaction monitoring(MRM) was performed and the m/z of ions selected for quantitation were m/z 825.4→807. 2(VCR) and m/z 811.3→223.9(IS, vinblastine sulfate). Dogs were injected VSTL and vincristine sulfate injection (VSI) via vein at the dose of 0.07 mg-1, respectively. VCR and internal standard were quantified in dog plasma using a high-performance liquid chromatography-tandem mass spectrometry, Pharmacokinetic parameters were calculated, and a comparative study of VSTL and VSI with six dogs was conducted. RESULTS: The chromatograms showed no endogenous interfering peaks in blank dog plasma. The linear range of VCR in plasma was 0.25-500 ng · mL-1 (r=0.994 3). The lower limit of quantification was 0.25 ng · mL-1. The intra-run and inter-run relative standard deviations(RSD) were less than 15%. The pharmacokinetic parameters of VSTL and VSI were as following: ρmax (121.00 ± 42.31) and (61 ±23.36) ng · mL-1; t1/2λz(23.95±9.03) and (37.91±8.02) h; CLz(0.37±0.07) and (0.35 ±0.09) L · h · kg-1; Vz(12.15 ±2.14) and (18.95 ±3.27) L · kg-1; AUC0-t(144.87 ± 1.10) and (127.7 ±2.45) ng · h · mL-1; AUC0-∞ (152.97 ±12.56) ng · h · mL-1; and (131.61 ±13.22) ng · h · mL-1. CONCLUSION: The method is shown to be sensitive, accurate, and convenient for assaying the concentration of vincristine sulfate in preclinical pharmacokinetic studies. The ρmax and AUC of VSTL are significantly higher than VSI after intravenous infusion, the other pharmacokinetic parameters are no significant difference.
ABSTRACT
Objective To establish a quick method to analyze vinorelbine ( NVB) in plasma of beagle dogs and study its pharmacokinetics of long-circulation and thermosensitive liposome loaded vinorelbine bitartrate.Methods The plasma was treated with liquid-liquid extraction after precipitation in methanol.The analysis was perfomed on a Venusil XBP C18 column(2.1 mm ×50 mm, 3 μm) at 35℃,the mobile phase consisted of methanol and water( containing 10 mmol/L ammonium acetate, 1%acetonitrile) 80∶20 and injection volume was 10μl.The type of mass spectrum was multireactive monitoring(MRM) in a positive mode.The monitor transitions were m/z 779.4-765.4 for vinorelbine and m/z 825.4-122 for vincristine.Results The concentration range from 10 to 2500 ng/ml had a good linearity ( r=0.0994).The precision, accuracy and extraction efficiency were acceptable.The plasma samples were stable for 10 days at -20℃ and 24 h at room temperature.Pharmacokinetic study in beagle dogs showed that the main parameters for injection and liposome were Cmax(833.51 ±150.42) and (1397.95 ±443.05)ng/ml, AUC(0-t) (577.16 ±223.57) and (1059.82 ±408.27) ng/ml· h, Cl(3014.64 ±1049.17)and 1633.10 ±551.77 ml/(h· kg), respectively.Conclusion A reliable HPLC-MS/MS method for vinorelbine analysis is established and can be applied to the pharmacokinetics study of liposome.The results show that liposome has a higher AUC, Cmax and longer Cl than injection.Meanwhile, liposome has a lower irritability.
ABSTRACT
Objective To investigate the pathologic mechanism of radiofrequency ablation ( RFA ) combined with intravenous infusion of thermosensitive liposome encapsulated vinorelbine (TL-Vin) in treating liver tumors, and to analyze the effect of combination therapy on the long-term survival rate. Methods H22 liver adenocarcinoma tissue was subcutaneously implanted into ICR mice to establish the animal models. At the first experimental period, 40 mice were randomly and equally divided into 5 groups to receive different therapeutic scheme (using different TL-Vin concentrations). Twenty-four hours after the treatment the tumor specimens were collected, the necrotic areas were measured separately, and the optimal TL-Vin concentration was determined. At the second experimental period, 13 mice were randomly selected to receive treatment. Half an hour after the treatment the tumor tissues were collected and the TL-Vin concentration within the tumor was determined. At the third experimental period, 32 mice were randomly and equally divided into 4 groups, and 90 days after treatment the tumor growth curve was drawn. The survival rate was compared between each other of the groups. Results Compared with pure RFA group, TL-Vin + RFA significantly increased tumor coagulation extent (P0.05). Tumor coagulation area in TL-Vin + RFA group was bigger than that in free-VIN + RFA group at the concentration of 10 mg/kg [(341.8 ± 65.4)mm2 vs (225.3 ± 25.4)mm2, P < 0.01]. In TL-Vin group the coagulation margin was clear. The mean intratumoral Vinorelbine accumulation in TL-Vin + RFA group was 10 folds of that in free-Vin group [(1 156.5 ± 158.3)ng/ml vs (194.5 ± 52.3)ng/ml, P = 0.005]. TL-Vin +RFA had better survival result than that of RFA alone (37.6 ± 20.1 days vs. 23.4 ± 5.0 days, P=0.015), as well as than that of free-Vin + RFA [(37.6 ± 20.1)days vs (23.3 ± 1.2)days, P = 0.016]. Conclusion Thermosensitive liposomal chemotherapies (Vinorelbine) can be selectively delivered at the edge of RFA coagulation area and thus effectively increase RFA-induced tumor coagulation and prolong the end-point survival in experimental mice.
ABSTRACT
OBJECTIVE: To prepare decitabine long-circulating thermosensitive liposome(DCA-LTSL), screen and optimize its formulation, and evaluate its properties. METHODS: DCA-LTSL was prepared by modified reverse phase evaporation method, and the encapsulation efficiency was determined by minicolumn centrifugation-HPLC method. The influences of the concentration of PC, the weight ratio of PC to Chol, the weight ratio of DCA to PC and buffer salts were studied. Orthogonal design was adopted to obtain the optimal prescription using encapsulation efficiency as the main index. RESULTS: The best prescription was as follows; the concentration of PC was 5 g · L-1, the weight ratio of PC to Chol was 4 : 1, the weight ratio of DCA to PC was 40: 1 and the pH value of aqueous phase was 7.0.The encapsulation efficiency of DCA-LTSL was (44.50 ± 1.08)% . The Zeta potential was -8.34 mV. The mean diameter of DCA-LTSL was (140.25 ± 2.40)nm. The burst release effectiveness of DCA-LTSL was 42-43°C. CONCLUSION: The formulation of DCA-LTSL has been optimized with excellent in vitro drug release characteristics at the phase-thransition temperature.