Study On Chitosan Chloride-Coated Nanoliposomes Containing Hydroxycamptothecin

Part 1 Study on the Formulation and Preparation Process of CS-C1 coated N-Iiposomes containing HCPTObjective: To screen the optimal formulation and preparation process of the coated hydroxycamptothecin (HCPT) nanoliposomes( N-liposomes).Methods: the HCPT liposomes were prepared by the film dispersion method. Liposomes and unloaded HCPT were separated by Sephadex-G50 chromatography .Ultraviolet spectrophotometry was used to determine the EE% of HCPT N-liposomes. Orthogonal design was used to select the best formulation.Chitosan chloride (CS-Cl)was used to coat the liposomes, then the liposomes were extruded through High Pressure Homogenizer.Zetasizer was used to determine the Zeta potential, average size and size distribution of the HCPT Liposomes.Different cryoprotectants were used during lyophilization in order to select the best one.Results :The results showed that the average Entrapment efficiency(EE%) of the optimal formulation was 68.8±0.9%(n=3) .The Zeta potential of the CS-C1 coated HCPT N-liposomes was 55.1 ± 1.04 mV (n=3) and average size was 90.9 ± 8.78 nm (n=3) with size distribution of 20-120nm.The particle size was changed least after lyophilization when 15%(w/v)trehalose was used as cryoprotectant.Conclusions: The results suggested that the formulation and preparation process were practical to prepare the CS-C1 coated HCPT N-liposomes with promising EE% and stablity.Part2 Study on the release of CS-C1 coated HCPT N-liposome in vitroObjective: review the release of CS-C1 coated HCPT N-liposome in vitro.Methods:The different preparations were enclosed in dialyzer then dissolved in intelligent lysimeter.The solutions were got at different time,and the HPLC was used to determine the HCPT concentration.Results:The results showed that the drug release curve accord with Higuchi equation. Q=0.055+0.0228t_1/2,r=0.9559.Conclusions: The results suggested that the CS-Cl coated HCPT N-liposome retarded drug release in vitro prominently.Parti Study on the CS-C1 coated HCPT N-liposome in tissue distribution in miceObjective: review the HCPT of CS-C1 coated HCPT N-liposome in tissue distribution in miceMethods:HCPT injection,common HCPT liposomes,non-coated HCPT liposomes and CS-C1 coated HCPT-nanoliposomes were injected in tail vein at a dose of 5mg ? kg"1 of HCPXrespectively in mice.The HPLC-FLD was utilized to the determine the HCPT concentration in mice tissue,including plasmajiver and spleen.Results :The results showed that The area under the curve(AUCo-48) of plasma of CS-C1 coated HCPT much higher than that of HCPT injection ^ common liposomes (P<0.01) and non-coated N-liposomes (P<0.05) .ConclusionsrThe AUC(ms of plasma was increased significantly and long circulation time can be obtained after coated by CS-C1.Part4 The antitumor activity of the CS-C1 coated HCPT N-liposome in miceObjective: Review the antitumor activity of the HCPT of CS-C1 coatedHCPT N-liposome in mice.Methods:Ehrlich Ascites Cancer(EAC,0.2ml/20g,4 X 106celis/ml)was transplanted onto the subcutaneous tissue of mice right back on day O.Mice were divided into 5groups,weighted and labeled,each group consisted of 10 mice. CS-C1 coated HCPT nanoliposomes, non-coated HCPT nanoliposomes,common liposomes*HCPT injection(free drug),0.9% sodium chloride were respectively administered at a dose of 5mg ? kg"'on days 7 after tumor inoculation.The animals were killed by cervical dislocation on day 15 after tumor inoculation.The tumor were then removed ,ringsed with saline solution and weighed.conculate the tumor weight inhibition rate of different groups.Then the tumor were fixed in 10% neutral carbonate-buffered formaldehyde,embedded paraffin using an embedding center and cutting to slices. The slices were stained with hematoxylin-eosin and observed under a light microscope . Each group of slices were devided into three types,namely4ow-grade putrescence^noderate putrescence high-grade putrescence.Results :The results showed that the inhibition of tumor weight and putrescence rate ofCS-Cl coated HCPT much higher than that of HCPT injection -, common liposomes (P<0.01) and non-coated N-liposomes (P<0.05) .Conclusions: The results suggested that the CS-C1 can improve the antitumor activity of HCPT in vivo.