| Objective：In this research,ligustrazin hydrochloride（LTH） wasselected to be model drug as antitumor drugs.Liposomes （LP）loadedligustrazin hydrochloride were prepared fistly,optimize the prescribedconditions,and then were incorporated into chitosan microcapsules.Thepreparation technology and the particle size of LTH-LIM.To investigatethe cytotoxicity of LTH-LP on HepG2cells and HUVECs cells.Method1. The preparation and characterization of LTH-LP The LTH-LP wereprepared using ammonium sulphate gradients method. The single factorand orthogonal experiment design was applied to screen the optimumformula of LTH-LP. The LTH-LP were characterized with regards to theparticle size, Zeta potential, entrapment efficiency,drug loading and thestability,and the dialysis method was used to determine the releasepreparations in vitro.LTH’s entrapment efficiency was applied to assess thestability of liposome at different envionment.2. Investigate the cytotoxicity of LTH-LP MTT assay was applied toinvestigate the cytotoxicity of LTH-LP, B-LP andLTH on HepG2cells and HUVECs cells. OD value was measured at490nm microplate reader andthen calculating the difference between the groups of drug concentrationand different action time of proliferation inhibition rate.3. The preparation and characterization of LTH-LIM LTH-LIM wereprepared by emulsion cross-linking method, the drug loading andencapment efficiency were affected by many factors, it could be used tooptimize preparation conditions,such as oil composition, emulsifiercomposition,phase volume ration, chitosan solution, amount ofglutaraldehyde,emulsifier ratio and emulsifier concentration on theinfluence of the preparation.The structure of LTH-LIM was demonstratedby scanning electron microspheres, DSC characterization ofmicrocapsules,dialysis method was used to determine the releasepreparations in vitro.Results1. The preparation and characterization of LTH-LP The LTH-LP wereprepared by optimized ammonium sulphate gradients method. Useing bythe single factor and orthogonal experiment design screen the bestprescription of LTH-LP.The optimum formula was asfollowed:phospholipids: cholesterol was2:1, octadecylamine was2mg,45℃decompression spin steaming for uniform thin film; Ammoniumsulfate solution concentration was200mmol·L-1,and the incubationtemperature60℃.The encapsulation rate of ligustrazine hydrochloride liposomes was about82.4%,drug loading was4.05%. The average size wasabout173.4nm, and the Zeta-potential was about11.5mv. The LTH-LPobserved through transmissiom electron microscopy and it shows theparticle size distribution is uniform;Dissolution experiment results showsLTH-LPhas the slow-release effect.LTH-LP is stable in fulling nitrogenatmosphere at4℃.2. Investigate the cytotoxicity of LTH-LP After48hours,the MTT resultsshowed that the proliferation inhibition effect of LTH-LP on HUVECs cellswas better than the cell proliferation inhibitionon on HepG2cells (P＜0.05).3.The preparation and characterization of LTH-LIM Preparation ofLTH-LIM method selected by chitosan emulsion cross-link method,theoptimum formula was as followed:dimethyl silicone was used as oil phase;tween-80and span-80at a ration of1:1was used as emulsifier; chitosansolution concentration is2%;The amount of glutaraldehyde is0.6%; Thewater phase composition proportion is chitosan, liposome suspensionliquid,and the ration is1:1.The average drug loading of optimized LTH-LPwas2.925%, average encapsulation efficiency was65.345%.The structureof LTH-LIM was demonstrated by scanning electron microspheres andelectron microscope,particles preparation rounded appearance, andaverage particle size distribution was5～8μm. DSC characterization forLTH-LIM, indicating that LTH-LP was coated in microcapsules.LTH- LIM release slowly and not completely in vitro.Conclusion： All these studies verified that the the experimentalpreparation LTH-LP has high encapsulation efficiency and uniform particlesize, potential stability,coating rate is high and uniform particle size, thedrug release ration was completely and slow in vitro.The stability resultshowed that LTH-LP stored in4℃would keep stable.The MTT resultsshowed that the proliferation inhibition effect of LTH-LP on HUVECs cellswas better than the cell proliferation inhibitionon on HepG2cells (P＜0.05).Obtain higher drug loading LTH-LIM, rounded appearance, particle sizemeets the test requirements. LTH-LIM combines the advantages ofliposomes and microcapsules is a new type of formulation.Thatpreparation of LTH-LIM has high drug loadings, the rounded appearance,particle size conform to the requirements of the experiments.LTH-LIMintegrated advantages of liposomes and microcapsule,which was a newdrug delivery system with good application prospersity. |
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