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ID:33661390
大小:3.03 MB
页数:67页
时间:2019-02-28
《聚乳酸卡氮芥载体研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、中文摘要卡氯芥是一种有效治疗恶性神经胶质瘤的药物,临床疗效显著,是目前脑瘤治疗的首选药物。但半衰期短,难溶于水,毒副作用大。为克服上述缺点,本文采用溶剂挥发法制备了抗癌药物BCNU的聚乳酸微球。用扫描电子显微镜(sEM),光学显微镜观察其表面形态,显色法测定微球载药率,考察了不同制备条件对微球的粒径和形态,载药率,包封率等性能的影响。可观察到所制备载药微球表面光滑圆整,粒径分布均匀。结合SEM分析,微球粒径受油相分散方式和聚乳酸分子量的影响显著。载药率可达15%左右,药物包封率可达40%左右。用差热扫描分析(DS
2、C)对载药微球中药物分布状态及稳定性进行测定:BCNU在PLA基质中以分子状态存在,其药物稳定性有所下降。载药微球体外释放试验显示聚乳酸分子量、药物含量、微球粒径对PLA.BCNU微球释放有不同程度的影响。微球释药时间长,可持续释放70天左右,释药速率较稳定,符合Higuchi时间平方根模型。提高微球表面光滑度可适当减小药物突释程度和时间。SEM观察水解后聚乳酸微球,其骨架仍然存在,但球形较不规则,表面出现一些凹凸不平,这与聚乳酸微球自身的降解和药物的溶出有关。并对PLA和PLA/PEG共混两种载药膜片的释放、降
3、解行为作出比较,PLA在加入PEG后,其药物释放速率和本身降解速率明显加快,可进一步改善PLA释药特性。关键词:溶剂挥发法卡氮芥聚乳酸药物释放聚乙二醇ABSTRACTBCNU,relativelyhighlipidsolubilityandlowmolecularweight,iswidelyusedforthetreatmentofmalignantgliomas.However,BCNUislimitedbyitssystemictoxicityandcharacteristic,suchasitswater
4、—insolutionandshorthalflife.InordertoSOlyetheseproblems,thefollowingworkhasbeendoneinthisdissertation.PLA—BCNUmicrospheres(MPs)werepreparedbySolventevaporationprocessviausingPLAaSthepolymermatrix.ThroughSEM(Seanningelectronicmicroscopelmicrograph,themicrosphe
5、ressizesandstandarddeviationwereeffectedbymolecularweightandoil-phasedistributionmodels.Smoothsurfacewithoutcavitiesorcrystalofthedrugcouldbegetinthisdissertation.ColorimetricmethodwasusedtodeterminatedrugloadedratioanddrugencapsulationefficiencyofMPs,and廿1ey
6、couldreach15%and40%,respectively.BCNUdispersionandstabilityintheMPswasstudiedbyDSC(Differentialscanningcalorimetryanalyses).TheinvitroreleaseexperimentsstudiedtheeffectsofmolecularweightofPLA.drugcontentinMPsandMPssizesonreleasebehaviorofmicrospheres.Therelea
7、seBCNUmicrospheresWasslow(>70day)andstable,andcouldbedescribedaSsquareroot—timeprocess.ImprovethesurfacesofⅣ咀scouldweakentheirdegreeofburstrelease.SomedegradationofMPsafterreleasingfor1monthcouldbeseenbySEM.Thebasicsphericitywasremainedbutwitllsomecavitieswhi
8、chwerethechannelsforBCNUwhendeliveredintotheenvironment.AdditionofPEGtoPLAfilmCanimprovereleasebehaviorofPLA.BCNUcarrierbyincreasingthespeedofdrugrelease.Keywords:Solventevaporationproces
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