【作者】 邱玉琴；

【导师】 高云华；

【作者基本信息】 中国科学院研究生院（理化技术研究所） ， 有机化学， 2009， 博士

【摘要】 多烯紫杉醇(Docetaxel, DTX)是一种新一代抗肿瘤药物,其新颖的抗肿瘤机制及在临床研究中显示的独特疗效,使得DTX及其合并用药方案在临床上被越来越多的应用于乳腺癌、非小细胞肺癌、卵巢癌及前列腺癌等多种肿瘤的治疗。由于DTX的水溶性差,市售制剂泰索帝(Taxotere)含有助溶剂吐温80,临床试验中部分患者产生严重过敏反应。开发安全有效的新型DTX制剂,消除现有DTX制剂所产生的问题,能够提高广大肿瘤患者的生活质量,具有重要的研究意义。本论文以改善难溶性药物DTX的经皮渗透性为主体思路,制备了DTX弹性脂质体制剂以解决DTX水溶性差和皮肤用药安全性问题,综合运用弹性脂质体和微针经皮给药技术改善DTX的经皮渗透性,对该药物经皮渗透的体内外药物动力学行为及经皮渗透机理进行了深入的研究,以期为以DTX为代表的低水溶性大分子药物的经皮给药新剂型开发提供研究基础。在本论文的文献综述部分,简单介绍了经皮给药系统,详细描述了改善药物经皮渗透性的药剂学、物理学及化学方法,对DTX的应用及制剂相关研究进展进行了阐述;在本论文的实验部分,主要围绕DTX弹性脂质体的研制及其与微针经皮给药技术结合的体内外药物动力学等方面开展了一系列研究。主要研究工作包括:1.建立了DTX弹性脂质体的制备方法。经处方优化后制备的DTX弹性脂质体为单层圆球形结构,载药量较水溶液提高了1000倍以上,具有良好的稳定性。2.运用体外扩散池实验研究了DTX弹性脂质体的体外经皮渗透性,并比较了DTX弹性脂质体、常规脂质体和对照溶液经猪皮的渗透性。DTX弹性脂质体的稳态渗透速率是常规脂质体的3倍(P<0.05),而对照溶液的接受池中药物浓度在定量限以下,这表明DTX弹性脂质体可显著性促进DTX的体外经皮渗透。通过空白制剂预处理实验和激光共聚焦成像法,提出在弹性脂质体改善DTX经皮渗透性的机理中,既存在渗透促进剂机制,又有完整弹性脂质体进入角质层机制,其中前者可能间接影响DTX的经皮传递,后者对渗透起主导作用。3.首次将弹性脂质体和微针经皮给药技术结合以改善药物的经皮渗透性,并对其促渗机理进行了探讨。微针作用可促进载有DTX的弹性脂质体的经皮传递,从而进一步改善DTX的经皮渗透。与微针技术结合时,DTX弹性脂质体的稳态渗透速率是对照溶液的1.7倍,且时滞仅为常规脂质体的1/4。上述研究结果表明DTX弹性脂质体微针给药系统在改善DTX经皮渗透性上具有显著优势,具有潜在应用价值。皮肤贮留量研究表明,DTX弹性脂质体进入微针作用产生的微孔道后,完整的弹性脂质体几乎无法穿透皮肤,而是贮留在皮肤中将DTX释放出来。4.初步研究了DTX弹性脂质体微针给药系统在小鼠体内药动学行为及抗肿瘤活性。DTX弹性脂质体微针经皮给药时,进入皮肤的DTX只有极少量会进入体循环。DTX弹性脂质体微针经皮给药治疗人乳腺癌裸鼠移植瘤的肿瘤体积和重量的增长均明显受到抑制。初步判断,DTX弹性脂质体微针给药系统具有一定程度的局部抗肿瘤作用。家兔皮肤刺激性实验结果表明,DTX弹性脂质体可降低DTX对皮肤的刺激性。更多还原

【Abstract】 The novel antitumor mechanism and the unique efficacy in clinical trials make docetaxel (DTX) one of the promising new generations of antitumor drugs. DTX and its combination therapy were widely used in the treatment of many cancers, such as breast, non-small-cell lung, ovarian, and prostate cancer etc. Severe allergies are seen in clinical test of the market formulation (Taxotere) by utilizing Tween 80 as the solubilizer. To develop a safe and effective new formulation of DTX would overcome the problems of current formulation and improve the life quality of tumor patients, which has great importance for tumor therapy.Improving the skin permeability of poorly water-soluble DTX was the main focus of this paper. Both the solubility and the cutaneous safety of DTX were significantly improved by loading DTX into elastic liposomes. Combining elastic liposomes with microneedle pretreatment, the skin permeability of DTX was remarkably improved. The in vitro/in vivo pharmacokinetic behavior of skin permeation of DTX and the relevant mechanism were thoroughly studied to provide new idea and materials on the study of new formulation of high molecular weight and poor water-soluble drugs of DTX kind.In the review sections of this work, the skin drug delivery system was briefly introduced. Pharmaceutical, physical and chemical methods to improve skin drug delivery were described in detail. Recent development on DTX application and formulation study was also reviewed. In the experimental sections, a series of research work was performed in association with the development of DTX elastic liposomes and the in vitro/in vivo pharmacokinetics of DTX elastic liposomes-microneedle combination system. The main works are described below:1. Preparation of DTX elastic liposomes. The DTX elastic liposomes prepared under optimized formulation were unilamellar and spherical. The drug loading dosage of DTX in elastic liposomes was more than 1000 times higher than that in water. The DTX elastic liposomes were confirmed stable in the stability test.2. The permeability of DTX through porcine skin from elastic liposomes, conventional liposomes and control solution was investigated and compared in vitro. The steady-state flux of DTX from elastic liposomes is 3-fold higher than that from conventional liposomes (P<0.05). In the meantime, concentration of DTX in the receptor cell from control solution was below the limit of determination. The above results indicated that using elastic liposomes could significantly improve the skin delivery of DTX. The mechanism of elastic liposomes to improve skin delivery of DTX was studied by blank formulation pretreatment experiment and laser confocal scanning microscopy (CLSM), which indicated that both the penetration enhancing effect and intact liposomal permeation into the stratum corneum mechanism play a role in it. Furthermore, the penetration enhancing effect may indirectly influence the skin delivery of DTX, and the intact liposomal permeation into the stratum corneum mechanism seems to play a predominant role through the DTX permeation.3. The effect and mechanism of improvement of skin drug delivery by combining elastic liposomes with microneedle skin drug delivery system were studied for the first time. Microneedle pretreatment can improve the permeation of DTX loaded elastic liposomes, so as to further improve skin delivery of DTX. Combining with microneedle pretreatment, steady-state flux of DTX from elastic liposomes is 1.7-fold higher than that from control solution. Furthermore, the lag time of DTX from elastic liposomes is only a quarter of that from conventional liposomes by microneedle pretreatment. The results above showed that combining DTX elastic liposomes with microneedle pretreatment significantly improved the skin delivery of DTX, and showed great potential application value. The skin deposition study showed that after DTX elastic liposomes entering the microchannels created by microneedle pretreatment, intact liposomes will be difficult to permeate through the skin, but to deposit in the skin and release DTX.4. The pharmacokinetic behavior and antitumor effect of DTX elastic liposomes -microneedle combination system in mice were preliminarily studied. Only little DTX can enter the systemic circulation after enter the skin by the combination system, if any. Both the tumor volume and tumor weight of the human breast carcinoma xenografts in nude mice were remarkably inhibited by treatment of DTX elastic liposomes-microneedle system. These results demonstrated that DTX elastic liposomes-microneedle system could improve the local antitumor activity to some extent. Skin irritation test in rabbits showed that the DTX elastic liposomes can decrease the irritation of DTX to the skin.更多还原