【作者】 邵瑞莹；

【导师】 唐星；

【作者基本信息】 沈阳药科大学 ， 药剂学， 2005， 硕士

【摘要】 脂质微球作为脂溶性药物的靶向给药载体已得到了广泛的关注，特别是作为抗癌药物、麻醉药物及抗炎药物载体。由于药物包裹于油相或乳化剂层中，可以避免与血管内壁直接接触，从而降低药物在注射部位所产生的刺激性及由此而引发的全身毒性，更显示其优势。去甲基斑蝥素（Norcantharidin，NCTD）为由我国首先合成的抗肿瘤药物，临床上主要应用于肝癌的治疗，具有药理活性明确、药效良好等特点。由于NCTD在水中溶解度较小，在临床上主要以其钠盐的注射液应用，但pH较高（约9.0），使用时因高pH值和NCTD本身的强大腐蚀性而产生较大的刺激性，限制了临床上的应用。本实验将NCTD制备成注射用脂质微球（Lipid microsphere，LM），将油相及由乳化剂组成的油水界面膜作为主要目标载药部位，通过各种处方及工艺因素的筛选，将药物的包裹率提高至80％以上，以充分发挥脂质微球的剂型优势，降低NCTD临床使用的刺激性、增效减毒。同时，本实验以NCTD注射液作为参比制剂，对NCTD脂质微球的大鼠体内药代动力学特征进行了考察，并进行了本制剂体外及动物体内安全性实验。建立了NCTD的HPLC—离子交换色谱分析方法，采用阴离子交换色谱柱分离样品，灵敏度较高，空白辅料、表面活性剂等辅料无干扰，适用于NCTD脂质微球的质量控制；其次对NCTD的溶解性能进行了考察，NCTD在pH1.0、pH5.6、pH8.0、pH10.0及蒸馏水中的溶解度分别为3.15、5.59、8.90、29.33、6.72mg·mL^-1，且表观油／水分配系数随水相pH值降低而增加。由于NCTD在油中及水中的溶解度均较低，且相对亲水性稍强，因此在处方因素及制备工艺的研究中，在确保NCTD脂质微球稳定性的基本前提下，将提高脂质微球载药量及提高药物在油相／乳化剂层的包裹率作为筛选处方及制备工艺的主要评价指标。在此过程中，优化出了NCTD加入方法、高压均质温度、压力及次数，卵磷脂的不同加入方法对脂质微球粒径及稳定性的影响，优化了乳化剂中卵磷脂与F68的比例、油酸钠的用量，并考察了pH值对脂质微球的影响。结果表明，乳化剂用量及卵磷脂与F68的比例等是影响脂质微球稳定性的主要因素，单独使用卵磷脂作为乳化剂的处方经高压灭菌后液面出现油滴，但卵磷脂用量低于0.6％时，制剂不稳定，以卵磷脂—F68（0.6∶0.6）作为乳化剂，总量为1.2％时脂质微球稳定性较好且粒度分布均匀（约200 nm）；油相中MCT的比例、pH值等是影响药物包裹率的主要因素，增加油相中MCT比例或降低制剂的pH值，均可提高药物在油相、油水界面膜中的分布，当pH值为7.0，MCT—LCT（7.5∶2.5）时，药物总包裹率可达80％以上，而单纯使用MCT作为油相时制剂不稳定。确定了NCTD脂质微球的最终处方及制备工艺为：油相组成为注射用大豆油—MCT（2.5∶7.5），乳化剂总量为1.2％（卵磷脂：F68=1∶1），油酸钠为0.03％；均质前调节pH值至7.0，高压均质的温度为40℃，压力为800 bar，6～10次，灌封氮气，121℃灭菌15 min。以上方法所制得三批脂质微球平均粒径约为195.2 nm，NCTD在油相及乳化剂层的总分布量为84.6％。与稀释剂混合后考察粒径经时变化的结果显示，本品以生理盐水稀释后油滴出现聚结现象，粒径、ζ-电位及药物包裹率经时变化较大；以葡萄糖注射液稀释样品的粒径、ζ-电位值变化较小，以5倍量稀释时制剂在2 h内的包裹率可保持在80％以上。因此建议临床使用葡萄糖注射液为稀释剂，稀释倍数为5，2 h内使用时安全的。稳定试验研究表明本品在25±2℃及6±2℃条件下放置6个月物理化学性质几乎没有改变。建立了HPLC-MS系统测定大鼠血浆中NCTD的测定方法，NCTD脂质微球和普通的注射液的大鼠体内药时过程均符合双隔室模型，非隔室模型分析结果表明，受试制剂药时曲线下面积（AUC）为125.30±18.46μg·mL^-1·h，为参比制剂的100.34％，两制剂药时曲线形状相同，各药动学参数无显著性差异。安全性试验表明，NCTD乳剂静脉给药的LD₅₀值为18.6mg／kg，大于NCTD注射液的16.1mg／kg，说明改变剂型后NCTD毒性降低，可能减轻临床应用时的毒副反应。NCTD脂质微球体外不引起溶血，兔耳缘静脉刺激性实验表明本品无血管刺激性。大鼠舐足实验结果显示，大鼠右后足注射NCTD脂质微球及参比制剂注射液后15 min内平均舐足次数存在显著性差异，分别为8.7次及18.2次，表明将NCTD制备成脂质微球后，注射部位局部刺激性较注射液可降低50％以上。更多还原

【Abstract】 Lipid microsphere （LM） is recently used as intravenous （i.v.） carriers for drugs, especially for anti-tumor or anti-inflammatory drugs, which have enough solubility in oil. Drugs are usually incorporated into the oil phase or into the interface of oil phase in LM, so it was presumed to avoid or reduce local or blood vessel irritation.Norcantharidin （NCTD） is one of new chemotherapy agent that was firstly synthesis in china. NCTD has proved to show excellent activity against cancer, especially against primary hepatic carcinoma. To enhance solubility of NCTD, the clinical used NCTD sodium salt is adjusted to high pH （about 9.0）, which is an important causation of its irritativeness in situ for intravenous infection. At the same time, NCTD itself was reported to cause irritation. In present study, a technique and formulation are developed to prepared a kind of NCTD corporated LM to decent irritation and elevate compliance in clinical. The oil phase or the surfactant layer were assignment as the main drug loading position during the preparation investigation. Different formulation and craft were sieved to raise the corporation ratio over 80%, and then the detection of pharmacokinetics character in rats and animal test of safety of NCTD LM was undertaken.An HPLC—anion-exchange method was established for determination of NCTD. The method is simple, rapid, acute, sensitive, reproducible and suitable for the quality control of NCTD LM. The solubility of NCTD in pH 1.0、pH 5.6. pH 8.0. pH 10.0 were 3.15、5.59、8.90、29.33、6.72 mg ? mL^-1 respectively. The coefficient of oil-water distribution rises with decent of pH.For the poor solubility of NCTD in both water and oil, so the corporation ratio was the main evaluation parameter with the stability of formulation was ensured beforehand. Different injectable excipients and preparation condition were compared to improve the stability and incorporation capacity of the LM system. The homogenization temperature, pressure, times and the way of addition of NCTD was optimized. The effect of pH and composition of oil phase as well as surfactant on the character of LM was detected.The result showed that the amount and composition hold the most distinct influence on the stability of NCTD LM. Little oil droplet was visible after sterilization in the formula that lecithin was used as sole surfactant. When the amount of lecithin dropped to 0.6%, the formula was unstable during sterilization either. The formula showed satisfactory stability character when the total amount of surfactant was 1.2% with leicithin-F68 （0.6:0.6）. The main factor affecting drug distribution were proportion of MCT in oil phase and pH of LM. The corporation ratio of NCTD in oil and surfactant layer increased with addition of MCT. But the formula is not stable when only MCT was used. Low pH can also enlarge the corporation ratio. When the pH was adjust to 7.0 and MCT—LCT （7.5: 2.5）, the distribution of NCTD in oil phase and surfactant layer was above 80%.The oil phase was composed of injectable soybean oil -MCT （2.5: 7.5）, the total amount of surfactant was 1.2% with leithin-F68 （1: 1）, and the oleate sodium was 0.03%. PH was adjusted to 6.5 before homogenization, and the homogenization condition was 800 bar, 6～10 times, filling in with nitrogen. The samples was autoclaving under 121℃, 15 min. The mean particle size was 195.2 nm, and the incorporation ratio was 84.6%.Dilution test revealed that the sodium chloride injection （0.9%） diluted samples turned to unstable with particle size,ζ-potential and drug corporation ratio changing markedly. The samples diluted with glucose injection （5.4%） show good stability. When the dilution multiple was 5, there was about 80% after 2 h. So the glucose injection （5.4%） was suggested to used as dilution medium. The stability test showed that NCTD LM showed no significant change after 6 months under 25±℃and 6±2℃.Established a HPLC-MS method for the determination of norcantharidin in rat plasma. The result plasma concentration showed that the NCTD LM and the reference NCTD solution were of two compartments. The relative AUC value ofNCTD LM to solution was 100.34% and the two c-t curves were alike with pharmacokinetics parameters showed no distinct differenceThe security test showed that the LD₅₀ of NCTD LM was 18.6mg/kg, while that of soluteion was 16.1 mg/kg, suggested that the reduction of side effect. The NCTD LM caused no hemolysis and no stimulation on vein. The rat paw lick test showed that there was distinct difference between times of rats licked their paw with same amount NCTD LM and solution been injected. The test suggested the possibility that the NCTD LM may be only 50% as painful as solution.更多还原