9-硝基喜树碱内酯型与羧酸盐型在大鼠体内的药动学与肾排泄研究

目的:比较静脉注射9-硝基喜树碱内酯型与羧酸盐型溶液后大鼠体内药动学和肾排泄情况。方法:采用HPLC法同时测定大鼠血浆中9-硝基喜树碱内酯型浓度与总(内酯型+羧酸盐型)浓度以及尿液中9-硝基喜树碱的总浓度。按4mg.kg-1剂量给大鼠静脉注射9-硝基喜树碱内酯型与羧酸盐型溶液,绘制药-时曲线,并采用DAS 2.0软件拟合药动学参数。按同剂量给大鼠静脉注射9-硝基喜树碱内酯型与羧酸盐型溶液,并在各时间段收集尿液,测定尿液中9-硝基喜树碱原形药物累积排泄量。结果:根据AUC计算,9-硝基喜树碱内酯型与羧酸盐型溶液给药以后内酯型的比例分别为(46.7±8.0)%和(8.8±2.5)%,两者的MRT分别为(21.6±2.1)min与(12.7±5.1)min,Vz分别为(0.91±0.16)L.kg-1与(0.56±0.13)L.kg-1,t1/2分别为(17.2±2.4)min与(13.3±3.9)min,差异均有显著性,但总量的AUC并无明显差别。9-硝基喜树碱羧酸盐型及内酯型给药后累积尿液排泄百分率为(30.3±6.4)%和(8.9±0.8)%。结论:9-硝基喜树碱内酯型与羧酸盐型的体内药动学过程存在显著差异,羧酸盐型给药后的肾排泄量远高于内酯型。     

吐温80对9-硝基喜树碱脂质体药物动力学性质的影响

目的:考察吐温80对9-硝基喜树碱(9-NC)脂质体体内药物动力学以及内酯型/羧酸盐型平衡的影响。方法:采用薄膜法制备9-NC脂质体以及吐温80修饰的9-NC脂质体;12只大鼠随机分为两组,按1.5 mg.kg-1剂量分别给予9-NC普通脂质体和吐温80修饰的脂质体,于不同时间点取血,处理后测定9-NC内酯型浓度和总浓度(内酯/羧酸盐)。采用统计矩模型利用3P97程序计算药物动力学参数。结果:采用表面活性剂吐温80进行修饰后,9-NC内酯型和总浓度的AUC分别提高了1.47倍和1.65倍,内酯型和总浓度的清除率CL和表观分布容积Vss显著下降(P<0.01)。此外,总浓度的MRT以及t1/2延长(P<0.05)。结论:吐温80修饰使得9-NC内酯型比例有所下降,但没有显著性差异,9-NC吐温修饰对9-NC脂质体具有一定的长循环效果。     

静脉注射不同比例内酯型9-硝基喜树碱的荷瘤小鼠药动学和组织分布

采用摇瓶法测定内酯型和羧酸盐型9-硝基喜树碱(1)的油水分配系数,结果为145.5±2.96和0.034±0.26.建立了HPLC法同时测定小鼠组织和血浆中1的内酯型浓度和总浓度.静脉注射给予S180荷瘤小鼠不同比例的内酯型1溶液,结果显示给药时内酯型比例对其在小鼠体内的组织分布有明显影响.在血浆中,测得的内酯型浓度随给药时内酯型比例的变化而变化,而总浓度却与给药时内酯型比例关系不大.在肿瘤组织中,给药的内酯型1比例为100％和75％时,测得的内酯型和总量的AUC结果相近;其他各组测得的内酯型和总量的浓度均随给药时内酯型1比例(50％、25％和0)降低而降低.肝、肾组织中测得的内酯型比例与给予比例没有明显相关性(如肾)或呈现出负相关(如肝).这可能与肝、肾是羧酸盐型1的主要排泄途径有关.     

共聚物胶束对硝基喜树碱内酯环稳定性的影响

目的 评价共聚物胶束对9-硝基喜树碱(9-NC)内酯环稳定性的影响.方法 采用HPLC法测定,以甲醇-PBS(70:30,pH6.5)为流动相,检测波长370 nm,流速1ml ·min-1.结果 内酯和羧酸盐形式的9-NC能完全分离;在PBS(pH7.4)中培养160 min后,载药胶束中具有抗肿瘤活性的9-NC内酯比例占80%,而无胶束包覆的原料药中内酯比例仅15%.结论 共聚物胶束能有效提高9-NC内酯环结构的稳定性.     

静脉注射9-硝基喜树碱脂质体后原形药物经大鼠胆汁的排泄

目的:考察静脉注射9-硝基喜树碱脂质体后原形药物经大鼠胆汁的排泄。方法:建立了利用HPLC法测定大鼠胆汁中9-硝基喜树碱浓度的方法;测定了9-硝基喜树碱在大鼠空白胆汁中的内酯型浓度、总浓度和内酯型比例的变化;测定了静脉注射3mg.kg-19-硝基喜树碱溶液和脂质体后大鼠胆汁中原形药物的排泄情况。结果:9-硝基喜树碱内酯型结构在胆汁中不稳定,内酯型浓度和比例迅速下降但总浓度保持恒定。静脉注射9-硝基喜树碱溶液和脂质体后12h胆汁中原形药物的累积排泄量分别为给药剂量的7.9%和8.1%。结论:脂质体包封对于9-硝基喜树碱静脉注射后的胆汁排泄没有显著影响     

9-硝基喜树碱在大鼠组织中的分布及内酯稳定性

考察9-硝基喜树碱(9-NC)静脉注射后在人鼠组织中的分布及内酯稳定性.建立了HPLC法间时测定组织和血浆中9-NC内酯浓度和总浓度.大鼠静脉注射9-NC溶液后测定各时间点组织中内酯浓度、总浓度和内酯比例.大多数组织中的9-NC内酯比例明显高于血浆;肝中的内酯比例最低,甚至低于血浆;血浆、肾和小肠中的内酯比例随时问延长而下降.9-NC在肝以外的组织中内酯稳定性显著优于血浆.     

羟基喜树碱脂肪乳的制备及其在人血浆中稳定性考察

目的:制备羟基喜树碱(HCPT)静脉注射脂肪乳,研究其在人血浆中对内酯型药物的保护作用.方法:采用乳化均质法,以注射级大豆油为油相,大豆卵磷脂为乳化剂制备O/W型的HCPT脂肪乳;测定乳剂的粒径和Zeta电位,考察含药脂肪乳的稳定性.通过体外血浆实验研究脂肪乳和注射液中的药物在人血浆中的稳定性.结果:HCPT静脉注射脂肪乳的物理稳定性良好,含量为(78.6±1.1)mg·L-1,平均粒径为(161.7±2.4)nm,Zeta电位为(-42.4±1.1)mV,115℃高压灭菌30min脂肪乳性状维持良好.与普通HCPT注射液相比,4h内脂肪乳可以显著降低血浆中药物内酯型向羧酸盐型的转化速率.结论:HCPT静脉注射脂肪乳剂可以显著提高血浆中内酯型药物的比例,从而提高药物的抗癌活性.     

静脉注射不同内酯型比例的羟基喜树碱后原形药物经小鼠尿液和粪便排泄的研究

目的:研究静脉注射不同内酯型比例的羟基喜树碱(HCPT)后原形药物经小鼠尿液、粪便的排泄情况。方法:静脉注射不同内酯型比例(100%,75%,50%,25%,0%)的HCPT溶液。分别收集给药后0~3,3~6,6~9,9~12,12~24,24~48 h的尿液和粪便样品,测定其中原形药的含量。结果:原形药从尿液中的累积排泄量分别为12.81%,20.00%,27.01%,32.75%,41.04%,从粪便中的累积排泄量分别为13.91%,18.58%,24.44%,27.48%,31.30%。结论:小鼠尿液和粪便中HCPT原形药物的累积排泄量与HCPT内酯型比例呈负相关,这可能与药物的极性有关。给药后3 h内药物以尿液排泄为主,3~12 h主要从粪便中排泄,12 h后极少从尿液和粪便中排泄。     

9-硝基喜树碱内酯型在大鼠体内外的稳定性9-硝基喜树碱内酯型在大鼠体内外的稳定性

目的考察9-硝基喜树碱内酯型在大鼠体内和离体大鼠血浆中的稳定性。方法建立利用HPLC法测定大鼠血浆中9-硝基喜树碱内酯型浓度和总浓度的方法；利用此法测定9-硝基喜树碱在离体大鼠血浆、全血及体内血浆中的内酯型比例变化以及大鼠尾静脉注射后不同时间点的内酯浓度和总浓度；并对体内外实验结果进行比较以确定影响血浆中内酯型稳定性的主要因素。结果9-硝基喜树碱内酯型在大鼠体内的稳定性显著优于体外，在体外全血中的稳定性显著优于血浆。结论血细胞具有稳定9-硝基喜树碱内酯型的作用；药物从血浆中的清除是影响体内大鼠血浆中9-硝基喜树碱内酯型比例的主要因素；9-硝基喜树碱内酯型浓度和总浓度在大鼠体内的药代动力学过程符合二室模型，而羧酸盐型浓度符合一室模型。     

9-硝基喜树碱内酯型在大鼠体内外的稳定性

目的考察9-硝基喜树碱内酯型在大鼠体内和离体大鼠血浆中的稳定性.方法建立利用HPLC法测定大鼠血浆中9-硝基喜树碱内酯型浓度和总浓度的方法;利用此法测定9-硝基喜树碱在离体大鼠血浆、全血及体内血浆中的内酯型比例变化以及大鼠尾静脉注射后不同时间点的内酯浓度和总浓度;并对体内外实验结果进行比较以确定影响血浆中内酯型稳定性的主要因素.结果9-硝基喜树碱内酯型在大鼠体内的稳定性显著优于体外,在体外全血中的稳定性显著优于血浆.结论血细胞具有稳定9-硝基喜树碱内酯型的作用;药物从血浆中的清除是影响体内大鼠血浆中9-硝基喜树碱内酯型比例的主要因素;9-硝基喜树碱内酯型浓度和总浓度在大鼠体内的药代动力学过程符合二室模型,而羧酸盐型浓度符合一室模型.     

Pharmacokinetics of lactone, carboxylate and total 9-nitrocamptothecin with different doses and administration routes in rats

9-Nitrocamptothecin (9-NC) is a newly developed poorly soluble derivative of camptothecin and has a wide spectrum of anticancer activity in preclinical evaluation. The effects of the dose and administration route on pharmacokinetics and lactone/carboxylate equilibrium of 9-NC were studied in rats. A single intravenous dose of 1.5, 3 or 6 mg/kg of 9-NC solution was given to male rats (n = 6 per dose level). In another study, a single dose of 6 mg/kg 9-NC solution was given orally to rats (n = 6). Plasma samples were drawn at predetermined intervals and the concentrations of lactone, carboxylate and total 9-NC were determined by a validated HPLC method. Pharmacokinetic analysis was performed using non-compartmental analysis. Analysis of variance showed that the pharmacokinetic characteristics of lactone, carboxylate and total 9-NC were all independent of dose (p > 0.05). Based on the AUC measurements, the lactone 9-NC constituted 52% +/- 4%, 49% +/- 6% and 55% +/- 6% of the circulating total 9-NC in rats after intravenous administration of 1.5, 3, 6 mg/kg 9-NC solution, respectively. After oral administration of 6 mg/kg, the pharmacokinetics parameters were significantly different from those of intravenous administration at the same dose (p < 0.05). The lactone ratio was 60% +/- 14%. The absolute bioavailability of lactone and total 9-NC were calculated to be 23.4% and 22.7%, respectively. In conclusion, the pharmacokinetics of lactone, carboxylate and total 9-NC are not dose-dependent. Lactone, carboxylate and total 9-NC are poorly absorbed following oral administration. Both the dose and the route of administration have little effect on the lactone/carboxylate equilibrium of 9-NC in rats in vivo. But the route of administration plays an important part on the pharmacokinetics of 9-NC.     

Effect of injection routes on pharmacokinetics and lactone/carboxylate equilibrium of 9-Nitrocamptothecin in rats

Pharmacokinetics and lactone/carboxylate equilibrium of 9-Nitrocamptothecin (9-NC) were compared after intravenous (i.v.) and intramuscular (i.m.) injection at a dose of 1.5 mg/kg 9-NC solution. The concentrations of three different forms of 9-NC, namely lactone, carboxylate and total 9-NC, were measured by HPLC analysis. Injection routes were demonstrated to have significant effect on pharmacokinetics of 9-NC. Compared with i.v. injection route, mean residence time (MRT) of 9-NC three forms was significantly prolonged following i.m. route (p < 0.05). The AUC_0–∞ ratios of i.m. to i.v. route were calculated to be 102 ± 43%, 273 ± 221% and 150 ± 62% for lactone, carboxylate and total 9-NC, respectively. Compared with i.v. injection route, although AUC_0–∞ was barely changed, MRT of lactone 9-NC was dramatically prolonged 4.5-fold after i.m. injection, which may account for the reported improved antitumor efficacy. However, the results of the present study also demonstrated that i.m. injection route increased both AUC_0–∞ and MRT of carboxylate 9-NC more significantly. Since the carboxylate form of CPT analogs including 9-NC is associated with their unwanted toxicity, i.m. injection route might lead to severe toxicity compared with i.v. route. Lactone/carboxylate equilibrium was also significantly influenced by injection routes. Based on the AUC_0–∞ measurements, the lactone 9-NC constituted 50 ± 8% and 32 ± 7% of circulating total 9-NC after i.v. or i.m. administration, respectively (p < 0.01).     

9-nitrocamptothecin polymeric nanoparticles: cytotoxicity and pharmacokinetic studies of lactone and total forms of drug in rats

The objective of this study was to evaluate the cytotoxicity and pharmacokinetics of total and lactone forms of 9-nitrocamptothecin (9-NC), an effective antineoplastic drug, after intravenous injection of drug incorporated into poly (DL-lactic-glycolic acid) nanoparticles (NPs). Drug-loaded NPs (9-NC.NP) were prepared by the nanoprecipitation method and examined for particle characteristics and in-vitro release in phosphate buffered saline. The best formulation showed a narrow size with an average diameter of 207+/-26 nm and a drug loading of more than 33.5%. The drug release profile showed a sustained 9-NC release up to 160 h. For a pharmacokinetic study, the concentration of 9-NC as the lactone form (9-NC.lac) and as the total of the lactone and carboxylate forms (9-NC.tot) in plasma was determined by using reverse-phase high performance liquid chromatography after intravenous administration of 9-NC.NP and a control solution to cannulated Wistar rats. In-vitro cytotoxic activity of 9-NC.NP and control solution was evaluated on the human ovarian cancer cell line (A2780sn) by MTT cell cytotoxicity assay. Results of in-vivo studies showed that NP encapsulation markedly increased the plasma concentration of both lactone and total forms of 9-NC compared with free drug. In comparison with free drug, NPs resulted in 3.63-fold and 5.40-fold increases in area under the plasma concentration-versus-time curve (AUC(0-infinity)) for lactone and total forms of 9-NC, respectively. The values of mean residence time and elimination half-life (T(1/2)) were also significantly higher for NPs than for free drug. The in-vitro cytotoxicity study revealed that the IC50 value of NPs decreased 10-fold compared with the drug solution. Prepared NPs described here were considered potentially useful in both stabilizing and delivering 9-NC and enhancing the efficacy of this drug for cancer treatment for which high drug retention in the body, protection from the drug-active lactone form, and gradual drug release appeared to be related.     

HPLC法测定人血浆中9-硝基喜树碱内酯型浓度和总浓度

目的:建立以高效液相色谱法测定人血浆中9-硝基喜树碱内酯型浓度和总浓度的方法。方法:血浆样品采用—20℃甲醇快速沉淀蛋白后进行测定,其中色谱柱为shim-packCLS-ODS,流动相为甲醇∶1%三乙胺(冰醋酸调pH6.5)=55∶45,流速为1.0mL·min-1,检测波长370nm,进样量为50μL,柱温为40℃。测定总浓度的样品采用冰醋酸酸化上清液。并以该法测定了不同时间点离体人血浆中9-硝基喜树碱内酯型、羧酸盐型浓度和总浓度的变化。结果:9-硝基喜树碱血药浓度在0.10～10.0μg·mL-1范围内线性关系良好(r=0.9991),定量下限为0.10μg·mL-1,平均方法回收率、酸化回收率各为101.02%、101.46%。结论:本法操作简便、快速,适用于9-硝基喜树碱内酯结构稳定性的研究。     

Excretion Into Gastrointestinal Tract of Irinotecan Lactone and Carboxylate Forms and Their Pharmacodynamics in Rodents

Purpose. To investigate the excretion of irinotecan hydrochloride (CPT-11) and its active metabolite, SN-38, into the gastrointestinal lumen via the biliary and/or intestinal membrane route after dosing with lactone and carboxylate forms of CPT-11, and to evaluate the toxic and antitumor effects of the two forms. Methods. The excretions of CPT-11 and SN-38 were investigated by the in situ perfusion technique using rats. The incidence of delayed diarrhea was evaluated after i.v. dosing (60 mg/kg) with CPT-11 lactone and carboxylate forms for 4 days. Antitumor activity and changes in body weight were investigated in mice with Meth A tumors. Results. The excretion of CPT-11 into bile was greater in dosing with CPT-11 carboxylate than that with its lactone form, whereas the exsorption across intestinal membrane was greater in dosing with CPT-11 lactone than that with its carboxylate form. Dosing with CPT-11 lactone dose-dependently inhibited the increase in tumor weights in Meth A tumor mice, whereas the dosing with its carboxylate form reduced the antitumor effect. Conclusions. The decreased antitumor effect caused by dosing with the CPT-11 carboxylate form could be due to less accumulation in the tissue including tumor cells resulting from the rapid elimination of the form in the body.     

9-硝基20（S）喜树碱在大鼠体内的药物动力学

目的:研究9-硝基喜树碱在大鼠体内的药物动力学及排泄。方法:利用高效液相色谱法对静脉注射或灌胃给药后的大鼠血浆及排泄物样品进行分析。绘制血浆药物浓度-时间曲线,并进行非室模型分析及房室模型拟合。利用线性回归评价药物浓度-时间曲线下面积(AUC)与剂量之间、血浆药物峰浓度(C_(max))与剂量之间的线性关系;不同剂量下的药物半衰期及清除率通过方差分析进行比较。计算原形药物自大鼠体内的排泄量。结果:大鼠分别以1.5、3、6mg/kg静脉给药后,AUC_(o-t)分别为633、1606和3011h·μg·L~(-1);t_(1/2)分别为0.5、0.5和0.7h;大鼠分别以3、6、12mg/kg灌胃给药后,C_(max)分别为203、417和1150μg/L,T_(max)均在0.3h左右,AUC_(o-t)分别为269、439和881h·μg·L~(-1);t1/2分别为1.7、0.9和0.9h。9-硝基喜树碱在大鼠体内的绝对生物利用度为14.6％,这与灌胃及静脉注射两种给药途径下原形药物(胆汁和尿中)累积排泄量之比值相一致。结论:9-硝基喜树碱在大鼠体内动力学过程符合二室模型。静脉给药后,药物在大鼠体内的动力学不依赖于剂量,肾排泄为原形药物的主要排泄途径;灌胃给药后,药物绝对生物利用度低,原形药物大部分经粪排泄。