冷冻干燥法制备莪术油脂质体

采用叔丁醇-水共溶剂、冷冻干燥法制备莪术油脂质体,用单因素试验优化处方,并进行体外释放试验。结果表明,莪术油脂质体呈球形,包封率为(92.2±3.4)%,平均粒径为(457.3±7.8)nm,ζ电位为-23.6mV,体外48h累积释放率为94.1%。     

冷冻干燥法制备α-细辛脑前体脂质体

目的:研制α-细辛脑前体脂质体.方法:采用冷冻干燥法,选择甘露醇/蔗糖做冻干剂,制备α-细辛脑前体脂质体,并考察水化后脂质体的形态、粒径分布、黏度和包封率.结果:α-细辛脑前体脂质体经水化后,脂质体粒径分布均匀,平均粒径为0.655μm,粘度为1.6 mPaS,药物包封率约96%.结论:冷冻干燥法可用于α-细辛脑前体脂质体的制备.     

阿糖胞苷多囊脂质体的制备及体外释放度考察

目的制备阿糖胞苷多囊脂质体,并考察其体外释放特性。方法采用复乳法制备阿糖胞苷多囊脂质体;RP-HPLC法测定含量、包封率和体外释放特性;以包封率为指标,单因素及正交试验筛选、优化工艺和处方;光学显微镜下观察多囊脂质体形态;以激光粒度测定仪测定粒径。结果一次乳化时间为8 min、氮气流速为0.3 m3.h-1时包封率最高;优化处方中二油酰磷脂酰胆碱(DOPC)、二棕榈酰磷脂酰甘油(DPPG)、胆固醇(CH)、三油酸甘油酯(TO)的质量浓度分别为10、2、7.5、4 g.L-1,赖氨酸浓度为40 mmol.L-1,有机溶剂选择氯仿-乙醚(体积比1∶1)。阿糖胞苷多囊脂质体在400倍显微镜下形态光滑、圆整,内部呈蜂窝状,无磷酯碎片;平均粒径19.49μm,跨距0.91;包封率达70%以上;以人空白血浆为释放介质,两周释放药物约60%。结论制备的阿糖胞苷多囊脂质体外观良好,包封率较高,体外释放试验表明药物缓慢释放,无突释现象。     

紫杉醇冻干脂质体的制备及含量稳定性

目的制备水化后粒径较小且分布较窄的,具有良好稳定性的紫杉醇冻干脂质体。方法以商品大豆磷脂为膜材,采用薄膜分散-微孔滤膜挤出(或高压均质)-冷冻干燥工艺制备冻干脂质体产品,采用HPLC和微柱离心-HPLC法测定冻干脂质体重建后的含量及包封率。并以加速和长期实验来证实该产品的稳定性。结果薄膜分散-微孔滤膜挤出-冷冻干燥工艺制备的紫杉醇冻干脂质体粒径均一,在130 nm左右,其对药物的包封率较高,可保证在90%以上,储存半年后紫杉醇的含量及包封率均未有降低。结论薄膜分散-微孔滤膜挤出-冷冻干燥工艺是制备紫杉醇脂质体的可工业化生产的方法。     

冷冻干燥对提高脂质体稳定性的研究概况

讨论了脂质体在冷冻干燥、复水化及贮存过程中的稳定性,并介绍了冻干保护剂的作用机理.     

喷雾冷冻干燥技术制备盐酸伊立替康脂质体冻干微粒及其理化性质考察

目的:考察喷雾冷冻干燥(SFD)技术制备脂质体冻干微粒的可行性。方法:以盐酸伊立替康为模型药物,采用硫酸铵梯度法制备盐酸伊立替康脂质体,SFD技术制备脂质体冻干微粒;以喷嘴高度、物料流速、雾滴/液氮质量比为因素,应用Box-Behnk-enDesign(BBD)试验考察三者之间的配比对微粒包封率的影响以优化SFD工艺,并对所制备的脂质体及冻干微粒的理化性质进行了考察。结果:SFD优化工艺为物料流速5.5mL·min-1,喷嘴高度18.5cm,雾滴/液氮质量比3.7%,由此制备的脂质体冻干微粒的外观和再分散性好,平均粒径、粒度分布、主药含量及包封率等理化性质与原脂质体基本保持一致,且放置6个月后与原脂质体溶液比较稳定性更好。结论:SFD技术制备脂质体冻干微粒具有可行性,并提高了脂质体的稳定性。     

叔丁醇-水共溶剂体系冻干脂质体

目的考察用叔丁醇水共溶剂体系冻干脂质体的可行性。方法以钙黄绿素脂质体为模型,考察了糖脂比、磷脂组成以及叔丁醇含量对钙黄绿素滞留率的影响。采用LS230粒度分析仪对冻干前后脂质体的粒径进行了测定。采用DSC分析和低温显微技术考察了样品的冻结行为。通过绘制升华曲线,确定叔丁醇的存在是否可以缩短冻干周期。结果与结论用叔丁醇水共溶剂体系冻干脂质体,最好使用HSPC脂质体。冻干前后,钙黄绿素在HSPC脂质体中的滞留率和以水为溶剂冻干脂质体时基本相同,并且脂质体的粒径没有显著变化。叔丁醇的存在可以加快升华速度,缩短冻干周期。     

HB-Ⅰa冻干脂质体粒径及其分布的研究

研究了降温速率、保护剂种类与浓度、复溶溶液对HB-Ⅰa冻干脂质体粒径的影响.由逆相蒸发法制得的HB-Ⅰa脂质体大多为大单室和多室脂质体,粒径主要分布在1～10μm之间.约20K/min的降温速率对HB-Ⅰa脂质体冻干较为有利;蔗糖的保护效果较优,甘露醇次之,PVP和甘氨酸相对较差,蔗糖和甘氨酸组成的二元保护剂保护效果较蔗糖更好;缓冲溶液较纯水或蔗糖溶液的复溶效果好.     

阿糖胞苷免疫脂质体的靶向抗单纯疱疹病毒研究

通过间接免疫荧光法和空斑形成抑制试验研究阿糖胞苷（Ara-C)免疫脂质体抗单纯疱疹病毒（HSV-1）的作用。结果证明含Ara-C2.82μg免疫脂质体的空斑抑制率是单纯用Ara-C500μg的2.84倍，是同量Ara-C脂质体5.57倍，同量单克隆抗体的无药免疫脂质体的3.21倍。充分说明Ara-C免疫脂质体是一种可以靶向结合，局部缓慢释放药物的特异靶向输药系统。     

去氢骆驼蓬碱脂质体冻干剂粉的制备工艺优选

目的:制备含有不同冻干保护剂的N-三甲基壳聚糖(TMC)包衣去氢骆驼蓬碱脂质体(TMC-HM-LP)的冻干粉,并筛选其最佳制备工艺。方法:用"薄膜分散-pH梯度法"制备去氢骆驼蓬碱脂质体,并采用孵育包衣法、低温高速离心法和结合高效液相色谱(HPLC)定量方法测定其包衣脂质体的包封率;以其冻干粉的外观在冻干前和复溶后脂质体的粒径、包封率作为对比指标,优选出最佳的冻干工艺以及冻干保护剂的种类及比例。结果:以葡萄糖-乳糖-甘露醇(2:1:0.5)作为冻干保护剂,通过"分步预冻"的方法和-80℃冷冻干燥技术得到的TMC-HM-LP外观良好,冻干前后粒径和包封率变化较小。结论:采用冷冻干燥技术并结合冻干保护剂的优选,可显著提高包衣脂质体的稳定性。     

Carboplatinum and cytosine arabinoside in patients with disseminated malignant melanoma

Summary Eighteen patients with disseminated malignant melanoma were treated with a combination of carboplatinum and cytosine arabinoside. There were 14 males and 4 females with median age of 51 years (range 36–68 years). We observed 4 complete responses (CR) and 3 partial responses (PR). Lung metastases, cutaneous and subcutaneous metastases responded more often, while liver and lymph node metastases did not respond. Two groups of toxicities were observed: gastrointestinal and hematological. Only nine grade 3 toxicities were observed. Response rates and low toxicity we observed during this study warrant its use for patients with disseminated malignant melanoma comparing it in a future studies with DTIC containing regimens.     

HPLC法测定血浆中阿糖胞苷及阿糖尿苷浓度

目的：建立同时测定血浆中阿糖胞苷和阿糖尿苷浓度的高效液相色谱法,并用于1例急性非淋巴细胞白血病患儿的血药浓度监测。方法：采用反相高效液相色谱法,色谱柱：XTerra C18（4．6mm×250mm,5μm）;流动相：0．01mol·L^-1的磷酸盐缓冲液（pH=6．0）;检测波长：280nm;流速：0．95mL·min^-1;柱温：30℃。结果：阿糖胞苷血药浓度在0．25～21．74mg·L^-1范围内线性关系良好（r=0．9996）,检测限为0．1mg·L^-1,日内、日间RSD小于5．0％和8．0％;阿糖尿苷血药浓度在0．99～86．96mg·L^-1范围内线性关系良好（r=0．9993）,检测限为0．4mg·L^-1,日内、日间RSD小于5．0％和8．0％。阿糖胞苷及阿糖尿苷平均提取回收率高于96．0％：结论：本方法简单、快速、准确。适用于临床上阿糖胞苷和阿糖尿苷的血药浓度监测及药动学研究．     

Neurofilament isoform alterations in the rat cerebellum following cytosine arabinoside administration

A number of neurotoxic agents could potentially exert their action by degrading or modifying cytoskeleton components like neurofilaments (NF). Cytosine arabinoside (AraC) is an anticancer drug commonly used in leukemia treatment. Its side effects include neuronal cell death in the cerebellum and severe motor coordination deficits. We have previously shown that AraC administration (400 mg/kg bw) in adult rats reduced NF immunostaining in cerebellar neurons. To further delineate the susceptibility of individual NF isoforms (NF-H, NF-M, NF-L) to AraC, in the present study we used Western blot analysis to quantify their level. A significant and selective reduction of NF-H isoform was observed in the cerebellum of AraC-treated animals, compared to the controls. Administration of the antioxidant N-acetylcysteine (NAC) for a period of 14 days (prior to and during AraC treatment), which was previously shown to ameliorate the AraC-induced motor deficits in these animals, largely prevented the reduction in NF-H isoform. Given the significant role of NF proteins and particularly NF-H in maintaining structural integrity and synaptic transport, the observed loss of this isoform may be a key-target of AraC action in cerebellar neurons. Moreover, this study provides further data on the neuroprophylactic role of NAC in vivo against chemotherapy-induced toxicity.     

The disposition of cytosine arabinoside and its metabolite after single doses to rabbits

Cytosine arabinoside (ara-C) is rapidly deaminated in vivo to ara-U by cytidine-deoxycytidine deaminase. The purpose of this study was to determine the contribution of the deamination pathway to the overall clearance of ara-C after a single dose to rabbits, as well as to determine the pharmacokinetics of ara-U itself. Male rabbits were cannulated in the marginal ear vein and received a single IV bolus dose (50 mg kg-1) of either ara-C (n = 10) or ara-U (n = 10). Blood samples were collected for up to 24 h. One week later, the rabbits received the opposite treatment. Plasma samples were analyzed by reversed-phase HPLC. The plasma clearance of ara-C (8.16 +/- 2.43 ml min-1 kg-1) was significantly higher than the clearance of ara-U (5.66 +/- 2.59 ml min-1 kg-1). The volume of distribution of ara-C was 0.64 +/- 0.16 l kg-1 (mean +/- SD) and was significantly smaller (p less than 0.05) than that of ara-U (1.22 +/- 0.70 l kg-1). As a result, the elimination rate constant of ara-C was significantly larger than that of ara-U (0.602 +/- 0.097 h-1 vs 0.258 +/- 0.05 l h-1). In the rabbits that received both treatments (n = 7), the fraction of the ara-C dose metabolized to ara-U (fm) was 0.53 +/- 0.20. Qualitatively, the pharmacokinetics of ara-C and ara-U resemble those in humans. This study provides the basis for further work into the modulation of ara-C disposition either by ara-U or other agents.     

注射用单磷酸阿糖腺苷无菌检查方法适用性研究

目的 建立注射用单磷酸阿糖腺苷无菌检查方法标准.方法 按照2015年版《中国药典》规定,采用薄膜过滤法,对14家企业生产的注射用单磷酸阿糖腺苷进行无菌方法适用性研究.结果 确定了规格为0.1g注射用单磷酸阿糖腺苷的无菌检查方法.14家企业(共111批次)无菌检验方法均为:取样品60支,采用薄膜过滤法,用pH 7.0氯化钠-蛋白胨缓冲液冲洗,每次100 mL,共冲洗2次.结论 通过对14家企业生产的注射用单磷酸阿糖腺苷的方法验证资料进行整理、归纳、分析、试验,最终确定严谨统一的无菌检查方法.     

The pharmacokinetics of subcutaneous bolus cytosine arabinoside in an arachis oil plus aluminium distearate suspension

Summary An attempt was made to create a delayed release preparation of cytosine arabinoside (araC) which could be administered subcutaneously, and would produce plasma levels similar to steady state infusion concentrations. A thixotropic suspension of araC in arachis oil and aluminium distearate was formulated. This preparation was similar to that previously used with bleomycin oil suspension and procaine penicillin. Two hundred mg/ml of araC in arachis oil containing varying amounts of aluminium distearate were administered firstly to New Zealand White rabbits and then to patients with acute myelogenous leukaemia. This preparation was well tolerated by both rabbits and patients but did not delay the release of araC from the subcutaneous tissues.     

Effects of Vial Packing Density on Drying Rate during Freeze-drying of Carbohydrates or a Model Protein Measured using a Vial-weighing Technique

Purpose To determine the effects of vial packing density in a laboratory freeze dryer on drying rate profiles of crystalline and amorphous formulations. Methods The Christ freeze-drying balance measured cumulative water loss, m(t), and instantaneous drying rate, , of water, mannitol, sucrose and sucrose/BSA formulations in commercial vials. Results Crystalline mannitol shows drying rate behaviour indicative of a largely homogeneous dried-product layer. The drying rate behaviour of amorphous sucrose indicates structural heterogeneity, postulated to come from shrinkage or microcollapse. Trehalose dries more slowly than sucrose. Addition of BSA to either disaccharide decreases primary drying time. Higher vial packing density greatly reduces drying rate because of effects of radiation heat transfer from chamber walls to test vial. Conclusions Plots of m(t) versus √t and versus layer thickness (either ice or dried-product) allow interpretation of changes in internal cake morphology during drying. Vial packing density greatly influences these profiles.     

Recent and remote spatial memory in mice treated with cytosine arabinoside

Clinical studies suggest that chemotherapy is associated with long-term cognitive impairment in some patients. A number of underlying mechanisms have been proposed, however, the etiology of chemotherapy-related cognitive dysfunction remains relatively unknown. As part of a multifaceted approach, animal models of chemotherapy-induced cognitive impairment are being developed. Thus far, the majority of animal studies have utilized a rat model, however, mice may prove particularly beneficial in studying genetic risk factors for developing chemotherapy-induced cognitive impairment. Various chemotherapy agents, including cytosine arabinoside (Ara-C), have been found to impair remote spatial memory in rats in the Morris water maze. The present study evaluated the effects of Ara-C on remote (30 d) spatial memory in mice. In addition, the possibility that time relative to chemotherapy treatment may modulate the effect of chemotherapy on spatial learning and/or recent (1 d) memory was explored. Male C57BL/6J mice received either Ara-C (275 mg/kg i.p. daily for 5 days) or saline. Spatial learning and memory was assessed using the Morris water maze. Half the mice performed a remote (30 d) memory version of the task and the other half performed a recent (1 d) memory version of the task. The experiment was designed such that the probe trial for the recent memory version occurred on the same day relative to chemotherapy treatment as the remote memory version. Despite significant toxic effects as assessed by weight loss, Ara-C treated mice performed as well as control mice during acquisition, recent memory, and remote memory portions of the task. As are some humans, C57BL/6J mice may be resistant to at least some aspects of chemotherapy induced cognitive decline.     

表没食子儿茶素没食子酸酯增强阿糖胞苷对HL-60细胞的抗肿瘤活性

目的 :研究表没食子儿茶素没食子酸酯 (EGCG)增强阿糖胞苷 (AraC)对人白血病HL 6 0细胞的抗肿瘤活性。方法 :采用生长曲线法、MTT法测定AraC合并应用EGCG前后对HL 6 0细胞的增殖抑制作用 ;以对消实验研究EGCG能否逆转脱氧胞苷 (dCdR)的补救作用 ;以流式细胞光度仪分析联合用药前后对细胞周期和细胞凋亡的影响。结果 :合并EGCG能增强AraC对HL 6 0细胞的增殖抑制作用 ,倍增时间从 4 8h延长到 70h ,生长饱和密度从 5 .78减少到对 5 .5 4 ;MTT法表明合并EGCG后 ,AraC对HL 6 0细胞的IC50 从 (0 .0 8± 0 .0 7) μg·ml-1减少到 0 .0 2 4± 0 .0 2 6 μg·ml-1(P <0 .0 5 ) ;对消实验表明单用AraC的IC50 为 6 .2 5ng·ml-1,加上dCdR后IC50 为 5 .2 4 μg·ml-1,而在给予EGCG后IC50 减少到 1.17μg·ml-1。细胞周期研究结果表明AraC可使HL 6 0细胞阻滞于G1期 ,S期细胞减少 ,低浓度的EGCG对细胞周期几无影响 ,但增强了AraC的细胞周期阻滞作用及细胞凋亡。结论 :AraC合并应用EGCG可增强对人白血病HL 6 0细胞的抗肿瘤活性。     

Drastic effect of cell density on the cytotoxicity of daunorubicin and cytosine arabinoside

White blood cell count (WBC) is generally accepted as a prognostic risk factor in acute myeloid leukemia (AML) outcome and displays a marked interindividual variation. The dose regimen currently used ignores the size of the tumor burden and the standardization of the dose is generally based on body surface area. In this study we have investigated the effect of cell density on the cytotoxic activity of daunorubicin (DNR) and cytosine arabinoside (AraC) towards HL60 cells and leukemic cells isolated from patients with AML. We demonstrate that drug cytotoxicity decreased with cell density and that apoptosis induction by DNR in isolated leukemic cells was greatly reduced at higher cell density. A marked reduction of the uptake of DNR and AraC in HL60 parental and mitoxantrone resistant cells was observed with increasing cell density. Such a drug depleting effect by cells at high density has been previously described for vincristine, doxorubicin and paclitaxel. By extrapolating the in vitro results to the in vivo situation, one could hypothesize that a high WBC can lower the plasma concentration through high uptake in the tumor burden, leading to a shortage of drug in leukemic blasts. Patients with high WBC might therefore benefit from a dose increase of DNR and/or AraC.