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1.
阿糖腺苷脂质体的制备及其稳定性   总被引:16,自引:0,他引:16  
本文比较了薄膜法、反相蒸发法、冰冻熔融法制备Ara-A脂质体的包裹率,采用正交设计法摸索Ara-A脂质体制备的最佳技术条件,利用自行设计的改良冰冻熔融法将难溶性药物Ara-A研制成脂质体,其包裹率可达约50%,为国外文献报道的采用反相蒸发法所制得的Ara-A脂质体的包裹率(5.2±0.9%)的10倍。本法操作简单、重现性好。本文还考察了Ara-A脂质体的物理和化学稳定性,实验表明:Ara-A脂质体采用100℃30min灭菌的方法,制品的形态、粒度分布、包裹率及含量均无明显改变,经恒温加速试验,表明Ara-A脂质体具有一定的化学稳定性。  相似文献   

2.
本文研究了高三尖杉酯碱多相脂质体(代号139—5号)注射液的物理稳定性。提出了研究此类分散物系粒度分布的简便方法即微孔滤膜—光密度法。以此方法研究了139—5号注射液室温及100℃的粒度变化动力学,结果表明,在9个月常温贮存后,体系中大于5μm 粒子小于0.6%;9个月贮存后以及加热100℃12小时后最大粒径不超过16μm。  相似文献   

3.
靶向给药系统——青蒿酯脂质体的制备研究   总被引:3,自引:0,他引:3  
采用乳化法制备了多层的青蒿酯脂质体,探讨了其制备工艺、荷电性、胆固醇含量及附加剂对青蒿酯脂质体包裹率的影响。结果表明,带正电荷的脂质体其包裹率明显高于中性或带负电荷的脂质体,而类脂中胆固醇含量及附加剂对包裹率均无明显影响,最佳处方组成的包裹率为3.63±0.09%。采用冷冻干燥技术可获得稳定性较好的脂质体冻  相似文献   

4.
采用溶剂注入法制备并优化了维A酸维生素C棕榈酸酯泡囊配方。所得制品呈球形,包封率达90%。4℃避光贮存6个月,含量和包封率无明显下降。  相似文献   

5.
甘草酸单铵盐脂质体的试制及稳定性研究   总被引:4,自引:1,他引:4  
采用薄膜水化超声-冷冻干燥法制备甘草酸单铵盐脂质体,建立RP-HPLC法测定脂质体含量及包封率,并从外观形态、粒径分布、含量、包封率等方面进行质量考察.所得制品平均粒径为146.4nm,包封率>75%,初步稳定性实验表明在4℃密闭保存3个月,稳定性良好.  相似文献   

6.
用放射自显影技术观察了三尖杉酯碱对小鼠白血病L-1210细胞周期的影响。氚标记的胸腺嘧啶脱氧核苷脉冲标记试验证明,接种后第6天的L-1210细胞的一代周期时间(T_C)为15.8小时,其S期(T_S),G_1期(T_G_1),G_2期(T_G_3)及M期时间(T_M)分别为10.7,2.0,2.7,0.4小时。腹腔注射三尖杉酯碱30μg/只一次,L-1210细胞的有丝分裂指数(MI)明显降低,其标记指数(LI)及每个细胞的标记颗粒数也明显减少,由S期向G_2及M期移行时间延长。鉴于三尖杉酯碱的限制性毒性为骨髓抑制,我们用脾集落形成试验(CFU-S)研究了三尖杉酯碱对CFW纯种小鼠骨髓干细胞的影响。实验表明,三尖杉酯碱的剂量小于0.5mg/kg时,对骨髓干细胞无明显影响。当剂量高于此剂量时,三尖杉酯碱对骨髓干细胞的杀伤呈剂量依赖性。实验证明,人参总皂甙对三尖杉酯碱的骨髓毒性有一定保护作用。  相似文献   

7.
目的 研究不同处方组成和制备方法对阿昔洛韦棕榈酸酯脂质体在 4℃和 2 5℃分别贮存 90d和 180d后的稳定性的影响。方法 用卵磷脂 (PC) 胆固醇 (CH) 磷脂酰丝氨酸 (PS) ,卵磷脂 (PC) 胆固醇 (CH) 硬脂酰胺 (SA) ,卵磷脂 (PC) 胆固醇 (CH) 胆固醇硫酸酯 (CS) ,神经酰胺 (CM) 胆固醇 (CH) 棕榈酸 (PA) 胆固醇硫酸酯 (CS) ,以薄膜分散法、逆向蒸发法和去水化 水化法 ,分别制备多室脂质体 (MLV)、大单室脂质体 (LUV)、去水化 水化脂质体(DRV) ,以平均粒径、渗漏率、pH值和Zeta电位 4个指标考察不同贮存条件下脂质体的稳定性。结果 脂质体稳定性顺序依次为 ,对不同脂质体处方 :PC CH CS >CM CH PA CS >PC CH PS >PC CH SA ;对不同制备方法 :LUV优于MLV和DRV ;4℃时脂质体的稳定性优于 2 5℃时的脂质体。结论 脂质体的稳定性与制剂处方和制备方法密切相关。  相似文献   

8.
青蒿酯脂质体的研究   总被引:6,自引:1,他引:5  
采用乳化法制备青蒿酯多层脂质体,脂质体带正电荷时其包裹率明显高于中性或带负龟荷时。类脂中胆固醇含量及加入α-生育酚对包裹率均无明显影响,最佳处方组成的包裹率为13.63±0.09%。采用冷冻干燥技术可获得稳定性较好的脂质体冻干品,且其结构粒径均无明显变化。通过微孔滤膜压滤,能有效地除去94%以上的游离药物。比较了青蒿酯及其脂质体在动物体内的抗疟作用,结果表明,后者对鼠疟原虫的抑制率明显地高于前者。  相似文献   

9.
盐酸小檗碱脂质体制备工艺研究   总被引:2,自引:1,他引:1  
目的用薄膜蒸发法制备盐酸小檗碱脂质体。方法用离子交换树脂法测定脂质体包封率。以盐酸小檗碱脂质体包封率为指标,考察脂质体包封率的影响因素。结果制备盐酸小檗碱脂质体的最佳工艺条件为孵化温度65℃,孵化时间40min;此时包封率最高,且随着卵磷脂浓度的变化而变化。结论薄膜蒸发法制备的盐酸小檗碱脂质体粒径小、包封率高,条件易掌握,故该法可作为盐酸小檗碱脂质体的常规制备方法。  相似文献   

10.
目的:考察高三尖杉酯碱氯化钠注射液的稳定性.方法:考察高三尖杉酯碱氯化钠注射液的外观、酸度和无菌检查等项目;用高效液相色谱法测定高三尖杉酯碱氯化钠注射液的含量及降解产物,以0.02 mol/L的磷酸二氢钾缓冲液-乙腈(80:20)为流动相,检测波长为288 nm.结果:由水针剂改为输液的3批高三尖杉酯碱氯化钠注射液样品,室温放置6个月后,各项指标(与刚放置时比较)均无明显变化.结论:高三尖杉酯碱氯化钠注射液输液剂型的稳定性良好.  相似文献   

11.
人红细胞膜脂三尖杉酯碱脂质体包裹率及稳定性的研究   总被引:4,自引:0,他引:4  
自Ryman等开始将脂质体作为药物载体研究以来已取得很大进展。但药物脂质体用于临床的报道甚少,原因之一是脂质体对药物的包裹率较低,稳定性也差。较大的脂质体进入体内后主要被网状内皮系统所吞噬,不能较多地到达靶区,而小单层脂质体则在肝脾的  相似文献   

12.
陈博 《中国药房》2014,(21):1973-1975
目的:提供一种制备稳定维A酸脂质体的新方法。方法:采用乙醇注入法制备维A酸脂质体,通过单因素试验和四因素三水平正交试验,以包封率为主要指标,优选药脂比、磷脂与胆固醇之比、水合介质(0.01 mol/L磷酸盐缓冲液)的pH和用量;并制备样品进行稳定性考察。结果:以药脂比为1∶10(维A酸用量1.0 mg),磷脂与胆固醇之比为4∶1,水合介质的pH为6.5、用量为30ml为最佳工艺;所制维A酸脂质体的包封率约为80%,平均粒径约为150 nm。在室温条件下密封放置10 d及4℃下保存6个月,其平均粒径及包封率差异无统计学意义(P>0.05)。结论:该制剂制备工艺简单可行;制剂处方合理,包封率较高,且在短期内稳定性良好。  相似文献   

13.
Preparation of novel double liposomes using the glass-filter method   总被引:4,自引:0,他引:4  
The glass-filter method, a newly developed preparative method for liposomes, was applied for preparation of novel double liposomes. Double liposomes were prepared by filtering a suspension of liposomes prepared using a G4 filter (pore size: 10-16 microm) into a G3 filter (pore size: 40-100 microm) coated with a similar lipid layer. The morphological structure of the double liposomes was confirmed using scanning electron microscopy by the freeze-fracture method to be multivesicular vesicles consisting of small liposomes enveloped in larger liposomes. The diameter of liposomes prepared using the G4 filter was 0.8-2 microm and that of liposomes prepared using the G3 filter or double liposomes was 5-10 microm. These results suggested that the particle size of liposomes is dependent on the pore size of the glass-filter. The encapsulation efficiencies of double liposomes for brilliant blue FCF (BB) and erythrosine (ER) were higher than those of liposomes prepared by the standard Bangham method. Double liposomes showed suppressed release of BB or ER compared with normal liposomes. In particular, no release of BB was observed from the double liposomes prepared with stearylamine. These findings implied that the outer lipid layer protects the inner liposomes. The glass-filter method is the only method that we can get the double liposomes in a short period, and double liposomes prepared by this novel method had adequate size and good stability in vitro.  相似文献   

14.
Large liposomes (1-10 microm) containing sodium diclofenac were prepared and lyophilized using lactose or mannitol (7.5% in respect to the lipid content) as cryoprotectants. The physical studies of liposomes were performed during 30 days of storage in a dry or resuspended form. Lyophilization of large liposomes and storage in the dry form at 5 degrees C increases their physical stability. Lactose is a cryoprotectant which does not influence changes of properties of liposomes regarding their size, encapsulation efficacy and release rate. Large liposomes lyophilized in the presence of mannitol tend to increase in size and encapsulation efficacy, but the lipid bilayers are stabilized and less permeable to the drug.  相似文献   

15.
The objective of this study was to examine the encapsulation of stavudine (d4T), an approved drug for AIDS treatment, in liposomes composed of various lipids and the in vitro release characteristics, and to evaluate the stability. The reverse phase evaporation method was used to prepare liposomes and the effect of cholesterol on drug encapsulation was studied by adding different amounts of cholesterol to a constant amount of lipid. The effect of charge of the lipid bilayer on drug encapsulation was also studied. Stearylamine or dicetylphosphate (10 mol%) were used to induce positive or negative charges, respectively. The particle size of the liposomes was measured using dynamiclightscattering. Stabilitystudies were performed by storing formulations at 4, 25, and 37 C for 12 weeks, and then subjecting them to alternate heat-cool cycles and simulated transportation conditions. Encapsulation of stavudine was found to be maximum (48%) in DSPC liposomes containing equimolar amounts of cholesterol. Encapsulation generally increased with increasing amounts of cholesterol, and also with the incorporation of both positive and negative charge. In vitro release was found to be biphasic, the release controlled by the dialysis membrane and the lipid bilayer. The release of the drug was inhibited in the presence of charge (30%), compared to neutral liposomes. Particle size distribution ranged from 0.6 mu m to 1.4 mu m and was polydisperse. Liposomes were stable with respect to the amount to drug retained for a period of 4 weeks. Beyond 4 weeks, there was a leakage of entrapped drug independent of the temperature of storage. An increase in particle size during storage was observed in the case of neutral but not charged vesicles. A high degree of encapsulation of stavudine in liposomes is feasible by reverse-phase evaporation. Liposomal formulations may be beneficial in alleviating the longterm side effects of stavudine and enhancing in vivo cellular uptake in HIV therapy.  相似文献   

16.
赵敏 《中国药业》2009,18(13):34-35
目的研制米非司酮脂质体。方法采用薄膜分散法制备米非司酮脂质体,应用葡聚糖凝胶法测定包封率,并考察该脂质体的形态、粒径、稳定性和体外释放特性。结果所制备的米非司酮脂质体包封率达85.2%,平均粒径为112.7nm,4℃冷藏保存3个月稳定性良好,具有体外缓释作用。结论米非司酮脂质体制备工艺简单可行,脂质体制剂学性质稳定。  相似文献   

17.
Liposomes containing sodium ioxitalamate were prepared by sonication. Suitable amounts of purified soybean phosphatidylcholine and cholesterol were used at various molar ratios. Stearylamine or dicetylphosphate were added to this lipid composition when charged liposomes were required. After sonication and removal of unencapsulated solute, this manufacturing process yielded small multilamellar vesicles as confirmed by electron microscopy. These liposomes did not exhibit a narrow range of size distribution; the mean particle size varied from 135 to 145 nm. With respect to the efficiency of encapsulation, two parameters were distinguishable: the volume of encapsulated aqueous space per unit of lipid weight and the percentage of the contrast agent added that became encapsulated in the liposomes. Investigation of the preparative parameters revealed that increased molar ratios of cholesterol yielded higher aqueous volume and iodine contents in the liposomes, which were attributed to a reduction of the liposome permeability to the contrast agent. However, the inclusion of cholesterol into the bilayer liposomal membrane was limited, probably by solubility restrictions. Negatively and positively charged liposomes had higher rates of encapsulation than did neutral liposomes. This result was expected since efficient encapsulation of polar compounds requires formation of large aqueous spaces within the vesicles per mole of lipids. Increase of the lipid fractions at a constant, reduced the aqueous volume entrapped per millimole of lipid and, consequently, the iodine content in the liposomes. However, an increase in the initial sodium ioxitalamate concentration diminished the aqueous volume entrapped in the liposomes but increased the iodine content.  相似文献   

18.
The severe toxicity and low therapeutic index of colchicine limit its therapeutic use. Encapsulation in liposomes might reduce these toxic effects. The objective of this study was to determine the factors influencing encapsulation of colchicine in liposomes and to optimize the encapsulation parameters. Colchicine was encapsulated in multilamellar liposomes and large unilamellar liposomes prepared using various phospholipids. The effects of method of preparation, type of vesicle, charge, and concentration of cholesterol on encapsulation of colchicine in liposomes were investigated. Also, stability of colchicine under stress conditions and at various temperatures, and in-vitro release characteristics were determined. A significant difference in encapsulation of colchicine in multilamellar liposomes was observed when prepared by two different methods. Induction of charge on the liposome surface increased encapsulation of colchicine in multilamellar liposomes, but did not affect large unilamellar liposomes. The liposome preparations could withstand simulated transport conditions and frequent changes in temperature. Particle size and concentration of colchicine did not change significantly during storage at various temperatures for six months. In order to retain encapsulated colchicine in liposomes, storage at or below room temperature was found to be suitable. In-vitro release of colchicine from large unilamellar liposomes was biphasic and was influenced by two rate-limiting barriers, the dialysis membrane and the liposome bi-layers. For optimum encapsulation and stability of colchicine liposomes were prepared from a mixture of 1,2-distearoyl-sn-glycero-3-phosphocholine, cholesterol and either stearylamine or dicetyl phosphate.  相似文献   

19.
用薄膜水化-高压均质法制备羟基喜树碱脂质体,以葡聚糖凝胶色谱法分离脂质体和游离药物,采用HPLC法测定包封率。通过差示扫描量热法测定含不同保护剂的脂质体的最低共熔点和玻璃化转变温度,并比较冻干品外观、冻干前后脂质体包封率和粒径的变化,优选出最佳的冻干工艺、冻干保护剂种类及比例。结果表明,以6%蔗糖为冻干保护剂,经4℃、1 h,-18℃、12 h和-35℃、5 h逐步预冻,然后于-54℃冷冻干燥24 h,制得的冻干品外观良好,脂质体复溶后粒径变化小,包封率达(87.0±2.7)%。  相似文献   

20.
目的:制备甘草次酸阳离子脂质体,并研究其稳定性。方法:用乙醇注入法制备甘草次酸阳离子脂质体。考察其粒径、包封率、过氧化值、在血浆中的稳定性和放样稳定性等性质。结果:所得脂质体的粒径小而均匀,呈球形和类球形,包封率为(91.6±1.2)%;离心加速试验结果显示脂质体的稳定性参数KE值较小,脂质体在血浆中释放缓慢,在4℃下放置6个月,其外观、包封率、粒径等各项指标无明显改变。结论:制得的甘草次酸脂质体包封率较高,稳定性良好。  相似文献   

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