羟基喜树碱长循环脂质体冻干剂的制备及理化性质

以羟基喜树碱（1）为模型药物，大豆磷脂为载体材料，泊洛沙姆F-68为膜表面修饰材料，所制备的1冻干长循环脂质体冻干剂包封率为82．3％，可在30s内分散为均匀的淡黄色胶体溶液。在pH7．4磷酸盐缓冲液和大鼠血浆中24h内无渗漏。用纯水复溶后测得相转变温度为73℃。稳定性初步试验表明所得脂质体基本稳定。     

水杨酸脂质体凝胶剂的制备工艺研究

目的制备水杨酸脂质体凝胶并优化制备工艺。方法采用逆相蒸发法制备水杨酸脂质体,以卡波姆为凝胶基质制备水杨酸脂质体凝胶。采用离心法测定脂质体包封率、渗透率,正交实验法优化水杨酸脂质体凝胶剂的制备工艺。结果水杨酸脂质体的包封率为75.86%,渗透率为1.37%;脂质体凝胶的最佳工艺为:卡波姆3g、甘油15g、搅拌温度40℃、搅拌时间15min。结论逆相蒸发法制备水杨酸脂质体,包封率较高,性质稳定;优化后所得产品性状稳定、均一,该法制备水杨酸脂质体凝胶可行。     

丝裂霉素C脂质体的制备工艺研究

本研究了不同的处方组成及制备工艺对丝裂霉素C脂质体包封率的影响．实验结果表明，当处方中加入油酸时．能使丝裂霉素C包封率由原来的7％增长至15%；当运用不同的制备工艺时．其药物包封率亦不相同：二次乳化法包封率>薄膜分散法>注入法。     

中空纤维离心超滤-HPLC法测定注射用两性霉素B脂质体的包封率

目的建立新型的中空纤维离心超滤法分离脂质体中游离药物,并结合HPLC法用于注射用两性霉素B脂质体的包封率的表征。方法采用新型中空纤维微量离心超滤(HF-CF-UF)装置,在离心力的作用下,利用中空纤维超滤膜分离游离药物和包封药物。色谱条件:色谱柱为Diamonsil C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-20 mmol·L-1乙二胺四乙酸二钠(体积比38∶62),流速为1.0 mL·min-1,检测波长为405 nm,柱温为30℃。结果两性霉素B质量浓度在0.670²1.4 mg·L-1内与峰面积呈良好的线性关系(r=0.999 7),回收率均在97%以上,RSD不大于2%。结论中空纤维离心超滤装置基本保持了脂质体处方的原始的、稳定的存在环境(物理化学环境),最大限度地减少了脂质体的泄露,结果准确且简便快速,为脂质体包封率的表征提供了一种新方法。     

蟾酥提取物长循环脂质体的制备及质量评价

目的研究蟾酥提取物长循环脂质体(chan su long-c ircu lation liposom e,CSLLP)的制备方法,并对其质量进行评价。方法考察不同方法制备CSLLP的包封率,最终确定选用乙醇注入法制备CSLLP,正交设计优化处方,用两亲性聚乙二醇2000-二硬脂酰磷脂乙醇胺(mPEG2000-DSPE)修饰脂质体膜,透射电镜观察形态,激光散射法测定粒径大小及分布,采用葡聚糖凝胶柱层析法和HPLC法测定CSLLP的包封率和渗漏率。结果乙醇注入法制备的CSLLP包封率最高,所得脂质体外观圆整而均匀,渗漏率小,稳定性好,平均粒径为69.8 nm,药物平均包封率为95.54%。结论用乙醇注入法可制备包封率高、稳定性好的CSLLP。     

克班宁长循环脂质体的制备工艺

目的:研究克班宁长循环脂质体的处方筛选和制备工艺。方法:采用硫酸铵梯度法制备克班宁长循环脂质体,以包封率和载药量为评价指标,采用葡聚糖凝胶过滤法分离脂质体,紫外分光光度法测定克班宁含量,采用正交设计优化制备工艺。结果:最佳工艺为:药脂比为1:6,胆固醇与磷脂比为9:12,0.15 mol·L^-1的硫酸铵溶液,以PBS液(pH7.4)为透析介质,在40 ℃水浴,40 r·min^-1条件下孵化20 min。结论:硫酸铵梯度法制备的克班宁长循环脂质体处方合理,工艺可行,包封率较高。     

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。     

猪苓多糖长循环脂质体的制备及其质量控制

目的：研究猪苓多糖长循环脂质体的制备方法，并对其质量进行控制。方法：逆相蒸发法制备猪苓多糖长循环脂质体，采用紫外分光光度法测定脂质体中猪苓多糖的包封率和载药量，透射电镜观察形态，激光散射法测定粒径大小，离心加速实验考查稳定性。结果：猪苓多糖长循环脂质体平均粒径为67．8nm，药物平均包封率为93．10％，平均载药量为13．68％。脂质体外观圆整而均匀，渗漏率小，稳定性好。结论：用逆相蒸发法可制备包封率高、稳定性好的猪苓多糖长循环脂质体。质量控制方法简单，快速准确，重复性好。     

依托泊苷长循环热敏前体脂质体的制备工艺研究

目的:对依托泊苷(Etoposide,VP-16)长循环热敏前体脂质体的制备工艺进行研究,并对该制备工艺进行方法学及制剂质量考察。方法:应用薄膜分散法制成VP-16长循环热敏脂质体,进一步借助冷冻干燥技术进行依托泊苷长循环热敏前体脂质体的制备;采用zeta电势测定仪及HPLC等技术进行方法学考察,主要包括脂质体的包封率、粒径、载药量、电位、释放度、稳定性。结果:VP-16长循环热敏前体脂质体水合形成长循环热敏脂质体,粒径为(105.2±3.4)nm,Zeta电位为(-11.9±1.7)m V,包封率可达96.8%;该脂质体在相变温度42℃下药物释放达到96%以上。结论:VP-16长循环热敏前体脂质体的制备工艺稳定,脂质体载药量大,包封率高;药物含量及包封率的测定方法简单、快速而准确,因而,该研究可为VP-16开发成静脉注射用新制剂提供数据支持。     

两性霉素B脂质体-微球的制备及工艺优化

目的 应用Box-Behnken响应面分析法优化两性霉素B脂质体-微球的制备条件。方法 采用乳化-相分离法制备包载两性霉素B脂质体的海藻酸钠微球,通过单因素实验确定显著影响微球成球性的因素,利用Box-Behnken响应面分析法考察氯化钙浓度、司盘80用量及搅拌速度对微球粒径、跨距、包封率、1h释放量及72h释放量的影响,筛选最佳制备工艺,并进行体外抑菌试验。结果 最佳制备工艺条件为氯化钙浓度41%,司盘80用量4.3%,搅拌速度678r/min。此优化条件下,制得的两性霉素B脂质体-微球平均粒径为8.0μm,药物包封率大于80%,体外抑菌试验结果显示载药微球具有较好的抑菌能力。结论 Box-Behnken响应面分析法可有效平衡各因素之间的相互影响,适用于两性霉素B脂质体-微球的制备工艺筛选。     

两性霉素B脂质体体内外毒性及抗真菌活性的研究

对自制的两性霉索B脂质体的体内外毒性以及抗菌活性进行了研究。结果表明,将两性霉索B制成脂质体后,其埘红细胞的溶血作用较市售注射剂有明显的降低,小鼠急性毒性试验的结果表明,两性霉索B脂质体的LD50为(14．89士2．18)mg／kg,约为市售注射剂LD50的6倍,其急性毒性显著下降;体外抗菌活性研究表明．两性霉素B脂质体保持了与市售注射剂相同的体外抑菌、杀菌活性。     

两性霉素B含量的HPLC测定

建立了两性霉素B与注射用两性霉素B含量的HPLC测定法方法：采用ODS柱,以0.01mol/L磷酸二氢钾溶液-乙腈（66:34）为流动相,检测波长为410nm,流速为1.0ml/min,柱温为室温,进样量为10ul。结果,线性范围1.25～3.75ug,日内RSD为0.3%,日间百分偏差为0.3%,提示本法快速简便,适用于两性霉素B与注射用两性霉素B的含量测定。     

Immunomodulator tuftsin increases the susceptibility of Cryptococcus neoformans to liposomal amphotericin B in immunocompetent BALB/c mice

The co-administration of immunomodulators and antibiotics has been proved very successful for treatment of opportunistic infectious diseases. In the present study, we evaluated the combination of liposomal amphotericin B (lip-Amp B) and immunomodulator tuftsin to cure Cryptococcus neoformans infection in BALB/c mice. Mice infected with C. neoformans were treated with Amp B deoxycholate and tuftsin free or tuftsin-loaded Amp B liposomes. The results of the present study demonstrated higher efficacy of tuftsin-loaded Amp B liposomes against experimental murine cryptococcosis, in terms of enhanced survival rate and reduced fungal burden in organs (lungs and brain) of the treated mice. Interestingly, pre-treatment of mice with liposomal tuftsin before challenging them with the C. neoformans infection resulted in 100% survival of the treated animals followed by treatment with lip-Amp B. Immunomodulator-based therapy seems likely to be more beneficial for treatment of fungal infectious diseases.     

二性霉素B阴道泡腾片的制备工艺研究

目的：用正交设计方法优选二性霉素B阴道泡腾片的制备工艺。方法：采用正交设计,选择干颗粒水分、制粒筛网的孔径、黏合剂的用量3个因素,每个因素安排3个水平,按L9（34）进行正交实验,用外观和稳定性2个指标的综合评分确定制备工艺条件。按选定的工艺制备3批样品,考察各项质量指标和加速试验稳定性,并与上市品对比。结果：选择本品的制备工艺如下：称取碳酸氢钠90g,加入淀粉27g,以10%淀粉浆制软材,40目筛制粒,干燥至水分1%,整粒,备用;称取酒石酸90g,硼酸78g,淀粉27g,混匀,加入10%淀粉浆制软材,40目筛制粒,干燥至水分1%,整粒,备用。将二性霉素B2.5g,PEG60006g混合均匀,与上述两种颗粒混匀压片,即得。制得的样品具有较好的外观,各项质量指标合格,加速试验结果表明稳定性较好,与上市品相当。结论：本研究确定的处方工艺可用于制备二性霉素B阴道泡腾片。     

Stability and transdermal absorption of topical amphotericin B liposome formulations

The aim of this study was to characterize the stability and transdermal absorption of amphotericin B (AmB: 0.05 mg/mg lipid) in hydrogenated soya phosphatidylcholine/cholesterol/charged lipid {dicetyl phosphate (−) or stearylamine (+)} liposomes at molar ratios of 1:1:0, 7:2:0, 7:2:1(−) and 7:2:1(+). The AmB contents in liposomes were determined by HPLC with UV detection at 382 nm. Stabilities of AmB in liposome formulations were compared with those in solution and powder forms, during storage at 4, 30 and 45 °C for 90 days. Absorption studies of AmB across the rat skin were conducted, using vertical Franz diffusion cells at 37 °C for 24 h. The slowest degradation was observed in the positive liposome (7:2:1(+)AmB), with shelf life of 1 year (30 °C). In comparison, the shelf lives of AmB in solution and powder were 4 and 14 days, respectively. AmB in positive liposomes seemed to demonstrate the highest flux in stratum corneum (58 ng/cm²/h), while the highest flux in viable epidermis (23 ng/cm²/h) was observed in negative liposomes. AmB entrapped in charged liposomes showed sustained skin absorption. The positively charged liposome might be the best formulation for AmB, due to its higher stability than other formulations.     

浊度法测定两性霉素B及其脂质体的效价

目的建立浊度法测定两性霉素B及其脂质体效价的方法。方法啤酒酵母为实验菌,加菌量2%～3.3%(V/V),(37±1)℃培养6～8h测定。结果抗生素线性浓度为0.04～0.10μg/ml,一剂量法、二剂量法的平均回收率分别为103.5%(n=5)、106.6%(n=2),日内RSD分别为1.64%、0.38%,日间RSD分别为2.79%(n=8)、0.87%(n=3)。结论本方法灵敏,快速,可作为测定两性霉素B及其脂质体的效价的方法。     

Comparative therapeutic efficacy of a novel lyophilized amphotericin B lecithin-based oil–water microemulsion and deoxycholate-amphotericin B in immunocompetent and neutropenic mice infected with Candida albicans

The in vivo efficacy of a new amphotericin B (AmB) oil-in-water lecithin-based microemulsion delivery system (M-AmB) compared to deoxycholate-AmB (D-AmB) was studied in an immunocompetent and neutropenic murine model of systemic candidiasis. D-AmB was administered at the maximum tolerated dose of 1 mg/kg whereas M-AmB was given at the doses of 1, 2 and 3 mg/kg; doses were well tolerated due to their reduced toxicity. Both formulations were administered 24, 48 and 72 h after infection in immunocompetent mice, and 2, 6 and 24 h after infection in neutropenic mice. Kaplan–Meier survival curves showed that the M-AmB treated group had a better survival time than infected mice without treatment used as a control group (P = 4.66 × 10⁻⁶), and the Mann–Whitney W statistical test indicated that it reduced the percentage of mortality and fungal load in the most representative organs. This new formulation is a designed competitor which has proved to present better results than D-AmB in an established infection not only in immunocompetent but in neutropenic mice as well.     

Design of amphotericin B oral formulation for antifungal therapy

Amphotericin B (AmB) remains the “gold standard” for systemic antifungal therapy, even though new drugs are emerging as the attractive antifungal agents. Since AmB has negligible oral absorption as a consequence of its unfavorable physicochemical characterizations, its use is restricted to parenteral administration which is accompanied by severe side effects. As greater understanding of the gastrointestinal tract has developed, the advanced drug delivery systems are emerging with the potential to overcome the barriers of AmB oral delivery. Much research has demonstrated that oral AmB formulations such as lipid formulations may have beneficial therapeutic efficacy with reduced adverse effects and suitable for clinical application. Here we reviewed the different formulation strategies to enhance oral drug efficacy, and discussed the current trends and future perspectives for AmB oral administration in the treatment of antifungal infections.     

A new vaginal delivery system of amphotericin B: a dispersion of cationic liposomes in a thermosensitive gel

Amphotericin B (AmB) is used in the treatment of fungal infections; however, its clinical use is limited by its toxic side effects. In this study, AmB-loaded cationic liposome gels were formulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and cholesterol (CH) at a molar ratio of DOPE:DOTAP:CH?=?4:5:1 in thermosensitive gel composed of poloxamer 407 (P407) and poloxamer 188 (P188). To enhance the solubility of AmB, 6 mol% of distearoyl phosphatidyl ethanolamine–polyethylene glycol was added prior to encapsulation of the drug into liposomes. Scanning electron microscopy was used to observe the AmB encapsulated cationic liposome gels. In vitro release, stability and cytotoxicity of AmB in cationic liposome gels were evaluated. The particle size and zeta potential of AmB-loaded liposomes were in the range of 400–500?nm and 40–60 mV, respectively. The thermosensitive gel at the ratio of P407:P188?=?15:15 (w/w) gelled at 37°C, approximating body temperature. Encapsulation efficiency of AmB was ～50–60%, which was influenced by the ratio of AmB to lipid. Moreover, AmB-loaded cationic liposome gels were more stable and less toxic than free AmB. From these results, cationic liposome gel formulations may be useful for vaginal delivery of AmB.