氧化苦参碱脂质体的制备和药物动力学研究
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摘要
氧化苦参碱(oxymatrine,OM)是从豆科槐属植物苦豆子及苦参根中提取分离得到的一种喹诺里西啶类生物碱,现代药理学研究表明它具有抗心律失常、抗炎、抗肿瘤、增强免疫等作用。目前临床主要用于慢性乙型肝炎的治疗,疗效较好。传统剂型给药,药物分布全身,体内消除快,肝脏组织局部浓度低,影响药物治疗效果。脂质体作为药物的载体,具有靶向性,缓释性,降低药物毒性等作用。因此本文进行了氧化苦参碱脂质体的制备研究,以期延长氧化苦参碱在体内的作用时间,增加药物对肝组织的靶向性。
本文采用pH梯度法制备氧化苦参碱脂质体,通过正交实验,筛选出制备氧化苦参碱脂质体的最佳处方为:药脂比1:10,磷脂-胆固醇比例3:1,外水相pH值为6.8,孵育温度为60℃。以最佳处方制备的脂质体平均包封率为51.35%。
采用高效液相色谱法测定了脂质体制剂中氧化苦参碱的含量和脂质体的包封率,以及兔血浆和小鼠组织匀浆中的氧化苦参碱的含量。实验结果表明,方法灵敏度高、专属性强,可满足分析的要求。用透射电镜观察脂质体呈完整的小单室结构,平均粒径为80nm左右。将脂质体分别在4℃和25℃下密闭放置1个月,以包封率、过氧化值为指标考察其稳定性。结果显示,脂质体于4℃贮存时,以上指标无显著变化,脂质体比较稳定。脂质体的体外释药实验表明氧化苦参碱经脂质体包裹后具有一定的缓释效果。
本文研究了氧化苦参碱脂质体和水溶液在兔体内的药物动力学特征和在小鼠体内的组织分布。药物动力学实验结果表明,氧化苦参碱脂质体的药时过程符合线性的二室模型动力学特征,其生物消除半衰期为185min,较水溶液制剂的消除半衰期延长了54min。小鼠体内组织分布实验结果表明,氧化苦参碱制备成脂质体后,在肝、肺、脾等网状内皮细胞丰富的器官中药物浓度较水溶液制剂都有明显提高。说明氧化苦参碱制备成脂质体后具有延长体内作用时间和提高药物靶向性的效果。
Oxymatrine(OM) is a alkaloid of quinolizidine group, extracted from a traditional Chinese medicine, Ku-dou-zi or the aired root of Sophora flavescens ait..The studies of pharmacological have shown that OM has wide pharmacological effects including anti-arrhythmic, anti-inflammatory, anti-tumor, immunol-ogical enhancement. At present, OM is widely used for the treatment of chronic type B hepatitis, but OM injection used clinically has some disadvantages including short half-life, low drug concentration in tissues.Liposomes are well recognized as drug delivery vehicles that have target effents, delayed drug release and degraded drug toxicity. Thus, in this study we intend to prepare the OM liposome(OM-L) to improve its pharmacokinetics characters such as half-life and target effect and enhance therapeutic efficacy.
We had applied a pH-gradient method to prepare OM-L. Through orthogonal experimental design, one optimum recipes of OM-L was founded that showed OM/EPC 1:10, EPC/Ch 3:1, pH 6.8, incubation tempreture 60℃. Under the optimal formulation, OM was encapsulated 51.35%.
A method was developed for the determination of OM concentration in liposomes and entrapment efficiency and biological samples by HPLC, it was proved that this method was accurate, sensitive, specific and good enough to be used in pharmacokinetic study of OM. The small unilamellar vesicle liposomes were observed by transmission electron microscope. The mean particle diameter is about 80nm. The stability of OM-L was valuated with the entrapment efficiency and preoxidation value in 4, 25℃for 1 month. The results showed that the OM-L stored in 4℃would keep stability.
The pharmacokinetic parameters and tissues distribution of OM water solution or OM-L were studied after intravenous administration OM or OM-L to rabbits and mice, respectively. The experimental results showed that the concentration-time curves of OM-L fit in a two-compartement model. To compare with water solution, biological half-life of liposomes prolonged 54 min in rabbits plasma and the concentrations of OM in liver, lung, spleen of mice were improved obviously. The result of pharmacokinetics and tissues distribution showed that OM-L had better tissues targeting and slow-release effect than OM.
本文采用pH梯度法制备氧化苦参碱脂质体,通过正交实验,筛选出制备氧化苦参碱脂质体的最佳处方为:药脂比1:10,磷脂-胆固醇比例3:1,外水相pH值为6.8,孵育温度为60℃。以最佳处方制备的脂质体平均包封率为51.35%。
采用高效液相色谱法测定了脂质体制剂中氧化苦参碱的含量和脂质体的包封率,以及兔血浆和小鼠组织匀浆中的氧化苦参碱的含量。实验结果表明,方法灵敏度高、专属性强,可满足分析的要求。用透射电镜观察脂质体呈完整的小单室结构,平均粒径为80nm左右。将脂质体分别在4℃和25℃下密闭放置1个月,以包封率、过氧化值为指标考察其稳定性。结果显示,脂质体于4℃贮存时,以上指标无显著变化,脂质体比较稳定。脂质体的体外释药实验表明氧化苦参碱经脂质体包裹后具有一定的缓释效果。
本文研究了氧化苦参碱脂质体和水溶液在兔体内的药物动力学特征和在小鼠体内的组织分布。药物动力学实验结果表明,氧化苦参碱脂质体的药时过程符合线性的二室模型动力学特征,其生物消除半衰期为185min,较水溶液制剂的消除半衰期延长了54min。小鼠体内组织分布实验结果表明,氧化苦参碱制备成脂质体后,在肝、肺、脾等网状内皮细胞丰富的器官中药物浓度较水溶液制剂都有明显提高。说明氧化苦参碱制备成脂质体后具有延长体内作用时间和提高药物靶向性的效果。
Oxymatrine(OM) is a alkaloid of quinolizidine group, extracted from a traditional Chinese medicine, Ku-dou-zi or the aired root of Sophora flavescens ait..The studies of pharmacological have shown that OM has wide pharmacological effects including anti-arrhythmic, anti-inflammatory, anti-tumor, immunol-ogical enhancement. At present, OM is widely used for the treatment of chronic type B hepatitis, but OM injection used clinically has some disadvantages including short half-life, low drug concentration in tissues.Liposomes are well recognized as drug delivery vehicles that have target effents, delayed drug release and degraded drug toxicity. Thus, in this study we intend to prepare the OM liposome(OM-L) to improve its pharmacokinetics characters such as half-life and target effect and enhance therapeutic efficacy.
We had applied a pH-gradient method to prepare OM-L. Through orthogonal experimental design, one optimum recipes of OM-L was founded that showed OM/EPC 1:10, EPC/Ch 3:1, pH 6.8, incubation tempreture 60℃. Under the optimal formulation, OM was encapsulated 51.35%.
A method was developed for the determination of OM concentration in liposomes and entrapment efficiency and biological samples by HPLC, it was proved that this method was accurate, sensitive, specific and good enough to be used in pharmacokinetic study of OM. The small unilamellar vesicle liposomes were observed by transmission electron microscope. The mean particle diameter is about 80nm. The stability of OM-L was valuated with the entrapment efficiency and preoxidation value in 4, 25℃for 1 month. The results showed that the OM-L stored in 4℃would keep stability.
The pharmacokinetic parameters and tissues distribution of OM water solution or OM-L were studied after intravenous administration OM or OM-L to rabbits and mice, respectively. The experimental results showed that the concentration-time curves of OM-L fit in a two-compartement model. To compare with water solution, biological half-life of liposomes prolonged 54 min in rabbits plasma and the concentrations of OM in liver, lung, spleen of mice were improved obviously. The result of pharmacokinetics and tissues distribution showed that OM-L had better tissues targeting and slow-release effect than OM.
引文
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[11]吕文莉,郭建新,平其能.灯盏花素脂质体的制备及其理化性质的测定[J].中国天然药物.2004,2(5):289～292
[12]刘湘新,肖洪波.吡喹酮脂质体的制备及包封率的测定[J].湖南农业大学学报.1998,24(3):251～253
[13]薛玉英,翁帼英.阿糖腺苷脂质体的制备及其稳定性[J].药学学报.1992,27(1):74～80
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[15]邓意辉,王绍宁,吴琼,等.主动载药法制备盐酸小檗碱脂质体[J].中国药学杂志.2004,39(1):40～42
[16]邓意辉,于彬,李焕秋,等.pH 梯度法制备阿霉素脂质体[J].沈阳药科大学学报.1997,14(4):239～242
[17]Kanter PM,Klaich GM, Bullard GA, et al.Liposome encapsulated vincristine:preelinical toxicologic and phammeologic comparison with free vincristine and empty liposomes in mice, rats and dogs[J]. Anti Cancer Drugs.1994, 5:579
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