【作者】 魏兰兰；

【导师】 潘卫三；

【作者基本信息】 沈阳药科大学 ， 药剂学， 2007， 博士

【摘要】 卡维地洛是一种高亲脂性药物，由于其水溶性差，溶出度差并且具有肝脏的首过效应，使其生物利用度低。本文旨在通过自乳化及自微乳化给药系统提高卡维地洛的生物利用度，为卡维地洛寻求一系列具有不同释药特点的液体、半固体、固体自乳化及自微乳化给药系统，并且通过对一系列不同释药行为的自乳化给药系统的研究，促进自乳化给药系统的发展。为了制备液体自乳化和自微乳化给药系统并对其进行质量评价，以卡维地洛为模型药物，首先建立了卡维地洛的HPLC分析方法，考察了卡维地洛的基本理化性质，因卡维地洛为弱碱性药物，亲脂性高，水溶性差，故其在水性介质中的溶解度随pH值的降低而升高，在pH 1.0的介质中中有最大的溶解度102.9μg／mL；其油水分配系数随着水相介质pH值的升高而升高，药物在pH1，ph5.8，pH6.8，pH7，pH7.4五种介质中的油水分配系数分别为2.57，2.67，3.51，3.78，4.08。DSC分析的结果表明，在200℃以下，卡维地洛的稳定性良好。考察了卡维地洛在不同油相、表面活性剂和辅助表面活性剂中的平衡溶解度，绘制三元相图，通过乳化区面积的大小及乳剂的外观对自乳化给药系统进行优选。在此实验的基础上，选择了Labrafil M 1944CS为油相，Tween 80为表面活性剂，Transcutol P为辅助表面活性剂制备自乳化制剂及自微乳化制剂。对自乳化制剂、自微乳化制剂的乳化时间进行了考察，实验结果表明，当表面活性剂从30％增加到60％时，体系的自乳化时间先减小，后增大，在表面活性剂为40％时，体系的自乳化时间最小，为22秒。对自乳化制剂、自微乳化制剂乳化后所形成的乳剂的粒度分布、ζ-电位及药物在乳剂各相的分布进行了考察。乳剂的粒径随着表面活性剂含量的增加而减小，苯甲酸的加入导致了自乳化后的乳剂荷正电。药物在乳剂各相的分布以及变化是pH值变化和自乳化给药系统表面活性剂比例变化的综合结果，药物有少量分布在水相（18.49％-25.87％），少量分布在油相（6.84％-29.79％），大量分布在界面层上（51.68％-67.29％）。通过直接释药法和总体液平衡反向透析释药法测定了四组自乳化处方的溶出度，结果表明，直接释药法四组自乳化处方溶出迅速完全，几乎不受溶出介质pH值的影响，随着表面活性剂含量的增加，药物释放加快。总体液平衡反向透析释药法结果表明，四组处方在30min时，约有50％的药物以游离形式释出，随释放介质pH值的增加，药物释放加快。为了验证自制自乳化给药系统和自微乳化给药系统是否能提高药物的生物利用度，对自制自乳化制剂，自微乳化制剂进行了beagle犬体内药物动力学的研究，络德片，自乳化制剂，自微乳化制剂的C_max分别为（510.15±156.20）ng·mL^-1、（2060.38±534.60）ng·mL^-1、（746.17±170.27）ng／ml；t_max分别为（0.79±0.1）h、（1.00±0.00）h、（0.91±0.13）h；AUC分别为（1755.79±409.75）ng·mL^-1·h、（7264.29±1911.35）ng·mL^-1·h、（4182.47±798.68）ng·mL^-1·h；自乳化制剂，自微乳化制剂的相对生物利用度分别为（446±190）％，（249±74）％；SPSS统计软件处理方差分析结果表明，自乳化制剂及自微乳化制剂均能显著提高药物的生物利用度。为了考察自制自乳化及自微乳化给药系统的的组织靶向性，进行了大鼠组织分布的研究。大鼠分别灌胃给药络德片混悬液、乳剂、微乳20mg后，自乳化制剂显著提高了药物在心、肺、肝、血液、淋巴的分布，减少了在肾脏内的分布（P＜0.05），对药物在脾脏、脑的分布没有显著性影响（P＞0.05）；自微乳化制剂显著提高了药物在心、血液、淋巴的靶向性，减少了在肝脏和肾脏内的分布（P＜0.05），对药物在肺、脑、脾的分布没有显著性影响（P＜0.05）。为了制备一种半固体自微乳化硬胶囊，测定了卡维地洛在几种半固体自乳化辅料中的溶解度，通过对三元相图的研究，优选出半固体自乳化胶囊的最佳处方，即以Gelucire 44／14为油相，Lutrol F68为表面活性剂，Transcutol P为辅助表面活性剂制备了三组自微乳化硬胶囊。考察了其体外溶出行为，三组处方均能快速完全地溶出，在30min溶出量达90％以上。分别用零级方程、一级方程、Higuchi方程、Ritger-Peppas方程、Weibull方程、Hixon-Crowell方程对释药曲线进行模型拟和，三个自微乳化处方的释药动力学最适合用Hixon-Crowell方程拟和，药物的溶出机理属于溶蚀机理。利用差式扫描量热法、红外光谱法、X-射线衍射法证明药物在半固体自微乳化制剂中以无定型的形式存在。为了制备一种新颖的自乳化渗透泵片，进行了以下研究。建立了卡维地洛紫外释放度测定方法。通过吸收性能的比较，确定了二氧化硅为半固体自乳化系统的吸收剂，通过崩解时间的测定，确定了以枸橼酸和碳酸氢钠作为崩解剂为自乳化过程提供动力。通过f₂因子法比较释放曲线的相似性，考察了渗透活性物质的种类、释药孔径、包衣增重对药物释放的影响。在此实验的基础上，确定了自乳化渗透泵的最优处方。即以二氧化硅为吸收剂，以枸橼酸和碳酸氢钠作为崩解剂，以甘露醇作为渗透活性物质，以滑石粉做润滑剂制备片芯；包衣液组成为：27g醋酸纤维素溶于1000mL丙酮，加入10g PEG400分散均匀后制得；包衣增重为15mg，双面打1.0mm小孔。在2小时至12小时时间内，药物以零级速率释放，在12h的累计释放量为85％。利用透射电镜对自乳化后所得乳剂进行形态观察，发现自乳化渗透泵遇水后能够形成形态圆整的乳剂，乳剂的粒度分布窄，体积径为246nm，表面积径为242nm。为了验证自制半固体自微乳化硬胶囊是否能提高生物利用度，自制自乳化渗透泵片是否既能提高生物利用度，又能减小血药浓度的波动，以络德片为参比制剂，进行了口服半固体自微乳化硬胶囊，自乳化渗透泵片的beagle犬体内药物动力学研究。洛德片，半固体自微乳化硬胶囊，自乳化渗透泵片的C_max分别为（1311.60±156.20）ng·mL^-1、（2006.38±633.26）ng·mL^-1、（640.23±162.79）ng／ml；t_max分别为（2.83±0.61）h、（1.63±0.74）h、（4.50±1.22）h；AUC分别为（4063.36±822.30）ng·mL^-1·h、（6578.15±2508.09）ng·mL^-1·h、（6189.68±1873.58）ng·mL^-1·h；半固体自微乳化硬胶囊，自乳化渗透泵片的相对生物利用度分别为（162±50）％，（152±33）％；SPSS方差分析结果表明，，半固体自微乳化硬胶囊的C_max显著增加，自乳化渗透泵片的C_max显著降低；秩和检验结果表明，半固体自微乳化硬胶囊使t_max显著提前，自乳化渗透泵片使t_max显著后移。SPSS方差分析结果表明，半固体自微乳化硬胶囊及自乳化渗透泵片均能显著提高药物的生物利用度，半固体自微乳化硬胶囊呈现速释特点，自乳化渗透泵片呈现缓释特点。用W-N法和L-R法进行自乳化渗透泵片体内外相关性的研究，两种方法均能对体内外相关性进行很好的拟和。更多还原

【Abstract】 Carvedilol is a highly lipophilicβ-adrenoceptor blocking. It has a low solubility in gastrointestinal fluids and undergoes extensive first-pass metabolism in the liver, which leads to the low absolute oral bioavailability which is about 20% in humans. The objectives of our researches are to improve its bioavailability by self-emulsifying drug delivery system （SEDDS） and self-microemulsifying drug delivery system （SMEDDS） and to prepare a series of liquid, semi-solid and solid self-emulsifying and self-microemulsifying formulations that have different release characteristics. Based on the above work, we hope to do contributions to the development of SEDDS and SMEDDS.To prepare a SEDDS and SMEDDS and evaluate their in vitro properties, first of all, the HPLC analytic methods were established. The physical and chemical properties of carvedilol were investigated. The solubility of carvedilol in solutions increases with respect to the decrease of pH value because it is a weak base. It has the biggest solubility in 0.1 mol·L^-1HCl which is 102.9μg/mL. The logP increases with the pH value of the water phase, the logP in pH1.0, Ph5.8, pH6.8, pH7, pH7.4 were 2.57, 2.67, 3.51, 3.78, 4.08 respectively. The DSC results showed that carvedilol is stable under 200℃. The balance solubility of carvedilol in different oil phase, surfactant and cosurfactant were assayed. Ternary phase diagrams were constructed. The optimal SEDDS were obtained by comparing the self-emulsifying and self-microemulsifying domain and by the evaluation of the resultant emulsion’s appearance. The optimal SEDDS was Labrafil M 1944CS, Tween 80, Transcutol P. The self-emulsifying time of self-emulsifying and self-microemulsifying formulations were investigated. When the surfactant content increase from 30% to 60%, the self-emulsifying time decreased firstly and then increased. The minimal self-emulsifying time which was 22s was found at the formulation that has 40% surfactant. The particle size distribution,ζ-potential and phase distribution of the resultant emulsion and microemulsion were studied. The diameter of the emulsion decreased with respect to the increase of surfactant content. Adding acid benzoic to formulations led to positively charged emulsions. Phase distribution is the results of pH value and the surfactant content. Drug distribution in water phase increased with respect to the decrease of pH value and the increase of surfactant content. Small amount of drug distributed into water phase （18.49%-25.87%） and oil phase （6.84%-29.79%）, most of the drug distributed into interface （51.68%-67.29%）. Direct dissolution test and bulk equilibrium reverse dialysis bag technique were used to evaluate the dissolution of drug from SEDDS and SMEDDS in media of different pH values. The results showed that the four formulations could release drug fast and completely. The dissolution rate increased with respect to the increase of surfactant content. The dissolution results of bulk equilibrium reverse dialysis bag technique showed that about 50% free drug was released at 30min. the dissolution rate increased with respect to the increase of pH values.To testify if the self-made SEDDS and SMEDDS could improve the bioavailability, the pharmacokinetic study of commercial available tablets, self-made SEDDS and SMEDDS in beagle dogs was carried out. The C_max of commercial available tablets, self-made SEDDS and SMEDDS were （510.15±156.20） ng·mL^-1、（2060.38±534.60） ng·mL^-1、（746.17±170.27） ng·mL^-1 respectively; t_max were （0.79±0.1） h、（1.00±0.00） h、（0.91±0.13） h respectively; AUC were （1755.79±409.75） ng·mL^-1·h、（ 7264.29±1911.35） ng·mL^-1·h、（4182.47±798.68） ng·mL^-1·h respectively; the relative bioavailability of SEDDS and SMEDDS were （446±190） %, （249±74）% respectively; the results of variance analysis by using SPSS software showed that self-made SEDDS and SMEDDS could improve the bioavailability of carvedilol significantly.To investigate the tissue distribution of self-made SEDDS and SMEDDS, the tissue distribution of Luode tablet suspension, emulsions and microemulsions were investigated after oral administration to rats at a dose of 20mg. SEDDS could improve the drug distribution at heart, lung, hepatic, blood, lymph, decrease drug distribution at kidney （P＜0.05）. SEDDS had no significant effect on the distribution at spleen and brain （P＞0.05）. SMEDDS improve the drug distribution at heart, blood, lymph, decrease drug distribution at hepatic and kidney （P＜0.05）. SMEDDS had no significant effect on the distribution at lung, brain and spleen （P＞0.05）.To prepare a semi-solid self-microemulsifying capsule, the solubility of carvedilol in different semi-solid self-emulsifying materials was investigated. By study of ternary phase diagrams, the optimal semi-solid formulation was optimized that is Gelucire 44/14 was used as oil phase, Lutrol F68 was used as surfactant, Transcutol P was used as cosurfactant. Three different semi-solid self-microemulsifying formulations could all release drug fast and completely, and the cumulated release of three formulations were all above 90% at 30min. Zero-order equation, first-order equation, higuchi equation, ritger-peppas equation, weibull equation, Hixon-crowell were used to calculate drug release kinetics. The results showed that the drug release fitted Hixon-crowell equation most. The dissolution mechanism is erosion dependent. Differential Scanning Calorimeter （DSC）, Infrared spectroscopy （IR）, X-ray diffraction （XRD） methods were used to investigate the physical characterization of drug in semi-SMEDDS. The results showed that carvedilol was amorphous in dosage form.To prepare a novel self-emulsifying osmotic pump tablet （SEOPT）, the following experiments were carded out. The release assay method by UV was established. By comparing the absorbing ability, silicon dioxide was used as the adsorbent. By assaying the disintegration time, citric acid and sodium hydrogen carbonate was used as disintegration substance. By comparing the similarity of profiles using f₂ factor method, the effects of the type of osmotic active agent, orifice size, coating weight gained on drug release were investigated. Based on the experiments, the SEOPT formulation was optimized, that is silicon dioxide was used as adsorbent, citric acid and sodium hydrogen carbonate was used as disintegration substance, mannitol was used as osmotic active agent, talc powder was used as lubricant. The coating solution was prepared by dissolving 27.0g cellulose acetate in 1000ml acetone and then adding 50 mL water solution with 10g PEG-400 dissolved in it. Then two orifice of 1.0mm were punched on two sides. In most release period, the drug was released at zero order, the cumulated release at 12h was 85%. The results of transmission electron microscope showed that self-made SEOPT could form regular and round emulsion particles. The volume diameter was 246nm, the surface diameter was 242nm.To investigate if the semi-SMEDDS and SEOPT could improve the bioavailability, the pharmacokinetics of Luode tablet, semi-SMEDDS and SEOPT was carried out. The C_max of Luode tablet, semi-solid SMEDDS and SEOPT were （1311.60±156.20）ng·mL^-1、 （2006.38±633.26） ng·mL^-1、（640.23±162.79） ng·mL^-1; the t_max of Luode tablet, semi-SMEDDS and SEOPT were （2.83±0.61） h、（1.63±0.74） h、（4.50±1.22） h; the AUC of Luode tablet, semi-SMEDDS and SEOPT were （4063.36±822.30） ng·mL^-1·h、（6578.15±2508.09） ng·mL^-1·h、（6189. 68±1873. 58 ） ng·mL^-1·h. The relative bioavailability of semi-SMEDDS and SEOPT were （162±50） %, （152±33）%. The results of variance analysis by SPSS software showed that C_max of semi-SMEDDS increased significantly, C_max of SEOPT decreased significantly. Rank sum test showed that tmax of semi-SMEDDS move forward greatly and t_max of SEOPT move backward greatly. SPSS variance analysis results showed that semi-solid SMEDDS and SEOPT could improve the bioavailabitliy significantly. Semi-solid SMEDDS showed fast release characteristics and SEOPT showed sustained release characteristics. W-N method and L-R method both can be used to calculated in vitro and in vivo correlation well.更多还原