【作者】 卢亚欣；

【导师】 唐星；

【作者基本信息】 沈阳药科大学 ， 药剂学， 2007， 博士

【摘要】 利培酮（Risperidone）为新一代的抗精神病药，可用于治疗急性和慢性精神分裂症以及其它各种精神病性状态明显的阳性症状和明显的阴性症状，具有良好疗效且副作用相对较小。乙酸异丁酸蔗糖酯（sucrose acetate isobutyrate，SAIB）为可生物降解的可注射原位贮库基质。具有水不溶性和高粘度的特点，然而少量溶剂即可极大的降低其粘度而易于注射，在体内通过溶剂交换而形成原位贮库。所制备的原位贮库由少量有机溶剂、SAIB及有效成分组成。本文将利培酮制备为可注射的SAIB原位贮库系统，旨在减少给药次数及药物总剂量，使副作用更小，进而更有效地利用药物，同时提高病人的顺应性。建立了利培酮体外高效液相色谱分析方法。测定了利培酮的基本理化性质包括平衡溶解度、油水分配系数、原料药稳定性。利培酮在水中微溶，溶解度为0.13mg／mL，溶解度及在正辛醇—水系统的分配系数具有pH依赖性，水中LogP值为2.02；SAIB／溶剂系统对利培酮具有一定的增溶作用；固体状态的利培酮在高温、高湿条件下稳定性良好，强光照射下稳定性较差，利培酮磷酸盐缓冲溶液（pH7.4）37℃放置，5天后药物含量为97.14％，较为稳定。测定SAIB／溶剂系统流变学性质，该系统接近于牛顿流体，溶剂种类及浓度、添加剂、药物、温度对流变学性质均有影响。其中乙醇使SAIB粘度降低的能力明显优于乳酸乙酯和N-甲基吡咯烷酮（NMP）；乙醇浓度由10％增加为20％时，系统粘度由1.29 Pa·s降低到0.11 Pa·s；聚乳酸（PLA）及利培酮的加入均使分子间作用力增大，粘度增加；而升高温度则可使粘度明显降低。20％的溶剂即可使SAIB／溶剂系统的粘度降低到易于注射范围。以喷雾干燥作为原料药的前处理方法，对利培酮的粒径范围进行控制，得到平均粒径为44.77±30.20μm的利培酮粉末（未添加任何辅料），93.5％的粒子小于100μm。以利培酮为活性药物，SAIB为基质，无水乙醇或乳酸乙酯或NMP为溶剂，PLA为释放调节剂，制备利培酮—SAIB原位贮库系统，通过药物在体外释放曲线的测定，研究药物从贮库中的释放和扩散行为及其影响因素。利培酮的体外释放符合Higuchi方程，以药物24 h的累计释放量代表突释量，对于SAIB／乙醇系统，随着SAIB的浓度由75％增加到85％时，利培酮突释量由30.7％降低到15.6％。介质的pH值只影响药物的初始释放量，对于贮库形成后的药物释放没有显著差别。载药量增加释放速率增大，且混悬药物颗粒的缓慢溶解可使释放速率略有增大。PLA可在原位贮库系统形成时在贮库表层包裹一层聚合物的薄膜，显著降低药物的初始释放量。0～31天的释放符合Higuchi方程，9～31天的释放较为均匀，零级拟合具有较好的相关性。PLA加入量为1％时，突释量即由20.0％降低到10.8％，从9到31天，每天的平均释药量为1.7％，31天的累计释放总量为75.0％。10％的PLA使突释极大降低至3.5％，且药物的释放速率显著降低，从9到31天，每天的平均释药量为1.2％，31天的累计释放总量为43.4％。建立了利培酮及其活性代谢产物9-OH-利培酮的UPLC／MS-MS分析方法，对利培酮—SAIB原位贮库系统肌肉注射后在大鼠体内的药动学过程进行了研究，采用非隔室模型计算了体内药动学参数。以12.5 mg／kg的剂量肌肉注射利培酮-SAIB原位贮库，当PLA的含量由1％增大到10％时，C_max由944.1±80.2 ng／mL降低到330.4±33.6 ng／mL，T_max由2 h延迟至4.3±2.0 h，AUC_0-2day则从16294.8±3946.4 ng·hour／mL显著降低到7025.3±1979.2 ng·hour／mL（P＜0.05）。将9至21天的平均血药浓度定义为稳态浓度（C_s），C_max／C_s的大小则可用以表示原位贮库的突释程度及初期血药浓度的波动程度。未加入PLA的处方C_max／C_s值为415.8，PLA含量的由1％增大至10％，C_max／C_s值由82.8逐渐降低至11.3。避免血药浓度过高而导致的不良反应，并使2至25天的AUC增大，药物能够持续释放，维持较长时间的治疗水平。原位贮库经肌肉注射后其药动学是非线性的。高载药量组含有的混悬颗粒可以作为药物贮库，持续溶出药物，以补充所消耗的药物分子，在释药后期阶段，其血药浓度较高，相对更为平稳。建立了肌肉渗析液中利培酮的HPLC分析方法，采用肌肉微渗析技术测定了不同时间药物在肌肉中的浓度，进行药物在注射部位的扩散动力学研究。利培酮水溶液注射后在肌肉中的浓度迅速下降，4 h后的浓度水平低于检测限。肌肉注射利培酮原位贮库系统，利培酮在肌肉中的C_max为1176.0 ng／mL，T_max为0.083 h，AUC_0-25day为57289.3 ng·hour／mL，与血浆中活性成分的浓度及动力学参数相比都具有可比性。将给药4 h后肌肉中药物的浓度与血浆中的浓度进行线性拟合，建立的二者相关性关系方程为y=3.085x—41.29，r=0.9964。利培酮在体内的释放百分率与体外的累积释药百分数进行线性拟合，建立的体内外相关性关系方程为y=0.371x—4.14，r=0.9708。对原位贮库系统的生物相容性进行了评价，考察了利培酮—SAIB原位贮库注射给药后的局部组织反应，观察到急性炎症反应、慢性炎症和纤维组织包裹，这是生物体对异物识别的正常生理反应，是大多生物材料植入后都会产生的反应。在第28天时，随SAIB的降解，异物排斥反应逐渐减轻，没有观察到严重的炎症反应及组织坏死，表明原位贮库系统具有较好的组织相容性。更多还原

【Abstract】 Risperidone, one of the newer high-potency antipsychotic agents, is an effective drug for the treatment of positive as well as negative symptoms of schizophrenia and it has a limited ability to cause causing extrapyramidal side effects at therapeutically effective doses.The sucrose acetate isobutyrate （SAIB） system is a biodegradable material for developing an injectable sustained-release in situ depot using a polymer-free solution consisting of a small amount of organic solvent, the active ingredient and SAIB. SAIB with high viscosity does not dissolve in water. However, the solution viscosity of SAIB is significantly degraded by adding small amount of solvent, and it can be easily injected in vivo, then form in situ depot by solvent exchange.In this study, the development of an effective injectable risperidone-SAIB in situ depot with limited adverse effects and with excellent treatment compliance would make an important contribution to the long-term management of schizophrenia.HPLC method was developed for the assay of risperidone. The solubility and oil/water partition coefficient of risperidone in different pH was determined. The solubility of risperidone in water was 0.13 mg/mL, but was affected by pH. The LogP was 2.02, showed that it was highly lipophilic. The use of the SAIB/solvent system was able to improve the solubility of risperidone to a degree which depended on the composition of the solvent systems. Risperidone showed its well stability by the results of the experiments in high temperature and humidity studies, but did not stable in light studies. The content of risperidone in PBS was 97.14% by 37℃after 5 days.The rheological properties of SAIB/solvent system was studied, and it was similar to Newtonian fluid. The factors such as the type of solvent, concentration, additive, drug and temperature had effect on the rheological properties. Ethanol was a suitable solvent compared with Ethyl lactate and N-methylpyrrolidone （NMP）. The solution viscosity of SAIB was reduced from 1.29 to 0.11 Pa.s with only increasing the content of Ethanol from 10% to 20%. Polylactic acid （PLA） and risperidone could increase the intermolecular force and viscosity. The solution viscosity reduced significantly by steping up the temperature. It is easy to inject for 20% solvent in SAIB system. The particle size distribution of risperidone was controlled by spray dried. 93.5% of the powders was below 100μm, and the mean size was 44.77±30.20μm. The risperidone-SAIB in situ depot contained SAIB, solvent （anhydrous ethanol, ethyl lactate or N-methyl-2-pyrrolidone）, and additives such as polylactic acid （PLA）. In-vitro release profiles of risperidone from the SAIB formulations, which followed the Higuchii square root law, were obtained. An increase in SAIB content from 75% to 85% resulted in a reduction in the initial burst from 30.7 to 15.6% for SAIB/EtOH system. The initial drug release could be increased by reducing the pH of the release medium, but the release in later stage was not effected. The release rate could be increased by an increase in drug loading and the slow dissolution of the suspended drug. The presence of PLA probably altered the initial release of risperidone by forming a diffusional membrane around the depot after contact with the aqueous buffer. The drug release profiles followed the Higuchii square root law from 0 to 31 day. In the later stage, the drug release rate was uniformity and close to zero from 9 to 31 day. The burst release fell from 20.0% to 10.8% following the inclusion of 1% （w/w） PLA in the formulations, the average percentage release was 1.7% for every day from 9 to 13 day, and the accumulative release was 75.0% on Day 31. When the concentration of PLA was increased to 10% （w/w）, the burst release was significantly reduced, the average percentage release was 1.2% for every day from 9 to 13 day, and the accumulative release was 43.4% on Day 31.The in vivo pharmacokinetic behavior of risperidone and 9-OH-risperidone were studied utilizing UPLC-MS/MS method. The pharmacokinetic study of risperidone after intravenous administration in rats Was performed. The pharmacokinetic parameters were studied according to non- compartment model. The result showed that PLA is effective in reducing the burst effect. After a 12.5 mg/kg IM injection of a 25 mg/g risperidone-SAIB in situ depot, the C_max was markedly reduced from 944.1±80.2 to 330.4±33.6 ng/mL by increasing PLA from 1% to 10% （w/w）, the T_max were prolonged from 2 to 4.3±2.0 h, and the area under the curve from day 0 to 2 (AUC_0-2day) was reduced significantly from 16294.8±3946.4 to 7025.3±1979.2 ng·hour/mL （P＜0.05）. The steady-state concentration （C_s） was the average value of the plasma concentration from 9 to 21 day, and the C_max/C_s was significantly reduced due to the increased PLA from 415.8 to 11.3. For the risperidone-SAIB in situ depot including 10% PLA, the high release rates over a short period allowed therapeutic plasma concentrations to be achieved in the initial stages after activation, and sustained release of the drug led to a stable plasma concentration. Non-linear pharmacokinetic was found for the SAIB in situ depot after IM administration. For the high drug loading, the suspended particles acted as a drug reservoir, continuously dissolving to replenish what was being lost and it led to a stable plasma concentration in later stage.Microdialysis technique was used to determine the concentration of risperidone in muscle after IM administration of risperidone solution and SAIB in situ depot.For injection of risperidone solution, the concentration decreased rapidly, and fell below detectability after 4 days. However, for the in situ depot, C_max was 1176.0 ng/mL, T_max Was 0.083 h, AUC_0-25day was 57289.3 ng-hour/mL. The results showed that the measured muscle microdialysis concentrations of risperidone, corrected for recovery were comparable to the drug active moiety levels in plasma concentrations, and the dependablity equation was y=3.085x—41.29, r = 0.9964. The percentage of release in vivo was plotted against the cumulative release percent in vitro to obtain a correlation relationship, and the dependablity equation was y=0.371x—4.14, r =0.9708.The biocompatibility of risperidone-SAIB in situ depot were evaluated in rats after IM injection. It was observed that acute inflammation, chronic inflammation and at the injection sites. It was because that injection or implantation of a biomaterial resulted in a foreign body response, and it was most often in the case of a biodegradable material. However, the foreign body reaction was gradually reduced by SAIB degradation, and no signs of serious inflammation and necrosis were evident. Therefore, these preliminary findings suggest that SAIB formulations are biocompatible and tolerated.更多还原