双嘧达莫中空微球的制备及评价

目的制备双嘧达莫中空微球,并对其进行初步评价。方法采用溶剂扩散-挥发法制备双嘧达莫中空微球,以外观、平均粒径、载药量及包封率为指标进行单因素考察优化处方,并对优化处方制备的中空微球进行体外漂浮及体外释放实验。结果双嘧达莫中空微球的最优处方及工艺为:乙基纤维素质量浓度为100 g.L-1、乙基纤维素与药物的质量比为5:1、乙醇与乙醚的体积比为4:l、乳化剂质量浓度为10 g.L-1、硬脂酸镁质量浓度为0.2 g.L-1,反应温度为30℃,搅拌速度为300 r.min-1。以最优处方制备的双嘧达莫中空微球,其载药量为11.57%,包封率为70.12%。该微球在人工胃液中12 h漂浮率可达94%,在人工胃液中12 h释放达80%,且无突释现象。结论双嘧达莫中空微球具有较理想的体外漂浮及缓释特性。     

盐酸雷尼替丁中空缓释微球的制备及其特性

目的:以盐酸雷尼替丁(RH)为模型药物,研究中空微球的制备,并对制备过程中的影响因素进行考察。方法:以乙基纤维素(EC)为载体材料,乙醇/乙醚为混合溶剂,采用溶剂扩散-挥发法制备盐酸雷尼替丁中空微球。以产率、平均粒径、载药量和微球形态为指标,考察了处方工艺对微球性能的影响。并考察了EC粘度,RH/EC比例以及粒径对微球释药速率的影响。结果:中空微球产率为84.51%,粒径分布均匀,平均粒径632μm,载药量13.71%,包封率55.86%。电镜扫描显示:微球外观圆整光滑,内部为中空结构。体外释药研究表明随着EC粘度的增加释药速率降低;随着RH/EC比例和搅拌速度的增加释药速率增加。最终所得到的中空微球缓释可达24h,体外漂浮实验表明在人工胃液中可持续漂浮48h以上。结论:该处方工艺简便可行,制得的盐酸雷尼替丁中空微球在人工胃液中缓释性和漂浮性良好。中空微球有望成为吸收窗药物的又一新型给药系统。     

法莫替丁生物黏附型中空微球的制备与评价

目的制备法莫替丁生物黏附型中空微球,并对其进行初步评价。方法采用溶剂-扩散挥发法制备法莫替丁生物黏附型中空微球,以微球包封率、收率及漂浮率为指标通过正交试验优化处方工艺,以优化处方制备的微球进行离体黏附性试验、体外溶出实验,并进行释药机理的探讨。结果法莫替丁生物黏附型中空微球的最优处方及工艺为:乙基纤维素质量浓度为27.0 g·L-1,法莫替丁质量浓度为4.8 g·L-1,无水乙醇与无水乙醚体积比为17∶3。最优处方下制得微球外观圆整,粒径分布较均匀,在扫描电镜下横切面可见明显中空结构,平均包封率和离体黏附率分别为82.0%和98.0%,在人工胃液中12 h漂浮率可达87.0%。12 h体外释放90%以上。结论该法所制中空微球在人工胃液中具有良好的漂浮、黏附及缓释特性,体外释药符合Higuchi模型。     

阿霉素聚乳酸微球的制备及体外释药特性研究

目的:对阿霉素聚乳酸微球的制备工艺、含量测定及体外释药特性进行初步研究.方法:以人工合成可生物降解聚合物聚乳酸为载体,采用乳化-溶剂挥发法制备阿霉素聚乳酸微球,用UV-260紫外分光光度计测定其药物含量和体外释药量.结果:所制备的阿霉素聚乳酸微球外形圆整,算术平均球径为55.2 μm,载药量为30.21 μg*mg-1,12 h体外累积释药量36%.结论:聚乳酸微球具有很好的控释能力,使用前景广阔.     

硝苯地平中空控释微球的处方研究及质量评价

目的:制备硝苯地平(NF)中空控释微球并评价其质量。方法:采用溶剂扩散挥发法制备微球。以2、12、24 h的累积释放度(Q_(2h)、Q_(12h)、Q_(24h))的综合评分为指标,设计正交试验筛选处方中载体材料乙基纤维素(EC)、聚乙烯吡咯烷酮(PVP)和主药NF用量;评价最优处方所制微球的外观形态、粒径分布、载药量、漂浮性及累积释放度,并与进口制剂NF控释片(Adalat~?)比较体外释放行为。结果:最优处方为NF 3.00 g、PVP 1.60 g、EC 15.65 g。所制NF中空控释微球外观呈球形,粒径主要分布于20~40目,载药量为8.66%;在释放介质中24 h的漂浮率为97.93%;(Q_(2h)、Q_(12h)、Q_(24h))分别为20.49%、52.90%、91.00%(RSD<10%,n=3),与进口制剂比较,累积释放度的相似因子(f_2)均大于50;体外释药符合零级动力学方程(r=0.999 3),其Ritger-Peppas方程(r=0.980 7)的n为0.478。结论:所制NF中空控释微球与进口制剂具有相似的释药行为,其释药机制为扩散和骨架溶蚀共同作用。     

罗哌卡因乳酸羟基乙酸共聚物微球的制备及体外释药研究

目的:优化罗哌卡因乳酸羟基乙酸共聚物微球制备工艺,并考察其粉粒学特征和体外释药特性。方法:以乳酸羟基乙酸共聚物为载体,采用W/O/W乳剂-扩散溶剂挥发法制备微球,以微球的粒径、药物包封率、载药量及微球形态等重要粉粒学特征为考察指标,通过正交分析试验优化微球制备工艺,并进行体外释药研究。结果:以优化处方制备的制剂,外观光滑圆整,平均粒径为(2.525±0.047)μm,粒径在1.8～5.0μm的占总数的80%以上,载药量(6.067±0.312)%,包封率(58.05±1.169)%。其体外释药曲线可用Higuchi方程拟合,192h累积释药率达82%,t1/2=60.16h。结论:罗哌卡因乳酸羟基乙酸共聚物微球具有明显的缓释性。     

替莫唑胺聚乳酸-羟基醋酸微球的制备及体外释药

目的:对替莫唑胺聚乳酸-羟基醋酸微球的制备工艺、含量测定及体外释药特性进行初步研究。方法:以人工合成可生物降解聚合物聚乳酸-羟基醋酸为载体,采用乳化-溶剂挥发法制备替莫唑胺聚乳酸-羟基醋酸微球,用紫外分光光度计测定其药物含量和体外释药量。结果:所制备的替莫唑胺聚乳酸-羟基醋酸微球外形圆整,算术平均球径为62.2μm,载药量为7.47%,包封率为83.53%,体外释放可达1个月。结论:替莫唑胺聚乳酸-羟基醋酸微球具有很好的控释能力,使用前景广阔。     

制备工艺对石杉碱甲微球体外释药机制的影响

目的考察制备工艺对石杉碱甲(Hup)乳酸-羟基乙酸共聚物(PLGA)微球体外释药机制的影响。方法 采用两种O/O型乳化溶剂挥发法工艺(A法和B法)制备Hup微球。考察微球的体外释药曲线，结合微球在释放介质中的降解速度和溶胀速度曲线以及微球的形态和微球中药物的分布情况阐述微球的释药机制。结果采用A法制备的微球包封率为47.60%，体外无明显突释现象，可缓释35 d，符合零级动力学方程，通过扩散和降解两种机制释药。采用B法制备的微球包封率为83.50%，体外可缓释21 d，整体释药曲线符合Higuchi方程，主要以扩散机制释药。结论采用A法制备的微球具有更理想的缓释效果。     

正交试验筛选西咪替丁分散片的处方

采用正交实验对西咪替丁分散片处方进行筛选。     

Floating microspheres of cimetidine: formulation, characterization and in vitro evaluation

The present study involves preparation and evaluation of floating microspheres with cimetidine as model drug for prolongation of gastric residence time. The microspheres were prepared by the solvent evaporation method using polymers hydroxypropylmethyl cellulose and ethyl cellulose. The shape and surface morphology of prepared microspheres were characterized by optical and scanning electron microscopy, respectively. In vitro drug release studies were performed and drug release kinetics was evaluated using the linear regression method. Effects of the stirring rate during preparation, polymer concentration, solvent composition and dissolution medium on the size of microspheres and drug release were also observed. The prepared microspheres exhibited prolonged drug release (approximately 8 h) and remained buoyant for > 10 h. The mean particle size increased and the drug release rate decreased at higher polymer concentration. No significant effect of the stirring rate during preparation on drug release was observed. In vitro studies demonstrated diffusion-controlled drug release from the microspheres.     

正交试验优选氯化血红素缓释固体分散体处方

目的：探讨氯化血红素缓释固体分散体处方组成。方法：以乙基纤维素为载体，聚乙二醇为致孔剂，采用溶剂法制备氯化血红素缓释固体分散体，用体外释放度为考察指标，运用正交试验对氯化血红素缓释固体分散体最佳处方组成优选。结果：按优选出的最佳处方组成，制备氯化血红素缓释固体分散体，2h的累积体外释放度为30．3％．符合药典规定，6h的累积体外释放度为62．5％，12h的累积体外释放度大于州）％，优化后处方药物释药过程符合Higuchi方程。结论：本处方组成制成固体分散体后，氯化血红素的缓释效果显著，提示本处方可行。     

干扰素-α微球的制备及其体外释药性能研究

目的:通过正交设计试验优化干扰素-a聚乳酸-羟乙酸共聚物微球的制备工艺,并考察其体外释药性能.方法:采用复乳-溶剂挥发法制备干扰素微球,通过L9(3)4正交试验设计优选微球最佳制备工艺条件,并对制备工艺的重现性、微球的性质及体外释药性能进行了考察.结果:干扰素微球的最佳制备工艺稳定、重现性好,微球的形态圆整,粒度分布均匀,平均粒径为10.71μm,干扰素被证明包裹在微球中,载药量为8.06%,包封率为36.97%.干扰素微球在61 h的累积释药量约为86%,t1/2为10.8 h.结论:本研究获得了较满意的干扰素微球制备工艺,其体外释药性能符合长效制剂特征.     

替莫唑胺壳聚糖缓释微球的制备及体外释药特性

目的:制备替莫唑胺壳聚糖缓释微球,并对其体外释药模式进行研究.方法:以替莫唑胺为模型药物,采用乳化交联法制备壳聚糖微球,两步优化法优化处方和制备工艺.通过测定微球的粒径及其分布、载药量、包封率和体外释放速度对微球进行质量评价.结果:优化工艺制得的微球平均粒径为(3.9±1.6)μm,载药量为(7.1±0.5)%(n=3),包封率为(25.0±0.8)%(n=3),体外释药特性研究具有良好的缓释特性,在0～8 h符合Higuchi方程,Q=11.717 26.951t1/2(r=0.980),8～24 h符合一级释放曲线,lnQ=4.37 0.007 5t(r=0.983).结论:通过优化处方和制备工艺,采用乳化交联法可制备出以壳聚糖为载体、替莫唑胺为模型药物的缓释微球,其体外释药具有明显的缓释作用.     

去甲斑蝥素壳聚糖微球的制备及其体外释放特性

目的:制备去甲斑蝥素壳聚糖微球,并考察其体外释放特性.方法:以液体石蜡为油相,Span-80为乳化剂,甲醛作为交联剂,采用乳化-交联法制备去甲斑蝥素壳聚糖微球.均匀设计优化制备工艺,扫描电镜观察微球表面形态,动态透析法检测微球的体外释放特性.结果:制备的微球形态圆整,粒径分布较为均匀,平均粒径(25±10)μm,载药量(15.08±2.85)%,包封率(57.80±1.35)%.微球在0.1 mol·L-1HCl、磷酸盐缓冲液(pH值5.3)和生理氯化钠溶液中的释放均遵循Higuchi方程.结论:所优化的制备工艺简单易行,载药量高,缓释作用显著.     

载羟基喜树碱聚乳酸微球的制备与体外释药研究

目的:研究载羟基喜树碱的聚乳酸微球的制备方法并考察其体外释药性质。方法:以PLA为成膜材料,采用改良乳化-溶剂挥发法,制备载羟基喜树碱的聚乳酸微球并优化制备工艺;对载药微球进行表征;超声介导下进行载药微球的体外释药试验。结果:微球粒径在1～7μm,大小均一;羟基喜树碱浓度在10mg.mL-1下,载药微球包封率为62.2%,载药量为1.69%;药物体外释药符合Higuchi方程。结论:采用乳化-溶剂挥发法,以PLA为成膜材料可制得具有较高包封率的羟基喜树碱微球,有望实现降低羟基喜树碱给药量、减少不良反应,提高靶向性的目标。     

Effect of formulation variables on in vitro drug release and micromeritic properties of modified release ibuprofen microspheres

Modified release microspheres of the non-steroidal anti-inflammatory drug, ibuprofen, were formulated and prepared using the emulsion solvent diffusion technique. The contribution of various dispersed phase and continuous phase formulation factors on in vitro drug release and micromeritic characteristics of microspheres was examined. The results demonstrated that the use of Eudragit RS 100 and Eudragit RL 100 as embedding polymers modified the drug release properties as a function of polymer type and concentration. Eudragit RS 100 retarded ibuprofen release from the microspheres to a greater extent than Eudragit RL 100. The drug/polymer concentration of the dispersed phase influenced the particle size and drug release properties of the formed microspheres. It was found that the presence of emulsifier was essential for microsphere formation. Increasing the concentration of emulsifier, sucrose fatty acid ester F-70, decreased the particle size which contributed to increased drug release properties. Scanning electron microscopy revealed profound distortion in both the shape and surface morphology of the microspheres with the use of magnesium stearate as added emulsifier. The application of an additional Eudragit RS 100 coat onto formed microspheres using fluid bed technology was successful and modulated the drug release properties of the coated microspheres.     

Naproxen-Eudragit microspheres: screening of process and formulation variables for the preparation of extended release tablets

The objectives of the present study were to screen the formulation and process variables for the preparation of extended release naproxen tablets with Eudragit L100-55. The tablets were prepared by compression of microspheres that were obtained by a coprecipitation technique. The process involved dissolution of naproxen and Eudragit L 100-55 in alcohol USP followed by the addition of an aqueous solution containing a surfactant and deaggregating agents. The mixture was stirred for a specified time period to obtain microspheres, which were filtered and air-dried to a constant weight. The microspheres were then compressed to obtain plain tablets with a diameter of 12 mm. A 7-factor 12-run Plackett-Burman screening design was employed to evaluate the main effects of homogenization time (X1), rate of water addition (X2), amount of polymer (X3), amount of precipitating solution (X4), concentration of electrolytes (X5), compression pressure (X6), and the concentration of lubricant (X7) on the rate of drug release. The response variable was cumulative percent of naproxen dissolved in 12 h in simulated intestinal fluid with constraints on responses that included percent yield, hardness, thickness, and the angle of repose. Mathematical relationship for percent of naproxen dissolved in 12 h (Y5) with various factors yielded the following polynomial equation; Y5 (% dissolved in 12 h) = 95.48 + 0.53 X1 + 3.51 X2 + 3.84 X3 - 3.80 X4 - 2.46 X5 - 2.90 X6 - 3.91 X7. The results showed that all the seven factors affected, with varying order, the release of naproxen from its compressed tablets.     

载药蒙脱石/丙烯酸树脂微球的制备与体外释放性能的研究

目的以丙烯酸树脂为膜材制备载药蒙脱石/丙烯酸树脂微球并考察其体外释放性能。方法以盐酸倍他洛尔为模型药物,采用O/O溶剂挥发法制备蒙脱石载药微球,通过正交实验设计,考察柠檬酸三乙酯及甘油用量、乳化剂与膜材比例及用量、内外相体积比等因素对微球载药量、包封率、体外释放性能的影响,采用扫描电镜对其外观形态进行表征。结果所得微球外观圆整,粒径分布较均匀,平均粒径为20.7μm,平均载药量为14.31%±0.47%,平均包封率为94.35%±1.01%。结论该法制备载药蒙脱石丙烯酸树脂微球是可行的,体外释放研究表明微球具有一定的缓释作用。