龟板水提物缓释微球的制备及其特性

目的：制备高包封率的龟板水提物缓释微球。方法：分别采用海藻酸钙凝胶珠、海藻酸钙-壳聚糖微胶囊和海藻酸钙-羧甲基纤维素钠微胶囊体系制备龟板水提物缓释微球,并考察其外观形态、包封率和体外释药等特性。结果：制得的龟板-海藻酸钙凝胶珠、龟板-海藻酸钙—壳聚糖微球和龟板-海藻酸钙-羧甲基纤维素钠微球外观圆整,表面光滑,且粒径均匀;包封率分别是46．7％、49．9％和82．3％;海藻酸钙凝胶珠有明显的突释现象,海藻酸钠—壳聚糖微球的突释现象和缓释效果有所改善,而海藻酸钙-羧甲基纤维素钠微球无突释现象,其缓释可达14小时以上。结论：龟板-海藻酸钙-羧甲基纤维素钠微球包封率高,同时具有优良的缓释性能。     

奥沙普秦壳聚糖-海藻酸钠缓释微球的制备

目的：目的：选择奥沙普秦作为模型药制备壳聚糖-海藻酸钠缓释微球。方法：采用滴制法制备奥沙普秦壳聚糖-海藻酸钠缓释微球，通过正交试验设计优化了处方和工艺，考察其理化特征及体外释药行为。结果：优化处方制得的微球包封率及载药量分别为98．36％和16．26％，平均粒径为（346．6±164．1）μm；1h药物释放达到36％，随后药物的释药行为是一个缓释过程。结论：制得了载药量较大，包封率较高的奥沙普秦壳聚糖-海藻酸钠缓释微球。     

多柔比星壳聚糖微球的制备及其特性研究

目的 以壳聚糖为载体材料,多柔比星为模型药物, 制备脑内局部给药缓释微球。方法 以液体石蜡为油相,L-抗坏血酸棕榈酸酯为交联剂,司盘-80为乳化剂,采用乳化化学交联技术制备多柔比星脑用微球。用动态透析法检测微球的体外释放特性。结果 多柔比星/壳聚糖的质量比为1：9的载药微球形态良好,粒径分布较为均匀,平均粒径为（9.41±2.43） μm,载药量为（8.49±0.37）%,包封率为（70.56±4.23）%。体外释放具有良好的缓释效果。结论 所优化的制备工艺稳定,适用于多柔比星壳聚糖脑用微球的制备.     

SPG膜乳化法制备槲皮素缓释微球的工艺优化与表征及体外释放研究

目的 以槲皮素作为模型药物,制备聚乳酸-羟基乙酸共聚物(PLGA)缓释微球,考察其粒径及其分布、形态、包封率、载药量和体外释药性质.方法 采用SPG膜乳化法制备微球,单因素法初步优化制备处方;粒径分析仪检测微球的粒径及其分布;光学显微镜观察微球形态;通过紫外分光光度法测定微球的包封率和载药量;利用直接释药法和超速离心法...     

美罗培南-海藻酸钙微球的制备与性能研究

目的 针对野战条件下战创伤感染缺乏长效抑菌杀菌药物现状,研制一种高效、安全、易用的新型外用抗感染复合材料.方法 应用天然高分子海藻酸钠、无水氯化钙为基质材料,强效抗生素美罗培南为包被药物,采用静电液滴法及冷冻干燥等制备工艺,制备美罗培南-海藻酸钙微球,并对其包封率、载药量、膨胀性及体外释药性进行检测,采用模拟药敏纸片法对其抑菌效果进行评估.结果 所制备的载药微球包封率为62.27%,载药量为19.40%,膨胀率可达80%;微球的释药模式符合缓释特征,可长效抑菌.结论 静电液滴法制备美罗培南-海藻酸钙微球具有可行性,微球性质稳定,释药模式理想、抑菌效果好.     

GM-l PLGA微球的制备及其体外释药性质研究

目的制备GM l PLGA微球，考察其一般性质和体外释药特性。方法应用W/O/W乳化溶剂干燥法制备GM l PLGA微球，测定微球粒径、载药量、包封率和体外释药曲线。结果微球形态规则，粒径约为（18±8） μm，载药量约为4.9%，包封率约为61%，微球体外释药规律符合Higuichi方程：Q=0.153t1/2+0.037 05(r=0.995)。结论GM l PLGA微球的制备工艺良好，体外释药呈明显的缓释作用。     

布比卡因缓释微球的制备及体外释药特性评价

目的研究布比卡因缓释微球制备方法并对其体外释药特性进行评价。方法采用紫外分光光度法测定布比卡因微球载药量、包封率;采用HPLC法测定微球体外释放;通过正交设计优选微球制备工艺;以乳酸羟基乙酸共聚物为载体,使用乳化溶剂挥发法制备布比卡因微球;用扫描电镜观察所得微球的粒径和形态;通过体外释药实验考察布比卡因乳酸羟基乙酸共聚物微球的缓释作用。结果微球载药量、包封率和体外释放的测定方法符合方法学要求;按照优选处方制备所得的微球为圆整球体,表面多孔,呈蜂窝状,粒径50~100μm之间的微球占80%;体外释放符合Ritger-Peppas方程,t1/2=242.05 h。结论乳化溶剂挥发法适用于布比卡因乳酸羟基乙酸共聚物微球的制备,所制得的微球形态圆整,在体外具有明显缓释作用。     

多柔比星聚合物胶束制备、表征及其体外释药研究

目的 制各多柔比星的soluplus聚合物胶束,并对其进行体外评价.方法 采用薄膜分散法-pH诱导法相结合制备多柔比星聚合物胶束;采用粒径测定仪、透射电镜、X-射线衍射(XRD)、差示扫描量热法(DSC)及红外光谱(FTIR)对其进行表征;采用HPLC法测定胶束的包封率和载药量;采用动态膜透析法考察载药胶束的体外释药特性.结果 本研究制备的胶束呈球形或类球形,平均粒径为(67.57±2.9)nm,平均包封率为(77.81±4.03)％,平均载药量(10.15±1.56)％;XRD和DSC结果表明多柔比星以无定型状态或分子状态包载在聚合物胶束中;FTIR结果表明多柔比星分子中羟基和聚合物的羰基之间形成了氢键;体外释放结果表明多柔比星的soluplus聚合物胶束具有缓释作用.结论 该胶束制备工艺简单,其粒径、包封率、载药量可控,具有缓释作用.     

阿西美辛海藻酸钙凝胶微丸释药影响因素考察

目的:考察阿西美辛海藻酸钙凝胶微丸的释药机制。方法:采用滴制法制备阿西美辛海藻酸钙微丸,考察海藻酸钠浓度,钙离子浓度,投药量,滴头直径大小对药物释放的影响。结果:海藻酸钠浓度增加,钙离子浓度增加,滴头直径增加,释药速率减慢。结论:在体外释放度实验中,阿西美辛海藻酸钙凝胶微丸具有良好的缓释作用,海藻酸钙凝胶微丸是一种非常有潜力的药物载体。     

乳酸环丙沙星淀粉微球的体外释药研究

目的：制备乳酸环丙沙星淀粉微球并对其体外释放行为进行考察。方法：采用反相乳液聚合法结合包埋载药法制备乳酸环丙沙星淀粉微球，应用体外恒温透析法考察其释药行为及影响因素，以紫外可见分光光度法测定并计算累积释药百分数。使用origin软件，将微球释药数据与载药微粒的主要释药方程进行拟合，以找出最佳拟合释药方程。结果：制备的乳酸环丙沙星淀粉微球置于生理盐水中约5小时后达到释放平衡，其释放行为受处方中球-药比和交联剂用量及释放介质的影响。该载药淀粉微球的释药行为最符合双指数双相动力学方程，即呈双相释放，前期为快速释放相，后期（5小时后）为缓慢释放相。结论：本制剂工艺切实可行，所得乳酸环丙沙星淀粉微球具有明显的缓释制剂特征。     

Sodium alginate microspheres of metformin HCl: formulation and in vitro evaluation

Metformin microspheres with sodium alginate alone and in combination with gellan were prepared using an emulsion-cross linking method. The prepared microspheres were evaluated for their physico-chemical characteristics like particle size, morphology using SEM, incorporation efficiency, equilibrium water content (swelling) and in vitro drug release. The effect of various formulation variables like polymer concentration (sodium alginate; and proportion of gellan in microspheres prepared by a combination of sodium alginate and gellan), drug loading, crosslinking agent concentration and cross-linking time on the in vitro dissolution of the prepared microspheres were evaluated. The results showed that both the particle size and the incorporation efficiency were proportional to the polymer concentration. In case of microspheres containing both sodium alginate and gellan, the mean diameter and the incorporation efficiency were higher than the corresponding microspheres containing only alginate, both increasing with an increase in proportion of gellan. The prepared microspheres were found to be discrete and spherical in shape and were successful in sustaining the drug release for 8 hours. Incorporation of gellan caused a significant decrease in drug release. The release followed a biphasic profile, in all cases, characterized by an initial phase of moderate drug release followed by a phase of higher release. Further, the kinetic treatment of the dissolution data revealed the prevalence of matrix diffusion kinetics.     

Chitosan microspheres with hydrocortisone and hydrocortisone–hydroxypropyl-β-cyclodextrin inclusion complex

In the present study, an inclusion complex composed of hydrocortisone acetate (HC) and hydroxypropyl-β-cyclodextrin (HPβCD) was prepared by the spray-drying method. HC alone, HC inclusion complex or HC with HPβCD as a physical mixture were incorporated into chitosan microspheres by spray-drying. The inclusion complex and microspheres were characterized by X-ray powder diffractometry and differential scanning calorimetry (DSC). Microspheres were studied with respect to particle size distribution, drug content and in vitro drug release. The results indicate that the HCHPβCD inclusion complex is more water soluble than HC alone. The HC release rates from chitosan microspheres were influenced by the drug/polymer ratio in the manner that an increase in the release rate was observed when the drug loading was decreased. However, release data from all samples showed significant improvement of the dissolution rate for HC, with 25–40% of the drug being released in the first hour compared with about 5% for pure HC. The complexation method and microsphere preparation method (spray-drying) is simple with great potential for industrial production.     

尼群地平缓释微球的制备及其体内外相关性的研究

目的制备具有固体分散体结构的尼群地平缓释微球 ,并筛选具有良好体内外相关性的释放介质。方法采用球晶造粒法制备尼群地平缓释微球 ,考察微球的粒径、载药量、包封率及释放行为 ,并根据 6只试验犬体内药物动力学试验结果 ,将不同时间的吸收分数与不同释放介质的相应时间点的体外累积释放百分数作线性回归 ,筛选具有良好体内外相关性的释放介质。结果制备的微球的粒径随搅拌速度的增加而减少 ,包封率均在 96 80 %以上 ,药物从微球中的释放速度随处方中固体分散体载体量的增加而增加 ,随阻滞剂量的增加而减小。以 1 7 4mmol L十二烷基硫酸钠为释放介质时 ,体外累积释放百分数与体内吸收分数相关系数较好 (r =0 985 1 ) ,方程为Fa =1 64 5 8ft-2 7 64 2。结论该方法较适用于难溶性药物制备缓释微球。以 1 7 4mmol L十二烷基硫酸钠水溶液为释放介质可作为控制微球内在质量的标准     

Preparation and in vitro in vivo evaluation of aceclofenac loaded alginate microspheres: An investigation of effects of polymer using multiple comparison analysis

The aim of this present research work was to prepare and evaluate alginate microspheres of aceclofenac by ionic gelation method for targeting the drug release in intestinal region and decrease distinct tissue protection in the stomach. This method offers to prepare microspheres which are important in controlling the release rate and the absorption of aceclofenac from the intestinal region. Variation in polymer concentration was studied systemically for their influence on the encapsulation efficacy, particle size and in vitro drug release. The enteric nature of the microspheres showed very less amount of drug released in acidic medium. The mucoadhesion property was strongly dependent on the pH of the medium and the polymer concentration in the formulations. In vitro drug release study proposed a mixed drug release mechanism, partially involving the sphere matrix disintegration and drug diffusion of the microspheres. Holm-Sidak multiple comparison analysis suggested a significant difference in measured t50% values among all the microsphere formulations. In vivo studies revealed that the anti-inflammatory effect induced by the aceclofenac loaded alginate microspheres was significantly high and prolonged than that induced by the pure aceclofenac. So, this aceclofenac loaded alginate microspheres exhibited promising properties to improve the patient compliance by controlling and prolonging the systemic absorption of aceclofenac along with a distinct tissue protection in the stomach.     

α-细辛脑海藻酸钙微球的制备及体外释放药物考察

目的研究α-细辛脑海藻酸钙微球的制备工艺,测定微球中α-细辛脑的体外释放度。方法采用乳化-内部凝胶化法制备海藻酸钙微球,正交试验设计优化制备工艺,分光光度法测定α-细辛脑的含量。结果最优工艺微球球形圆整,载药量为1.17%,包封率为2.40%,微球的平均粒径为17.97μm,大部分微球粒径分布在7~30μm（93.67%）,体外释放符合双相动力学方程Q/100=0.8276-0.0506exp（-1909t）-0.777exp（-0.4405t）。结论以海藻酸钠为载体、乳化-内部凝胶化法制备了海藻酸钙微球,获得微球制备工艺。     

Effect of tabletting compaction pressure on alginate microspheres

Alginate and alginate-hydroxypropylmethylcellulose (HPMC) microspheres were prepared by the emulsification method. The compaction of microspheres for producing tablet dosage forms raises concerns about possible damage to microsphere walls with subsequent unpredictable dissolution rates. The effect of different compaction pressures on the integrity of the microspheres was investigated. The addition of a diluent, microcrystalline cellulose (MCC), was required to make compacts containing alginate and alginate-HPMC microspheres. Compacts containing alginate-HPMC (7:3) microspheres had the highest crushing strength followed by compacts containing alginate-HPMC (9:1) microspheres and alginate microspheres. However, compact crushing strength did not vary significantly with increased compaction pressures over the range of compaction pressures investigated. Differences in the drug release profiles of the original non-compacted and compacted alginate and alginate HPMC microspheres were slight and not marked. Although dentation and distortion of the microspheres were observed with increasing compaction pressures, the microspheres generally remained intact, with minimal rupture/fracture.     

Preparation and evaluation of fast-release mephenamic acid microspheres

Mephenamic acid is characterized by low solubility, which affects its dissolution rate and bioavailability. The objective of this study was to develop fast-release microspheres of ammonium salt of the drug (AMM) by emulsion congealing.The effect of polymer, drug to polymer ratio, surfactant, type and volume of oil phase, stirring rate, microsphere size, encapsulation efficiency and stability of the microspheres were investigated. The results pointed out a good yield (69–98%) and encapsulation efficiency (71–100%). Optimum conditions include moderate molecular weight PEG, inclusion of Tween 20 and/or Span 80, high ratio of PEG (1 : 4, drug : PEG), use of mineral oil and high stirring rate (2000 rpm). Dissolution efficiency ranged between 57% and 90%. Effect of ageing on drug content and release revealed that the microspheres prepared remained stable throughout 1 year of storage. The described method was simple, efficient and resulted in stable microspheres with enhanced drug release.     

Evaluation of furosemide-loaded alginate microspheres prepared by ionotropic external gelation technique

Alginate microspheres containing furosemide were prepared by the ionotropic external gelation technique using Ca2+, Al3+ and Ba2+ ions. The incorporation efficiency of the prepared microspheres ranged between 65% and 93%. The effect of sodium alginate concentration, cross-linking ions and drying conditions was evaluated with respect to entrapment efficiency, particle size, surface characteristics and in vitro release behavior. Infrared spectroscopic study confirmed the drug-polymer compatibility. Differential scanning calorimetric analysis revealed that the drug was molecularly dispersed in the alginate microsphere matrices. Scanning electron microscopic study of microspheres showed the rough surface due to higher concentration of drug molecules dispersed at molecular level in the alginate matrices. The mean particle size and entrapment efficiency were found to be varied by changing various formulation parameters. The in vitro release profile could be altered significantly by changing various formulation parameters to give a sustained release of drug from the microspheres. The kinetic modeling of the release data indicate that furosemide release from the alginate microspheres follow anomalous transport mechanism after an initial lag period when the drug release mechanism was found to be Fickian diffusion controlled.     

Effect of tabletting compaction pressure on alginate microspheres

Alginate and alginate-hydroxypropylmethylcellulose (HPMC) microspheres were prepared by the emulsification method. The compaction of microspheres for producing tablet dosage forms raises concerns about possible damage to microsphere walls with subsequent unpredictable dissolution rates. The effect of different compaction pressures on the integrity of the microspheres was investigated. The addition of a diluent, microcrystalline cellulose (MCC), was required to make compacts containing alginate and alginate-HPMC microspheres. Compacts containing alginate-HPMC (7:3) microspheres had the highest crushing strength followed by compacts containing alginate-HPMC (9:1) microspheres and alginate microspheres. However, compact crushing strength did not vary significantly with increased compaction pressures over the range of compaction pressures investigated. Differences in the drug release profiles of the original non-compacted and compacted alginate and alginate-HPMC microspheres were slight and not marked. Although dentation and distortion of the microspheres were observed with increasing compaction pressures, the microspheres generally remained intact, with minimal rupture/fracture.     

Sustained release properties of alginate microspheres and tabletted microspheres of diclofenac sodium

This study focused on the properties of diclofenac sodium (DNa) alginate (alg) microspheres and tabletted DNa alg microspheres using different polymers as additives. DNa alginate microspheres were prepared by the emulsification method and different polymers such as Eudragit (Eud) NE 30 D, Eudragit (Eud) RS 30 D and Aquacoat, which were incorporated into alg gel to control the release rate of drug. The release properties of DNa alg microspheres (1:1) were affected by the size, drug load of microspheres and also by the incorporated polymers, pH and ionic strength of dissolution medium. Tabletting of alg microspheres using carrageenan (carr), alg, pectin, NaCMC, tragacanth (trgh) and HPMC as additives in a (50:50) ratio produced tablets with good physical properties and also better controlled release of DNa. Dissolution studies were carried out in pH7.2 phosphate buffer and phosphate buffers whose pH values were gradually changed from pH 3 to 7.4. The rank order of DNa release from tablets was carr<alg<pectin<NaCMC<trgh<HPMC which relates to the viscosity and swelling properties of polymers. The drug release was very slow from trgh and HPMC based tablets, but addition of carr or alg in different ratios could adjust the release rate of drug.