盐酸倍他洛尔/蒙脱石微球滴眼剂的制备及初步刺激性考察

目的制备新型盐酸倍他洛尔/蒙脱石微球滴眼剂并研究其初步刺激性。方法以蒙脱石为离子交换载体材料,用2种处方以O_1/O_2溶剂挥发法制备盐酸倍他洛尔缓释微球;对比微球的载药量和包封率等物化性能以得到最优处方,并将最优处方制备的微球制成滴眼剂以研究其初步刺激性。结果最优处方为丙烯酸树脂300mg(RS∶RL=1∶3),柠檬酸三乙酯60mg,甘油30mg,乳化剂400mg(吐温-80∶司盘-80=1∶2),盐酸倍他洛尔30mg,蒙脱石50mg,内外相体积比为1∶6。最优处方制得的微球载药量和包封率分别为14.31%和94.35%,初步刺激性实验显示微球滴眼剂对眼部组织无明显刺激性。结论微球制备方法简便易行,重复性好;制备的微球滴眼剂无明显刺激性,具有广阔的应用前景。     

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。     

新型载药蒙脱石复合微球滴眼剂的刺激性及角膜前滞留时间的荧光示踪法考察

目的： 将阳离子型药物盐酸倍他洛尔（BH）,与具有离子交换性能的蒙脱石及聚丙烯酸树脂联合使用制备新型盐酸倍他洛尔／蒙脱石聚丙烯酸树脂微球（Mt-BH-MP）新型眼用微纳米混悬剂,考察其刺激性及眼前端滞留能力。方法： 采用油包油乳化-溶剂挥发法制备微球,以BH水溶液和市售贝特舒为对照,分别采用永生化人角膜上皮细胞（iHCECs）构筑角膜前滞留的细胞模型和荧光示踪法评价Mt-BH-MP在细胞模型及兔眼眼表的滞留能力;以MTT法、兔眼眨眼实验及角膜荧光损失来共同评价该新型给药系统的刺激性。结果： iHCECs细胞模型角膜前滞留实验结果表明,Mt-BH-MP的眼部滞留能力明显优于贝特舒组和BH水溶液组;Mt-BH-MP兔眼在体角膜前荧光可维持（46±1） min,亦明显长于BH水溶液和贝特舒滴眼液组（P<0.05）,上述二项实验结果一致。MTT实验结果显示,iHCECs与各制剂接触2 h后,细胞存活率大小顺序为：空白微球>Mt-BH-MP> BH水溶液>贝特舒;兔眼眨眼刺激性及荧光角膜损伤实验结果表明,Mt-BH-MP给药后并无明显异物感及角膜机械损伤。结论： 制备的新型微球眼部递药系统具有良好的眼部滞留能力且刺激性相对较小,具有良好的眼部递药应用前景。     

盐酸倍他洛尔蒙脱石微球的制备及其体外释放性能的研究

目的制备可满足缓释要求的镶嵌蒙脱石的离子交换缓释微球。方法采用S/O1/O2/O3复乳-溶剂挥发法制备微球,考察处方因素包括复乳相体积比例、药物质量浓度、膜材用量和乳化剂质量分数对微球制备的影响。以微球体外释放为考察指标,优化微球处方。结果研究所得到的微球最佳处方为大豆油∶药物=6∶1,药物∶膜材=1∶5,乳化剂质量分数为0.5%²%。除乳化剂外,其他因素对微球体外释放均有较大影响。所制备微球的体外释放可以达到10h,基本无突释现象。进行形态观察发现,微球较为圆整,粒径比较均匀。结论采用优化处方以复乳-溶剂挥发法所制备盐酸倍他洛尔蒙脱石微球体外具有缓释性能。     

镶嵌蒙脱石载体的离子交换微球给药系统的研制

目的以新型微纳米载体制备镶嵌蒙脱石的载药缓释微球离子交换给药系统。方法先考察蒙脱石对模型药盐酸倍他洛尔的静态吸附、动态吸附过程,后以丙烯酸树脂RS和RL,采用乳化-溶剂扩散法制备载药蒙脱石的缓释微球,对微球收率、载药量和包封率等理化性能进行考察。结果该法所制微球形态圆整,分布均匀,粒径在10～30μm之间。微球收率为101.9%,载药量为25.5%,包封率为45.84%。结论该微球制备工艺重复性较好,可用于制备镶嵌蒙脱石新型载体的离子交换给药系统。     

溶剂挥发法制备酒石酸卡巴拉汀微球及其性能测定

以丙烯酸树脂为载体,利用O／O溶剂挥发法制备酒石酸卡巴拉汀微球,水洗微球载药量为1．424％,包覆率为78．15％。从而得出结论：利用溶剂挥发法制备酒石酸卡巴拉汀微球工艺稳定可行,微球质量较高。     

PLA/CoFe_2O_4载药微球的制备、表征及释药性能

采用 乳化-溶剂挥发法制备了聚乳酸(polylactie acid,PLA)载硫酸庆大霉素复合微球.通过正交设计实验优选PLA载药微球的最佳实验条件.在此基础上利用微乳法制备的铁酸钴(CoFe2O4)制备了PLA/CoFe_2O_4载硫酸庆大霉素复合微球.通过透射电子显微镜(TEM)、X-射线衍射(XRD)、振动样品磁强计(VSM)对铁酸钴进行微观结构表征和性能分析.采用傅立叶变换红外光谱(FT-IR),扫描电子显微镜(SEM)、生物数码显微镜对聚乳酸载药微球和PLA/CoFe_2O_4载药微球进行了微观结构的表征和分析.结果 表明两种载药微球呈规则球形,表面光滑,分布较均匀,平均粒径约为20μm.通过体外模拟释药试验考查了PLA载药微球和PLA/CoFe_2O_4载药微球的释药性能.结果 表明聚乳酸作为药物载体具有明显的药缓控释作用,PLA/CoFe_2O_4载药微球药物释放持续的时间最长.     

乳化溶剂挥发法在微球制备中的应用

微球(microspheres)是药物溶解或分散于高分子材料中形成的微小球状实体,一般制备成混悬剂供注射或口服用。用于制备缓控释微球的可生物降解高分子材料中,以聚乳酸(polylactic acid,PLA)及其共聚物为代表的羟基酸聚合物应用最广。制备药物缓释微球的方法很多,包括乳化溶剂挥发法、相分离法、乳化溶剂萃取法、喷雾干燥法、熔融法等,其中乳化溶剂挥发法最为常用。笔者对乳化溶剂挥发法制备微球的方法及制备过程中影响微球质量的因素进行综述。1乳化溶剂挥发法主要包括O/W乳化法、O1/O2乳化法、复乳-液中干燥法。O/W乳化法适合脂溶性药物微…     

两种方法制备肺靶向地塞米松磷酸钠微球的比较

目的:研究两种制备方法所制备的肺靶向地塞米松磷酸钠微球的特性,确定两种方法是否适合用于制备该微球。方法:对油／水型乳化-溶剂挥发法的工艺进行优化,以优化后的油／水型乳化-溶剂挥发法和水／油／水型乳化-溶剂挥发法制备微球,考察微球的大小、载药量、体外释药等性质。结果:两法所制的微球的平均粒径相近,载药量和体外释药特性各不相同。结论:两种方法都适合用于制备肺靶向的地塞米松微球。从载药量方面分析,优化后的油／水型乳化-溶剂挥发法较好。     

替莫唑胺乳酸-羟基乙酸共聚物微球的制备及表征

采用乳化-溶剂挥发法制备替莫唑胺微球,考察了制备工艺中影响微球粒径、载药量和包封率的主要因素,筛选处方工艺.按优化工艺制得的微球形态圆整,表面光滑,平均粒径62.2μm,载药量7.5%,包封率83.5%,体外试验表明该载药微球有明显的缓释效果.     

盐酸多西环素微球的制备及质量控制

目的:制备盐酸多西环素(DXY)微球并建立其质量控制方法。方法:以乳酸-羟基乙酸共聚物(PLGA)为载体材料,采用O/O型乳化溶剂挥发法制备微球,用光学显微镜观察微球的外观形态和粒径,采用紫外分光光度法测定微球的载药量和体外释放度等。结果:所制微球外观光滑圆整,平均粒径为(49±6.9)μm,跨距为0.9,平均载药量为(3.3±0.2)%,平均包封率为(52.4±3.2)%(n=3),0.5h的累积释放度为28%,并可持续释药30d以上。结论:DXY微球的制备工艺可行,质量可控。     

处方和工艺参数对盐酸昂丹司琼微球体外释放度的影响

目的：考察处方工艺参数对微球体外释放度的影响.方法：采用O/O型乳化溶剂挥发法,以乳酸-羟基乙酸共聚物为载体,制备盐酸昂丹司琼（Ondansetron hydrochloride,OND）微球.采用紫外分光光度法测定微球的体外释放度.结果：选择对OND具有较好溶解能力的混合溶剂为内油相溶剂,可以降低突释;增加理论载药量,延缓正己烷加入的时间和减小粒径可以增加OND微球的释药速度.结论：通过对处方和工艺的调节可使OND微球的体外释药曲线符合Higuchi方程,2周的累积释放量在80%左右.     

Surface morphology control of polylactide microspheres enclosing irinotecan hydrochloride

In order to reduce the initial burst from polylactide (PLA) microspheres enclosing an antitumor agent, we prepared the microspheres with a smooth surface by varying solvent evaporation conditions such as operating temperature and pressure. PLA microspheres enclosing irinotecan hydrochloride (CPT) were prepared using the O/O emulsion system for solvent evaporation. The mean diameter and enclosing efficiency were almost constant because they were independent of solvent evaporation conditions. Scanning electron microscopic (SEM) observation verified the smooth surface of the PLA microspheres produced by varying the preparation conditions. In vitro release experiments show that the initial burst of microspheres with a smooth surface was less than that of those with a rough surface.     

Particle size and loading efficiency of poly(D,L-lactic-coglycolic acid) multiphase microspheres containing water soluble substances prepared by the hydrous and anhydrous solvent evaporation methods

PLGA multiphase microspheres were prepared by the multiple emulsion solvent evaporation method using acetonitrile as the polymer solvent and mineral oil as the evaporation medium. The preparation process was further developed in the present study to reduce the particle size and to increase the loading capacity of brilliant blue, bovine serum albumin (BSA) and tumour necrosis factor-alpha (TNF-alpha) which were used as water soluble model drug substances. Sorbitan sesqui-oleate (SO-15EX), present at the 1% w/w level in the evaporation medium, prevented agglomeration of the microspheres containing a solid-in-oil (S/O) suspension as the core phase. This S/O suspension core provided significantly higher loading efficiency of the proteins to the W/O emulsion core. The W/O emulsion system resulted in agglomeration of the protein-loaded microspheres and the loading efficiency decreased significantly. When brilliant blue was included as the model compound, the loading efficiencies were not influenced by the core type. Heavy mineral oil was employed to stabilize the dispersed unhardened microspheres rather than light mineral oil that was reported previously. This anhydrous emulsion system employing the S/O suspension core and containing a dispersion of TNF-alpha enabled the encapsulation of this protein without loss of activity. It was concluded that the anhydrous emulsion system is asuitable approach toprepare multiple microspheres as an alternative to the W/O emulsion system, especially when solvent sensitive proteins are incorporated into the microspheres.     

Preparation of multi-phase microspheres of poly(D,L-lactic acid) and poly(D,L-lactic-co-glycolic acid) containing a W/O emulsion by a multiple emulsion solvent evaporation technique.

Multi-phase microspheres of poly(D,L-lactic acid) (PLA) or poly(D,L-lactic-co-glycolic acid) (PLGA) containing a water-in-oil (W/O) emulsion were prepared by a multiple emulsion solvent evaporation technique. Acetonitrile was used as the solvent for the polymers and light mineral oil as the dispersion medium for the encapsulation procedure. Process and formulation parameters to optimize the microencapsulation of a W/O emulsion containing water-soluble drugs were investigated. Drug loading efficiencies of 80-100 per cent were obtained under specific preparative conditions. The drug loading efficiency in the microspheres was dependent upon the ratio of the W/O emulsion to polymer and the concentration of surfactant in the mineral oil. Compared to conventional microspheres, in which fine drug particles are homogeneously dispersed in the polymer beads, the multi-phase microspheres permit the higher encapsulation efficiency of water-soluble drugs and eliminate partitioning into the polymer-acetonitrile phase which results in low encapsulation efficiency with conventional solvent evaporation techniques.     

Effects of the rate of solvent evaporation on the characteristics of drug loaded PLLA and PDLLA microspheres

We investigated the effects of the rate of solvent removal by varying ambient pressure at a fixed temperature on the morphology, particle sizes, drug encapsulation efficiency and releases pattern of lidocaine loaded poly-L-lactatide (PLLA) and poly-D,L-lactatide (PDLLA) microspheres, prepared with O/W emulsion-solvent evaporation process. Prepared in the fast rate of solvent evaporation (FRSE) process by reducing ambient pressure, smoothly morphological surface of drug loaded PLLA and PDLLA microspheres was observed. While in the normal rate of solvent evaporation (NRSE) process, roughness or pinhole surface was only found at drug loaded PLLA microspheres. Fabricated in the FRSE process, both PLLA and PDLLA microspheres showed smaller particle sizes and lower drug encapsulation efficiencies than those prepared in NRSE process. In regard to two materials, PLLA microspheres had higher drug encapsulation efficiencies than PDLLA ones for both processes. Although initial burst releases of drug were observed for both PLLA and PDLLA microspheres prepared in whatever solvent removal process, drug release for PLLA microspheres was slightly less than that for PDLLA ones in the earlier stage of drug release. However, in the subsequent stage of drug release, there was no difference between two materials. In corporation with different crystalline characteristics of PLA polymer and its derivatives, FRSE process by reducing ambient pressure could be further applied to produce different characteristics of microspheres for drug delivery.