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。     

In vitro and in vivo evaluation of targeting efficiency of Adriamycin hydrochloride magnetic microspheres

The objective of this study was to prepare magnetic microspheres as a targeting drug delivery system and to specifically evaluate its targeting efficiency. The magnetic microspheres were prepared by emulsion cross-linking techniques. Targeting efficiency was specifically investigated by experiments of biodistribution on rats and histological study. Adriamycin hydrochloride (ADR)-loaded magnetic microspheres were successfully prepared with the mean diameter of 3.853 μm (± 1.484 μm), and had its speciality of superparamagnetism. The results of the targeting efficiency study showed that application of the external magnetic field significantly increased the ADR concentration from 40.28 μg/ml to 100.70 μg/ml at 10?min, 36.99 μg/ml to 91.16 μg/ml at 60?min, and 13.71 μg/ml to 28.30 μg/ml at 180?min in liver as the targeting tissue. The relative uptake efficiencies in liver by injection treatment of ADR magnetic microspheres with external magnetic field were 3.87, 5.59, and 3.34 at 10?min, 60?min, and 180?min after administration, respectively. In conclusion, distinguished targeting efficiency was displayed, which indicated that the magnetic microspheres could be applied as a novel targeting drug delivery system.     

In vitro and in vivo evaluation of ranitidine hydrochloride ethyl cellulose floating microparticles

The real issue in the development of oral controlled release dosage forms is not just to prolong the delivery of drugs but also to prolong the presence of dosage forms in the stomach in order to improve the bioavailability of drugs with a ‘narrow absorption window’. In the present study, an anti-ulcer drug, ranitidine hydrochloride, is delivered through a gastroretentive ethyl cellulose-based microparticulate system capable of floating on simulated gastric fluid for?>?12 h. Preparation of microparticles is done by solvent evaporation technique with modification by using an ethanol co-solvent system. The formulated microspheres were free flowing with good packability and encapsulation efficiencies were up to 96%. Scanning electron microscopy confirmed porous, spherical particles in the size range 300–750 µm. Microspheres showed excellent buoyancy and a biphasic controlled release pattern with 12 h. In vivo bioavailability studies performed on rabbits and T_max, C_max, AUC were calculated and confirmed significant improvement in bioavailability. The data obtained thus suggests that a microparticulate floating delivery system can be successfully designed to give controlled drug delivery, improved oral bioavailability and many other desirable characteristics.     

长春西汀s-PLGA长效缓释微球的体内外评价

目的:本研究以星状聚乳酸羟基乙酸共聚物(star poly D,L-lactide-co-glycolide,s-PLGA)为载体制备长春西汀长效缓释微球,对其体内外性质进行评价。方法:采用开环聚合法制备s-PLGA,以此作为载体材料,采用乳化-溶剂挥发法制备长春西汀s-PLGA长效缓释微球(VIN-MS),并对其包封率、粒径和体内外性质进行了考察。结果:本研究制备的VIN-MS的平均粒径为(18±2)μm,包封率为62.20%,载药量为37.43%。扫描电镜观察结果表明,微球外观圆整、均匀,流动性好,分散性好。体外释放结果表明,VIN-MS具有明显的缓释特性,其突释率为6.96%。体内结果表明,VIN-MS制剂体内周期能维持15 d,与长春西汀普通注射剂相比,VIN-MS的曲线下面积(AUC)和平均滞留时间(MRT)分别是普通注射剂的40倍和38倍。结论:长春西汀s-PLGA长效缓释微球的成功制备将有利于脑血管病的治疗。     

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。     

Chitosan microspheres of aceclofenac: In vitro and in vivo evaluation

The objective of this investigation was to achieve controlled drug release of Aceclofenac (ACE) microspheres and to minimize local side-effects in the gastrointestinal tract (GIT). Sustained release chitosan microspheres containing ACE were prepared using double-emulsion solvent evaporation method (O/W/O). Chitosan microspheres were prepared by varying drug to polymer ratio (1:3, 1:4, 1:5 and 1:6). Microspheres were characterized for morphology, swelling behavior, mucoadhesive properties, FTIR and DSC study, drug loading efficiency, in vitro release, release kinetics, and in vivo study was performed on rat model. ACE-loaded microspheres were successfully prepared having production yield, 57–70% w/w. Drug encapsulation efficiency was ranging from 53–72% w/w, Scanning electron microscopy (SEM) revealed particle size of microspheres was between 39 and 55 μm. FTIR spectra and DSC thermograms demonstrated no interaction between drug and polymer. The in vitro release profiles of drug from chitosan microspheres showed sustained-release pattern of the drug in phosphate buffer, pH 6.8. In vitro release data showed correlation (r² > 0.98), good fit with Higuchi/Korsmeyer-Peppas models, and exhibited Fickian diffusion. ACE microspheres demonstrated controlled delivery of aceclofenac and apparently, no G.I.T. erosion was noticed.     

In vitro evaluation of chondroitin sulphate-chitosan microspheres as carrier for the delivery of proteins

A novel formulation based on chondroitin sulphate/chitosan microspheres (CS/CH) has been investigated for oral delivery of macromolecules using ovalbumin as the model protein (OVA). The microspheres were prepared by a new emulsion-complex coacervation method. Physico-chemical properties of the polymers constituting microparticulate matrix were investigated by IR, DSC, TGA and X-ray diffraction analyses. In vitro tests were performed to evaluate the drug delivery system degradation and the protein release under conditions simulating the intestinal fluids. The ability of colonic enzymes to degrade the microparticulate systems was simulated employing the chondroitinase ABC enzyme. Results showed that the different CS/CH compositions influenced both microparticles stability and the protein release rate. Only the microspheres composed by 1:1 chondroitin sulphate–chitosan ratio achieved an OVA release profile suitable to a possible colon targeting. These microspheres released ～30% of ovalbumin encapsulated in 24 h in the different aqueous media tested, while they released 100% of protein in the presence of chondroitinase. The preliminary results demonstrated that chondroitin sulphate-chitosan microspheres can be a suitable delivery system for protein drug envisaged to oral administration.     

Controlled release effervescent buccal discs of buspirone hydrochloride: in vitro and in vivo evaluation studies

Abstract

In the present study controlled release effervescent buccal discs of buspirone hydrochloride (BS) were designed using HPMC as rate controlling and bioadhesive polymer by direct compression method. Sodium bicarbonate and citric acid were used in varying amounts as effervescence forming agents. Carbon dioxide evolved due to reaction of sodium bicarbonate and citric acid was explored for its potential as buccal permeation enhancer. The designed buccal discs were evaluated for physical characteristics and in vitro drug release studies. Bioadhesive behavior of designed buccal discs was assessed using texture analyzer. In vivo animal studies were performed in rabbits to study bioavailability of BS in the designed buccal discs and to establish permeation enhancement ability of carbon dioxide. It was observed that effervescent buccal discs have faster drug release compared to non-effervescent buccal discs in vitro and effervescent buccal discs demonstrated significant increase in bioavailability of drug when compared to non-effervescent formulation. Hence, effervescent buccal discs can be used as an alternative to improve the drug permeation resulting in better bioavailability. However, the amount of acid and base used for generation of carbon dioxide should be selected with care as this may damage the integrity of bioadhesive dosage form.     

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。     

Preparation and in-vitro evaluation of sustained-release metoclopramide hydrochloride microspheres

Abstract

Sustained-release metoclopramide microspheres were successfully prepared using cellulose propionate polymer at 1:2 drug to polymer ratio employing solvent evaporation technique and using acetone as the polymer solvent. The prepared microspheres at three stirring speeds were characterized with regard to their drug content, particle size distribution, surface topography using SEM and their release profiles at two different pHs at 37°C. The surface of all samples was smooth with very few irregular elevations or depressions. The average particle size decreases as the rotational speed increases and was found to be 1320, 774 and 345 μm at 600, 900 and 1200rpm, respectively. The average % drug entrapped was found to be 90.5, 100.1 and 60.0% at 600, 900 and 1200 rpm, respectively. Small differences in the release rate were observed due to different rotation speeds with an apparent lower dissolution for batches produced at 1200 rpm probably due to the properties of the coat. The effect of storage under accelerated conditions for 10 weeks on the release characteristics of these microspheres was also studied. The release properties of the microspheres did not change after storing them at 40°C/80% relative humidity for 10 weeks.     

盐酸噻吩诺啡缓释微球的体外释放度及其体内外相关性研究

目的 建立体内外相关性良好的盐酸噻吩诺啡缓释微球的体外释放度测定方法.方法 采用直接释药法和透析释药法测定盐酸嚷吩诺啡缓释微球的体外释放度;采用高效液相色谱法测定盐酸噻吩诺啡缓释微球在大鼠注射部位的残留量,计算微球在体内的释药速度.通过相关性评价确定最佳的体外释放度测定方法.结果 透析释药法和直接释药法均可获得良好的体内外相关性.结论 直接释药法和透析释药法均可用于测定盐酸噻吩诺啡微球的体外释放度.     

漂浮药物传递系统的新进展——中空微球

目的介绍漂浮药物传递系统的新进展———中空微球,就胃排空的机理、中空微球的制备及体内外表征作一综述。方法查阅相关文献,进行整理和归纳。结果该剂型可以延长药物在胃内的滞留时间,改善药物吸收,从而提高生物利用度。结论中空微球作为漂浮药物传递系统的一种新剂型,具有广阔的发展前景     

西替利嗪联合雷尼替丁治疗慢性荨麻疹疗效观察

目的：观察盐酸西替利嗪与雷尼替丁联合治疗慢性荨麻疹的疗效。方法：68例患者随机分为两组,治疗组口服盐酸西替利嗪与雷尼替丁,对照组单服盐酸西替利嗪,均连续服药4周为1疗程后评估疗效,记录不良反应。结果：治疗组和对照组有效率分别为88．89％和68．75％,差异有显著性（χ^2=4.20,P〈0．05）。结论：盐酸西替利嗪联合雷尼替丁治疗慢性荨麻疹,疗效满意,安全可靠。     

Development and in-vitro evaluation of modified release tablets including ethylcellulose microspheres loaded with diltiazem hydrochloride

In this study, development of modified release tablet formulations containing diltiazem hydrochloride-loaded microspheres to be taken once rather than two or three times a day was attempted. For this purpose, ethylcellulose microspheres were prepared by emulsion-solvent evaporation technique. The influence of emulsifier type and drug/polymer ratio on production yield, encapsulation efficiency, particle size, surface morphology and in-vitro release characteristics of the microspheres was evaluated. Suitable microspheres were selected and tabletted using different tabletting agents, Ludipress®, Cellactose®80, Flow-Lac®100 and excipients Compritol®888 ATO, Kollidon®SR. Tablets were evaluated from the perspective of physical and in-vitro drug release characteristics. It was seen that type and ratio of the excipients played an important role in the tabletting of the microspheres. As a result, two tablet formulations containing 180?mg diltiazem hydrochloride and using either Compritol®888 ATO or Kollidon®SR were designed successfully and maintained drug release for 24?h with zero order and Higuchi kinetics, respectively.     

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。     

In vitro and in vivo evaluation of diclofenac sodium loaded albumin microspheres

The use of polymeric carriers in formulations of therapeutic drug delivery systems has gained widespread application, due to their advantage of being biodegradable and biocompatible. Among the microparticulate systems, microspheres have a special importance since it is possible to target drugs and provide controlled release. Diclofenac sodium (DS), is a potent drug in the NSAID group having non-steroidal, anti-inflammatory properties, and is widely used in the treatment of rheumatoid arthritis, osteoarthritis and ankylosing spondylitis. In this present study, it was aimed to prepare microsphere formulations of DS using a natural biodegradable polymer as a carrier for intraarticular administration to extend the duration period of the dosage form in the knee joint. Microsphere formulations of DS which were prepared were evaluated in vitro for particle size, yield value, encapsulation efficiency, surface morphology, and in vitro drug release. Two appropriate formulations were selected for in vivo trials. For the in vivo studies, Technetium-99m labelled polyclonal human immunogammaglobulin (99mTc-HIG) was used as the radiopharmaceutical to demonstrate arthritic lesions by gamma scintigraphy. After the induction of arthritis in knee joints of rabbits, the radio-labelled microspheres loaded with DS were injected directly into the articular cavity and at specific time points gamma scintigrams were obtained to find the residence time of the microspheres in knee joints in order to determine the most suitable formulation.     

In vitro and in vivo evaluation of ranitidine hydrochloride ethyl cellulose floating microparticles

The real issue in the development of oral controlled release dosage forms is not just to prolong the delivery of drugs but also to prolong the presence of dosage forms in the stomach in order to improve the bioavailability of drugs with a 'narrow absorption window'. In the present study, an anti-ulcer drug, ranitidine hydrochloride, is delivered through a gastroretentive ethyl cellulose-based microparticulate system capable of floating on simulated gastric fluid for > 12 h. Preparation of microparticles is done by solvent evaporation technique with modification by using an ethanol co-solvent system. The formulated microspheres were free flowing with good packability and encapsulation efficiencies were up to 96%. Scanning electron microscopy confirmed porous, spherical particles in the size range 300-750 microm. Microspheres showed excellent buoyancy and a biphasic controlled release pattern with 12h. In vivo bioavailability studies performed on rabbits and T(max), C(max), AUC were calculated and confirmed significant improvement in bioavailability. The data obtained thus suggests that a microparticulate floating delivery system can be successfully designed to give controlled drug delivery, improved oral bioavailability and many other desirable characteristics.     

In vitro and in vivo evaluation of diclofenac sodium loaded album in microspheres

The use of polymeric carriers in formulations of therapeutic drug delivery systems has gained widespread application, due to their advantage of being biodegradable and biocompatible. Among the microparticulate systems, microspheres have a special importance since it is possible to target drugs and provide controlled release. Diclofenac sodium (DS), is a potent drug in the NSAID group having non-steroidal, anti-inflammatory properties, and is widely used in the treatment of rheumatoid arthritis, osteoarthritis and ankylosing spondylitis. In this present study, it was aimed to prepare microsphere formulations of DS using a natural biodegradable polymer as a carrier for intraarticular administration to extend the duration period of the dosage form in the knee joint. Microsphere formulations of DS which were prepared were evaluated in vitro for particle size, yield value, encapsulation efficiency, surface morphology, and in vitro drug release. Two appropriate formulations were selected for in vivo trials. For the in vivo studies, Technetium-99m labelled polyclonal human immunogammaglobulin (99mTc-HIG) was used as the radiopharmaceutical to demonstrate arthritic lesions by gamma scintigraphy. After the induction of arthritis in knee joints of rabbits, the radio-labelled microspheres loaded with DS were injected directly into the articular cavity and at specific time points gamma scintigrams were obtained to find the residence time of the microspheres in knee joints in order to determine the most suitable formulation.     

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。     

盐酸维拉帕米脉冲胶囊的制备及其体外释药考察

目的:制备一种新型脉冲式胶囊给药系统,探索影响药物在一定的时滞后脉冲释放的因素。方法:以蘸胶工艺制备不溶性半透膜囊体,灌装药物粉末或药物与渗透促进剂混合物,以果胶直接压片制备胶塞,塞入囊体后,套上胃溶性囊帽和囊体后外包肠溶衣,进行体外释放试验。结果:该给药系统在人工胃液中不变形,药物不释放,在pH7.4人工肠液中药物的脉冲释放受肠溶包衣厚度、不溶性囊体中致孔剂含量和填充物渗透促进剂比例的影响。结论:胶囊系统设计原理简单,各组成部分可单独制备,药物释放可根据要求来设计调节,可应用于多种药物,有望开发成一种新型药物脉冲释放系统。