吲哚美辛结肠靶向胶囊的制备及体外释药评价

目的 开发一种结肠靶向胶囊,使吲哚美辛达到结肠部位实现靶向释放。方法 以蘸胶工艺制备不溶性半透膜囊体,灌装药物后以果胶片封住囊体,外套上普通胶囊壳后外包肠溶衣,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,采用PEG-2 000∶CA为60%的不溶性囊体,包衣增重90%,药物∶NaCl为1∶1制备的胶囊,药物在人工肠液中3 h释放<10%,在人工结肠液中10 h药物释放超过70%,基本释放完全,达到结肠定位释放要求。结论 吲哚美辛结肠靶向胶囊能实现在结肠定位释放药物。     

美洛昔康肠道2次脉冲释药组合片的研制

目的:制备美洛昔康肠道内两次脉冲释药系统,并考察其体外释放影响因素。方法:以美洛昔康为模型药物,以欧巴代OY-P-7171为肠溶包衣、以EudragitNE30 D为延时脉冲包衣材料制备2种包衣片,用释放度测定法考察影响药物释放的因素。结果:组合制剂在人工胃液中不释放药物、在人工肠液中可以实现2次脉冲释药。释药时滞分别约为2和4 h。结论:服用美洛昔康组合片治疗风湿性关节炎,将给药后药物单次快速释药方式变成2次脉冲释药,不仅可减少胃刺激,而且能满足关节炎的时辰药理学治疗要求。     

多糖凝胶骨架结肠定位给药缓释系统的体外释放研究

目的: 筛选多糖材料作为水凝胶骨架,以达到结肠定位释药目的.方法: 选用海藻酸钠、果胶、壳聚糖、瓜木耳胶与药物混和制粒,灌装肠溶或结肠溶胶囊,考察其在人工胃液,人工肠液及人工结肠液中的释放情况.结果: 难溶性药物的海藻酸钠骨架结肠溶胶囊在人工胃液和小肠液中均不释放,人工结肠液中3 h释药低于30%;果胶骨架肠溶胶囊在人工胃液亦不释药,人工肠液中5 h释药仅为15%.水溶性药物在人工肠液中5 h释放可达50%.结论: 难溶性药物的海藻酸钠/结肠溶胶囊和果胶/肠溶胶囊体外释放度结果符合结肠定位的要求,可以作为建立酶触发体外释放评价方法和体内评价的制剂形式.水溶性药物的果胶/肠溶胶囊是较理想的缓释剂型.     

渗透泵控释胶囊的制备与释药影响因素研究

目的 探讨渗透泵控释胶囊的制备方法并研究影响其药物释放的因素,为该渗透泵控释胶囊剂型的开发提供参考. 方法 以对乙酰氨基酚为模型药物,乙酸纤维素为囊膜材料,采用蘸胶工艺结合机械钻孔技术制备渗透泵胶囊壳. 通过选择不同的增塑剂、致孔剂、渗透促进剂等研究其释药行为的规律,并进行线性方程拟合;通过扫描电镜观察药物释放前后囊壳表面的结构. 结果 以乙酸纤维素量10%的聚乙二醇(PEG)-400作为增塑剂、30% PEG-2000为致孔剂制备的渗透泵胶囊和以药物：聚维酮 K30(PVP-K30)＝1：1.3,药物：PVP-K30：氯化钠＝2：1：2作为内容物填充时制备的渗透泵胶囊,药物24 h平均释放＞90%,释放曲线符合零级释药规律. 结论 渗透泵控释胶囊剂有望发展成为一种新型控释给药系统.     

灌注法制备脉冲给药装置的新型非渗透性胶囊体

目的制备一种用于脉冲给药装置的新型非渗透性胶囊体,优化制备工艺并考察处方对其渗透行为的影响,研究其药剂学性质。方法灌注法制备非渗透性胶囊体,通过HPLC法测定渗透介质中药物磷酸川芎嗪的浓度,考察影响药物通过胶囊体渗出量的影响因素。结果用11%的45 cps乙基纤维素(EC)溶液制备的胶囊体可在24 h内保持非渗透能力。随着制备胶囊体的EC粘度级别的增加和EC溶液浓度的增大,制得的EC胶囊体的非渗透能力逐渐增大。结论调整EC黏度级别和EC浓度,用灌注法可制备在一定时间内保持非渗透的合适胶囊体,为进一步制备用于时辰治疗的脉冲释药装置奠定基础。     

磷酸川芎嗪脉冲塞胶囊的制备与体外释放

目的制备一种由溶蚀塞控制时滞的新型脉冲给药系统并对其体外释药行为进行评价。方法用灌注法制备非渗透性胶囊体,用湿法制粒压片法制备含药片和溶蚀塞,将填充剂和含药片用溶蚀塞密封在非渗透性胶囊体中制备磷酸川芎嗪(TMPP)脉冲塞胶囊,用释放度测定法研究溶蚀塞的制剂学特征及溶出条件对释药时滞的影响。结果溶蚀塞的处方组成和重量能显著影响磷酸川芎嗪脉冲塞胶囊的释药时滞,释药时滞随溶蚀塞中凝胶形成赋形剂羟丙甲基纤维素(HPMC)含量和溶蚀塞重量的增加而增加,而溶蚀塞的硬度对时滞无显著影响。此外,释药时滞还随搅拌桨转速的增加而缩短。溶出介质的pH则对时滞无显著影响。结论通过调节溶蚀塞的处方组成和重量可获得具有适当时滞的脉冲给药系统,满足时辰治疗的要求。     

磷酸川芎嗪脉冲塞胶囊的制备与体外释放

目的　制备一种由溶蚀塞控制时滞的新型脉冲给药系统并对其体外释药行为进行评价。方法　用灌注法制备非渗透性胶囊体 ,用湿法制粒压片法制备含药片和溶蚀塞 ,将填充剂和含药片用溶蚀塞密封在非渗透性胶囊体中制备磷酸川芎嗪 (TMPP)脉冲塞胶囊 ,用释放度测定法研究溶蚀塞的制剂学特征及溶出条件对释药时滞的影响。结果　溶蚀塞的处方组成和重量能显著影响磷酸川芎嗪脉冲塞胶囊的释药时滞 ,释药时滞随溶蚀塞中凝胶形成赋形剂羟丙甲基纤维素 (HPMC)含量和溶蚀塞重量的增加而增加 ,而溶蚀塞的硬度对时滞无显著影响。此外 ,释药时滞还随搅拌桨转速的增加而缩短。溶出介质的pH则对时滞无显著影响。结论　通过调节溶蚀塞的处方组成和重量可获得具有适当时滞的脉冲给药系统 ,满足时辰治疗的要求     

聚乙二醇1000维生素E琥珀酸酯的药剂学应用进展

聚乙二醇1000维生素E琥珀酸酯(TPGS)作为一种特性生物材料,有着广阔的药剂学应用前景。在药剂辅料中,TPGS可作为增溶剂、吸收促进剂、乳化剂、渗透促进剂。在新型给药系统中,可用于制备固体分散体、胶束、前体药物,亦可作为P-糖蛋白抑制剂,发挥抗多药耐药作用。本文就TPGS在传统药剂学和新型给药系统中的最新应用进行综述,为其进一步应用研究提供参考。     

茶碱盖塞控制型脉冲胶囊的制备及影响因素考察

分别制备了不溶性囊身、茶碱速释片和溶蚀性盖塞片.在不溶性囊身中依次填入羧甲淀粉钠、速释片、盖塞片,再盖上水溶性囊帽组装成茶碱盖塞控制型脉冲胶囊.考察了盖塞片处方工艺对释药时滞的影响.结果显示,所得胶囊在体外呈明显的时滞脉冲释放,且释药时滞随盖塞片中乳糖用量的减小和片重增加而增加.     

兰索拉唑肠溶微丸胶囊的制备

目的:制备兰索拉唑肠溶微丸胶囊。方法:采用流化床包衣技术,在空白丸芯上依次包以主药层、隔离层和肠溶层,制备成兰索拉唑肠溶微丸,将肠溶微丸装入普通胶囊制成兰索拉唑肠溶微丸胶囊,并考察3批制剂的载药率及在人工肠液和人工胃液中的释放情况。结果:所制微丸圆整度高,外观亮泽,载药均匀、载药率高(平均值在96%以上),包衣效果好;其在人工肠液中45min的体外累积释放率大于(94.3±0.76)%,在人工胃液中2h的释放量小于(6.2±1.6)%。结论:所制兰索拉唑肠溶微丸胶囊工艺可行,重现性良好,质量稳定可靠,具有良好的体外释药性和耐酸力。     

Chronopharmaceutical drug delivery from a pulsatile capsule device based on programmable erosion

We report the development of a chronopharmaceutical capsule drug delivery system capable of releasing drug after pre-determined time delays. The drug formulation is sealed inside the insoluble capsule body by an erodible tablet (ET). The release time is determined by ET erosion rate and increases as the content of an insoluble excipient (dibasic calcium phosphate) and of gel-forming excipient (hydroxypropylmethylcellulose; HPMC) increases. The time-delayed release of a model drug (propranolol HCI) was investigated by dissolution testing (USP XXIII paddle method). Both composition and weight of ET influence the time of drug release. Moreover it was found that drug release was controlled by the quantity of HPMC, irrespective of lactose content within the tablet weight range 80-160 mg, when above a threshold concentration of 20% HPMC. Programmable pulsatile release has been achieved from a capsule device over a 2-12-h period, consistent with the demands of chronotherapeutic drug delivery. The time of drug release can be controlled by manipulation of tablet formulation.     

Development and evaluation of pulsatile drug delivery system using novel polymer

The aim of the present investigation was to develop a pulsatile drug delivery system based on an insoluble capsule body filled with theophylline microspheres and sealed with a swellable novel polymer plug isolated from the endosperm of seeds of higher plant Delonix regia family-Fabaceae. Theophylline microspheres were prepared by solvent evaporation method using Eudragit S 100. The swellable plugs of varying thickness and hardness were prepared by direct compression, which were then placed in the capsule opening. The drug delivery system was designed to deliver the drug at such a time when it was needed most to offer convenience to the chronic patients of asthma. Formulated dosage forms were evaluated for an in vitro drug release study, which showed that the release might be consistent with a release time expected to deliver the drug to the colon depending on the thickness and hardness of the hydrogel plug. Thus, thickness and hardness of the novel polymeric plug plays an important role in controlling the drug release from the formulated drug delivery system.     

Formulation and evaluation of sustained release floating capsules of nicardipine hydrochloride

Nicardipine hydrochloride, a calcium channel blocker with significant vasodilating and antihypertensive activities, was formulated in this work as sustained release floating capsules. A hydrocolloid of high viscosity grade was used for the floating systems. The inclusion of sodium bicarbonate to allow evolution of CO2 to aid buoyancy was studied. Polymers that retard drug release were included as coprecipitates with the drug and/or as additives in the formulated capsules. Both simple powder mixing of the ingredients and granule preparation via wet granulation were used. Seven capsule formulae were prepared. The prepared capsules were evaluated in vitro by testing drug dissolution, floating time and the kinetics of drug release. In vitro evaluation of a commercially available conventional 20 mg capsule of nicardipine hydrochloride, "Micard", was carried out for comparison. The hydrocolloid used succeeded in effecting capsule buoyancy. Floating time increased with increasing the proportion of the hydrocolloid. Inclusion of sodium bicarbonate increased buoyancy. All of the seven floating capsule formulae prepared proved efficient in controlling drug release. The sustained release floating capsule formulation of choice was evaluated in vivo in comparison to "Micard" capsules using rabbits. Reversed phase HPLC with UV detection was used for drug determination in rabbit plasma. Plasma concentration time curves revealed a longer drug duration for administration in the sustained release formula than the conventional "Micard" capsule being 16 h in the former versus 8 h for the latter.     

Evaluation of high molecular weight poly(oxyethylene) (Polyox) polymer: studies of flow properties and release rates of furosemide and captopril from controlled-release hard gelatin capsules

The powder characteristics and the effect of the molecular weight of polymers as diluents on the release rate of furosemide and captopril from hard gelatin capsules were evaluated. The high molecular weight polymers studied were poly(oxyethylene) homopolymers (Polyox), with molecular weight ranging from 4,000,000 to 7,000,000. Powder characteristics suggested good flowability for these materials and predicted capsule fill weight uniformity. Swelling experiments showed a very high degree of swelling for these materials in both gastric and buffer solution. These polymers can sustain the release rate of both water-soluble and insoluble drugs from drug delivery systems. The low molecular weight polymers have a less pronounced sustained-release effect compared to the high molecular weight polymer material (i.e., those with 7,000,000 molecular weight). An increase in the content of polymer results in a decrease in the release rate of the drug. The solubility of the drugs clearly influenced the release rate. Release kinetics were evaluated and appeared to be influenced by the molecular weight of the polymer, the solubility of drug, and the ratio of the drug to polymer in the capsule. Bimodal release kinetics were exhibited by a number of furosemide formulations (i.e., F5 and F8).     

The effect of wet granulation on the erosion behaviour of an HPMC-lactose tablet, used as a rate-controlling component in a pulsatile drug delivery capsule formulation.

The purpose of this study was to investigate the variability in the performance of a pulsatile capsule delivery system induced by wet granulation of an erodible HPMC tablet, used to seal the contents within an insoluble capsule body. Erodible tablets containing HPMC and lactose were prepared by direct compression (DC) and wet granulation (WG) techniques and used to seal the model drug propranolol inside an insoluble capsule body. Dissolution testing of capsules was performed. Physical characterisation of the tablets and powder blends used to form the tablets was undertaken using a range of experimental techniques. The wet granulations were also examined using the novel technique of microwave dielectric analysis (MDA). WG tablets eroded slower and produced longer lag-times than those prepared by DC, the greatest difference was observed with low concentrations of HPMC. No anomalous physical characteristics were detected with either the tablets or powder blends. MDA indicated water-dipole relaxation times of 2.9, 5.4 and 7.7x10(-8)ms for 15, 24 and 30% HPMC concentrations, respectively, confirming that less free water was available for chain disentanglement at high concentrations. In conclusion, at low HPMC concentrations water mobility is at its greatest during the granulation process, such formulations are therefore more sensitive to processing techniques. Microwave dielectric analysis can be used to predict the degree of polymer spreading in an aqueous system, by determination of the water-dipole relaxation time.     

Time and pH dependent colon specific, pulsatile delivery of theophylline for nocturnal asthma

In this study, investigation of an oral colon specific, pulsatile device to achieve time and/or site specific release of theophylline, based on chronopharmaceutical consideration. The basic design consists of an insoluble hard gelatin capsule body, filled with eudragit microcapsules of theophylline and sealed with a hydrogel plug. The entire device was enteric coated, so that the variability in gastric emptying time can be overcome and a colon-specific release can be achieved. The theophylline microcapsules were prepared in four batches, with Eudragit L-100 and S-100 (1:2) by varying drug to polymer ratio and evaluated for the particle size, drug content and in vitro release profile and from the obtained results; one better formulation was selected for further fabrication of pulsatile capsule. Different hydrogel polymers were used as plugs, to maintain a suitable lag period and it was found that the drug release was controlled by the proportion of polymers used. In vitro release studies of pulsatile device revealed that, increasing the hydrophilic polymer content resulted in delayed release of theophylline from microcapsules. The gamma scintigraphic study pointed out the capability of the system to release drug in lower parts of GIT after a programmed lag time for nocturnal asthma. Programmable pulsatile, colon-specific release has been achieved from a capsule device over a 2-24h period, consistent with the demands of chronotherapeutic drug delivery.     

盐酸维拉帕米不溶性微孔膜缓释胶囊的制备和体外释药试验

目的制备盐酸维拉帕米不溶性微孔膜胶囊剂并研究其体外释药行为。方法以乙酸纤维素（CA）为囊膜材料,聚乙二醇400为增塑剂,蘸胶法制备囊壳,并从致孔剂种类、比例、不同释放条件和内容物配方等因素考察盐酸维拉帕米的释药行为,通过扫描电镜对释药后囊壳结构进行观察。结果选用泊洛沙姆为致孔剂,增加其用量能使药物释放加快;囊内添加柠檬酸,能使药物释放更平稳。结论维拉帕米不溶性微孔膜缓释胶囊在体外能得到缓释效果,通过胶囊内微环境的控制,可以得到平稳的体外释药速度。     

Control of drug release from capsules using high frequency energy transmission systems

In the present investigations new drug delivery systems have been developed, which are controlled by a computer and a high frequency energy transmission system. The capsules consist of a drug reservoir, a high frequency receiver, a gas generating section and a piston to pump a drug solution or drug suspension out of the reservoir. Mechanical energy is generated inside the capsule through electrolysis, if a 27 MHz high frequency field is in resonance with the receiver inside the capsule. Two different miniaturised oscillatory circuits were constructed, which act as the receivers in the capsules. Tramadol was used in release experiments as a model drug. Delayed and pulsed release profiles were obtained. A computer-controlled system was constructed, in which the programmed release profiles are compared with the actual release of the drug.     

Pulsatile Drug Release from an Insoluble Capsule Body Controlled by an Erodible Plug

Purpose. The objective of this study was to develop and evaluate a pulsatile drug delivery system based on an impermeable capsule body filled with drug and an erodible plug placed in the opening of the capsule body. Methods. The erodible plugs were either prepared by direct compression followed by placing the tablets in the capsule opening or by congealing a meltable plug material directly within the capsule opening. The disintegration/erosion properties of these plugs were determined and optimized for the final delivery system. In order to assure rapid drug release of the capsule content after erosion of the plug, various excipients (fillers, effervescent agents) and drugs with different solubilities were evaluated. The lag time prior to drug release and the subsequent drug release were investigated as function of capsule content, plug composition, plug preparation technique, plug hardness, weight, and thickness. Results. The erosion time of the compressed plugs increased with increasing molecular weight of the hydrophilic polymer (e.g. hydroxypropyl methylcellulose, polyethylene oxide), decreasing filler (lactose) content and decreased with congealable lipidic plugs with increasing HLB-value and inclusion of surfactants. For complete and rapid release of the drug from the capsule body, effervescent agents had to be included in the capsule content. The drug delivery system showed typical pulsatile release profiles with a lag time followed by a rapid release phase. The lag time prior to the pulsatile drug release correlated well with the erosion properties of the plugs and, besides the composition of the plug, could be controlled by the thickness (weight) of the plug. Conclusions. A single-unit, capsular-shaped pulsatile drug delivery system was developed wherein the pulsatile release was controlled by the erosion properties of a compressed or congealed plug placed within the opening of the capsule opening.     

A novel system for three-pulse drug release based on "tablets in capsule" device

The objective of the present study was to obtain programmed drug delivery from a novel system, which contains a water-soluble cap, impermeable capsule body, and two multi-layered tablets. Types of materials for the modulating barrier and its weight can significantly affect the lag time (defined as the time when drug released 8% of the single pulse dosage). We chose sodium alginate and hydroxy-propyl methyl cellulose (HPMC E5) as the candidate modulating barrier material. Through adjusting ratio of sodium alginate and lactose, lag time was controllable between the first two pulsatile release. Linear relationship was observed between the ratio and the lag time. Through adjusting the ratio of HPMC E5/lactose, lag time between the second and the third pulse can be successfully modulated. In further studies, drug release rate of the second pulsatile dose can be improved by adding a separating layer between the third and the modulating barrier layer in the three-layered tablet. To evaluate contribution of bulking agent to drug release rate, lactose, sodium chloride, and effervescent blend were investigated. No superiority was found using sodium chloride and effervescent blend. However, lactose favored it. The results reveal that programmed drug delivery to achieve pulsatile drug release for three times daily can be obtained from these tablets in capsule system by systemic formulation approach.