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1.
Drug release from fatty suppository bases containing a solid dispersion of diazepam with amylodextrin or a complex of prednisolone with amylodextrin was analyzed in a flow-through model. Being present as a suspension in the fatty base, particles of complex or solid dispersion are transported to the lipid–water interface by sedimentation. After entering the aqueous phase they partially dissolve. The suppositories showed increased drug release compared with the corresponding suppositories containing drug only. Because of the partial solubility of amylodextrin, drug release was lower than the release from drug–cyclodextrin complexes. Use of the soluble fraction of amylodextrin for both the solid dispersion and the complex further enhanced drug release, but it was still below that of drug–cyclodextrin complexes.  相似文献   

2.
The ability of amylodextrin (a linear dextrin) to act as a complexing agent or as a carrier for solid dispersion was evaluated. Blends of amylodextrin with diazepam or prednisolone were freeze-dried and kneaded at elevated temperatures, respectively. The products were analyzed by DSC, X-ray diffractometry, and FTIR spectroscopy. Complex formation with amylodextrin by freeze-drying was found not to occur for diazepam but for prednisolone at a molar ratio of 1 to 1. The freeze-dried product of diazepam with amylodextrin proved to be a solid dispersion. Solid dispersions were formed by both wet (with ethanol) and dry kneading at elevated temperatures of low-melting drugs such as lidocain, diazepam, and methyl-PABA with amylodextrin. No solid dispersions were obtained for high-melting drugs such as prednisolone and salicylic acid. The results point to the formation of solid dispersions by a melting mechanism during the process of kneading at elevated temperatures of low-melting drugs with amylodextrin.  相似文献   

3.
5-氨基水杨酸结肠定位给药酶控释小丸的制备与体外释放   总被引:3,自引:0,他引:3  
目的:用水分散体包衣技术制备5-氨基水杨酸(5-ASA)结肠定位释放小丸给药系统。方法:乙基纤维素水分散体(Surlease)和直链淀粉(Amylosf)为控释包衣材料,邻苯二甲酸二乙酯为增塑剂,使用流化床包衣设备,制备酶控释的结肠定位释放小丸,研究小丸在模拟人体胃肠道环境中的释放度,并观察游离包衣膜的消化性。结果:此种小丸在模拟胃肠道上部的介质中不释药,在模拟结肠介质条件下3h释药80%以上,10h内释药完全,具有脉冲释药特征。药物的释放时滞由衣膜厚度和衣膜处方组成控制。增加衣膜厚度以及处方中SurleaseE的用量,可延长释药时滞。膜的消化性试验表明,释放机制是衣膜中Amylose被结肠菌酶特异性降解而使衣膜破裂释药。结论:包衣液中加入被结肠酶特异性降解的Amylose可以使小丸具有结肠定位释放的特性。  相似文献   

4.
PURPOSE: Amylodextrin, a starch-based controlled release excipient, spontaneously absorbs moisture during storage. The aim of this study was to investigate plasticisation of amylodextrin by moisture and its effect on compaction and tablet characteristics. METHODS: The glass transition temperature (T(g)) of amylodextrin powders with moisture fractions (x(w)) 0.070相似文献   

5.
直链淀粉与水杨酸包合物的制备及影响因素考察   总被引:1,自引:0,他引:1  
目的以直链淀粉为包合载体,水杨酸为模型药物,采用密封控温技术制备包合物,确定最佳制备工艺参数。方法将直链淀粉、水杨酸密封于容器内,通过控制加热温度、时间等因素使其形成包合物。通过红外扫描、粉末X-射线衍射等方法验证包合物的形成。结果红外扫描和粉末X-射线衍射验证了直链淀粉与水杨酸包合物的形成。水杨酸以分子状态存在于直链淀粉中。直链淀粉与水杨酸的配比,加热温度、时间会对包合率产生影响。对直链淀粉与水杨酸系统,采用密封控温技术制备包合物的最佳条件为:直链淀粉与水杨酸的质量比为1∶2,密封控温80℃,加热60 m in。结论直链淀粉可作为载体制备药物包合物,采用密封控温技术制备直链淀粉与药物包合物,方法简便,迅速有效。  相似文献   

6.
This study demonstrates the preparation and characterization of ibuprofen (IBP) microparticles with some excipients by a controlled crystallization technique with improved dissolution performance. Using the optimum concentrations pluronic F127, hydroxypropyl methyl cellulose, D-mannitol, and l-leucine in aqueous ethanol, the IBP microparticles were prepared. The dissolution tests were performed in phosphate buffer saline using a United States Pharmacopoeia dissolution tester at 37°C. The Raman spectroscopy was used to investigate the interactions and distribution of the IBP with the additives in the microcrystals. The prepared IBP microparticles showed higher dissolution compared to that of the smaller sized original IBP particles. The Raman data revealed that the excipients with a large number of hydroxyl groups distributed around the IBP particle in the crystal enhanced the dissolution of the drug by increasing the drug-solvent interaction presumably through hydrogen bonding. The Raman mapping technique gave an insight into the enhanced dissolution behavior of the prepared IBP microparticles, and such information will be useful for developing pharmaceutical formulations of hydrophobic drugs. The controlled crystallization was a useful technique to prepare complex crystals of IBP microparticles along with other additives to achieve the enhanced dissolution profile.  相似文献   

7.
BACKGROUND AND THE PURPOSE OF THE STUDY: During the last two decades one of the most important problems in drug formulations has been low aqueous solubility of new molecules. However, numerous techniques, such as milling, co-solvent solubilization and solid dispersion have been used conventionally for aqueous solubility enhancement and the rate of solubility. Recently, nanoparticle engineering processes have been developed and reported for pharmaceutical applications to increase the dissolution rate of low-soluble drugs which in turn may leads to substantial increases in bioavailability. In this study, a controlled precipitation method was used to produce indomethacin nano-solid suspension in a polymeric matrix (as a model), in order to increase the solubility and rate of the dissolution of poorly soluble model drug. METHODS: Nano-solid suspension of indomethacin in polyvinyl pyrrolidine (PVP) was prepared by controlled precipitation technique, characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and evaluated for in vitro solubility and dissolution rate. RESULTS AND MAJOR CONCLUSION: Absence of thermal and diffractional peaks in DSC and XRD studies indicated that indomethacin interacts with PVP in solid phase. The solubility of indomethacin in nano-solid suspension compared to crystalline form was increased to about four-fold. It was found that particle size distribution depend to the polymer MW and drug: polymer ratios. Spectroscopy methods and Transmission Electron Microscopy (TEM) images showed that indomethacin dispersed as amorphous nanosize particles in freeze dried powder. Enhanced solubility and dissolution rate of indomethacin compared to physical mixtures and crystalline form of indomethacin (polymorph I), demonstrated that it interacts with PVP via hydrogen bond and probably forming eutectic mixture.  相似文献   

8.
目的制备水飞蓟素固体分散体,加快药物的溶出,并进行特征考察。方法以聚乙二醇6000(PEG6000)为材料,采用熔融法将难溶性药物水飞蓟素制成固体分散体,通过体外释药试验考察固体分散技术对水飞蓟素的增溶作用,并以X-射线粉末衍射、傅立叶变换红外光谱(FT-IR)考察水飞蓟素固体分散体的特性。结果与原药比较,固体分散体中药物的释放速率明显增大,PEG6000固体分散体系能显著加快水飞蓟素的溶出。X-射线粉末衍射分析表明,PEG6000及药物在固体分散体中的晶格点阵面间距离、衍射峰位移及其相对强度等均发生了规律性变化,FT-IR分析表明PEG6000与药物间无相互作用。结论PEG6000固体分散体系的对难溶性药物溶出和扩散的加快,与载体材料和药物的晶格参数的改变密切相关。  相似文献   

9.
目的将难溶性微管蛋白抑制剂SUD-35制备成固体分散体,以增加其溶解度及溶出速率。方法以聚乙二醇6000为载体,溶剂-熔融法制备SUD-35固体分散体。采用差示扫描量热分析与X-射线衍射观察药物在载体中的存在状态,并进行溶解度和体外溶出度研究。采用MTT法对SUD-35固体分散体对小鼠白血病L1210细胞药效进行测定。结果 SUD-35固体分散体中SUD-35的溶解度和溶出速率相对原料药和物理混合物均有明显提高,差示扫描量热分析与X-射线衍射结果显示SUD-35以无定型状态存在于固体分散体中,细胞药效结果显示SUD-35固体分散体对小鼠白血病L1210细胞增殖抑制率强于SUD-35纯药。结论聚乙二醇6000为载体制备SUD-35固体分散体,可显著提高SUD-35的溶解度及溶出速率。  相似文献   

10.
Ezetimibe (EZE), a water insoluble drug, depicts variable bioavailability. The objective of the present investigation was to improve dissolution characteristics of EZE, which might offer improved bioavailability. The solid dispersions were prepared using poloxamer 407 (L 127) and polyvinyl pyrrolidone by melt and solvent method, respectively. Phase solubility studies indicated linear relationship between drug solubility and carrier concentration. In vitro release studies revealed improvement in the dissolution characteristics of EZE in solid dispersions. Solid dispersion with L 127 gave better rate and extent of dissolution. The best fit model indicating the probable mechanism of drug release from solid dispersions was found to be Korsemeyer–Peppas. The results of characterization of solid dispersions by Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffraction revealed reduction in drug crystallinity which might be responsible for improved dissolution properties. The tablets of solid dispersion, containing L 127 prepared by direct compression, exhibited better drug release as compared to marketed formulation.  相似文献   

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