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51.
This work introduces results on a new drug delivery system (DDS) based on the use of chitosan/layered double hydroxide (LDH) biohybrid beads coated with pectin for controlled release in the treatment of colon diseases. Thus, the 5-aminosalicylic acid (5ASA), the most used non-steroid-anti-inflammatory drug (NSAID) in the treatment of ulcerative colitis and Crohn's disease, was chosen as model drug aiming to a controlled and selective delivery in the colon. The pure 5ASA drug and the hybrid material prepared by intercalation in a layered double hydroxide of Mg2Al using the co-precipitation method, were incorporated in a chitosan matrix in order to profit from its mucoadhesiveness. These compounds processed as beads were further treated with the polysaccharide pectin to create a protective coating that ensures the stability of both chitosan and layered double hydroxide at the acid pH of the gastric fluid. The resulting composite beads presenting the pectin coating are stable to water swelling and procure a controlled release of the drug along their passage through the simulated gastrointestinal tract in in vitro experiments, due to their resistance to pH changes. Based on these results, the pectin@chitosan/LDH-5ASA bionanocomposite beads could be proposed as promising candidates for the colon-targeted delivery of 5ASA, with the aim of acting only in the focus of the disease and minimizing side effects.  相似文献   
52.
Cross-linked pectin/high amylose mixtures were evaluated as a new excipient for matrix tablets formulations, since the mixing of polymers and cross-linking reaction represent rational tools to reach materials with modulated and specific properties that meet specific therapeutic needs. Objective: In this work the influence of polymer ratio and cross-linking process on the swelling and the mechanism driving the drug release from swellable matrix tablets prepared with this excipient was investigated. Methods: Cross-linked samples were characterized by their micromeritic properties (size and shape, density, angle of repose and flow rate) and liquid uptake ability. Matrix tablets were evaluated according their physical properties and the drug release rates and mechanisms were also investigated. Results: Cross-linked samples demonstrated size homogeneity and irregular shape, with liquid uptake ability insensible to pH. Cross-linking process of samples allowed the control of drug release rates and the drug release mechanism was influenced by both polymer ratio and cross-linking process. The drug release of samples with minor proportion of pectin was driven by an anomalous transport and the increase of the pectin proportion contributed to the erosion of the matrix. Conclusion: The cross-linked mixtures of high amylose and pectin showed a suitable excipient for slowing the drug release rates.  相似文献   
53.
目的 探讨胃炎宁颗粒联合胶体果胶铋胶囊治疗慢性萎缩性胃炎的临床疗效。方法 选取2017年4月—2018年4月在儋州市人民医院进行治疗110例慢性萎缩性胃炎患者作为研究对象,根据入院的顺序将患者分为观察组(55例)和对照组(55例)。对照组给予胶体果胶铋胶囊,2粒/次,4次/d;观察组在对照组的基础上口服胃炎宁颗粒,15 g/次,3次/d。两组均治疗4周。观察两组患者的临床疗效,同时比较两组治疗前后的症候积分、SF-36量表评分、血清炎性因子水平和血清学指标。结果 经治疗,对照组有效率为85.45%,显著低于观察组的98.18%,两组比较差异具有统计学意义(P<0.05)。治疗后,两组相关临床症候积分均显著降低(P<0.05),且以观察组最为明显(P<0.05)。治疗后,两组SF-36量表评分均显著提高(P<0.05),且以观察组最明显(P<0.05)。治疗后,两组在血清超敏C反应蛋白(hs-CRP)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)、可溶性白细胞介素-2受体(sIL-2R)水平均显著改善(P<0.05),且观察组更为明显(P<0.05)。治疗后,两组血清前列腺素E2(PGE2)、血管内皮生长因子(VEGF)、胃泌素(GAS)、胃泌素-17(G-17)、生长抑素(SS)水平均显著改善(P<0.05),且观察组更明显(P<0.05)。结论 胃炎宁颗粒联合胶体果胶铋胶囊治疗慢性萎缩性胃炎可有效改善患者临床症状,降低机体炎症反应和改善机体血清学指标水平,具有良好临床应用价值。  相似文献   
54.
Summary The structure and expression of the polygalacturonase-encoding pgaII genes of two recently recognized species, Aspergillus niger and Aspergillus tubigensis, was investigated. While the structure of the pgaII genes is very similar, showing 83% DNA sequence identity and 94% identity at the amino acid level, they have diverged significantly. The NH2-terminal sequence suggests that these PGs are made as pre pro-proteins and the secretory propeptide of the PGII precursors shows sequence homology with some other fungal pro-peptides. The expression of the pgaII genes is strongly regulated by the carbon source and the A. tubigensis gene is expressed and regulated in A. niger transformants. The low similarity of the fungal PGs with those of bacterial and plant origin is discussed in relation to the possible functional role of specific amino acids.The nucleotide sequence reported in this paper will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession numbers X58893 (A. niger) and X58894 (A. tubigensis)  相似文献   
55.
本文通过查阅近年来果胶抗肿瘤活性研究的相关文献,对近年来果胶改善肿瘤效果以及果胶和部分抗肿瘤药物之间的相互作用进行总结,并分析果胶与体内半乳糖凝集素-3 在抗肿瘤中的作用,对果胶抗肿瘤机制进行探讨。同时指出果胶抗肿瘤研究的发展趋势,为果胶的抗肿瘤研究提供参考依据。  相似文献   
56.
目的:对胶体果胶铋泡腾片的生产工艺进行改进。方法:优化处方,减缓发泡速度,改进生产工艺,改善产品外观和稳定性。结果:中试产品的质量指标达到设计标准。结论:工艺改进后的胶体果胶铋泡腾片外观光洁,质量稳定,刺激性少。  相似文献   
57.
The preparation of dipyridamole (DIP) alginate (alg) microspheres by different methods or the incorporation of tragacanth (trgh), pectin or Eudragit L-100 55 (Eud) in alg microsphere formulations did not provide a prolonged release of DIP at pH 1.2. Tabletted microsphere formulations containing alg, trgh, pectin, sodium carboxymethyl cellulose (CMC), sodium starch glycolate (SSG), carrageenan (carrg) or Eud as diluents in different ratios, produced tablets with good physical properties which did prolong DIP release. The type, viscosity and the ratio of the diluent polymer, microsphere size and the compression pressure were found to be important factors to produce tablets with desired properties. No advantage of the tablets containing alg microspheres and granulated diluents was observed over the tablets containing powdered diluents.  相似文献   
58.
Catabolic conditions like acquired immunodeficiency syndrome, cancer, and burn can cause immunosuppression. Amino acids such as alanine and glutamine are essential for the activity of the immune system. Propolis is immunostimulant and the waste of propolis extraction has been reused with technological and therapeutic purposes. Therefore, this study describes the association of propolis byproduct extract (BPE) with pectin to prepare spray-dried microparticles containing the dipeptide l-alanyl-l-glutamine as stimulant systems of neutrophils. The use of a factorial design allowed selecting the best formulation, which was characterized by morphology, size, and entrapment efficiency analyses. In addition, the systems were characterized by thermal and X-ray diffraction analysis, Fourier-transform infrared spectroscopy, in vitro drug release, and in vitro cytotoxicity and stimulation test of neutrophils. Small well-structured microparticles with good entrapment efficiency values were achieved. Thermal stability of formulation was observed, and it was proved that pectin, BPE and l-alanyl-l-glutamine were dispersed throughout the matrix. The drug was released from the microparticles during 24?h governed by swelling and diffusion. The drug-loaded formulations showed a significant stimulating effect on neutrophils. These structures could increase the activity of immune cells, and other in vitro and in vivo studies should be performed in the future.  相似文献   
59.
The objective of this study was to identify the important factors for the drug permeability and mucoadhesion of casted free pectin/chitosan combination films. The factors varied were: the type of pectin (low and high methoxyl pectin) and the ratio pectin:chitosan (25:75, 50:50 and 75:25). The model drug used for measuring drug permeability was paracetamol. A texture analyzer was used for measuring mucoadhesion by using two different setups: (1) in vitro tensile tests measuring the detachment force of films versus a mucin dispersion and (2) ex vivo shear tests measuring the friction forces between pre-hydrated films and fresh porcine small intestine, with the system immersed in phosphate buffer, pH 6.8.The type of pectin used in the combination films did not have a significant effect on the drug permeability. The ex vivo mucoadhesion test revealed significant differences between low and high methoxyl pectin only for the 50:50 pectin:chitosan films. For that type of film, the peak and friction forces were highest for high methoxyl pectin. Both the mucoadhesion and drug permeability generally increased with decreasing amounts of pectin relative to chitosan in the films.  相似文献   
60.
INTRODUCTION Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis (UC), are characterized by chronic and spontaneously relapsing inflammation resulting in tissue destruction[1]. At present, there is no radical treatment for …  相似文献   
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