Green microwave-assisted procedure to generate bio-based pectin materials

New eco-friendly materials have been developed via esterification of several natural fatty acids by pectin alcoholic functions. The quaternization of the obtained pectin-fatty acid conjugates was performed as subsequent synthetic step. By using microwave heating and solvent-free conditions, the conjugation procedure of fatty acid chains and quaternary ammonium groups to the natural polysaccharide was clean, fast and efficient. In other words, it can be considered a low environmental impact process.     

胶体果胶铋干混悬剂治疗幽门螺杆菌阳性消化性溃疡的疗效分析

背景:对于胶体果胶铋干混悬剂治疗幽门螺杆菌(Hp)阳性消化性溃疡的疗效是否优于胶体果胶铋胶囊,目前尚无相关的临床研究。目的:比较胶体果胶铋干混悬剂与胶体果胶铋胶囊对Hp阳性消化性溃疡的临床疗效。方法:选取2012年1月~2013年4月中南大学湘雅二医院门诊初治的126例Hp阳性的消化性溃疡患者,随机分为观察组和对照组,分别给予胶体果胶铋干混悬剂+标准三联方案以及胶体果胶铋胶囊+标准三联方案,评估比较临床症状缓解情况、内镜下溃疡愈合情况以及Hp根除率。结果:观察组患者胃溃疡(84.6%对55.6%)、十二指肠溃疡(84.8%对62.1%)2周末症状消失率均显著高于对照组(P0.05),但两组4周末症状消失率无明显差异(P0.05)。观察组的溃疡治疗总有效率(98.2%对84.0%)、总体Hp的PP根除率(89.5%对72.7%)和ITT根除率(81.0%对63.5%)均显著高于对照组(P0.05)。两组均未见严重不良反应。结论:胶体果胶铋干混悬剂治疗Hp阳性消化性溃疡的疗效优于胶体果胶铋胶囊。     

Gamma scintigraphic evaluation of film-coated tablets intended for colonic or biphasic release

The gastrointestinal transit and in vivo drug release behaviour of a film-coated tablet formulation was investigated in five healthy human subjects using the technique of gamma scintigraphy. The film coating system consisted of a mixture of pectin, chitosan and HPMC in a ratio of 6:1:0.37 applied to 750 mg cores at a coat weight gain of 9%. The estimated mean values of the gastric emptying time (62±17 min), small intestinal transit time (219±53 min), ileocaecal junction lag time (79±30 min) and the colon arrival time (345±33 min), were similar to published values for the transit of similar sized tablets in humans. The amount of radioactive tracer released from the labelled tablets was minimal when the tablets were in the stomach and the small intestine. There was increased release of radioactivity when the tablets were in the colon due to increased degradation of the film coatings by pectinolytic enzymes resident in the colon. The pectin/chitosan/HPMC film coating system thus acts as a colonic delivery system.     

An in vitro investigation for vaginal bioadhesive formulations: bioadhesive properties and swelling states of polymer mixtures

Bioadhesive tablet formulations have been developed for mucosal application. Sixteen different bioadhesive tablet formulations were prepared and evaluated. Their bioadhesion to vaginal mucosa were studied by tensile testing method. The swelling behaviour of the tablets in three different solutions was also investigated. In addition, the effect of the formulations on pH of the medium was followed. The most favorable formulation resulted a mixture of Carbopol 934 and Pectin (2:1). The highest bioadhesive strength, the highest swelling volume and the lowest pH reduction were obtained with this formulation.     

A New Pectin-Based Material for Selective LDL-Cholesterol Removal

Abstract: A new material, natural polysaccharide-pectin, was tested for removal of human blood lipoproteins. Pectin was prepared in a granular form with the help of the specifically designed gelification device and tested in batch sorption experiments in vitro for removal of total cholesterol (TC), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C) from human plasma. Pectin granules removed 40% of TC, 45% of LDL-C, and 36% of HDL-C on average with respect to the initial amounts whereas corresponding values for LA-40 Kanegafuchi adsorbent were 69%, 81%, and 33% in the same experimental conditions (shaking 1 g of sorbent sample with 2 ml of plasma).     

Effect of pectin,type of fat,and growing rate on lipid metabolism in rats

The effects of pectin, type of fat, and growing rate on lipid metabolism were investigated. Male Wistar rats weighing 122±1 g were fed ad libitum for 8 weeks a nutritionally adequate diet containing 0.5% cholesterol, 12% fat, either corn oil (CO) or beef tallow (BT), and 5% fiber, either cellulose (CE) or pectin (PE). At the end of the feeding period, the rats in each diet group were divided according to their body weight into two groups, slow-growing (range 360 g to 426 g, SG) or fast-growing (range 444 g to 479 g, FG). The difference between the means of the two groups was highly significant (P<0.01). Dietary pectin compared to cellulose lowered liver cholesterol and total liver lipid. However, there was a significant interaction between the type of dietary fiber and the type of dietary fat so that liver total lipid concentration was lower in the BT-fed than in the CO-fed rats. Liver triglyceride level (only measured in the FG group) was not influenced by fiber but was markedly higher in the CO-fed than the BT-fed rats. A significant triple interaction between type of dietary fiber, type of dietary fat, and growth rate was observed for serum cholesterol. Serum cholesterol was significantly lower in the PE-fed than the CE-fed animals except when BT was the dietary fat fed the SG rats and CO was the dietary fat fed the FG rats. The present results suggest that in determining lipid metabolism the interaction between extrinsic factors and intrinsic factors such as growing rate should be taken into consideration.     

Preactivated thiomers: Evaluation of gastroretentive minitablets

The object of this study was to evaluate the potential of a recently developed preactivated thiolated pectin derivative as mucoadhesive excipient in drug delivery to the gastric cavity. Pectin (Pec) was chemically modified with l-cysteine (Cys). The free thiol groups of resulting thiomer were activated with 2-mercaptonicotinic acid (MNA) in order to improve stability and reactivity of attached thiol groups over a broad pH range. Multiunit dosage form properties of the resulting conjugate (Pec–Cys–MNA) were compared to unmodified pectin and the intermediate thiolated using rosuvastatin calcium as a model drug in loaded minitablets. Obtained results were compared with unmodified pectin and the intermediate thiolated pectin. Approximately half of attached thiol groups (507 μmol/g polymer) have been preactivated. Minitablets were evaluated regarding mucoadhesive properties, hardness, disintegration behavior, swelling characteristics and release of rosuvastatin calcium. Mediated by covalent bonds between the polymer and cysteine-rich subdomains in mucus, total work of adhesion increased more than 5-fold. The modification had no impact on hardness of compressed tablets but implementation of the aromatic ligand went along with reduction in hydrophilic properties. Disintegration time was prolonged more than 2-fold while water uptake capacity increased. Weight gain for Pec–Cys–MNA was at least 16-fold. Further, a sustained release of rosuvastatin calcium over 36 h was determined. Neither biodegradability nor CaCo-2 cell viability was affected. The study shows that Pec–Cys–MNA is a promising excipient for the development of mucoadhesive gastric dosage form.     

Hydrogel blends with adjustable properties as patches for transdermal delivery

The effect of different preparation parameters were analyzed with respect to the rheological and pharmaceutical characteristics of hydrogel blend patches, as transdermal delivery formulation. Mixtures of pectin and gelatin were employed for the production of patches, with adjustable properties, following a two-step gelation procedure. The first gelation, a thermal one, is trigged by the presence of gelatin, whereas, the second gelation, an ionic one, is due to the formation of the typical egg box structure of pectin. In particular, the patch structural properties were assessed by oscillation stress sweep measurements which provided information concerning their viscolelastic properties. In addition, different modalities for drug loading were analyzed with respect to drug homogeneous distribution; testosterone was employed as model drug for transdermal administration. Finally, the performances of the produced transdermal patches were studied, in term of reproducibility and reliability, by determination of in vitro drug release profiles.     

胶体果胶铋阴道泡腾片生产工艺研究

目的:确定胶体果胶铋泡腾片的生产工艺。方法:以发泡量作为产品的主要检测标准筛选确定组方和生产工艺。结果:检测结果符合设计标准,加速实验前后产品的各项指标均符合规定。结论:研究所得的胶体果胶铋泡腾片的生产工艺可行,产品质量稳定。