Microemulsion-based delivery of triamcinolone acetonide to posterior segment of eye using chitosan and butter oil as permeation enhancer: an in vitro and in vivo investigation

The aim of the study was to formulate a microemulsion (ME) using chitosan (CH) and the butter oil (BO) as a permeation enhancer for targeting drug to the posterior segment of the eye, via topical route. Triamcinolone acetonide (TA) was selected as the model drug since it undergoes extensive first-pass metabolism, leading to poor oral bioavailability of 23%. For optimisation of BO concentration, different ratios of TA:BO were prepared by simple physical mixing in the ratio of 1:9 to 9:1 and diffusion study was performed. MEs containing TA, TA:BO and TA CH ME were formulated by water titration method. Globule sizes of TA ME, TA:BO ME and TA CH ME were found to be 66.06?±?0.32?nm, 78.52?±?1.50?nm and 97.30?±?2.50?nm, respectively. In ex vivo diffusion studies using goats eye, TA:BO ME (31.33?±?0.46 and 33.98?±?0.23) and TA CH ME (24.10?±?0.41 and 27.00?±?0.18) showed higher percentage of drug diffusion in comparison to TA ME (13.29?±?0.41and 15.56?±?0.34) and TA solution (8.20?±?1.04 and 10.39?±?0.22) in presence and in absence of vitreous humour. Fluorescence intensity of coumarin-6 (as a marker) loaded ME with BO and CH was found to be higher, confirming their role in altering membrane permeability and facilitating coumarin-6 diffusion to the posterior chamber. Overall, it was concluded that BO enhances the bioavailability of TA across the retina, thereby proving its potential as permeation enhancer in facilitating drug delivery to the posterior segment of the eye.     

Toxicological and ecotoxicological properties of gas-to-liquid (GTL) products. 2. Ecotoxicology

Gas-to-liquid (GTL) products are synthetic hydrocarbons produced from natural gas using a catalytic process known as the Fischer–Tropsch process. This process yields a synthetic crude oil that consists of saturated hydrocarbons which can subsequently be refined to a range of products analogous to those obtained from petroleum refining. However, in contrast to their petroleum-derived analogs, GTL products are essentially free of unsaturated or aromatic compounds and do not contain any sulfur-, oxygen-, or nitrogen-containing compounds. Under new chemical substance notification requirements, an extensive testing program covering the entire portfolio of GTL products has been undertaken to assess their hazardous properties to human health and environment. The results of these studies have been summarized in a two-part review. Part 1 provides an overview of the mammalian toxicity hazardous properties of the various GTL products. This second part of the review focuses on the aquatic, sediment, terrestrial, and avian toxicity studies which assess the ecotoxicological hazard profile of the GTL products. Many challenges were encountered during these tests relating to dosing, analysis and interpretation of results. These are discussed with the intent to share experiences to help inform and shape future regulatory mandates for testing of poorly soluble complex substances. As was the case with the mammalian toxicology review, there were a few cases where adverse effects were found, but overall the GTL products were found to exert minimal adverse ecotoxicological effects and these were less severe than effects observed with their conventional, petroleum-derived analogs.     

Definitions and statistical properties of master protocols for personalized medicine in oncology

ABSTRACT

Within the field of cancer research, discovery of biomarkers and genetic mutations that are potentially predictive of treatment benefit is motivating a paradigm shift in how cancer clinical trials are conducted. In this review, we provide an overview of the class of trials known as “master protocols,” including basket trials, umbrella trials, and platform trials. For each, we describe standardized terminology, provide a motivating example with modeling details and decision rules, and discuss statistical advantages and limitations. We conclude with a discussion of general statistical considerations and challenges encountered across these types of trials.     

4种不同药材来源郁金饮片中挥发油成分的GC-MS分析

目的:分析4种不同药材来源郁金饮片中挥发油成分,找出其共有及差异成分,为该饮片的合理使用提供依据。方法:采用水蒸气蒸馏法提取挥发油,利用GC-MS对4种不同药材来源郁金饮片挥发油成分进行测定,载气高纯度氦气,进样温度250℃,压力49.5 k Pa,总流量36.0 m L·min~(-1),柱流量1.0 m L·min~(-1),线速度36.1 cm·s~(-1);电离方式电子轰击离子源,电离电压70 e V,离子源温度200℃,接口温度280℃,溶剂延时3.5 min,m/z 40~400。结果:4种不同来源郁金饮片挥发油均检测出了50种成分,其中有3种共有成分,3种郁金共有成分达13种,2种郁金共有成分达15种;4种郁金共有、交互存在的挥发油成分达31种。结论:4种不同药材来源郁金饮片挥发油中存在共有及交互存在的成分。吉马酮可作为温郁金、桂郁金、绿丝郁金的含量测定指标成分;姜黄素、姜黄酮、芳姜黄酮等可作为黄丝郁金的含量测定指标成分。     

岷当归有效成分对高同型半胱氨酸血症兔TXB_2的影响

目的:探讨岷当归有效成分(当归挥发油、当归多糖、阿魏酸)对高同型半胱氨酸血症(HHcy)兔致动脉粥样硬化(AS)的影响。方法:将48只日本大耳白兔随机分为正常组、模型组、当归挥发油组、当归多糖组、阿魏酸组和叶酸对照组,每组8只。采用L-蛋氨酸皮下注射法建立HHcy家兔模型。造模8周后,当归挥发油组、当归多糖组、阿魏酸组分别给予岷当归有效成分灌胃治疗,叶酸组给予叶酸+维生素B_6+维生素B_(12)灌胃治疗。12周后检测各组血清同型半胱氨酸(Hcy)、血浆血栓素B_2(TXB_2)水平。结果:模型组血清Hcy水平高于正常组,差异有统计学意义(P0.05),HHcy模型形成;与模型组比较,当归挥发油组、阿魏酸组、叶酸组血清Hcy水平明显降低,差异有统计学意义(P0.05);与模型组比较,叶酸组、当归挥发油组、当归多糖组、阿魏酸组血浆TXB2水平降低,差异有统计学意义(P0.05)。阿魏酸组血浆TXB_2水平比叶酸组、当归挥发油组、当归多糖组较低,差异有统计学意义(P0.05)。结论:岷当归有效成分阿魏酸能够降低血清Hcy与血浆TXB2水平,减少Hcy对血管内皮的损伤及毒性作用。     

The effect of German chamomile (Marticaria recutita L.) extract and tea tree (Melaleuca alternifolia L.) oil used as irrigants on removal of smear layer: a scanning electron microscopy study

AIM: To compare the cleaning effectiveness of chamomile hydroalcoholic extract and tea tree oil to 2.5% sodium hypochlorite (NaOCl) solution as an intracanal irrigant for the removal of the smear layer. METHODOLOGY: Forty extracted, single-rooted, mature, permanent, human teeth were allocated at random into one of three experimental groups of ten teeth and two control groups of five teeth. For each tooth, the pulp chamber was accessed and the canal prepared using K-type files and Gates-Glidden burs, using a step-back technique; the apical stop was prepared to a size 30. Each canal was subsequently irrigated with one of the following solutions: distilled water (as a negative control), 2.5% NaOCl + 17% ethylenediamine tetraacetic acid (EDTA) (as a positive control), chamomile or tea tree oil or 2.5% NaOCl. Each tooth was split longitudinally and prepared for examination by scanning electron microscopy (SEM). The quantity of smear layer remaining on the three levels of each canal (coronal, middle and apical) was examined using magnifications of 2000 and 5000x. The data were analysed using nonparametric Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: The most effective removal of smear layer occurred with the use of NaOCl with a final rinse of 17% EDTA (negative control) followed by the use of a chamomile extract. Chamomile extract was found to be significantly more effective than distilled water and tea tree oil (P < 0.008).The use of a 2.5% NaOCl solution alone, without EDTA and that of tea tree oil, was found to have only minor effects. There was no statistical difference between distilled water, 2.5% NaOCl and tea tree oil. CONCLUSIONS: The efficacy of chamomile to remove smear layer was superior to NaOCl alone but less than NaOCl combined with EDTA.     

鸦胆子油注射液治疗晚期恶性肿瘤临床观察

目的评价鸦胆子油注射液在治疗晚期恶性肿瘤中的疗效。方法选取有明确病理诊断的晚期肿瘤患者,随机分为试验组和对照组。试验组应用鸦胆子油注射液,对照组根据病种选择单药化疗方案,均化疗2个周期。结果所有患者均完成治疗,试验组患者的治疗总有效率明显高于对照组,差异具有统计学意义(P<0.05)。结论对晚期恶性肿瘤患者应用鸦胆子油注射液治疗有一定的抗肿瘤作用,有利于减轻患者痛苦、改善生活质量,提高机体免疫功能。