Effect of tocopheryl polyethylene glycol succinate on the percutaneous penetration of minoxidil from water/ethanol/polyethylene glycol 400 solutions

We described to achieve the local retention of minoxidil which has penetrated the skin with minimization of its absorption into the general circulation and elimination of local irritation induced by propylene glycol. The effect of tocopheryl polyethylene glycol succinate (TPGS) on the penetration flux of minoxidil and its retention in the skin from topical minoxidil formulations consisting of water, alcohol, and polyethylene glycol 400 was characterized by an experimental design of ten solvent formulations in this study. Results show that the addition of TPGS was only able to improve the solubility of minoxidil in those solvent systems containing higher proportions of water and PEG 400, and the extent of improvement was also more profound with the addition of TPGS at concentrations higher than 5%. For those solvent systems containing a higher fraction of alcohol, an insignificant change in minoxidil solubility with increasing added amounts of TPGS was noted even with the tendency to decrease the solubility of minoxidil with higher amounts of TPGS. Increasing the amount of TPGS added gradually increased the flux and the corrected flux from solvent formulations with a lower solubility parameter, but decreased those from solvent systems with a higher solubility parameter. With the addition of TPGS, solvent formulation F6 (alcohol:PEG 400 of 50:50) was demonstrated to be the optimal choice by having an improved local effect and a reduced systemic effect compared to the reference of 2% Regaine®. Tocopheryl polyethylene glycol succinate (TPGS) was mainly retained locally in the stratum corneum, and the amount was proportional to the increase in the amount of TPGS added to these ten solvent formulations.     

A Note on the Solubility of Progesterone in Aqueous Polyethylene Glycol 400

Abstract

The solubility curve of progesterone in aqueous polyethylene glycol (PEG) 400 at ambient room temperature (～25°C) is bimodal, a break occurring at approximately 60% w/w PEG.

It is speculated that the presence of unbound water in the PEG 400/water system depresses the solubility of progesterone in PEG 400 disproportionately.     

不同含量聚乙二醇对碳化硅喷雾造粒的影响

通过研究碳化硅及其烧结助剂碳化硼、纳米碳黑在水溶液中的共分散性.制得了分散性良好的混合浆料·研究结果发现碳化硅及其烧结助剂碳化硼、纳米碳黑在碱性条件下可以实现共分散.同时聚乙二醇(PEG)作为浆料的分散剂和粉体的粘结剂,PEG含量对碳化硅喷雾造粒有重要的影响,结果显示随着PEG含量的增加,喷雾造粒的球状颗粒形貌趋于规整,粉体的流动性增加.     

Influence of Sucrose Esters on the In Vivo Percutaneous Penetration of Octyl Methoxycinnamate Formulated in Nanocapsules,Nanoemulsion, and Emulsion

ABSTRACT

The influence of sucrose laureate and sucrose oleate on the in vivo percutaneous penetration of octyl methoxycinnamate (OMC) formulated in i) colloidal suspensions (nano-emulsions and nanocapsules), and ii) conventional o/w emulsions was evaluated. The results showed that nano-emulsions formulated with sucrose laureate exhibited the highest penetration in the stratum corneum compared to the other formulations. A two-fold increase in OMC skin deposition was observed with the nano-emulsion containing sucrose laureate when compared to the control. The data obtained suggest that the total amount of OMC detected in the stratum corneum and the penetration depth are strongly dependent upon the formulation's nature, the particle size, and the type of enhancer.     

聚乙二醇/硅藻土复合助剂对聚丙烯流变行为和力学性能的影响

研究了聚乙二醇(PEG)/硅藻土复合助剂对聚丙烯(PP)流变行为和力学性能的影响。结果表明,PEG/硅藻土复合助剂明显降低了聚丙烯树脂熔体黏度,改善了加工性能。复合助剂含量越多,降粘效果越显著。DSC和偏光显微镜分析表明,加入复合助剂可以诱导β晶的生成,使PP球晶细化,PP的冲击强度和断裂伸长率得到提高。     

聚乙二醇对硅藻土制备超细白炭黑的影响

以硅藻土为原料,采用沉淀法制备白炭黑,研究聚乙二醇的用量对白炭黑吸油率和比表面积的影响。结果表明,在用硅藻土制备白炭黑工艺中添加聚乙二醇,可以得到粒度分布均匀的纳米级白炭黑产品,用质量分数为4.5%的聚乙二醇改性所得产品具有最大的比表面积,其值为191.521 m2/g,聚乙二醇分子与白炭黑颗粒面发生物理吸附要多于化学吸附。     

Thermodiffusion in Ternary Mixtures of Water/Ethanol/Triethylene Glycol: First Report on the DCMIX3-Experiments Performed on the International Space Station

We report on thermodiffusion experiments conducted on the International Space Station ISS during fall 2016. These experiments are part of the DCMIX (Diffusion and thermodiffusion Coefficients Measurements in ternary Mixtures) project, which aims at establishing a reliable data base of non-isothermal transport coefficients for selected ternary liquid mixtures. The third campaign, DCMIX3, focuses on aqueous systems with water/ethanol/triethylene glycol as an example, where sign changes of the Soret coefficient have already been reported for certain binary subsystems. Investigations have been carried out with the SODI (Selectable Optical Diagnostics Instrument) instrument, a Mach-Zehnder interferometer set up inside the Microgravity Science Glovebox in the Destiny Module of the ISS. Concentration changes within the liquids have been monitored in response to an external temperature gradient using phase-stepping interferometry. The complete data set has been made available in spring 2017. Due to additionally available measurement time, it was possible to collect a complete data set at 30^°C and an almost complete data set at 25^°C, which significantly exceeds the originally envisaged measurements at a single temperature only. All samples could be measured successfully. The SODI instrument and the DCMIX experiments have proven reliable and robust, allowing to extract meaningful data even in case of unforeseen laser instabilities. First assessments of the data quality have revealed six out of 31 runs with some problems in image contrast and/or phase step stability that will require more sophisticated algorithms. This publication documents all relevant parameters of the conducted experiments and also events that might have an influence on the final results. The compiled information is intended to serve as a starting point for all following data evaluations.     

不同聚乙二醇相对分子质量的聚碳酸酯聚氨酯的防水透湿性

采用不同相对分子质量的聚乙二醇(PEG)分别与聚碳酸酯二元醇(PCDL)、二苯基甲烷二异氰酸酯(MDI)反应,合成了一系列聚碳酸酯聚氨酯(PU)。通过差示扫描量热分析、红外光谱分析、原子力显微镜分析等研究了不同相对分子质量的PEG对聚碳酸酯聚氨酯的形态结构和防水透湿性的影响。研究结果表明,分子链中引入PEG后,PU软段的Tg逐渐下降,且PU软硬段均不结晶。随着PEG相对分子质量的提高,PU微相分离程度先减小后增大,PU的亲水性提高,透气性先减小后增大。     

温度、浓度对水/乙醇混合溶剂中壳聚糖溶液黏度的影响

研究了溶解于水/乙醇混合溶剂中的壳聚糖溶液黏度随温度和浓度的变化规律。混合溶剂中,乙醇是壳聚糖的不良溶剂,而水是壳聚糖的良溶剂,将乙醇与水按一定比例混合,再加入1%的乙酸,配制成水/乙醇混合溶剂。实验使用乌氏黏度计测量溶液黏度,通过分析黏度随温度、浓度的变化规律,揭示了混合溶剂对壳聚糖溶液黏度的影响规律。研究发现,壳聚糖溶液黏度随着温度的升高而降低;恒定温度,壳聚糖溶液黏度随浓度的增加而增加。而随着温度的升高,壳聚糖在良溶剂中产生的增比黏度变化率要比其在不良溶剂中高;随着浓度的增加,壳聚糖溶液产生的增比黏度的变化率也相应增加。当浓度极稀时,壳聚糖溶液的(ηsp/C)/C曲线会出现反常现象——体系黏度随着浓度的减小而急剧上升。     

L-DBTA印迹中空纤维复合膜分离乙醇-水的研究

以聚砜中空纤维超滤膜为基膜,以二苯甲酰-L-酒石酸(L-DBTA)为模板分子,甲基丙烯酸甲酯为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用表面热聚合方法制备L-DBTA印迹中空纤维复合膜(CM IHFCM)。40℃时实验研究表明,CM IHFCM具有优良的优先透水性能,20%乙醇-水溶液的分离因子和渗透通量分别为1086和2093 g/m2.h;50%乙醇-水溶液的分离因子和渗透通量分别为2181和2185g/m2.h。此外,CM IHFCM的渗透汽化表观活化能为16.9 kJ/m o l。     

PEG对陶瓷凝胶注模成型坯体表面起皮的抑制作用研究

在凝胶注模成型的丙烯酰胺单体溶液中加入适量的聚乙烯乙二醇(PEG),可有效克服在空气气氛下单体聚合形成凝胶网络的氧阻聚问题,从而消除陶瓷坯体的表面起皮现象,使坯体的尺寸得以精确控制.研究了加入PEG对碳化硅粉体的分散性、浆料的流变学特性、素坯的强度以及微观结构等的影响,并初步讨论了PEG对单体凝胶化过程中氧阻聚效应的抑制作用机理.     

Effect of Steareth-20 on the Release of Nitrofurantoin from Propylene Glycol Monostearate Microspheres

In vitro release of nitrofurantoin (NFT) from microspheres of propylene glycol monostearate (PGM) was investigated at NFT:PGM ratios of 1:1, 1:1.5, 1:3, 1:4, 1:5, and 1:9 in distilled water at 37°C. The rate and extent of drug release declined with decreasing NFT:PGM ratio. A maximum drug release of 52.4% over 24 hr was recorded for the microspheres of formulation I (highest load). The effect of Steareth-20 (ESA) over the concentration range of 0.01% to 0.1% w/w of PGM on the size of the microspheres and on the release profile of nitrofurantoin from the microsphere formulations was examined at NFT.PGM ratios of 1:1 and 1:4. The cumulative % of NFT released over a 24-hr period was found to be maximum at ESA concentration of 0.03% and 0.05% w/w of PGM. The plots of T₅₀ versus %w/w of ESA exhibited two minima, the first at 0.03% ESA and a second, weaker than the first, at 0.05% ESA, paralleling the earlier observations. Scanning electron micrographs of the exhausted microspheres revealed a very porous matrix of PGM at the ESA concentration of 0.03%. The formulations containing 0.03% and 0.05% ESA had the smallest mean particle diameter and the minimum contact angles (water over PGM-ESA films) corresponding to the two critical micelle concentrations (CMC), at 0.025% and 0.05% w/w.     

高密度聚乙烯/尼龙6共混物的形态结构对其性能的影响

本文利用微层共挤方法制备了具有层状交替结构的HDPE/PA6共混物,利用常规熔融共混挤出方法制备了与层状共混物具有相同组成比的海岛结构共混物。通过DSC,FT-IR及力学性能测试等方法研究了共混物的形态结构对其界面化学反应、结晶行为和力学性能的影响。研究结果表明:在共混物中引入少量马来酸酐接枝高密度聚乙烯时,化学反应在界面进行,与海岛结构的共混物界面面积相比,层状共混物的界面接触面积小,界面化学反应相对较弱,但层状共混物的屈服强度和断裂伸长率有大幅度提高。层状结构对HDPE和PA6的结晶行为影响很小。     

水、乙醇和丙醛对二氧化碳和环氧丙烷共聚反应的影响

系统考察了以负载戊二酸锌为催化剂的二氧化碳(CO2)和环氧丙烷(PO)共聚反应体系中添加不同含量的杂质水、乙醇和丙醛分别对催化效率、反应产物组成及含量和共聚物结构、分子量及其分布等结果的影响。结果显示,乙醇的存在显著降低催化效率,水和丙醛次之。1H-NM R及13C-NMR表明,所得聚合物为聚碳酸丙烯酯(PPC),且三种添加物对共聚物分子链中碳酸酯结构单元含量影响不大,都在49%以上。GPC测试表明三种添加物都不同程度地降低了PPC的分子量,同时使分子量分布变宽。副产物环碳酸丙烯酯(POC)及聚醚(PE)的含量都随添加量的增加而增加。     

Effect of CaCO3 on the Mechanical Properties of Polyethylene Terephthalate/Polypropylene Blends

The aim of this work was to study the influence of CaCO3 in both tensile and flexural mechanical properties of a PET(polyethylene terephthalate)/PP(polypropylen...     

The Effect of Ethanol on the Release of Opioids from Oral Prolonged-Release Preparations

Recent experience has prompted the US FDA to consider whether ethanol ingestion may modify the release characteristics of prolonged-release formulations, where dose dumping may be an issue for patient safety.

The influence of ethanol on the in vitro release of opioid drugs from some prolonged-release formulations utilizing different release technologies was examined. Results indicated that the prolonged-release mechanisms remained intact under the testing conditions, although one product showed initial sensitivity to ethanol in its release characteristics. Nevertheless, in this case, extrapolation of the findings to likely outcome in vivo indicated no risk of dose-dumping.

It is proposed that prolonged-release medicinal products should be tested during development to ensure robustness to the effects of ethanol on drug release.     

蒙脱土/碳纳米管组成对聚乙烯复合材料性能的影响

将改性的纳米蒙脱土(MMT)和官能化的多壁碳纳米管(MWCNTs)进行复合,然后负载TiCl4催化组分,制备出纳米载体Ziegler-Natta催化剂,最后进行乙烯原位聚合得到含有多维纳米材料的聚乙烯基复合材料。通过调控纳米载体中两种材料的组成,研究蒙脱土/碳纳米管组成对纳米复合材料性能的影响。结果表明:纳米蒙脱土、改性碳纳米管复合作为催化剂的载体,能够得到高活性的乙烯聚合催化剂。两种纳米材料组成的改变,会影响聚乙烯复合材料的力学性能。当多壁碳纳米管与蒙脱土比例为1∶1时,所得到的复合材料的拉伸强度为38.7MPa。     

Interaction of Tenoxicam with Cyclodextrins and Its Influence on the In Vitro Percutaneous Penetration of the Drug

Solid complexes of tenoxicam (TEN) with cyclodextrins (CDs), in a 1:1 molar ratio, were obtained by the coprecipitation method and characterized by x-ray diffractometry, infrared spectroscopy, and differential scanning calorimetry. The binding capacity of the CDs with TEN was also demonstrated in aqueous solution and in water-propylene glycol mixtures. The purpose of this study was to determine the effect of CDs on the in vitro percutaneous penetration of TEN from carbopol gels, taking into account the role of the CD cavity size and the nature of the substituents. The effect of pretreatment was studied too. In vitro permeation experiments were carried out on Franz diffusion cells using cellulose nitrate membranes and abdominal rat skin. In these results, the release rates of the drug scarcely decreased when the CDs were added, probably because of a lower concentration of the free drug and an increased gel viscosity. However, it was also found that CDs, particularly γ-CD and M-β-CD, can improve slightly TEN absorption through the skin. Pretreatment studies with CDs, however, provided no effects on TEN permeation, but lag time was markedly reduced, suggesting a faster partitioning of TEN into the skin. Therefore, the use of pretreatment with CDs would be interesting when a quick action of the drug is desired.