电致孔经皮给药:表面活性剂对孔道存在时间和药物传输的影响(英文)

Electroporation creates aqueous pathways by short high-voltage pulses resulting in a transient perme- abilization of stratum corneum and an increase in the transdermal delivery rate.However the aqueous pathways will reseal after pulsing,which leads to the rapid drop of transdermal flux.In the present study,the surfactants were added to the donor solution to hinder the shrinkage and resealing of the electropore,and to prolong the lifetime of the aqueous pathways with the consideration that the surfactants could reduce the surface energy of the electropore. These effects of surfactants were demonstrated by the dynamic electrical resistance of the skin and the fluorescent imaging of the local transport regions.Piroxicam(PIX)was transported percutaneously in the presence of surfac- tants in vitro.Owing to the longer lifetime of aqueous pathways,together with the promotion of PIX availability at the barrier exterior and the improvement in the partition of PIX into the aqueous pathways,the presence of surfac- tants led to a remarkable increase in the transdermal delivery rate during electroporation and a significant growth of the accumulative transdermal amount of PIX.     

鼓泡塔中低浓度表面活性剂对CO2吸收传质系数的影响（英文）

The effect of different surfactants (n-octyltrimethylammonium bromide (OTABr), sodium dodecyl benzene sulfonate (SDBS) and Tween 80) with different critical micelle concentrations (CMC) on the CO2 absorption into aqueous solutions in a bubble column is analyzed in the present work. The presence of these surfactants in-creased the gas–liquid interfacial area, and decreased the liquid phase mass transfer coefficient, but with signif-icant different extent. The results indicated that the CMC can be a key parameter affecting the mass transfer of CO2 absorption into a dilute aqueous solution of a surfactant. Sardeing's model was used to fit the experimental data successfully by re-correlating the parameters.     

Physicochemical properties of aqueous solutions of sodium glycinate in the non-precipitation regime from 298.15 to 343.15 K

The physicochemical properties, including the density, viscosity, and refractive index of aqueous solutions of sodium glycinate as a solvent for CO2 absorption in the non-precipitation regime were measured under the wide temperature range of 298.15 to 343.15 K. The concentration of the sodium glycinate in an aqueous form in the non-precipitation regime was identified up to 2.0 mol·L?1. The coefficients of thermal expansion values were estimated from measured density data. It was found that, the densities, viscosities and refractive indices of the aqueous sodium glycinate decrease with an increase in temperature, whereas with increasing sodium glycinate concentration in the solution, all three properties increase. Thermal expansion coefficients slightly increase with rising temperature and concentration. The measured values of density, viscosity and refractive index were correlated as a function of temperature by using the least squares method. The predicted data obtained from correlation equations for all measured properties were in fairly good agreement with the experimental data.     

Erosion corrosion control of 6061 aluminum alloy in multi-phase jet impingement conditions with eco-friendly green inhibitor

Erosion corrosion performance of 6061 aluminum alloy in simulated sea water slurry was investigated under multi-phase jet impingement conditions. The main objective of the work is to study erosion–corrosion of a material with engineering application and mitigate it using eco-friendly green inhibitor. Experiments were performed with the sand concentration of 0.3% and 0.3 μm size. The effect of temperature and flow rate on the performance of inhibitor was explored. Electrochemical methods were adopted for erosion-corrosion measurements. Experiments revealed that starch could mitigate erosion-corrosion with a maximum reduction efficiency of 58% at temperature of 303 K and flow rate of 4 L·min~(–1). Inhibition efficiency decreased with increase in flowrate and temperature. EIS spectrum demonstrated that the corrosion process in the presence on inhibitor was both charge transfer and mass transfer controlled. A key role of hydrodynamics in the performance of corrosion inhibitor was confirmed by the present study.     

Solvent extraction of lanthanum and cerium ions from hydrochloric acidic aqueous solutions using partly saponified 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester

In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000 mol·L~(-1); EHEHPA in a range of 0.2877–0.8631 mol·L~(-1) with saponification rate of 0.3(mole fraction), and the initial aqueous p H in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with.The calculation results are in good agreement well with the experimental data.     

Kinetics and the difference for extraction of praseodymium and neodymium from nitrate aqueous solution by[A336] [NO3] using the single drop technique

The kinetics and the difference for Pr(Ⅲ) and Nd(Ⅲ) extraction from nitrate aqueous solution using trialkylmethylammonium nitrate([A336][NO_3]) as extractant were investigated by the single drop technique.The dependence of the extraction rate of Pr(Ⅲ) and Nd(Ⅲ) on the concentrations of free Pr(Ⅲ) and Nd(Ⅲ)ions, the concentrations of Na NO_3 and H~+in aqueous solutions, and the concentrations of [A336][NO_3] in kerosene solutions were discussed and the corresponding extraction rate equations for Pr(Ⅲ) and Nd(Ⅲ) were obtained. These equations demonstrated that the reaction rate constant of Pr(Ⅲ) with [A336][NO_3] was double than that of Nd(Ⅲ). The effect of the addition of diethylenetriaminepentaacetic acid(DTPA) on the difference in the extraction rate of Pr(Ⅲ) and Nd(Ⅲ) by [A336][NO_3] was also investigated. It was revealed that the difference in the complex formation rates of Pr(Ⅲ) and Nd(Ⅲ) with DTPA made a significant impact on the difference in the extraction rates of Pr(Ⅲ) and Nd(Ⅲ) with [A336][NO_3]. The ratio of extraction rates of Pr(Ⅲ) to Nd(Ⅲ) with[A336][NO_3] was in proportion to the ratio of complex formation rates of Pr(Ⅲ) to Nd(Ⅲ) with DTPA. The extraction rate difference for Pr(Ⅲ) and Nd(Ⅲ) with [A336][NO_3] increased due to a higher complex formation rate constant of DTPA with the free and un-complexed Nd(Ⅲ) ions in the aqueous nitrate solution than that with Pr(Ⅲ) ions. Therefore, the addition of DTPA in the aqueous nitrate solution is an effective method to intensify the separation of Pr(Ⅲ) and Nd(Ⅲ) in kinetics. The study on the extraction mechanism indicated that both the extraction of Pr(Ⅲ) and Nd(Ⅲ) by [A336][NO_3] were diffusion controlled, and the reactions obeyed SN2 mechanism. The present work highlights a possible approach to strengthen the kinetic separation of Pr(Ⅲ) and Nd(Ⅲ).     

水溶性铑络合物催化1-十二碳烯氢甲酰化反应器构型的初步探索

Hydroformylation of 1-dodecene was studied in a biphasic system using water-soluble rhodium complex [RhCl(CO)(TPPTS)2] as catalyst in the presence of cetyl trimethyl ammonium bromide as surfactant to enhance the reaction rate. Efforts were devoted to improve the performance of hydroformylation by exploring reactor the reaction configuration which enhanced the mixing, dispersion and interphase mass transfer. Experiments were carried out in a 0.5L autoclave at the total pressure of 1.1MPa and temperature from 363K to 373K. Several surface aeration configurations were tested, and higher hydroformylation rate with higher normal/branched aldehyde ratio produced were achieved. The experience suggest that improved reactor configuration by taking reaction engineering, measures is beneficial to better process economy in alkene hydroformylation.     

Effect of different additives on the phase separation behavior and thermodynamics of p-tert-alkylphenoxy poly (oxyethylene) ether in absence and presence of drug

Cloud point(CP) determinations of 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol(TX-100(nonionic surfactant)) was carried out in aqueous as well as in the attendance of drug(ceftriaxone sodium trihydrate(CFT))/(CFT + different inorganic salts) and discussed thoroughly. Nonionic surfactants are employed extensively in different formulations. In aqueous solution, the values of CP of TX-100 are obtained to increase by means of enhancing of their concentration in the solution. The CP values of TX-100 solutions were found to decrease in the presence of drug and their values decrease more with rising concentrations of the drug. The values of CP of CFT and TX-100 mixtures were found to further decrease in the attendance of inorganic salts in comparison to their absence. The effect of different sodium salts in decreasing CP values of TX-100 was achieved in the following order: NaCO_3 Na_2SO_4 Na Cl. However, in the case of potassium and ammonium salts, the decreasing order obtained is K_2SO_4 KCO_3 KCl and(NH4)2 SO_4 Na_2CO_3 NH_4Cl respectively. Various thermodynamic parameters for example standard free energy(ΔG_c~Θ), standard enthalpy(ΔH_c~Θ) as well as standard entropy(Δ Sc?)changes of phase separation were also evaluated and discussed in detail on the basis of their behavior.     

Desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system using aqueous phase of acids

Aqueous phase of acids as catalysts for the desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system was investigated. Two types of model gasoline with and without aromatics and olefins were employed in this work. The desulfurization rates were above 90% on these two types of model gasoline using formic acid and H_3PW_(12)O_(40)(0.8 mol·L~(-1)), indicating that the presence of aromatics and olefins has no effect on the desulfurization rate. High temperature(above 90 °C) was more favorable to the process for desulfurization. Four hours was considered to be the proper treating time for the sulfur removal. In addition,aqueous phase of acids could be recycled at least 4 times without decreasing desulfurization rate. Finally, the possible process for the integration of condensation desulfurization into the existing refinery process for the production of gasoline with low sulfur content was proposed.     

有机硅表面活性剂对水体中多环芳烃的浊点萃取研究

Cloud point extraction （CPE） processes with two silicone surfactants, Dow Coming DC-190 and DC-193, were studied as preconcentration and treatment for the water polluted by three trace polycyclic aromatic hydrocarbons （PAHs）： anthracene, phenanthrene and pyrene. For all cases, the volumes of surfactant-rich phase obtained by two silicone surfactants were very small, i.e. a lower water content in the surfactant-rich phase was obtained. For example, less than 3% of the initial solution was obtained in a 1% （by mass） surfactant solution, which was much smaller than that of TX-114 in the same surfactant concentration. And TX-114 is known as a high compact surfactant-rich phase among most nonionic surfactants, thus the comparison showed that an excellent enrichment was ensured in the analysis application by the CPE process with the silicone surfactants, and the lower water content obtained in the surfactant-rich phase is also important in the large scale water treatment. The influences of additives and phase separation methodology on the recovery of PAHs were discussed. Comparing with DC-193, DC-190 has a lower cloud point and a higher recovery （near 100%） of all the three PAHs in same surfactant concentration, which was required for application as a preconcentration process prior to HPLC system. However the DC-190 solution is hard to be phase separated only by heating, whereas DC-193 has a relative higher phase separating speed by heating, but a high cloud point （around 360K） limits its application. Due to the phase separation by heating is the only method of CPE suitable to the large scale water treatment, the mixtures of two silicone surfacrants solutions were investigated in this study. A solution containing 1% of mixed DC-190 and DC-193 （in the ratio of 90 ： 10） removed anthracene, phenanthrene and pyrene near 100% with a relative low cloud point and quick phase separating speed.     

Microemulsion of erythromycine for transdermal drug delivery

The aim of this work was to prepare an erythromycin (EM) microemulsion (EM‐ microemulsion) for transdermal EM delivery using isotropic mixtures of oil and aqueous phases. The prepared EM‐microemulsion is a white dispersion, with a suitable viscosity for transdermal delivery. In stability experiments, the EM‐microemulsion showed no marked change in appearance for up to 3 weeks at 25°C. In accelerated stability experiments at 37 and 60°C, however, precipitated crystalline EM particles were observed in the EM‐microemulsion. Diffusion of EM into the skin exhibited a first order release profile. Fluorescein (FL)‐microemulsion penetrated to the dermis layer of skin. In conclusion, we confirmed that EM‐microemulsion could serve as an excellent transdermal carrier of EM. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

微针给药系统的研究进展

微针是一种具有微米尺度的经皮给药技术,从内部结构可分为实心与空心微针.制作微针的材料主要有硅、金属、聚合物等.微针增强了皮肤对药物尤其是大分子药物的渗透性,不会到达神经分布丰富的皮肤深层组织,并且使用方便,因此是一种高效、无痛、安全的经皮给药方式.微针在胰岛素给药、卵清蛋白的免疫接种、缓控释给药、微量输液等方面的研究为微针经皮给药提供了应用可能.     

Aggregation and Phase Separation Phenomenon of Amitriptyline Hydrochloride Under the Influence of Pharmaceutical Excipients

The interaction between the amphiphilic drug amitriptyline hydrochloride (AMT) and the nonionic surfactants used in drug delivery has been investigated. Herein, we report the micellization behavior of AMT in presence of ethoxylated alkyl phenols in aqueous medium and the clouding phenomenon in the absence and presence of different nonionic surfactants in buffer solution. The values of critical micelle concentration (CMC) of AMT obtained using the conductivity method, decrease as nonionic surfactant concentration increases. With an increase in temperature, the CMC first increases and then decreases. At 303.15 K, the maximum CMC values were obtained with or without nonionic surfactant. The results obtained indicate attractive interactions (synergism) between the two mixing amphiphiles in solution. The experimentally obtained critical micelle concentration (CMC) values are always lower than ideal CMC values. Micellar mole fraction (X₁) values, calculated by different proposed models, show the contribution of nonionic surfactant concentration. At a fixed drug concentration (50 mmol kg^?1) and pH (=6.7) nonionic surfactants show continuous increase in cloud point (CP). Increase in drug concentration and pH, in the presence of fixed amounts of nonionic surfactant, increases and decreases the CP, respectively.     

Optimization of square microneedle arrays for increasing drug permeability in skin

Microneedles array is a new transdermal drug delivery technique designed to create holes in the epidermis and penetrate the stratum corneum, thus avoiding the high resistance of this barrier. Microneedles have been shown to increase the skin permeability of drugs with no or little pain. However, the skin permeability of epidermis while using microneedle arrays has yet to be fully studied. In some cases, microneedle and microneedle array designs which were developed based on certain criteria (e.g., material of the microneedles) have to be related to other criteria (e.g., drug permeability in skin, skin thickness, etc.). Therefore, in order to determine the optimum design of the microneedle arrays, the effect of different factors (e.g., number of the microneedle, surface area of the patch, etc.) along with skin permeability by using microneedles should be determined accurately. In this work, an optimization framework for transdermal delivery of high molecular weight drug from microneedle is presented. The outputs of this framework have allowed us to identify the optimum design of various microneedles. Data from this optimization algorithm is then used to predict skin permeability of high molecular weight injected into the skin from a microneedle system. The effect of the optimized microneedles on blood drug concentration has been determined. The outcome of this study is useful to propose an optimum design based on different measurement (e.g., variation of skin thickness) for transdermal delivery of drugs.     

Hydroxypropylmethylcellulose–anionic surfactant interactions in aqueous systems

The increase in the viscosity of an aqueous solution or gel of hydroxypropylmethylcellulose (HPMC) in the presence of an anionic surfactant is attributed to a two-step process: (a) the surfactant undergoes ion–dipole interaction with the ethereal oxygen in HPMC, in the absence or presence of water, and (b) hydrocarbon moieties in the now pendant surfactant molecules undergo hydrophobic bonding, in the presence of water, resulting in an apparent increase in the molecular weight of the HPMC. DSC of dry blends and dried gels or films confirmed HPMC–sodium lauryl sulfate interaction. Work-to-break measurements on films cast from aqueous solutions of HPMC, in the absence or presence of anionic surfactants, indicated an apparent increase in the molecular weight of HPMC in the presence of surfactants.     

亲水性聚氨酯压敏胶经皮给药应用性能研究

针对目前经皮给药制剂发展急需性能优良的亲水性新型压敏胶基质,制备了亲水性聚氨酯压敏胶。对一些影响压敏胶贴剂力学性能的因素进行了考察,并重点研究了载药压敏胶贴剂经皮释放规律。结果表明,该聚氨酯压敏胶贴剂具有良好的药物控释能力,适用于经皮给药系统。     

Refining natural rubber matrix for electrically stimulated transdermal drug delivery

This work focuses on the enhancement of transdermal delivery of indomethacin (IN) from natural rubber matrix by deproteinization, the addition of ethylene glycol (EG) as a plasticizer, and the enlarged matrix size under electrical field. The starting double-centrifuge natural rubber (DCNR) was deproteinized to produce the deproteinized natural rubber (DPNR). Both DCNR and DPNR patches were fabricated by the UV curing method, and blended with EG to enhance the IN loading and release–permeation. Using a pig skin to simulate the human skin, the IN release–permeation was found to increase with increasing plasticizer, removed protein, and applied electrical potential.     

Experimental Study on Foam Properties of Mixed Systems of Silicone and Hydrocarbon Surfactants

Silicone surfactants are inevitably involved in industrial applications in combination with hydrocarbon surfactants, but properties of the mixtures of silicone and hydrocarbon surfactants have received little attention, especially foam properties of the mixtures. In this study, aqueous solutions of respective binary mixtures of a nonionic silicone surfactant with anionic, cationic, and nonionic hydrocarbon surfactants were prepared for evaluation of their foam properties. Surface tension of aqueous solutions of the mixtures were measured with the maximum bubble pressure method. Foaming ability and foam stability of the mixtures were then evaluated with the standard Ross–Miles method. The findings show that the addition of the silicone surfactant results in a decrease in surface tension for aqueous solutions of the hydrocarbon surfactants. The critical micelle concentration (CMC) of the hydrocarbon surfactants is also changed by the additive silicone surfactant. Additionally, clear foam synergistic effects were observed in the mixtures of silicone and hydrocarbon surfactants, regardless of the ionic types of the hydrocarbon surfactant. The foam stability of the hydrocarbon surfactant was shown to generally improve with the increasing concentration of the silicone surfactant. Even so, aqueous solutions of different ionic hydrocarbon surfactants in the presence of the silicone surfactant will give different foam stabilities. The results of the present study are meant to provide guidance for the practical application of foams generated by the mixtures of the silicone and hydrocarbon surfactants.     

胰岛素经皮给药研究的新进展

经皮给药是胰岛素一种理想的给药方式,但是皮肤角质层的阻力、胰岛素分子在皮肤中的积累以及促渗方法的安全性等限制了胰岛素的经皮给药。作者分析了胰岛素经皮给药的优势和存在的问题,从减小角质层阻力、强化被动扩散和应用传递体为透皮给药载体3个方面,综述了近几年来国内外在胰岛素的经皮给药的研究上取得的最新进展,指出了存在的问题和研究的趋势。