Maslinic Acid Nanoparticles: A Drug to Carry Others

Maslinic acid (MA), a triterpene widely found in natural sources, is a compound which is gaining interest due to its multiple therapeutic activities and its lack of harmful effects. However, MA is practically insoluble in water, which limits its clinical application. Here, we present a solvent displacement method to produce MA Solid Lipid Nanoparticles (SLNs) as a nanoplatform to carry hydrophobic drugs. A systematic study of the experimental parameters that may have some influence on the colloidal characteristics of MA SLNs was carried out. The effect of the aqueous/organic phase volume ratio and the organic phase composition on the size of SLNs evidence the role of the solvent diffusivity on the colloidal characteristic of the SLNs. On the other hand, the effect of surfactant/MA ratio proved the relevance of the surfactant on stabilizing the SLNs interface, owing to the changes on the interfacial tension that it promotes. MA SLNs have proved to be highly stable over time and in a wide range of pH and salinity conditions, as well as having a high curcumin encapsulation efficiency. The MA SLNs prepared in this work provide a starting point to develop functionalized active nanocarriers which allow establishing a synergistic relation with the loaded drug.

The Investigation of Silica Nanoparticles-CO2 Foam Stability for Enhancing Oil Recovery Purpose

Carbon dioxide (CO2) gas injection is one of the most successful Enhanced Oil Recovery (EOR) methods. But the main problem that occurs in immiscible CO2 injection is the poor volumetric sweep efficiency which causes large quantities of the oil to be retained in pore spaces of reservoir. Although this problem can be improved through the injection of surfactant with CO2 gas where the surfactant will stabilize CO2 foam, this method still has some weaknesses due to foam size issue, surfactants compatibility problems with rocks and reservoir fluids and are less effective at high brine salinity and reservoir temperature such as typical oil reservoirs in Indonesia. This research aims to examine the stability of the foams/emulsions, compatibility and phase behavior of suspensions generated by hydrophobic silica nanoparticles on various salinity of formation water as well as to determine its effect on the mobility ratio parameter, which correlate indirectly with macroscopic sweep efficiency and oil recovery factor. This research utilizes density, static foam, and viscosity test which was carried out on various concentrations of silica nanoparticles, brine salinity and phase volume ratio to obtain a stable foam/emulsion design. The results showed that silica nanoparticles can increase the viscosity of displacing fluid by generating emulsions or foams so that it can reduce the mobility ratio toward favorable mobility, while the level of stability of the emulsion or foam of the silica nanoparticles suspension is strongly influenced by concentration, salinity and phase volume ratio. The high resistance factor of the emulsions/foams generated by silica nanoparticles will promote better potential of these particles in producing more oil.

Liquid-liquid extraction of mineral acids using Tri-n-octylamine

The present work reports the extraction behaviors of mineral acids: HClO4, HNO3, HCl and H2SO4 (commonly found in acidic bleed solutions from the hydrometallurgical route of metal extraction processes) by tri-n-octylamine (TOA) dissolved in distilled colorless kerosene. The systems have been investigated as functions of various experimental parameters, such as time, [acid], [TOA], temperature, extraction stage and the organic to aqueous phase volume ratio (O/A). Strippings was also examined. Equilibration time is less than 60 min. The acid concentration in the organic phase at equilibrium is increased with increasing initial acid concentration in the aqueous phase for all systems. However, the is after %extraction decreased with increasing initial acid concentration in the aqueous phase. The % extraction increased remarkably with increasing [TOA] for all cases. Being the ratio of the [acid] in the organic to aqueous phase at equilibrium equal to extraction ratio, D; the log D vs. log [TOA] plot is almost a curve with slope 1 at lower concentration region and with slope ~2 at higher concentration region. The extraction efficiency of TOA varies in the order: HClO4> HNO3> HCl > H2SO4. The acid-base-neutralization (extraction) reactions are exothermic with ΔH value much higher than -57 kJ/mol obtainable for of a strong acid - strong base neutralization. The loading capacity of extractant (g per 100 g TOA) for acids varied in the order: HClO4 (30.69) > HNO3 (20.49) > H2SO4 (17.87) > HCl (10.31). On using lower organic to aqueous phase volume ratio (O/A), the organic phase saturated with acid can be obtained on stage-wise extraction. The extracted organic phase, for all systems (excepting H2SO4-system) under investigation, can be stripped effectively in a single stage by 0.10 g eq/L NaOH solution to the extents of more than 96%. However, for H2SO4-system, two-stage stripping will be found effective. Bangladesh J. Sci. Ind. Res.54(4), 339-346, 2019

Method of computing hydraulic gradient for the case of a two-phase mixture flowing in sloping pipes

The paper investigates two-phase mixture flows in sloping pipes employing two computational methods in the transitional region of pipe slope angle. We used methods of computing two-mixture flows in horizontal and vertical pipes as the basis for our equations. When flowing downwards through a sloping pipe, the solid phase volume ratio distribution changes most significantly: an axisymmetric flow through a vertical pipe transforms into a flow featuring a markedly non-uniform distribution of the solid phase along the vertical plane in the sloping pipe. When flowing upwards, the solid phase volume ratio profile is inversely transformed. Comparison of the experimental and computational data showed that the datasets are in a sufficiently good agreement. The computational method developed is semi-empirical and may be recommended for calculating hydraulic gradient in sloping pipes.

Effect of Key Parameters on Jacalin Extraction from Aqueous Phase into Anionic Reverse Micelles

This study demonstrates the extraction of jacalin from crude extract of jackfruit seeds using anionic surfactant based reverse micellar system, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane. Effects of various parameters, such as, NaCl concentration (0.05 – 1 M), pH of aqueous phase (pH 4 – 10), AOT concentration (5 – 150 mM), contact time (5 – 30 min) and phase volume ratio (0.5-5) on the transfer efficiency of jacalin was evaluated by changing one factor at a time (OFAT) while keeping the other parameters constant. A maximum of 83% of protein transfer was achieved after equal volume of organic and aqueous phase was stirred for 20 min using 20 mM AOT at pH 5 aqueous phase containing 0.1 M NaCl. The findings demonstrated AOT reverse micellar system as a promising and effective method to extract and purify jacalin from crude protein mixture.

Solvent extraction of scandium from chlorination system with EHPAEH

The extraction of scandium from hydrochloric acid media with EHPAEH is investigated. Fe3+ in synthesized solution would reduce the purity of scandium, therefore, N235 is selected as extractant for separating Fe3+ and Sc3+. Experimental results indicated that separation factor βFe/Sc reached 5416.4 with the organic system consisting of 20 vol% trinoctylamine(N235), phase volume ratio(O/A) of 1:1, extraction stage of 3. Then mono(2-ethyl hexyl)-2-ethyl hexyl phosphonate(EHPAEH) is employed to extract Sc3+ from the leaching solution of Fe3+ free. With the organic phase containing 5 vol% EHPAEH, phase volume ratio O/A of 1:5, at pH 0.3, nearly 99% scandium is extracted. Finally, the scandium-loaded organic phase is stripped with 4.5N hydrochloric acid, under phase volume ratio of 1:1 at 65°C.

Phosphoric acid recovery from concentrated aqueous feeds by a mixture of di-isopropyl ether (DiPE) and tri-n-butylphosphate (TBP): extraction data and modelling

This paper reports experimental data and modelling about the extraction of H3PO4 from concentrated aqueous feeds (3 to 14 M) by the mixture of DiPE and TBP at 25 °C: distribution ratios of H3PO4 and water, and associated change of phase volume ratio.

Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology

To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.