Search

The phase behavior of binary blends of AB diblock copolymers of compositions f and 1 − f is examined using field-theoretic simulations. Highly asymmetric compositions (i.e., f ≈ 0) behave like homopolymer blends macrophase separating into coexisting A- and B-rich phases as the segregation is increased, whereas more symmetric diblocks (i.e., f ≈ 0.5) microphase separate into an ordered lamellar phase. In self-consistent field theory, these behaviors are separated by a Lifshitz critical point at f = 0.2113. However, its lower critical dimension is believed to be four, which implies that the Lifshitz point should be destroyed by fluctuations. Consistent with this, it is found to transform into a tricritical point. Furthermore, the highly swollen lamellar phase near the mean-field Lifshitz point disorders into a bicontinuous microemulsion (BμE), consisting of large interpenetrating A- and B-rich microdomains. BμE has been previously reported in ternary blends of AB diblock copolymer with its parent A- and B-type homopolymers, but in that system the homopolymers have a tendency to macrophase separate. Our alternative system for creating BμE is free of this macrophase separation. [ABSTRACT FROM AUTHOR]

[Display omitted] Switchable microemulsions (MEs) are those capable of adaptively responding to the action of internal or external stimuli. For redox-switchable MEs to obtain high-efficiency phase separation and surfactant recycling, it may be one of the keys to adequately turn off the interfacial activity of surfactants and reduce the solubility of the closed surfactants in the oil phase. Monophasic MEs consisting 11-butylselanyl-undecyl sulfate sodium (C 4 SeC 11 SO 4 Na), n -butanol, n -octane, and water were fabricated using the pseudo-ternary phase diagram method. Their structural features and droplets size were characterized by conductivity, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM), respectively. The redox response of MEs was studied using a combination of visual observations and DLS, cryo-TEM, nuclear magnetic resonance (NMR) and thin-layer tomography. The efficient recycling of C 4 SeC 11 SO 4 Na from a well-emulsified eluent is conceptually demonstrated. The reversible transition between C 4 SeC 11 SO 4 Na and C 4 SeOC 11 SO 4 Na is achieved under the alternating action of H 2 O 2 and N 2 H 4 , by which C 4 SeC 11 SO 4 Na-based monophasic MEs are able to efficiently demulsify and regenerate, respectively, regardless of their type. After H 2 O 2 -induced demulsification of the MEs, C 4 SeOC 11 SO 4 Na can be efficiently recycled with the water phase. We hope that such a redox-switching method may benefit some technological applications. For example, it offers exciting possibilities for simultaneous recycling C 4 SeC 11 SO 4 Na and removal of oil from a well-emulsified eluent. Around 97.1 ± 0.3 % of C 4 SeC 11 SO 4 Na could be recycled over five cycles with no apparent loss. After a simple and conventional treatment with anion-exchange resin and active carbon, the total organic carbon and chemical oxygen demand of the waste water were 17.4 ± 2.8 and 26.2 ± 1.4 mg/L, respectively. [ABSTRACT FROM AUTHOR]

Environmental‐friendly carbon dots (CDs) have found wide applications in the fields of white light emitting diode (WLED), chemical sensor, wide‐gamut display, etc. However, for the aggregation‐caused quenching (ACQ) effect, high dose of CDs immobilization generally suffers from the great fluorescence quenching, hindering their practical uses in many cases. In the present work, a one‐step microwave‐assisted microemulsion process is developed to prepare matrix‐free green CDs powders with absolute fluorescent quantum yield (QY) up to 48.34%. From dilute solution to matrix‐free powder, the QY of CDs decreases only about 20%, significant smaller than the sample prepared without surfactant (74%). Structural characterization and fluorescent lifetime measurements suggest that the passivation of hydrophobic long‐alkyl chains from surfactant Span‐80 is very key for their good solid‐state photoluminescence (PL). For the good solid‐state PL and various solvent‐compatibility, the CDs reported show promising applications in the fabrication of WLED and the measurement of water content of ethanol/water solution. This work provides a new idea to design and simply synthesize desirable CDs‐based luminescent materials with good solid‐state PL. [ABSTRACT FROM AUTHOR]

Microemulsion based fuels (MBF) have gained significant attention in recent years due to their potential to enhance combustion efficiency, reduce emissions, and improve overall engine performance. This research paper enlightens the effects of physiochemical properties on the emission characteristics of CI engine. The microemulsions are formulated using surfactants, co‐surfactants, water or alcohols, and fuel components. The effects of density, viscosity, calorific value, cold flow properties, and cetane number along with the stability and the multi‐component characteristics of (MBF) has been taken into consideration to examine its effects on Emission characteristics such as nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide (CO), particulate matter (PM), and unburned hydrocarbons (UHC). Microemulsion‐based fuels lower emissions of NOx and PM, recognized to the more complete combustion. The review highlights various studies that have investigated the benefits of microemulsion fuels, including reduced emissions of different pollutants and thus reduce the adverse effect on environment. In conclusion, microemulsion‐based fuels show likely physiochemical properties, as well as favorable emission characteristics, with reduced NOx, SOx, CO, PM, and UHC emissions. This study highlights the potential of microemulsion‐based fuels as environment friendly alternatives, flagging the way for further research. [ABSTRACT FROM AUTHOR]

Hypothesis : Amphiphilic diblock copolymers are known to increase the surfactant's efficiency to stabilize microemulsion, leading to higher structural order and monolayer rigidity. We thus seek to evaluate whether the addition of such polymers alters the shear behavior of bicontinuous microemulsions, in particular, their shear transformation towards lamellar structures. Experiments : We examine the initial structure and shear response of bicontinuous ▪/ n -octane/▪/PEP 5 - b -PEO 5 microemulsions by coupling microfluidics with small-angle neutron scattering (SANS), attaining wall shear rates in excess of ▪. The azimuthal analysis of the obtained 2D scattering patterns allows us to follow their structural transformation by means of the degree of anisotropy. Findings : The amphiphilic diblock copolymer promotes the shear-induced transformation of bicontinuous microemulsions, resulting in up to ∼▪ higher degrees of anisotropy than for corresponding polymer-free microemulsions. The increased shear response observed with increasing polymer content is rationalized by combining the influence of domain size and viscosity with the stability limits of the bicontinuous microemulsion in the isothermal phase diagram. As a result, a consistent description of the degree of anisotropy is obtained, enabling the prediction of the shear-induced bicontinuous-to-lamellar transformation. [ABSTRACT FROM AUTHOR]

The current research is focused on the discovery and optimization of an effective cosmetic carrier of alpha-bisabolol as a first step in the development of a cosmetic product with cleansing and antimicrobial action for facial skin hygiene. A micellar solution of Poloxamer 407 was selected as a cosmetic base because of the good washing ability, easy application, and high tolerability of this polymeric surfactant. The solubilization capacity of a 5% micellar solution with respect to α-bisabolol was investigated by applying varying solubilization techniques and increasing concentrations of the oily active substance. The test samples were subjected to an accelerated physical stability test, viscosimetry, dynamic light scattering (DLS), electrophoretic light scattering (ELS), foamability test, and antimicrobial screening. Over the course of this research, the advantage of the film-hydration method over direct solubilization was demonstrated by the narrower size distribution and smaller hydrodynamic size of the micellar nano-carriers (ranging from 29.02 to 116.5 nm) and the respective higher physical stability of the dispersions. The optimized composition was found to be suitable for application on large skin areas in terms of viscosity in the temperature range from 20 °C to 40 °C (3.4–2.3 mPa.s). Preservation of the washing capacity of the micellar solution in the presence of solubilized α-bisabolol was established. The active composition demonstrated inhibitory activity against Staphylococcus aureus and Escherichia coli and fungicidal activity against Candida albicans. This study concludes that the optimal concentration of α-bisabolol to be solubilized in a 5% Poloxamer 407 micellar solution by the film-hydration technique is 1%, considering the desirable physical endurance and antimicrobial activity. [ABSTRACT FROM AUTHOR]

Here, we demonstrate a synthetic approach to precise size control of PNIPAM-based core@shell nanoparticles prepared by microemulsion polymerization as well as control of low critical solution temperature (LCST) of their water dispersions. The size of the PS-core can be tuned to ∼30 nm by a simple increase of mechanical stirring up to 1200 rpm, while the thickness of the thermoresponsive @poly(N-isopropyl acrylamide-co-acrylamide) shell can be controlled by varying the polymerization time. The effect of not only a molar ratio or co-monomer nature but also a strong influence of a thermoresponsive shell thickness on the LCST was found. [ABSTRACT FROM AUTHOR]

Aims Evaluate the in vitro efficacy of the essential oils derived from Aloysia citrodora (Verbenaceae), Cymbopogon winterianus (Poaceae), and Ocimum gratissimum (Lamiaceae) against Acanthamoeba polyphaga trophozoites. Additionally, microemulsions formulated with these essential oils, along with their major components, were analyzed. Methods and results The prepared microemulsions were characterized using polarized light microscopy and rheological techniques. The amoebicidal activity was determined by measuring the inhibitory concentration (IC50). Flow cytometry was employed to detect membrane damage and alterations in trophozoites size. The results revealed transparent and thermodynamically stable microemulsions. The essential oil from O. gratissimum exhibited a lower IC50, with values of 280.66 and 47.28 µg ml−1 after 24 and 48 h, respectively. When microemulsions containing essential oils were tested, the IC50 values exhibited a reduction of over 80% after 24 h. Particularly, eugenol, a constituent of the O. gratissimum essential oil, displayed higher amoebicidal activity. The essential oils also caused damage to the cell membrane, resulting in the subsequent death of the trophozoites. Conclusions The EOs of A. citrodora, C. winterianus , and O. gratissimum and their microemulsions showed antiparasitic effect against A. polyphaga trophozoites, representing promising alternatives for the treatment of diseases caused by this protozoan. [ABSTRACT FROM AUTHOR]

A method to determine aceclofenac, ketorolac, and sulindac in human urine samples using microemulsion electrokinetic chromatography (MEEKC) has been developed in this study. The optimization of MEEKC conditions was carried out by changing the microemulsion compositions including the buffer pH, borate salt concentration, surfactant concentration, co-surfactant concentration, organic modifier concentration, and oil droplet concentration. The optimum separation of selected drugs was obtained with a composition of microemulsion containing 10 mM borate buffer pH 9, 0.5% sodium dodecyl sulphate (SDS), 6.6% n-butanol, 6.0% acetonitrile, and 0.8% ethyl acetate. Excellent linearity was obtained in the range concentration of 25 to 200 ppm with r2 > 0.999. Limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) were 2.72 to 4.75 and 9.08 to 15.85 ppm, respectively. The solid-phase extraction (SPE) method using C-18 as an adsorbent and the solid phase micro-tip extraction (SPMTE) method using multiwalled carbon nanotubes (MWCNTs) as an adsorbent were used to clean-up and pre-concentrate the urine samples prior to the MEEKC analysis. The best recoveries of the selected drugs in the spiked urine sample were 91 to 103% with RSD of 1.26 to 4.03% (n = 3) using the SPE-MEEKC method. [ABSTRACT FROM AUTHOR]

[Display omitted] Microemulsion (ME) has been investigated as a chemical polishing (CP) fluid for effective polishing of single crystal potassium dihydrogen phosphate (KDP), perfectly avoiding the generation of mechanical stress. In this work, a water-in-deep eutectic solvent ME was proposed as the polishing fluid for CP of single crystal KDP. Deep eutectic solvent (DES) is formulated using n -octanol as hydrogen bond donor and methyltrioctylammonium chloride (MTOAC) as hydrogen bond acceptor, with a mass ratio of 2:1. The ME was prepared by mixing DES as the oil phase (12.5 %, wt.), a hydrochloric acid solution as the water phase (12.5 %, wt.), and isopropanol as the cosolvent (75 %, wt.), without adding any other surfactants. The properties of the ME were characterized by conductivity measurements and ultraviolet (UV) spectroscopy. The reactivity of ME with KDP was measured by the conductivity method, and it was higher at low pH values. A hydrochloric acid solution with a pH of 3 was selected as aqueous phase, considering its effects on particle size, salt loading, and static etching rate. The water content affects the polarity of ME and the final water content was determined to be 12.5 % to ensure high polarity of ME. The surface quality of the KDP crystals before and after polishing was examined using grazing incidence X-ray diffraction (GIXRD) analysis. The average roughness of the KDP crystal surface was decreased from 1.96 nm to 1.43 nm, and the root-mean-square (RMS) roughness was reduced from 2.81 nm to 1.86 nm, demonstrating a significant polishing effect. Finally, the polishing mechanism was elucidated in terms of the irreversible chemical reaction between the active components in the microemulsion and the KDP crystals. [ABSTRACT FROM AUTHOR]

[Display omitted] The commonly used artificial light sources, such as fluorescent lamps and white light-emitting diodes, often have a high ratio of blue light emission, which poses potential blue light hazards, especially one of the main culprits leading to eye diseases. Therefore, developing novel white lighting sources with low blue-hazard is highly appreciated. In this work, an air-stable and color-tunable triplet–triplet annihilation upconversion (TTA-UC) mechanism was proposed to realize the low blue-hazard white-light emission. The proposed design was composed of three primary RGB colors from the annihilator (9,10-diphenylanthracene, DPA), the laser excitation source, and the photosensitizer (palladium (II) octaetylporphyrin, PdOEP), respectively. The introduction of oil-in-water (o/w) microemulsion can effectively block the potential oxygen-induced triplet-quenching and benefit high UC efficiency. Moreover, either raising ambient temperatures or adding isobutanol can activate the UC process to yield white-light emission. Notably, the white-light emission with a Commission Internationale de l'Eclairage (CIE) coordinate of (0.33, 0.33) as well as a low ratio of blue emission (14.2 %) was achieved at an ambient temperature of 42 °C. Therefore, the proposed air-stable TTA-UC mechanism can significantly lower the blue-hazard and provide a novel solution for applications in lighting and display. [ABSTRACT FROM AUTHOR]

Nanopesticides have been acknowledged by International Union of Pure and Applied Chemistry as a critical tool for revolutionizing future agricultural practices. However, the existing nanopesticides are often plagued by high costs, strict preparation conditions, uncontrollable size, and poor stability. Herein, taking the non‐systemic insecticide lambda‐cyhalothrin (LC) as a model pesticide, a series of LC‐loaded poly(octyl acrylate) nanogel formulations (LONFs) simultaneously featuring easy‐preparation, size‐controllable, and targeted delivery using microemulsion polymerization are developed. By adjusting the ratio of surfactants, the size of LONFs can be accurately designed to be 20, 50, 100, and 200 nm, exhibiting good stability under unconventional storage conditions (0 °C, 54 °C, ultraviolet radiation). Furthermore, reducing the particle diameter enhances the bidirectional translocation of LONFs in Vicia faba L., potentially reaching an optimal diameter (≈20 nm) for unique and rapid transport. LONFs increase the acute toxicity of LC to Aphis craccivora compared to conventional microemulsions (with a maximum reduction of 82.40% in LC50 at 24 h). Additionally, LONFs alter the lethal process of LC in human embryonic kidney 293T cells, with minimal cytotoxicity at a concentration of general application (40 mg L−1). This strategy simultaneously considers convenience, size controllability, and efficiency, providing a feasible method for the industrial development of nanopesticides. [ABSTRACT FROM AUTHOR]

Biofumigation was proposed as an alternative to synthetic pesticides for the disinfection of agricultural soils, in view of the biocidal effect of isothiocyanates (ITCs) released by some vegetal species, like Brassicaceae. However, biofumigation also presents limitations; thus, a novel and viable alternative could be the direct introduction of ITCs into agricultural soils as components loaded into biodegradable hydrogels. Thus, in this work, ITCs-based microemulsions were developed, which can be loaded into porous polymer-based hydrogel beads based on sodium alginate (ALG) or sodium carboxymethyl cellulose (CMC). Three ITCs (ethyl, phenyl, and allyl isothiocyanate) and three different surfactants (sodium dodecylsulfate, Brij 35, and Tween 80) were considered. The optimal system was characterized with attenuated ATR-FTIR spectroscopy and differential scanning calorimetry to study how the microemulsion/gels interaction affects the gel properties, such as the equilibrium water content or free water index. Finally, loading and release profiles were studied by means of UV–Vis spectrophotometry. It was found that CMC hydrogel beads showed a slightly more efficient profile of micelles' release in water with respect to ALG beads. For this reason, and due to the enhanced contribution of Fe(III) to their biocidal properties, CMC-based hydrogels are the most promising in view of the application on real agricultural soils. [ABSTRACT FROM AUTHOR]

Background Materials and Methods Results Conclusion Methimazole, an oral antithyroid drug, has recently gained attention for its skin‐brightening effects when applied topically to treat melasma. This study aims to develop, optimize, and characterize a methimazole microemulsion as a novel, safe approach for local melasma treatment.We prepared microemulsion formulations containing 3% methimazole by combining appropriate amounts of surfactants (Tween 80 and Span 20), propylene glycol cosurfactant, and an oil phase (oleic acid‐transcutol p at a 1:10 ratio). We then assessed droplet size, stability, viscosity, and skin permeation using rat skin models.The microemulsions' droplet sizes ranged from 7.06 to 28.13 nm, with viscosities between 120 and 254 centipoises. Our analysis identified droplet size, viscosity, and membrane release as significant independent variables. We determined the permeability parameters of the optimal formulation through rat skin, including steady‐state permeability rate (Jss), permeability coefficient (p), lag time (Tlag), and apparent diffusion coefficient (Dapp).We found that the microemulsions' characteristics, physicochemical properties, and in vitro release depended on the surfactant‐to‐cosurfactant ratio, water content, and oil content. We developed an optimal formulation with a high surfactant‐to‐cosurfactant ratio and low water and oil percentages. This formulation shows potential for commercialization and manufacturing of final products. [ABSTRACT FROM AUTHOR]

In this study, the compound 1-(4-(tert-butyl) phenyl)-3-hydroxy-2-methylpyridine-4 (1H) - one (hereinafter referred to as HAINU-19) was used as the active ingredient to prepare the microemulsion and determine its antifungal activity. First, through the screening solvents, co-solvents, and transparent, the formulation of 2.5% HAINU-19 microemulsion (mass fraction) was determined as follows: 2.5% HAINU-19, 15% ethanol, 10% cyclohexanone, 20% transparent (1601# : 500# : AC1810 = 3 : 3 : 1), with distilled water making up to 100%. All indicators meet national standards. The bioassay result of pot experiments showed that the protective and curative effects of 2.5% HAINU-19 microemulsion on wheat stripe rust were 100% at 1000, 500, and 250-fold dilutions, and curative effects were 76.67%, 81.00%, and 82.33%, respectively. The field trial results showed that the 2.5% HAINU19 microemulsion had a control efficacy of 86.13% on rice sheath blight at a 100-fold dilution and 71.24% at a 200-fold dilution. This study can provide an experimental basis and technical support for the development and application of the antifungal compound HAINU-19. [ABSTRACT FROM AUTHOR]

The OphthalMimic is a 3D-printed device that simulates human ocular conditions with artificial lacrimal flow, cul-de-sac area, moving eyelid, and a surface to interact with ophthalmic formulations. All tests with such a device have used a continuous artificial tear flow rate of 1 mL/min for 5 min. Here, we implemented protocol variations regarding the application time and simulated tear flow to increase the test's discrimination and achieve reliable performance results. The new protocols incorporated the previously evaluated 0.2% fluconazole formulations containing or not chitosan as a mucoadhesive component (PLX16CS10 and PLX16, respectively) and novel moxifloxacin 5% formulations, either in a conventional formulation and a microemulsion (CONTROL and NEMOX, respectively). The flow rate was reduced by 50%, and a pre-flow application period was also included to allow formulation interaction with the membrane. The OphthalMimic model was used with both polymeric and hydrogel-based hybrid membranes, including a simulated eyelid. Lowering the flow made it feasible to prolong the testing duration, enhancing device discrimination potential. The hydrogel membrane was adequate for testing nanostructure formulations. The OphthalMimic device demonstrated once again to be a versatile method for evaluating the performance of ophthalmic drug formulations with the potential of reducing the use of animals for experimentation. [ABSTRACT FROM AUTHOR]

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO2 NPs corresponding to anatase, rutile, or an anatase/rutile/brookite mixture were obtained at 80 °C by an inverse microemulsion method in a ternary system of water/cetyltrimethylammonium bromide/1-hexanol in a weight ratio of 17:28:55. The only synthesis variables were the preparation of the aqueous component and the nature of the Ti precursor (Ti(IV) ethoxide, isopropoxide, butoxide, or chloride). The materials were characterized with X-ray diffraction, scanning/transmission electron microscopy, N2 adsorption–desorption isotherms, FTIR and Raman vibrational spectroscopies, and diffuse reflectance spectroscopy. The synthesis products differed significantly not only in phase composition, but also in crystallinity, textural properties, and adsorption properties towards water. All TiO2 NPs were active in the photocatalytic decomposition of rhodamine B, a model dye pollutant of wastewater streams. The mixed-phase anatase/rutile/brookite nanopowders obtained from alkoxy precursors showed the best photocatalytic performance, comparable to or better than the P25 reference. The exceptionally high photoactivity was attributed to the advantageous electronic effects known to accompany multiphase titania composition, namely high specific surface area and strong surface hydration. Among the single-phase materials, anatase samples showed better photoactivity than rutile ones, and this effect was associated, primarily, with the much higher specific surface area of anatase photocatalysts. [ABSTRACT FROM AUTHOR]

In order to solve the problems of high cost of microemulsion use and the limitation of microe- mulsion application in high temperature and high salt strata, this paper conducted a systematic research on the development of chemically driven microemulsions and the unique properties of nanoparticles, and summarized the synergistic effect between nanoparticles and microemulsions, the effect of nanoparticle incorporation on the applicability of salinity to the microemulsions as well as the influence on the rheological properties. The current status of nanoparticle synergistic microemulsion research at home and abroad is summarized and reviewed, and the synergistic effect between nanoparticles and microemulsions is summarized to produce mechanisms such as low interfacial tension, change of wettability, reduction of chemical adsorption, enhancement of stability, and improvement of rheological ratio. At present, the application of nanoparticles in microemulsions is still in the exploratory stage, which requires further theoretical analysis and experimental research. [ABSTRACT FROM AUTHOR]

Current research of triplet–triplet annihilation upconversion (TTA-UC) faces difficulty such as overuse of organic solvents and quenching of excited triplet sensitizers by molecular oxygen. Herein, we propose an efficient and facile preparation strategy of TTA-UC microemulsion to overcome these issues. With simple device and short preparation process, air-stable TTA-UC with a high upconversion efficiency of 16.52% was achieved in microemulsion coassembled from TritonX114, tetrahydrofuran and upconverting chromophores (platinum octaethyl-porphyrin and 9,10-diphenylanthracene). This is comparable to the highest UC efficiency ever reported for TTA-UC microemulsion systems. The excellent UC performance of TX114–THF could be attributed to two perspectives. Firstly, small-size micelle accommodated chromophores up to high concentrations in organic phase, which promoted efficient molecular collision. Additionally, high absorbance at 532 nm ensured full use of excitation light, getting more long wavelength photons involved in the TTA-UC process. Moreover, air-stable TTA-UC also performed well in microemulsion with various surfactants, including nonionic surfactants (Tween 20, Tween 80, Triton X-110, Triton X-114), ionic surfactants (sodium dodecyl sulfate, cetyltrimethyl ammonium bromide) and block copolymers (pluronic F127, pluronic P123), through three conjectural assembly models according to the structural characteristics of surfactant molecules (concentrated, uncompacted and scattered). These discoveries could provide estimable reference for selection of surfactants in relevant fields of TTA-UC. [ABSTRACT FROM AUTHOR]

Ketoprofen is a non-steroidal, anti-inflammatory drug frequently incorporated in topical dosage forms which are an interesting alternatives for oral formulations. However, due to the physiological barrier function of skin, topical formulations may require some approaches to improve drug permeation across the skin. In this study, ketoprofen-loaded microemulsion-based gels with the addition of menthol, commonly known for absorption-enhancing activity in dermal products, were investigated. The main objective of this study was to analyze the physicochemical properties of the obtained gels in terms of topical application and to investigate the correlation between the gel composition and its mechanical properties and the drug release process. Microemulsion composition was selected with the use of a pseudoternary plot and the selected systems were tested for electrical conductivity, viscosity, pH, and particle diameter. The polymer gels obtained with Carbopol® EZ-3 were subjected to rheological and textural studies, as well as the drug release experiment. The obtained results indicate that the presence of ketoprofen slightly decreased yield stress values. A stronger effect was exerted by menthol presence, even though it was independent of menthol concentration. A similar tendency was seen for hardness and adhesiveness, as tested in texture profile analysis. Sample cohesiveness and the drug release rate were independent of the gel composition. [ABSTRACT FROM AUTHOR]

Microemulsions are thermodynamically stable, optically isotropic, transparent, or semi-transparent mixed solutions composed of two immiscible solvents stabilized by amphiphilic solutes. This comprehensive review explores state-of-the-art techniques for characterizing microemulsions, which are versatile solutions essential across various industries, such as pharmaceuticals, food, and petroleum. This article delves into spectroscopic methods, nuclear magnetic resonance, small-angle scattering, dynamic light scattering, conductometry, zeta potential analysis, cryo-electron microscopy, refractive index measurement, and differential scanning calorimetry, examining each technique's strengths, limitations, and potential applications. Emphasizing the necessity of a multi-technique approach for a thorough understanding, it underscores the importance of integrating diverse analytical methods to unravel microemulsion structures from molecular to macroscopic scales. This synthesis provides a roadmap for researchers and practitioners, fostering advancements in microemulsion science and its wide-ranging industrial applications. [ABSTRACT FROM AUTHOR]

With the ongoing advancement in oil exploration, microemulsion, as an innovative oil displacement method, has garnered considerable attention owing to its exceptional physicochemical properties in enhancing crude oil recovery. As such, this study initially delineates the fundamental concepts, classifications, formation mechanisms, advantages, and preparation methodologies of microemulsions. Subsequently, it introduces the selection criteria for microemulsion components, followed by an elucidation of the characterization methods for microemulsions based on these criteria. Furthermore, it examines the factors influencing the efficacy of microemulsions in enhancing oil recovery through two distinct methods, along with the effects of various formulation microemulsions under laboratory and oilfield conditions. Additionally, it outlines prospects, challenges, and future development trends pertaining to microemulsions. [ABSTRACT FROM AUTHOR]

Herein, non-conventional lanthanum phosphate (LaPO4) nanospheres were synthesised in water-in-oil (W/O) microemulsion (Tween 20/1-butanol/water/toluene) scaffolds and employed in the assessment of surfactant-free TiO2-based Pickering emulsion formulations. TEM and FESEM microstructural analyses were carried out to examine the nanospheres inside the core of the reverse micelles. Both types of electron microscopy identified two distinct phases in the growth of the nanospheres: a nucleation phase (5–15 min) in which only nanospheres of smaller dimensions were seen and a growth phase (15–60 min) wherein larger dimensions nanospheres were observed. LaPO4 nanospheres are extremely hydrophilic and alone would fail to provide stability to the oil-in-water (O/W) Pickering emulsions and consequently require in situ hydrophobization. The determined zeta potentials suggested that the LaPO4 nanospheres have a positive surface charge (+57 mV) and eventually, oppositely charged solid TiO2 nanoparticles were therefore introduced onto the surface of the synthesised LaPO4. The adsorption of TiO2 ensured the evaluation of the amphiphilic nature of the nanospheres through the formation of LaPO4@TiO2 nanocomposites. Additionally, TEM analysis supported that no morphological alterations occurred upon the adsorption. The as-prepared nanocomposites thereafter started to provide extra stability (due to the lower interdroplet coalescence) to the O/W Pickering emulsions, which could be sustained for up to 4 weeks and even more. The stability of the emulsion droplets was supported by the optical micrography analysis. Moreover, such an attainment of stability therefore, successfully opens a new idea for obtaining surfactant-free stable Pickering emulsion formations. [ABSTRACT FROM AUTHOR]

Microemulsions (µEs) are particularly suitable systems for the efficient delivery of anticancer drugs due to their thermodynamic stability, structural flexibility, and patient-friendly chemotherapies. Moreover, µE formulations can efficiently encapsulate the anticancer drugs and deliver them to the desired location. Herein, three new Tween-60-based µE formulations were developed to enhance the dissolution profile of anticancer methotrexate (MTX). For this, µE formulations using an appropriate ratio of castor oil (~9%), water (~11%), and Tween-60 (~40%) were used, while ethanol, 2-propanol, and 1-butanol were selected as co-surfactants for each formulation, respectively. Preliminarily, the phase compatibility of the µE ingredients, the average µE region, and the structural transformation in the microstructure of µE were delineated by mapping the pseudoternary phase diagram, as well as electrical conductivity, viscosity, and optical microscopic measurements. The size distribution profile of the as-formulated µEs analyzed by dynamic light scattering (DLS) revealed the fine monomodal assembly of MTX-µE nanodroplets (~65 nm), which remained stable over a half year of storage. FTIR analysis showed good compatibility of MTX with µE ingredients with no apparent chemical interaction, while fluorescence measurements endorsed the acquisition of MTX in nonpolar microenvironments. Furthermore, an enhanced dissolution rate (>98% ± 1.5%, p ≥ 0.001) and superior bioavailability of the lyophilized non-aggregated methotrexate nanoparticles (MTX-NPs) were achieved, making them a suitable formulation for oral administration. [ABSTRACT FROM AUTHOR]

The n-butanol/low-carbon alcohol/diesel microemulsion system is a good alternative fuel to diesel. In this study, the microemulsions were formulated in four ways: ultrasonication, vortex oscillation, shaker mixing and spontaneous formation. The results reveal that the ultrasonication method is significantly influenced by temperature. Specifically, at 45 °C, the quantity of cosolvent added during the ultrasonic process can be reduced by a maximum of 25% compared to that at 25 °C. However, while the amount of cosolvent required is the lowest at 45 °C, the stability of the emulsion is the poorest. In all cases of this study, the stability of the microemulsion increases when the volume ratio of the lower carbon alcohol exceeds 60%. The lowest amount of co-solvent and high stability were achieved using the shaker mixing method at both 25 °C and 35 °C. Although the quantity of cosolvent required at 45 °C is second only to the lowest, its stability surpasses that of the ultrasonication method. Therefore, it is more effective to choose the shaker mixing method that provides uniform and ordered forces for the preparation of microemulsion liquids. [ABSTRACT FROM AUTHOR]

Concerns surrounding breast cancer have been increasing, as it leads to the current global cancer incidence and causes a high mortality rate in women. This study investigated the physiological effects of common dietary polyphenols that might prevent breast cancer progression. Quercetin, kaempferol, and rosmarinic acid were selected to explore their potential bioactivities. Each polyphenol was formulated into a microemulsion to improve its bioactivity and bioavailability. In vitro antioxidant and cytotoxicity activities of the selected polyphenols and their microemulsion forms were further investigated. The optimized microemulsion carrier with 1% oleic acid, 3% ethanol, 10% polysorbate 20, and 86% ultrapure water achieved more than 90% polyphenol encapsulation efficiency. The microemulsion was stable for more than 30 days when encapsulating polyphenol in the fluctuating temperature treatment. In vitro studies suggested that rosmarinic acid-loaded microemulsion had the best antioxidant activity compared with other polyphenol-loaded microemulsions (PL-MEs). Blank microemulsion and all PL-MEs significantly inhibited the proliferation of both hormone-dependent (T47D) and hormone-independent (MDA-MB-231) breast cancer cells. More studies are warranted to confirm the contribution of the microemulsion carrier components to the polyphenols' improved antioxidant activity and high toxicity of PL-MEs on breast cancer cells. [ABSTRACT FROM AUTHOR]

The administration of hydrophilic therapeutics has always been a great challenge because of their low bioavailability after administration. For this purpose, W/O/W microemulsion resulted to be a potential successful strategy for the delivery of hydrophilic compounds, interesting for the nasal mucosal therapy. Herein, an optimized biphasic W/O microemulsion was designed, through a preliminary screening, and it was inverted in a triphasic W/O/W microemulsion, intended for the nasal administration. In order to enhance the mucosal retention, surface modification of the biphasic W/O microemulsion was performed adding didodecyldimethylammonium bromide, and then converting the system into a cationic triphasic W/O/W microemulsion. The developed samples were characterized in terms of droplet size, polydispersity, zeta potential, pH and osmolality. The physical long-term stability was analyzed storing samples at accelerated conditions (40 ± 2 °C and 75 ± 5 % RH) for 6 months in a constant climate chamber, following ICH guidelines Q1A (R2). In order to verify the potential retention on the nasal mucosa, the two triphasic systems were analyzed in terms of mucoadhesive properties, measuring the in vitro interaction with mucin over time. Furthermore, fluorescein sodium salt was selected as a model hydrophilic drug to be encapsulated into the inner core of the two triphasic W/O/W microemulsions, and its release was analyzed compared to the free probe solution. The cytocompatibility of the two platforms was assessed on two cell lines, human fibroblasts HFF1 and Calu-3 cell lines, chosen as pre-clinical models for nasal and bronchial/tracheal airway epithelium. [Display omitted] • The preformulative screening allowed the development of W/O/W microemulsions adequate for the intended nasal administration. • Accelerated stability studies demonstrated a long-term stability for the prepared W/O/W microemulsions. • W/O/W microemulsions showed good mucoadhesive properties, which could guarantee the adhesion on the nasal mucosa. • A rapid and sustained release of fluorescein from the neutral W/O/W microemulsion was obtained. • Neutral W/O/W microemulsion represents a promising system due to its high biocompatibility on HFF1 and Calu-3 cell lines. [ABSTRACT FROM AUTHOR]

Cannabidiol (CBD) is a safe and non-psychotropic phytocannabinoid with a wide range of potential therapeutic anti-inflamatory and antioxidant activities. Due to its lipophilicity, it is normally available dissolved in oily phases. The main aim of this work was to develop and characterize a new formulation of a microemulsion with potential anti-inflammatory and antioxidant activity for the topical treatment of inflammatory skin disorders. The microemulsion system was composed of a 20% CBD oil, which served as the hydrophobic phase; Labrasol/Plurol Oleique (1:1), which served as surfactant and cosurfactant (S/CoS), respectively; and an aqueous vegetal extract obtained from Sambucus ebulus L. (S. ebulus) ripe fruits, which has potential anti-oxidant and anti-inflammatory activity and which served as the aqueous phase. A pseudo-ternary phase diagram was generated, leading to the selection of an optimal proportion of 62% (S/CoS), 27% CBD oil and 11% water and, after its reproducibility was tested, the aqueous phases were replaced by the vegetal hydrophilic extract. The defined systems were characterized in terms of conductivity, droplet size (by laser scattering), compatibility of components (by differential scanning calorimetry) and rheological properties (using a rotational rheometer). The designed microemulsion showed good stability and slight pseudo-plastic behavior. The release properties of CBD from the oil phase and caffeic acid from the aqueous phase of the microemulsion were studied via in vitro diffusion experiments using flow-through diffusion cells and were compared to those of a CBD oil and a microemulsion containing only CBD as an active substance. It was found that the inclusion of the original oil in microemulsions did not result in a significant modification of the release of CBD, suggesting the possibility of including hydrophilic active compounds in the formulation and establishing an interesting strategy for the development of future formulations. [ABSTRACT FROM AUTHOR]

This study explores developing and optimizing a nanoemulsion (NE) system loaded with dipyridamole and roflumilast, aiming to improve skin penetration and retention. The NE formulation was further transformed into a nanoemulgel to enhance its application as a topical treatment for psoriasis. Solubility studies were conducted to select the oil, surfactant, and co-surfactant. Phase diagrams were constructed using the aqueous phase titration method. All the formulations were in nanoscale, and Formula (F2) (which contains oleic acid oil as the oil phase, a mixture of Surfactant Tween 80 and co-surfactant (ethanol) at a ratio of 1:2 in addition to distilled water as an aqueous phase in a ratio of 1:5:4, respectively) was the selected formula depending on the particle size, PDI, and zeta potential. Formula (F2) has the best ratio because it gives the smallest nanoemulsion globule size (particle size average of 167.1 nm), the best homogenicity (lowest PDI of 0.195), and the highest stability (higher zeta potential of −32.22). The selected formula was converted into a nanoemulgel by the addition of 0.5% (w/w) xanthan gum (average particle size of 172.7 nm) and the best homogenicity (lowest PDI of 0.121%) and highest stability (higher zeta potential of −28.31). In conclusion, the selected formula has accepted physical and chemical properties, which enhanced skin penetration. [ABSTRACT FROM AUTHOR]

To construct the microemulsion delivery system (ME) loading ATSO and NA and study their physicochemical characteristics to enhance their stability and water solubility. By plotting ternary phase diagrams, the composition and proportions of the MEs were determined. The physicochemical characteristics and stability of MEs were evaluated by mean diameter, polydispersity index (PDI), pH, electrical conductivity, transmission electron microscopy (TEM), rheological behaviour measurement, and phase inversion temperature (PIT). The MEs was composed with EL-40 as a surfactant and specifically with the addition of ethanol as a cosurfactant in NA-loaded ME. The mean diameters of ATSO-loaded ME and NA-loaded ME were 39.65 ± 0.24 nm and 32.90 ± 2.65 nm, and PDI were 0.49 ± 0.01 and 0.28 ± 0.14, respectively. The TEM confirmed the spherical and smooth morphology of MEs. The rheological results indicated that MEs are dilatant fluids with the advantages of low viscosity, high fluidity, and tolerance to temperature fluctuations. The mean diameter and PDI of MEs showed no significant change after storage at 25 °C for 28 days and centrifugation. The prepared microemulsions could expand the application prospects of ATSO and NA products in cosmetics, medicine, foods and other fields. [ABSTRACT FROM AUTHOR]

Chirality plays a significant role in the manufacture of pharmaceuticals and fine chemicals. The use of chemical catalysts to control stereoselectivity relies on the use of chiral catalysts with labor–intensive synthesis and purification. Natural enzymes offer inherent stereoselectivity, making them attractive catalysts for this purpose. We report here chiral biocatalytic oxidations in microemulsions driven by horseradish peroxidase coupled with a synthetic Cu2+‐polymer catalyst. This hybrid system features crosslinked layer–by–layer (LBL) films composed of polyions with Cu2+‐containing pyrene–labelled poly(2‐hydroxy‐3‐dipicolylamino) propyl methacrylate (Py−PGMADPA) to drive oxygen reduction to form hydrogen peroxide. Peroxide in turn activates horseradish peroxidase (HRP) crosslinked in LbL films on magnetic particle beads to biocatalytically oxidize styrene, ethylbenzene, and methyl phenylacetate to chiral products. R‐stereoisomers of these reactants were selectively formed with a high enantiomeric excess of ≥80 % at 90 °C. The enzyme films show high thermal stability at 90 °C in cetyltrimethylammonium bromide microemulsion. Reactions at 90 °C were essentially complete in 2 hr. This hybrid approach opens a door to new designs of biocatalytic syntheses using a separate electrocatalyst for enzyme activation. [ABSTRACT FROM AUTHOR]

The aims of this work are to study the rheological behaviors of a microemulsion of Glucopone–water–hydrocarbon systems and to use a fractional model to describe several experimental results of these systems. Four different types of hydrocarbons were considered. The frequency dependent storage, G′, and loss modulus, G″, were investigated below the critical strain. The critical strain was found to decrease as the alkane chain lengths increased, while the opposite behavior was observed for zero shear viscosity, η0. Most of the microemulsions exhibited stable elastic fluid behavior (G′ > G″) below 10 rad s−1 angular frequency. For all systems, elastic modulus values were found to be greater than loss modulus in the frequency range studied, indicating more elastic behaviors. Shear-thinning behaviors were observed, and the complex viscosity decreased with an increase in hydrocarbon chain lengths. The effects of hydrocarbon types on the rheological behaviors were more profound in the dodecane systems which showed maximum values of G′ and η0. The Friedrich–Braun model was introduced and was used to describe several experimental results on Alkyl polyglocoside solutions. Fractional rheology successfully described the viscoelastic phenomena in Glucopone surfactant solutions and the comparisons between the experimental results and the theoretical predictions were found to be satisfactory. [ABSTRACT FROM AUTHOR]

Background: Epilation is a very effective way to remove unwanted hair because of its long-lasting effects. However, there are some disadvantages such as pain during the procedure, the possibility of ingrown hairs and perifollicular inflammation. In the present study, we investigated whether a protease-containing post-epilation microemulsion is effective in improving epilation performance and alleviating the above problems. Methods: The application characteristics and effects of the tested microemulsion were evaluated during and after three applications in 30 female volunteers. This was conducted by measuring hair density, assessing hair strength, and evaluating the subjective experience of the volunteers using a questionnaire. Results: The measurements showed that after three applications, the apparent hair density in the axilla was reduced from 43.89 ± 12.44 hairs/cm2 to 16.67 ± 6.61 hairs/cm2 (p < 0.0001). In general, volunteers observed a reduced hair regrowth rate, resulting in longer epilation intervals, and more soothed and moisturized skin. Volunteers who previously experienced ingrown hairs or perifollicular inflammation reported the absence or improvement of these problems. Conclusions: The protease-containing microemulsion not only improves the performance of the epilation procedure, leading to less frequent epilation, but also improves possible negative effects of epilation such as ingrown hairs and perifollicular inflammation. [ABSTRACT FROM AUTHOR]

Finding more efficient surfactants for water emulsification in diesel or its blends with vegetable oil biodiesels, to resolve their environmental and technical issues is an important research field. Ionic liquid-type Gemini surfactants (ILGS), 1,2-bis[N-(N ´ -dodecyl imidazole)]ethane diacetate ([C12-2-im][2Ac]) and 1,5-bis[N-(N ´ -dodecyl imidazole)]pentane diacetate ([C12-5-im][2Ac]) are synthesized and evaluated for formulation of gasoil/sunflower oil (80:20) fuel microemulsions. ILGS have two connected head-groups on each molecule, a tunable chemical structure and emulsification performance, and it was expected that their structure can be designed to form highly stable micelles. The performance of Tween80, Span80 and ILGS were compared in formulation of a single-phase fuel microemulsions via titration with 1-butanol as cosurfactant. ILGS with longer spacer length ([C12-5-im][2Ac]) has exhibited better performance than [C12-2-im][2Ac] with shorter spacer length resulting to lower 1-butanol consumption, which is attributed to the formation of more stable micelles. The 70:27:3 mixture of Tween80:Span80:ILGS has been determined as optimum surfactant mixture resulting in samples which have been remained stable as a single phase for upto 6 months. A narrowly distributed DLS hydrodynamic water droplets size of 8 and 4 nm, and a kinematic viscosity of 6.4434 and 6.6055 mm2/s (comparable to diesel) were measured for samples prepared by [C12-2-im][2Ac] and [C12-5-im][2Ac].

This paper presents the first integrated techno-economic and life cycle assessment of microemulsion systems being applied for rhodium-catalyzed hydroformylation of long-chain alkenes at industrial scale. The case study describes a projected 150 kt/a production of tridecanal (US gulf coast, 2019). The industrial success of the hydroformylation of short-chain alkenes lies in the continuous recycling of the rhodium-containing water phase. Microemulsion systems can be applied to transfer this concept to long-chain alkenes by overcoming the miscibility gap between the aqueous catalyst phase and the unipolar alkene phase and, moreover, by generating a temperature-induced multi-phase system enabling the immobilization of the catalyst and its continuous recycling, as demonstrated in miniplant operations with dodecene and rhodium/SulfoXantPhos. Customizable simulation models have been developed for scale-up and assessment of the miniplant data. Surprisingly, a profitability-driven sensitivity study indicates a base case optimum at low residence time with low alkene conversion leading to large throughput streams and high raw material purge rates. The comparison to the industrial cobalt-based benchmark system shows an economic advantage regarding net present value (Rh: 68 M$; Co: 62 M$), while about half of the environmental indicators are in favor or equivalent. In a best-case scenario considering zero leaching of expensive rhodium the net present value increases by almost 40% accompanied by a shift to overall lower environmental impacts than the benchmark. In conclusion, the investigated miniplant data suggest microemulsion systems to be competitive when applied in continuous processes at a large scale. [ABSTRACT FROM AUTHOR]

The study describes the synthesis of disiloxanes, R3SiOSiR3, tetraorganodisiloxanes-1,3-diols, (RR1SiOH)2O, and silanol, t-Bu2Si(H)OH, by AuNP-catalyzed hydrolytic oxidation of Si–H bond(s) in organosilanes. The method relies upon the en-route formation of an oil-in-water microemulsion that is dispersed in the continuous water phase and stabilized by amphiphilic AuNPs. The reaction of (MePhSiOH)2O with (HMe2Si)2NH proceeds via O-silylation of silanol groups to afford an Si–H-terminated chain with the liberation of NH3 as the byproduct. The application of this approach provides a viable synthetic solution to organosilica colloidal structures using primary organosilanes, RSiH3 (R = Ph, n-hexyl) as substrates. [ABSTRACT FROM AUTHOR]

Patterning of graphene (functionalizing some areas while leaving others intact) is challenging, as all the C atoms in the basal plane are identical, but it is also desirable for a variety of applications, like opening a bandgap in the electronic structure of graphene. Several methods have been reported to pattern graphene, but most of them are very technologically intensive. Recently, we reported the use of microemulsions as templates to pattern graphene at the μm scale. This method is very simple and in principle tunable, as emulsions of different droplet size and composition can be prepared easily. Here, we explore in detail the scope of this methodology by applying it to all the combinations of four different emulsions and three different organic reagents, and characterizing the resulting substrates exhaustively through Raman, SEM and AFM. We find that the method is general, works better when the reactive species are outside the micelles, and requires reactive species that involve short reaction times. [ABSTRACT FROM AUTHOR]

Traditional pesticide formulations have some shortcomings, including limited efficacy and the usage of huge amounts of insecticide, which has a negative impact on the environment. Using nano‐pesticide formulations reduces the amount of pesticide applied, minimizing pest control expenses and environmental contamination. As a result, this study was conducted to develop a microemulsion formulation containing emamectin benzoate or beta‐cyfluthrin with improved morphology, droplet size, emulsion stability, and persistence of foam. Moreover to assess the efficacy of the developed microemulsion in comparison to the convention alone against the Egyptian cotton leaf worm, Spodoptera littoralis (Boisd.) under both laboratory and field conditions. The results showed that the optimum conditions for emamectin benzoate microemulsion was 2% active ingredient, 5% (w/w) ethyl acetate, and DMF (3:2), 3.5% (w/w) Geronol ff4 and Etocas 35 (6:1), 5% (w/w) ethanol, and 86.5% (w/w) water, while for beta‐cyfluthrin, a 5.0% active ingredient, 15% (w/w) Solvesso 100 and ethyl acetate (2:1), 7.0% (w/w) Geronol ff4 and Etocas 35 (6:1), 10% (w/w) ethanol, and 68% (w/w) water. Under laboratory conditions, emamectin benzoate was more toxic than beta‐cyfluthrin to Spodoptera littoralis second and fourth instar larvae. Emamectin benzoate was more effective that beta‐cyfluthrin against Spodoptera littoralis in the field, whether as a microemulsion or a commercial product. Thus, microemulsions of tested insecticides with better formulation qualities may be more effective than traditional ones in controlling cotton leaf worm. [ABSTRACT FROM AUTHOR]

The transdermal delivery of non-steroidal anti-inflammatory drugs (NSAIDs) has the potential to overcome some of the major disadvantages relating to oral NSAID usage, such as gastrointestinal adverse events and compliance. However, the poor solubility of many of the newer NSAIDs creates challenges in incorporating the drugs into formulations suitable for application to skin and may limit transdermal permeation, particularly if the goal is therapeutic systemic drug concentrations. This review is an overview of the various strategies used to increase the solubility of poorly soluble NSAIDs and enhance their permeation through skin, such as the modification of the vehicle, the modification of or bypassing the barrier function of the skin, and using advanced nano-sized formulations. Furthermore, the simple yet highly versatile microemulsion system has been found to be a cost-effective and highly successful technology to deliver poorly water-soluble NSAIDs. [ABSTRACT FROM AUTHOR]

The current study reports the development of a novel, robust, and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of teriflunomide (TFD) and quercetin (QCN) in dual drug-loaded microemulsion. TFD and QCN have been reported to exhibit anti-inflammatory effects by targeting various inflammatory mediators involved in the pathogenesis of rheumatoid arthritis (RA). This analytical method employs a risk-based approach and follows the principles of analytical quality by design (AQbD). The study involved preliminary screening trials and systematic risk analysis to identify critical method attributes, that significantly impact the critical quality attributes (CQAs). For the optimization of method,a face centered central composite design was utilized, and 16 experimental runs were performed using design expert software version 7.0.0. Chromatographic conditions were carefully optimized using AQbD, falling within the design space and consisting of ammonium acetate buffer (pH 3.5) and acetonitrile (60:40, % v/v) with a flow rate of 1.0 mL/min. An analytical Hibar Lichospher 100 RP-18e column (250 × 4.6 mm, 5 µm) was employed, with detection wavelength of 280 nm and 367 nm for TFD and QCN, respectively. The optimized method underwent validation according to ICH guidelines and demonstrating applicability for evaluating topical microemulsion. [ABSTRACT FROM AUTHOR]

Surfactant huff-n-puff (HnP) has been shown to be an effective protocol to improve oil recovery in tight and ultratight reservoirs. The success of surfactant HnP for enhanced oil recovery (EOR) process depends on the efficiency of the designed chemical formula, as the formation of an in situ microemulsion by surfactant injection is considered to be the most desirable condition for achieving an ultra-low interfacial tension during the HnP process. In this work, we conducted experimental studies on the mechanism of in situ microemulsion EOR in the Mahu tight oil reservoir. Salinity scan experiments were carried out to compare different surfactants with crude oil from the Mahu reservoir, starting with the assessment of surfactant micellar solutions for their ability to form microemulsions with Mahu crude oil and examining the interfacial characteristics. Subsequently, detailed micromodels representing millimeter-scale fractures, micron-scale pores, and nano-scale channels were utilized to study the imbibition and flowback of various surfactant micellar solutions. Observations of the in situ microemulsion system revealed the mechanisms behind the enhanced oil recovery, which was the emulsification's near-miscibility effect leading to microemulsion formation and its performance under low-interfacial-tension conditions. During the injection process, notable improvements in the micro-scale pore throat heterogeneity were observed, which improved the pore fluid mobility. The flowback phase improved the channeling between the different media, promoting a uniform movement of the oil–water interface and aiding in the recovery of a significant amount of the oil phase permeability. [ABSTRACT FROM AUTHOR]

Functional fillers in the polymerization system cannot be arranged in an orderly manner when exposed to natural conditions. The application of magnetic fields in the material preparation process has been shown to greatly enhance the distribution of functional fillers, leading to the organized alignment of functional fillers and the production of polymer matrix composites with remarkable characteristics. In this experiment, rod‐like ZnFe2O4 was synthesized by reverse microemulsion method, and amorphous carbon was coated on the surface of ZnFe2O4 by freeze‐drying method to obtain ZnFe2O4@Carbon core‐shell particles. The composite films were prepared by dispersing ZnFe2O4 with different volume contents into P(VDF‐HFP) matrix. The external parallel magnetic field was used to manipulate the ZnFe2O4@C/P(VDF‐HFP) composite film during the hot‐pressing process, resulting in an oriented ZnFe2O4@C/P(VDF‐HFP) composite film. The experiment revealed that when ZnFe2O4@C is aligned with the film orientation, the dielectric constant of the composite film is 50(50 Hz), which is 130 % higher than that of the unoriented composite film and 290 % higher than that of pure P(VDF‐HFP). When the filling amount is 40 Vol.%, the energy storage density of ZnFe2O4@C/P(VDF‐HFP) composite film is 1.18 times higher than that of unoriented composite material and 1.32 times higher than that of pure P(VDF‐HFP). [ABSTRACT FROM AUTHOR]

Vaginal inflammation is a prevalent gynecological condition. If left untreated, it can potentially spread to the urinary and reproductive systems. In this study, we propose a resveratrol-loaded microemulsion-based thermosensitive hydrogel (Res-Me-Tsgel) and compare it with a chitosan hydrogel-based Res-Me-Cogel. We characterized the different characters of Res-Me-Tsgel. The safety of Res-Me-Tsgel was also evaluated in vitro and in vivo. Finally, we measured the retention of Res in the vagina after drug administration. The Res-Me-Tsgel we prepared is a transparent liquid solution at room temperature that rapidly forms a gel at 37oC. Compared to Res solution and Res-Me, both Res-Me-Cogel and Res-Me-Tsgel demonstrate superior sustained release properties. Both in vitro and in vivo studies confirm the excellent biosafety profile of Res-Me-Cogel and Res-Me-Tsgel. Vaginal administration of these formulations in rats results in prolonged retention of resveratrol within the vagina. Notably, due to its improved flow into vaginal folds after administration, the retention of Resveratrol was approximately three times higher for the Res-Me-Tsgel group compared to the Res-Me-Cogel group at 24 h post-administration. Overall, these findings highlight the potential application of Res-Me-Tsgel as an effective means for vaginal inflammation. We developed a novel micromulsion based thermosensitive hydrogel for the delivery of Res. The sustained release of Res and favorable vaginal retention from Res-Me-Tsgel make them promise as a potential candidate for local intravaginal therapy. [ABSTRACT FROM AUTHOR]

In this research work, a new biocompatible microemulsion containing castor oil has been formulated to increase the solubility of celecoxib, as a well-known anti-inflammatory drug. In this formulation castor oil has also anti-inflammatory properties. The proposed oil-in-water microemulsion composed of Tween 80 as surfactant, isobutanol as co-surfactant, and castor oil as the oil phase. In the first step, the phase diagrams of the proposed colloid systems with surfactant to co-surfactant mass ratios of 4 : 1 and 2 : 1 were prepared at ambient temperature. Then, using the obtained phase diagrams, the appropriate formulations were selected by combining different percentages of water, oil, surfactant and co-surfactant in the microemulsion region. Some of physico-chemical properties, such as electrical conductivity, density, refractive index, surface tension and particle size of the selected microemulsion formulations have been determined at 298 K. After that, the solubility of celecoxib in the selected formulations was determined and compared with other reported microemulsion formulations. Interesting results from this section indicated that the solubility of celecoxib significantly increased compared to pure water and the previous proposed formulations. The results of this study can be used to provide suitable formulations based on the biocompatible microemulsions for celecoxib in pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The targeted delivery of a hydrophilic Tripeptide-3 to the skin using microemulsions or nanoemulsions for facial oil reduction was the focus of this study. The impact factors affecting oil/water transparent dispersion formation, such as the surfactant system, HLB value, and co-solvent, were identified through the water titration method and pseudoternary phase diagram plots. The interfacial tension between caprylic/capric triglyceride (CCT oil) and water was significantly reduced by the surfactant/co-surfactant combination (Smix) of Cremophore® RH40 and a double-tails co-surfactant, polyglycerol-3-diisostearate, at an HLB of 13 together with a water-to-co-solvent (PG) ratio of 1:1. A two-level full factorial design of experiment (FFD-DoE) emphasized the independent variables of the HLB value, co-solvent, and CCT oil contents affecting the optimal compositions for micro- or nanoemulsion formation. The low-energy spontaneous emulsification of the optimized combination at a low Smix content (10%) yielded the translucent oil-in-water Tripeptide-3 nanoemulsions with an internal droplet size of 25.7 ± 1.20 nm, a narrow polydispersity index of 0.237 ± 0.129, and 70.6 ± 0.58% transmittance. The in vitro skin permeation study revealed a significantly higher skin penetration and retention of the Tripeptide-3 nanoemulsions compared to the high surfactant microemulsions and coarse emulsions. Skin irritation and oil control efficacy were evaluated in healthy volunteers before and after product application for 28 days. The obtained nanoemulsions not only decreased sebum production but also enhanced skin moisture levels. In conclusion, the meticulously designed nanoemulsions, incorporating suitable excipients, show a promising delivery system for hydrophilic peptides to control sebum overproduction in oily facial skin. [ABSTRACT FROM AUTHOR]

The effective pharmacological treatment of inflamed wounds such as pyoderma gangraenosum remains challenging, as the systemic application of suitable drugs such as glucocorticoids is compromised by severe side effects and the inherent difficulties of wounds as drug targets. Furthermore, conventional semi-solid formulations are not suitable for direct application to open wounds. Thus, the treatment of inflamed wounds could considerably benefit from the development of active wound dressings for the topical administration of anti-inflammatory drugs. Although bacterial cellulose appears to be an ideal candidate for this purpose due to its known suitability for advanced wound care and as a drug delivery system, the incorporation of poorly water-soluble compounds into the hydrophilic material still poses a problem. The use of microemulsions could solve that open issue. The present study therefore explores their use as a novel approach to incorporate poorly water-soluble glucocorticoids into bacterial cellulose. Five microemulsion formulations were loaded with hydrocortisone or dexamethasone and characterized in detail, demonstrating their regular microstructure, biocompatibility and shelf-life stability. Bacterial cellulose was successfully loaded with the formulations as confirmed by transmission electron microscopy and surprisingly showed homogenous incorporation, even of w/o type microemulsions. High and controllable drug permeation through Strat-M® membranes was observed, and the anti-inflammatory activity for permeated glucocorticoids was confirmed in vitro. This study presents a novel approach for the development of anti-inflammatory wound dressings using bacterial cellulose in combination with microemulsions. [ABSTRACT FROM AUTHOR]