Transparent Emulsions Research Articles

Solubility enhancing lipid-based vehicles for artemether and lumefantrine destined for the possible treatment of induced malaria and inflammation: in vitro and in vivo evaluations

BackgroundThe lipid self-emulsifying system has been advanced as a promising delivery vehicle for improving the solubility and bioavailability of artemether and lumefantrine. However, the observed kinetic instability (propensity of lumefantrine to rapid crystallisation from nano-scale droplets) in aqueous acid has impelled some researchers to incorporate surfactants/solubilizers in the dissolution medium prior to dissolution studies. Thus, in our present work, we sought to prepare micro/large nano-scale (> 100 nm) and yet kinetically stable lumefantrine lipid self-emulsifying system (that would not require an external drug dissolution enhancing agent in the dissolution medium) and palm kernel oil-based 100 nm kinetically stable artemether lipid self-emulsifying system with rapid emulsification time. COVID-19 and Plasmodium falciparum-infected Africans with previous long exposure to malaria have manifested attenuated inflammatory cytokines more than malaria-naive patients. Therefore, the ingestion of artemether-lumefantrine with enhanced solubility may further promote blunting of cytokines. Therefore, this work was aimed at preparing (< 100 nm) stable artemether and aqueous acid-stable micro/large nano-scale (> 100 nm) lumefantrine lipid self-emulsifying system destined for improved antimalarial and anti-inflammatory activities.ResultsThe droplet sizes of all the liquid artemether and lumefantrine formulations were between 8.95–39.88 and 1018–4195 nm, respectively. The loading efficiency for all the formulations was, between 72.91 ± 2.89 and 100.00 ± 0.29%. All the artemether and lumefantrine batches emulsified within the range of 3.90 ± 0.69 to 12.26 ± 0.69 s. Stable and transparent emulsions were formed on aqueous dilution to 1000 ml. The percentage drug released for artemether and lumefantrine ranged from 76.25 ± 2.98 to 99.22 ± 1.61%. The solid lipid self-emulsifying systems produced, had fair and passable flow properties. Differential scanning calorimetry revealed that the solid artemether and lumefantrine lipid self-emulsifying system were amorphous. Solidification with Neusilin FH2 or surfactant replacement with Kolliphor EL and Kollidon VA 64 fine prevented micro-or large nano-scale lumefantrine lipid self-emulsifying system from crystallisation in aqueous acid (pH 1.2). Higher antimalarial activity and remarkable anti-inflammatory effects (P < 0.05) favoured the lipid self-emulsifying formulations.ConclusionOptimal in vitro and in vivo results (enhanced antimalarial and anti-inflammatory activities) were obtained with kinetically stable lumefantrine micro/large nano-scale droplets and kinetically stable palm kernel oil-based (< 50 nm) artemether lipid self-emulsifying system droplets.

Effectiveness of Snedds (Self-Nanoemulsifying Drug Delivery System) Etil Acetate Fraction of Kadara Fruit (Caesalpinia bonduc) Seed Extract on Bacteria Diabetic Gangreen

High glucose level conditions cause many fatal complications, such as the increased risk of developing gangrene. The incidences of amputation worldwide have happened of 25% and 14.3% mortality after amputation. Patients with diabetic gangrene are often treated with a broad-spectrum antibiotic. However, nowadays antibiotic-resistant bacteria are emerging problems to cure the infection in diabetic gangrene. Scientists are looking for natural compounds to develop new medication as an alternative antibacterial. Kadara (Caesalpinia bonduc) is a plant from Dompu, West Nusa Tenggara. Flavonoids, the primary constituent of Caesalpinia bonduc seeds, are responsible for broad-spectrum antibacterial action. Flavonoids are poorly soluble in water, so as the solution for increasing the stability of flavonoids, it needs development of dosage form in the self-nanoemulsion drug delivery system (SNEDDS). This study aims to determine the effectiveness of the Snedds ethyl acetate fraction of the extract of the seeds of the fruit (Caesalpinia bonduc) against diabetic gangrene bacteria. This research begins with maceration to obtain a thick extract followed by fractionation, then make the SNEDDS formula using the trial-error method. Characterization is carried out, and the antibacterial activity test is carried out. The results showed that the SNEDDS formula that met the criteria was obtained from a comparison of tween 80 and PEG 400 (7:2) with an emulsification time of 29.67±0.58 seconds, a transparent emulsion formation medium, and a particle size of 16.8nm. The results of the bacterial inhibition test showed that the SNEEDS formula was not significantly different from the tetracycline positive control (*p&gt;0.05), with the inhibitory diameter values of 15.67±2.31mm and 15.67±1.15mm.

A Review on Novel Drug Delivery System Nanoemulsion

various researcher are innovate a replacement therapy regarding improvement of drug action. Improve drugs absorption, distribution also we improve its efficacy. Amongst that a replacement innovative technology are develops. A nanoemulsion is technique to enhance the solubility, bioavability, pharmacokinetic and pharmacodinemics of medicine .in this review article us familiar about the novel technique nanoemulsion and its preparation methods, charactorization of nanoemulsion. Nanoemulsion has been identified as a promising delivery system for various drugs including biopharmaceuticals. Nanoemulsion may be a heterogeneous system composed of one immiscible liquid dispersed as droplets within another liquid. The droplets size of nano emulsion is between 20 to 500 nm. Diameter and surface properties of droplets of nanoemulsion plays a crucial role in the biological behavior of the formulation. Small droplet sizes cause transparent emulsions so that product appearance is not altered by the addition of an oil phase during this paper various aspects of nanoemulsion have been discussed including advantages, disadvantages and methods of preparation. Furthermore new approaches of stability of formulation, effect of types and concentration of surfactant, process variables and method also are discussed to improve the stability of nanoemulsion formulation.

Botanical insecticide nanoemulsion of Piper Aduncum extract to control Cabbage Head Cartepillar Crocidolomia pavonana F. (Lepidoptera: Crambidae)

Botanical insecticide nanoemulsion is an insecticide with a transparent emulsion system, and it is an oil and water dispersion stabilized by a surfactant molecule, which has a size ranging from 50 to 500 nm. The experiment was conducted in Biota Sumatera Laboratory Faculty of Pharmacy and Insect Bioecology Laboratory Faculty of Agriculture Andalas University Padang on from July to August year 2018. The purpose of this research was to obtain the nanoemulsion of Piper aduncum fruit as a botanical insecticide capable of controlling the pest of cabbage larvae Crocidolomia pavonana. The experimental design used Completely Randomized Design (CRD) that consists of control treatment and nanoemulsion treatment of P. aduncum. Observations were used PSA with Zetasizer Nano ZS Malvern tools. Insecticidal activity of nanoemulsion was tested against C. pavonana. As the study found, the nanoemulsion has the following characteristics; its size ranges from 18.56 to 216.7 nm, its polydispersity index ranges from 0,202 to 0,371, its zeta potential ranges from -0,410 to -28,7 mV, and its distribution width range from 8,11 to 5570 nm. It has insecticidal activity against C. pavonana.

Engineered transparent emulsion to optically study particulate flows in yield stress fluids

We have engineered a model suspension consisting of rigid particles and yield stress fluids. The suspending fluid is an emulsion with adjustable density, rheological behavior, and refractive index. We explain the design procedure in detail. The optically transparent emulsion opens the possibility of exploring particle tracking/image velocimetry (PIV/PTV) techniques in studying dynamic flows involving particles in complex fluids. As a proof of concept, we have performed PTV to provide accurate measurements of solid volume fractions for the dispersion of particles in a Taylor–Couette cell.

A Cost-effective Method to Fabricate a Super-non-wetting Self-cleaning Transparent Emulsion Paint Coating

The procedure to fabricate an industrially-producible, practically-applicable and easily-reconstructible transparent paint coating with luminescence is introduced step- -by-step in this paper. Without chemical modification, an ultrahydrophobic transparent paint coating with luminescence can be readily created using cost-effective commercially available materials. Grinding the ultrahydrophobic transparent paint coating surfaces using appropriate emery papers can generate appropriate surface roughness and thereby endows the coating surfaces with super-non-wettability and self-cleaning property. The applications of the coating to the external walls of buildings can provide the walls with self-cleaning property, decorate the walls and save outdoor illumination power during the night.

Nanoemulsion: A new concept of Delivery System

Nanoemulsion has been identified as a promising delivery system for various drugs including biopharmaceuticals. Nanoemulsion is a heterogeneous system composed of one immiscible liquid dispersed as droplets within another liquid. The droplets size of nano emulsion is between 20 to 500 nm. Diameter and surface properties of droplets of nanoemulsion plays an important role in the biological behavior of the formulation. Small droplet sizes lead to transparent emulsions so that product appearance is not altered by the addition of an oil phase. In this paper various aspects of nanoemulsion have been discussed including advantages, disadvantages and methods of preparation. Furthermore new approaches of stability of formulation, effect of types and concentration of surfactant, process variables and method are also discussed to improve the stability of nanoemulsion formulation

Preparation and characterization of photocatalytic TiO2/WO3 films on functionalized stainless steel

In this study, both TiO2 and WO3 were synthetized using controlled hydrolysis followed by dialysis. The produced transparent emulsions were dried into powders. Then, TiO2–WO3 photocatalyst films were deposited by pulsed electrophoretic deposition. The substrates were made of stainless steel pre-functionalized in a conversion bath. The conversion layer played an important role in the adhesion of the composite film into the substrate. Film surface morphology, crystallinity, roughness, thickness, and elemental composition were determined from XRD, optical profilometry and SEM–EDX measurements. The mechanical properties were resolute by nano-indentation test and adhesion was investigated using a scratch test. The photocatalytic decolorization of the Amido Black-10B dye was studied over TiO2–WO3 coatings under UV irradiation. TiO2 film doped 5% WO3 film exhibited the best photocatalytic activity due to its crystalline size and three-phase structure as well as a synergetic effect of TiO2–Fe2O3 and TiO2–WO3. This film showed also good adhesion properties.

Nanoemulsion: A Droplet Nanocarrier System for Enhancing Bioavailability of Poorly Water Soluble Drugs

The approach for drug delivery has changed vastly with the use of nanotechnology, polymeric system and target drug delivery. One such a way to increase the bioavailability of a drug which is poorly water soluble, is nanoemulsion. Nanoemulsion is a system where one of immiscible liquid dispersed within another immiscible liquid as droplets leading to transparent emulsions. The surface characteristics of these droplets of nanoemulsion play an important role in the biological behavior of the formulation. The methods used for the preparation of nanoemulsions include high pressure homogenization, microfluidization, ultrasonication, and spontaneous emulsification. As application point of view nanoemulsions are crucial in different fields such as pharmaceutics, food technology and cosmetics. Here in this review, different features of nanoemulsion has been discussed along with the method of preparations,applications & advantages over other dosage forms.

Preparation and characterization of photocatalytic TiO2 films on functionalized stainless steel

In this study, TiO2 was synthesized using controlled hydrolysis of TiCl4, followed by dialysis. We produced a transparent emulsion that was later dried into TiO2 powder. TiO2 photocatalyst films were deposited applying the technique of pulsed electrophoretic deposition, which decreased bubble formation caused by direct current. The substrates were bare stainless steel (SS) and stainless steel pre-functionalized in a conversion bath. Film surface morphology, crystallinity, elemental composition, and wettability were determined using XRD, SEM–EDAX, and contact angle measurements. The mechanical properties were determined by nano-indentation test. The adhesion was investigated using scratch test. The obtained results showed that the TiO2 film over a conversion layer had better adhesion and mechanical properties than TiO2 over bare SS. The optical characteristics of TiO2 films were tested using PL measurement. The photocatalytic decolourization of the amido black-10B dye was studied over TiO2 coating under UV and visible light irradiation. TiO2 film over a conversion layer without heat treatment exhibited the best photocatalytic activity as a result of its crystalline size and three-phase structure as well as the synergetic effect of TiO2 and Fe2O3.

Highly Transparent w/o Pickering Emulsions without Adjusting the Refractive Index of the Stabilizing Particles.

Pickering emulsions with a remarkable transmittance of up to 86% across the visible spectrum have been prepared without adjusting the refractive index (RI) of the stabilizing particles to those of the aqueous and oil phases. Commercially available hydrophilic silica particles with a diameter of 20 nm, which are hydrophobized partially in situ, were used to stabilize water droplets with diameters below 400 nm in IsoparM. In this system, the stabilizing particles and the emulsion droplets act as one single scattering object, which renders RI-matching of the particles unnecessary. By either evaporation of some water from the droplets or addition of an appropriate organic liquid to the oil phase, it is possible to match the RI of the droplets (aqueous phase + particles) with that of the continuous phase, which minimizes scattering and results in highly transparent emulsions.

Emulsion-based gels with thermally switchable transparency

Optical transparency (high light transmittance) of materials is relevant for various applications, and it is of particular interest if it can be switched by stimuli such as temperature. Oil-in-liquid crystal (O/LC) emulsions are a kind of soft materials with excellent workability because of their gel-like and self-standing characteristics. Transparent O/LC emulsions can be obtained by matching the refractive indices of dispersed (oil) and continuous (liquid crystalline) phases. If the refractive indices of the dispersed and continuous phases have different temperature sensitivity, i.e., different thermo-optic coefficients, thermally switchable optical transparency can be realized. In this paper, we report the effect of temperature on the light transmittance of oil-in-cubic phase (O/I1) emulsions in water/poly(oxyethylene) dodecyl ether (C12EO25)/oil systems, with isopropyl hexanoate (IPH) and isopropyl myristate (IPM) as oil components. Transparent emulsions were obtained at 25°C at surfactant mass fractions in water (WS) of 0.5 for IPH and 0.7 for IPM. The temperature range at which the samples remained transparent was 20–50°C for the IPH system and 10–70°C for the IPM system, away from which, the samples were turbid, confirming that the transparency is thermally switchable. We also confirmed the reversibility of switching transparency in the IPH system. Refractive indices of pure oils and the I1 phase were measured at different temperatures. The refractive indices changed linearly with temperature, but the slope (i.e., the thermo-optic coefficient) was different depending on the type of oil, surfactant concentration, and oil solubilization in the I1 phase, which explains the different effect of temperature on the optical transparency of the IPH and IPM systems.

Fabrication of Transparent Lemon Oil Loaded Microemulsions by Phase Inversion Temperature (PIT) Method: Effect of Oil Phase Composition and Stability after Dilution

This research was addressed to develop transparent microemulsions as delivery system of lemon oil. To this aim, phase inversion temperature (PIT) method was employed. The effect of the surfactant Tween 80 content as well as lipid phase type and concentration (lemon oil, peanut oil and their mixtures) on microemulsion characteristics was studied. Transparent emulsions were obtained up to 1.3 and 7.5% (w/w) of lemon oil and peanut oil, respectively. Only by considering as lipid phase a mixture of lemon oil and peanut oil, it was possible to increase the delivering capacity of emulsions up to 15% of lemon oil (total oil phase 20%). Therefore, blending peanut oil rich in long chain fatty acids with lemon oil expanded the lipid phase loading capacity of microemulsions while maintaining particle size lower than 30 nm and thus system transparency. Microemulsions showed good dilutability in aqueous solutions simulating beverage formulations with different pH values.

铕掺杂纳米二氧化钛透明光触媒乳液的制备及光催化性能研究

铕掺杂纳米二氧化钛透明光触媒乳液的制备及光催化性能研究

Physical and antimicrobial properties of cinnamon bark oil co-nanoemulsified by lauric arginate and Tween 80

Lauric arginate (LAE) is a water-soluble cationic surfactant which has antimicrobial activity against a broad spectrum of foodborne pathogens. Some spice essential oils are effective lipophilic antimicrobials. Combining both antimicrobials may reduce their usage levels and possible negative sensory impacts when applied in complex food matrices. The objective of this study was to combine a nonionic surfactant (Tween 80) with LAE to form stable nanoemulsions with cinnamon bark essential oil (CBO) and to characterize the antimicrobial activity of these nanoemulsions. CBO was homogenized at 1% w/w in the aqueous phase with 3% w/w Tween 80 and 0.05–0.375% w/w LAE, followed by heating at 90°C for 30min to obtain final emulsions. With 0.125% and higher LAE, transparent emulsions with ~100nm in hydrodynamic diameter were observed to be stable during 30-day storage at 21°C. Antimicrobial activities of the nanoemulsion prepared with Tween 80 and 0.375% w/w LAE were studied. The respective minimum inhibitory concentrations (MICs) of the nanoemulsion in tryptic soy broth (TSB) were 12, 7, and 8ppm LAE for Salmonella enteritidis, Escherichia coli O157:H7, and Listeria monocytogenes, while those of free LAE were 11, 6, and 6ppm, respectively. MICs of CBO were 400ppm for the tested bacteria and Tween 80 at 6% w/w did not show inhibitory effect. Growth kinetics of the bacteria in TSB treated with the nanoemulsion or individual components at concentrations corresponding to the MICs of free LAE showed that binding among the LAE and Tween 80 and CBO components resulted in the antibacterial activity of nanoemulsion being lower than same concentrations of free LAE and CBO. Conversely, little difference was observed for the individual antimicrobials and the nanoemulsion in 2% reduced fat milk, and 750ppm LAE and 2000ppm CBO were observed to be the dominant antimicrobial against Gram-positive and Gram-negative bacteria, respectively. The growth of L. monocytogenes in 2% reduced fat milk at 4°C was not observed when treated by the nanoemulsion corresponding to 187.5ppm LAE and 500ppm CBO. Therefore, stable and transparent nanoemulsions of EOs can be prepared with the combination of LAE and Tween 80 without compromising antimicrobial activities.

Preparation and evaluation of trans-resveratrol NanoSolve

ABSTRACTNanoSolve, which enables the production of transparent emulsions with particle sizes of approximately 100 nm, is a promising carrier system for various lipids or lipophilic actives. The purpose of this study was to prepare a trans-Resveratrol NanoSolve which can enhance the water solubility and physical stability. The particles of trans-Resveratrol NanoSolve showed spherical morphology under transmission electron microscope and the mean size was 122 ± 0.8 nm. The zeta potential was −41.7 ± 0.9 mV at dilution 200 folds. In-vitro permeation results showed that trans-Resveratrol NanoSolve presented good skin compatibility. Consequently, trans-Resveratrol NanoSolve has a very promising potential in cosmetic industry.

Local Multiphase Flow Characterization with Micro Particle Image Velocimetry Using Refractive Index Matching

AbstractAn accurate flow characterization is crucial for the understanding and optimization of emulsification processes. A method is presented to determine velocity fields of droplet‐containing phases flowing through an orifice by micro particle image velocimetry (µPIV). In order to overcome optical inaccessibility of emulsions, a recipe of a transparent emulsion system was developed using refractive index matching. Velocity fields could successfully be determined for an emulsion containing 30 vol % of droplets in a rectangular orifice channel with the narrowest gap being 200 µm. Emulsion flow was compared to a pure continuous phase and the influence of the dispersed phase was analyzed for each individual step of µPIV image processing. For the presented experimental conditions, one‐ and two‐phase flows exhibited no difference in flow characteristics.

Antimicrobial activity of thyme oil co-nanoemulsified with sodium caseinate and lecithin

Emulsions of essential oils are investigated as potential intervention strategies to improve food safety and are preferably prepared from generally-recognized-as-safe emulsifiers. Stable thyme oil nanoemulsions can be prepared using combinations of sodium caseinate (NaCas) and soy lecithin. The objective of the present research was to study the antimicrobial activity of these nanoemulsions and understand the impacts of emulsifier concentrations. 10g/L thyme oil was emulsified using combinations of (A) 4% w/v NaCas and 0.5% w/v lecithin or (B) 2% w/v NaCas and 0.25% w/v lecithin by high shear homogenization. Combination A resulted in a transparent emulsion with a mean droplet diameter of 82.5nm, while it was turbid for the Combination B with an average diameter of 125.5nm. Nanoemulsified thyme oil exhibited quicker initial reductions of bacteria than free thyme oil in tryptic soy broth (TSB) and 2% reduced fat milk at 21°C, due to the improved dispersibility of thyme oil. In TSB with 0.3g/L thyme oil, it took less than 4 and 8h for two nanoemulsions and free oil, respectively, to reduce Escherichia coli O157:H7 and Listeria monocytogenes to be below the detection limit. The emulsified thyme oil also demonstrated more significant reductions of bacteria initially (4 and 8h) in 2% reduced fat milk than free thyme oil. Especially, with 4g/L thyme oil, the nanoemulsion prepared with Combination A reduced L. monocytogenes to be below the detection limit after 72h, while the free thyme oil treatment was only bacteriostatic and the turbid nanoemulsion treatment with Combination B resulted in about 1logCFU/mL reduction. However, E. coli O157:H7 treated with 3g/L emulsified thyme oil and Salmonella Enteritidis treated with 4g/L emulsified thyme oil recovered to a higher extent in milk than free thyme oil treatments. The increased concentration of emulsifiers in Combination A apparently reduced the antimicrobials available to alter bacteria membrane permeability as tested by the crystal violet assay at low antimicrobial concentrations and short time (1h). The findings suggest that nanoemulsions can be potentially used to incorporate thyme oil for use as antimicrobial preservatives in foods.

Physical and oxidative stability of fish oil nanoemulsions produced by spontaneous emulsification: Effect of surfactant concentration and particle size

Nanoemulsion-based delivery systems offer many potential benefits for incorporating omega-3 oils into foods and beverages. Nanoemulsions are gaining popularity because of their ease of preparation, small particle size, relatively high stability, and production of optically transparent emulsions. In this study, spontaneous emulsification, a low-energy method, was used to fabricate fish oil nanoemulsions. The influence of surfactant-to-oil-ratio on particle size and physical stability was evaluated. Optically transparent nanoemulsions were formed and maintained physical stability at 37°C for 14days. Furthermore, the effect of particle size and surfactant concentration on oxidative stability of these nanoemulsions was compared to emulsions produced by microfluidizer, a high-energy method. These nanoemulsions had similar oxidative stabilities at 55°C for 14days. These results demonstrate that spontaneous emulsification can produce fish oil nanoemulsions that are physically stable and oxidize at similar rates as traditionally prepared nanoemulsions, and therefore may be suitable for fortifying clear food systems.

Facile Synthesis and Photocatalytic Properities of PbS Quantum Dots/Boron and Nitrogen Co-Doped TiO&lt;sub&gt;2&lt;/sub&gt; Transparent Photocatalyst Emulsion

PbS quantum dots/ Boron and Nitrogen co-doped TiO2 photocatalyst emulsions were synthesized by a complexation-controlled hydrolysis method at room temperature. Boron compounds and Nitrogen compounds were added to TiO2 precursor solution, and PbS quantum dots were attached to TiO2 particles surfaces by using chemical reaction. The hybird composite photocatalysts were characterized by nanoparticle size analyzer. Their photocatalytic properties were evaluated through the degradation of acid red 3R dye. The results indicate that when TiO2 emulsion added to Boron ions, Nitrogen ions, and PbS quantum dots, the reflux time is 15 min, the photocatalytic performance of the emulsion is the best.