Hydrophile-lipophile Balances Research Articles

Tyrosine-derived polymeric surfactant nanospheres insert cholesterol in cell membranes

HypothesisThe design of biodegradable tyrosine-derived polymeric surfactants (TyPS) through the use of calculated thermodynamic parameters could lead to phospholipid membrane surface modifiers capable of controlling cellular properties such as viability. Delivery of cholesterol by TyPS nanospheres into membrane phospholipid domains could provide further controlled modulation of membrane physical and biological properties. ExperimentCalculated Hansen solubility parameters (∂T) and hydrophile:lipophile balances (HLB) were applied to design and synthesize a small family of diblock and triblock TyPS with different hydrophobic blocks and PEG hydrophilic blocks. Self-assembled TyPS/cholesterol nanospheres were prepared in aqueous media via co-precipitation. Cholesterol loading and Langmuir film balance surface pressures of phospholipid monolayers were obtained. TyPS and TyPS/cholesterol nanosphere effects on human dermal cell viability were evaluated by cell culture using poly(ethylene glycol) (PEG) and Poloxamer 188 as controls. FindingsStable TyPS nanospheres incorporated between 1% and 5% cholesterol. Triblock TyPS formed nanosphere with dimensions significantly smaller than diblock TyPS nanospheres. In accord calculated thermodynamic parameters, cholesterol binding increased with increasing TyPS hydrophobicity. TyPS inserted into phospholipid monolayer films in a manner consistent with their thermodynamic properties and TyPS/cholesterol nanospheres delivered cholesterol into the films. Triblock TyPS/cholesterol nanospheres increased human dermal cell viability, which was indicative of potentially beneficial TyPS effects on cell membrane surface properties.

Effects of pre-emulsion prepared using sucrose esters with different hydrophile-lipophile balances on characteristics of soy protein isolate emulsion films

The preparation of emulsion films using pre-emulsification has received extensive attention due to the enhancement of oil binding capacity. However, the different effects of water in oil (W/O) and oil in water (O/W) pre-emulsions on the physicochemical properties of films are still unclear. Therefore, the soy protein isolate (SPI) based emulsion films were prepared by W/O or O/W pre-emulsion using sucrose esters with different hydrophile-lipophile balances to investigate the properties of SPI emulsion (SPIE) films. The viscosity, storage moduli, and loss moduli of film-forming solutions (FFSs) with O/W pre-emulsion were higher than those of FFSs with W/O pre-emulsion. The oil droplets of FFSs with W/O pre-emulsion were large and uneven, and the oil droplet size increased after drying. Phase separation and macroporous network appeared in cross-sectional of SPIE films with W/O pre-emulsion according to scanning electron microscope images. Meanwhile, the SPIE films with W/O pre-emulsion demonstrated higher oil concentration and hydrophobicity on the upper surface compared with the SPIE films with O/W pre-emulsion. Low tensile strength, glass transition temperature, and high elongation at break and transparency value of SPIE films with O/W pre-emulsions were founded. The water vapor permeability of SPIE films with W/O pre-emulsion increased with the addition of oil, whereas the opposite trend appeared in that with O/W pre-emulsion. In conclusion, the structure and porosity of emulsion films could be affected by the pre-emulsion types, which can determine the application ranges.

Stabilization of Aqueous MMA Emulsions Using Mixtures of Surfactants and Implications on MMA Miniemulsion Polymerizations

AbstractMiniemulsion polymerization is a robust and simple method for manufacture of polymer nanoparticles. However, it is strongly dependent on the precursor monomer‐in‐water emulsion stability. Thus, the present study investigates the influence of concentration and combination of nonionic surfactants (resulting in different hydrophile–lipophile balances, HLB) on the stabilization of emulsions of methyl methacrylate in water. Backscattering profiles obtained with Turbiscan show that a combination of Tween80 and Span80 can grant the desired initial system stabilization, although the optimum HLB values depend on the amount of surfactant mixture. Miniemulsion polymerizations are then successfully performed with nonionic surfactant mixtures, providing high monomer conversion in less than 1 h and poly(methyl methacrylate) nanoparticles with average diameters ranging from 300 to 500 nm. Finally, it is observed that the addition of small amounts of an anionic surfactant to the surfactant mixture (10 wt.%) can be very beneficial for the process, allowing the control of reaction rates, the production of smaller nanoparticles with average diameters from 100 to 300 nm, and the enhanced stabilization of the final solid dispersion, while simultaneously keeping the concentration of ionic surfactants small.

Ethyl methacrylate diblock copolymers as polymeric surfactants: Effect of molar mass and composition

Well-defined amphiphilic diblock copolymers and statistical copolymers were synthesised and investigated as polymeric surfactants. Specifically, two series of linear diblock copolymers-totaling 21 copolymers-were studied. In both series, the same hydrophobic monomer (ethyl methacrylate, EtMA) was used, whereas the hydrophilic monomer was changed. The first series was based on the non-ionic hydrophilic monomer, poly(ethylene glycol) methyl ether methacrylate (PEGMA, 300 g/mol), while the second series was based on the ionic, hydrophilic monomer, 2-(dimethylamino)ethyl methyl methacrylate (DMAEMA). The molar mass (MM) and compositions were systematically varied to investigate their effect on the final properties of the polymer. The aqueous solution properties of the copolymers, such as their cloud points, effective pKa values, hydrodynamic diameters, critical micelle concentrations and hydrophile-lipophile balances were determined. The hydrophobic content affected the thermoresponsive ability and the pKa of the polymer solutions significantly. Finally, the emulsifying properties of block copolymers were studied by preparing emulsions containing 1 w/w% of the polymer at the same water to methyl laurate ratio and observing their stability for 1 month. The stability of the emulsions was affected by both the MM and composition of the polymers, but to different extents for the non-ionic compared to the ionic series of polymeric macrosurfactants.

Formulasi Krim Ekstrak Daun Kersen (Muntingia calabura L.) Dengan Variasi Kombinasi Span 60 dan Tween 80 Sebagai Emulgator

The ethanol extract of 1,04% Muntingia calabura L. folium has the effectiveness of healing burns. An emulgator is needed to maintain the stability of the cream formulation. Span 60 and tween 80 are non-ionic emulgators, non-toxic, non-irritating, and have low potential to couse hypersensitivity reactions. This research was conducted to determine the effect of the emulgator on physical properties and physical stability of Muntingia calabura L. folium extract cream and get the best formula from the cream. This study was compare the value of Hydrophile-Lipophile Balances (HLB) from a mixture of span 60 and tween 80, which is the HLB value of 5; HLB 6.5 and HLB 8. Evaluation of physical properties is done by testing organoleptic, homogeneity, pH, viscosity, adhesion, and ability to spread. Physical stability was assessed using the centrifugation method. The effect of emulgator variations was determined by One Way Anova testing using SPSS software. The best formula is chosen from those that fit the criteria for testing physical properties and which has the best stability. The results showed different variations in the combination of span 60 and tween 80 emulgators showed effects on adhesion and pH. Formula I with HLB value of 5 produces a cream formula with good physical properties and physical stability

One-Step Synthesis of Amphiphilic Nonylphenol Polyethyleneimine for Demulsification of Water in Heavy Crude Oil Emulsions.

The demulsification of water-in-heavy crude oil emulsion with water droplet size in the microscale has drawn great attention because of their high stability and difficulty of separation. In the present work, a series of ethylene amine-based demulsifiers were prepared in one step through the interaction of pentaethylene hexamine, tetraethylene pentamine, and triethylene tetramene with glycidyl 4-nonylphenyl ether. The amphiphilic polyethyleneimine (APEI) abbreviated as DNPA-6, DNPA-5, and DNPA-4 were prepared to adjust their hydrophile–lipophile balances (HLB) to meet the requirement of the demulsification. 1HNMR, 13CNMR, and FTIR spectra were utilized to verify their chemical structures. The surface properties and zeta potential were also investigated. Demulsifier dose, separation time, and HLB values were taken into account to evaluate the demulsification efficiency of the synthesized APEI. The results suggested that the prepared demulsifiers had high ability to reduce the surface and interfacial tensions and also broke successfully water-in-Arabian heavy crude oil emulsions. The demulsification efficiency of DNPA-5 reached 100% for crude oil/water emulsion (90/10 vol %).

EFFECT OF HYDROPHILICITY SURFACTANTS TOWARD CHARACTERIZATION AND IN VITRO TRANSFERSOMES PENETRATION IN GELS USING FRANZ DIFFUSION TEST

Objective: Capsaicin is a bioactive compound with poor solubility in water. Transfersomes can increase the solubility and thus the penetration ofcapsaicin into the epidermis. Transfersomes also offer the advantage of being ultradeformable vesicles that are made using the thin layer hydrationmethod. The aim of this study is to determine the effect of the hydrophilicity of surfactants on the characterization and in vitro penetrative ability ofcapsaicin transfersomes in gels using non-ionic surfactants with different hydrophile-lipophile balances, namely, Span 80, Tween 80, and a mixtureof Span 80, and Tween 80.Methods: The best characterization result for transfersomes is the formula using Tween 80. The total cumulative amount of capsaicin penetratedfrom the transfersome gel using Tween 80 is 1663.89±1.58 mg/cm2, the percentage is 57.96±0.05%, and the flux is 166.38±0.15 μg/cm2.hr−1.Results: In terms of the transfersome gel using a mixture of Span 80 and Tween 80, the cumulative amount of capsaicin penetrated is1539.8±21.23 μg/cm2, the percentage is 54.47±0.75%, and the flux is 153.98±2.12 μg/cm2.hr−1. Finally, from the transfersome gel using Span 80, thecumulative amount of capsaicin penetrated is 1395.10±7.23 mg/cm2, the percentage is 50.80±0.26%, and the flux is 139.51±0.72 mg/cm2.hr−1.Conclusions: The best characteristics resulted from the transfersome formulation using Tween 80, which demonstrated the highest entrapmentefficiency calculation result, the smallest particle size, the best deformability index, and the highest penetration when compared to the other twoformulations.

Effect of EO and PO positions in nonionic surfactants on surfactant properties and demulsification performance

Demulsifiers provide an important means of breaking water-in-oil emulsions that occur in industrial processes. The properties and the performance of 20 blocked copolymers from four surfactant families were investigated and three pairs isomeric compounds were compared. The results show that different positions of the ethylene oxide (EO) and propylene oxide (PO) in block copolymers lead to different hydrophile–lipophile balances (HLB) of surfactant. The sequential block copolymer is more hydrophilic than the reverse-sequential one with similar chemical composition. The greater the molecular weight, the greater the difference between the hydrophile–lipophile balances of the two surfactant types. Generally, the demulsification performance of sequential copolymers is better than that of reverse-sequential copolymers. Position isomerism of the surfactant affects demulsification performance by changing the hydrophile–lipophile balance, interfacial properties, and steric characteristics at the interface.

Polyoxyethylenated dodcylphenol for breaking up water in oil emulsions

Polyethylene glycol (PEG) of different molecular weights, namely, 200, 400, 600 and 1,000 g/mol was reacted with dodecyl phenol to form compounds having different hydrophile-lipophile balances and hence different surface activities. The demulsification efficiency of the prepared surfactants in breaking up water-in-crude oil emulsions was evaluated. The data revealed that demulsification efficiency increases with increasing demulsifier concentration, contact time and hydrophilicity. The effect of temperature, NaCl concentration (salinity) and solvents on demulsification efficiency was investigated. The demulsification efficiency of the studied surfactants was found to increase with increasing temperature and decreasing salinity of the aqueous phase. A mixture of xylene and isopropanol was found to be the best solvent for the prepared demulsifier with respect to demulsification properties.

Surfactants Based on Recycled Poly(Ethylene Terephthalate) for Breaking Water-in-Oil Emulsions

Poly(ethylene terephthalate), waste was depolymerized with propylene glycol to an oligoester. The glycolyzed product was reacted with polyethylene glycol of different molecular weights, namely 600, 1000 and 4000, to form surfactants having different hydrophile–lipophile balances and hence different surface activities. The interfacial tension at the aqueous–benzene interface was determined. It was found that the demulsifier concentration that causes a minimum interfacial tension is always less than that inducing maximum efficiency. The data revealed that the efficiency increases on increasing the concentration of demulsifier, contact time and hydrophilicity.

Polyoxyethylenated Bisphenol-A for Breaking Water-in-oil Emulsions

Polyethylene glycol (PEG) of different molecular weights, namely, 600, 1000 and 4000 g/mol was reacted with bisphenol A to form compounds having different hydrophile–lipophile balances and hence different surface activities. The interfacial tension at the aqueous/benzene interface was determined. It was found that the concentrations of demulsifiers required to cause a minimum interfacial tension are always less than those inducing a maximum demulsification efficiency. The demulsification efficiency of the prepared surfactants in breaking synthetic water in benzene emulsions stabilized by petroleum asphaltenes was evaluated. The data revealed that the demulsification efficiency increases with increasing demulsifier concentration, contact time and hydrophilicity.

Polyoxyethylenated Bisphenol-A for Breaking Water‐in‐oil Emulsions

Polyethylene glycol (PEG) of different molecular weights, namely, 600, 1000 and 4000 g/mol was reacted with bisphenol A to form compounds having different hydrophile–lipophile balances and hence different surface activities. The interfacial tension at the aqueous/benzene interface was determined. It was found that the concentrations of demulsifiers required to cause a minimum interfacial tension are always less than those inducing a maximum demulsification efficiency. The demulsification efficiency of the prepared surfactants in breaking synthetic water in benzene emulsions stabilized by petroleum asphaltenes was evaluated. The data revealed that the demulsification efficiency increases with increasing demulsifier concentration, contact time and hydrophilicity.

Preparation of Microemulsions Using Polyglycerol Fatty Acid Esters as Surfactant for the Delivery of Protein Drugs

Phase diagrams containing the microemulsion region were constructed for pseudo-ternary systems composed of polyglycerol fatty acid ester/cosurfactant/Captex 300/water. It was found necessary to add ethanol, 1-propanol, or 1-butanol as cosurfactant to produce microemul-sions. The results also demonstrated microemulsions were only able to form when employing polyglycerol fatty acid esters with hydrophile-lipophile balances (HLBs) between 8 and 13, such as MO500, MO750, SO750, and ML310. Most microemulsions were determined to be Winsor type IV by dilution and dye solubility tests. Microemulsions stored at ambient temperature maintained constant viscosity, indicating that the system was thermodynamically stable for long periods. Further, several microemulsion formulations were demonstrated to be promising for oral delivery of insulin based on the results of stability tests and acid-protection efficiency.

Investigation of thermal phase inversion in emulsions

In this paper the phase inversion temperature (PIT) in emulsions was determined by measuring the electrical conductivity, dielectric constant and viscosity. In addition, the detection of the PIT by measuring the interfacial tension was studied. The temperature-dependent rheological properties of the emulsions were also examined. The influence of the oil-phase and emulsifier polarity, the hydrophile—lipophile balances (HLB) value of the surfactant mixture and the phase volume ratio on the PIT were studied. The phase inversion phenomenon and aspects of percolation theory are discussed. Knowledge of PIT-influencing factors is fundamental for the PIT-type production method of K. Shinoda and H. Saito (J. Colloid Interface Sci., 30 (1969) 258) by which fine dispersed emulsions are produced. Furthermore, the determination of the PIT is important for obtaining optimal storage conditions. The rheological method used (coaxial cylinder) as well as the conductivity measurements can be utilized routinely in process production control.

Three-Phase Behavior in a Mixed Sucrose Alkanoate and Polyethyleneglycol Alkyl Ether System

Interesting three-phase behavior was investigated in water/sucrose monolaurate/tetraethyleneglycol dodecyl ether/heptane and water/sucrose dilaurate/octaethyleneglycol dodecyl ether/heptane systems. The three-phase region is largely skewed to a higher temperature in a dilute region, and phase inversion in emulsion type is observed twice at a fixed composition in the former system. In contrast, the three-phase body is shifted toward lower temperatures with decreasing surfactant concentration in the latter system. Although a sucrose ester is a mixture of isomers, it can be treated as a pseudo-single component because its monodisperse solubilities in water and oil are very small. These phenomena were analyzed by an equation that describes a particular three-phase triangle in a space of compositions. The difference in monodisperse solubilities of each surfactant in oil causes the interesting three-phase behavior in the mixed surfactant system. The Hydrophile-Lipophile Balances (HLBs) of sucrose alkanoates were also evaluated from the three-phase behavior using the same equation.

The Preparation and Efficacy of Manually Emulsified Newcastle Disease Oil-Emulsion Vaccines

Experimental Newcastle disease oil-emulsion vaccines were prepared by manually shaking small quantities of antigen, surfactant, and mineral oil and compared with oil-emulsion vaccines made by the more conventional mechanical methods. Emulsion stability (prolonged emulsification of aqueous antigen) of the manually prepared vaccines was achieved by four different processes and tested for efficacy in broilers. White rock broilers were vaccinated at 3-5 weeks of age and bled at 1- to 2 week intervals thereafter for 8 weeks. Cumulative 8-week hemagglutination-inhibition (HI) mean titers (reciprocals) ranged from 15 to 250 for manually emulsified vaccines and from 18 to 240 for mechanically emulsified vaccines. Eight-week cumulative mean HI responses induced by manually emulsified vaccines were never significantly (P less than 0.05) lower than their specific mechanically emulsified comparison vaccines and were occasionally significantly higher. Highest HI titers were induced when hydrophile-lipophile balances of 7, 9, and 6 were used for the preparation of manually emulsified vaccines. In general, most of the vaccine emulsions were stable for more than 30 days. Vaccine efficacy, however, was not always diminished by poor emulsion stability. These results indicate that manual emulsification can be used for the production of oil-emulsion vaccines of high efficacy that can provide benefits over existing mechanical methods.

The effect of structural modifications on the hydrophile—lipophile balance of ionic surfactants

The effect of various types of structural modification on the critical micelle concentrations (CMC) and hydrophile-lipophile balances (HLB) of certain surfactants has been considered. Using the concept of effective chain length for the substituted species, an index of hydrophobicity (I) has been defined. It is hoped that such an index will allow one to choose surfactants for particular purposes in a less arbitrary fashion than heretofore.