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This study aimed to optimize the preparation of multiple oil–water–oil (O/W/O) emulsions using varying amounts of Tween 20 emulsifier, different homogenization methods, and optimal preparation temperatures as carriers for encapsulated curcumin. Following the optimization process, the optimal preparation temperature was found to be 25 °C, with a homogenization speed of 10,000 RPM and an emulsifier concentration of 0.5% Tween 20. Subsequently, the effects of physicochemical and viscoelastic properties on the different types of oils used in the outer phase, as well as the impact of storage time, were monitored. The novelty of this work lies in its comprehensive analysis of the stability and encapsulation efficiency of multiple emulsions using various oils, an area that has not been extensively explored before. After identifying the optimal preparation procedure, all samples with different edible oils demonstrated excellent stability and encapsulation efficiency, showing minimal variation in results. The most stable multiple emulsion was found to be the one with coconut oil in the outer phase, exhibiting half the particle size compared to other samples and the lowest encapsulation efficiency losses over 50 days of storage. This study provides new insights into the formulation of stable multiple emulsions for the effective delivery of curcumin and similar bioactive compounds. [ABSTRACT FROM AUTHOR]

Multiple emulsions can dissolve some substances with different properties, such as hydrophilicity and lipophilicity, into different phases. They play an important role in protection, controlled release and targeted release of the encapsulated substances. However, it's poor stability has always been one of the main problems restricting its application in the food industry. For this reason, a heat-induced aggregate (HIA) of Maillard graft product of isomalto-oligosaccharides (IMO), as well as egg white protein (EWP), was used as hydrophilic emulsifier to improve the stability of W1/O/W2 emulsions. Moreover, gelatin was added into the internal aqueous phase (W1) to construct W1/O/W2 emulsion-gels system. The encapsulation efficiency of HIA-stabilized W1/O/W2 emulsions remained nearly unaltered, dropping by only 0.86%, significantly outperforming the conjugates and physical mixture of IMO and EWP in terms of encapsulation stability. The emulsion-gels system was constructed by adding 5% gelatin in the W1, and had the highest EE% and good salt and heat stability after 30 days of storage. This experiment provides guidance for improving the stability of W1/O/W2 emulsions system and its application in the package delivery of functional substances in the food field. [ABSTRACT FROM AUTHOR]

Purpose: Alginate beads intended to float in the stomach have several advantages over the traditional oral dosage forms. However, the formulation of these beads to deliver hydrophilic drugs such as captopril is a big challenge in terms of entrapment efficiency (EE) and extending the drug release. Here, we investigated the feasibility of using the double emulsion (DE) technique during the preparation of alginate floating beads to enhance the EE. This technique allows the incorporation of captopril into the oil droplets, the floating agent within the beads, which provides a hydrophobic barrier preventing drug loss. Methods: Different DE beads were prepared using ionotropic gelation methods and compared with ordinary oil-entrapped beads based on the floating properties, EE, and drug release. Results: The results revealed that all the prepared beads have comparable floating properties, however, the EE was significantly increased from 11% for ordinary beads to 25% for DE beads. Moreover, the release of captopril from DE beads was markedly prolonged in comparison to that from ordinary beads. The SEM images clearly showed that the use of surfactant, tween 80, has a significant effect on the prepared beads through stabilizing the primary emulsion, maintain the drug dispersed within the oil droplets, and producing smooth beads with well-crosslinked surface and small well-dispersed oil droplets. Conclusion: The findings of this study highlighted the potential of DE alginate beads as a promising drug delivery system, addressing the challenges associated with hydrophilic drug encapsulation. [ABSTRACT FROM AUTHOR]

The structure and size of droplets of the inner phase of a multiple emulsion and rheological properties of the produced multiple emulsion are presented in this paper. The multiple emulsion was produced in a stirred vessel equipped with four baffles. In the study, two different stirrers: turbine impeller and Rushton turbine impeller were used. The liquids used in the produced multiple emulsion were: distilled water and refined sunflower oil. 8 g and 16 g lecithin from soya beans were used as an emulsifier. The preparation time was respectively 15 min. and 45 min. The structure of the obtained emulsions is presented in the form of photos taken with the diagnostic inverted microscope. The results size of droplets were presented in the form of graphics as a distribution of drops. The rheological properties of the multiple emulsion were presented graphically and it was described using the rheological model.

AbstractLipid-based delivery systems (LDS) have emerged as cornerstone techniques for bolstering the bioavailability of lipophilic bioactive compounds, addressing challenges related to solubility, stability, and absorption. This critical review examined a substantial dataset of 6,907 scientific articles and 3,021 patents from 2001–2023, elucidating the multifaceted evolution of LDS, with a particular focus on its industrial and patent-driven perspective. Notably, there were pronounced surges in functional food patent applications in 2004, 2011, and 2019. The trajectory revealed a shift from foundational nanoemulsions to more complex structures, such as double/multiple emulsions, solid lipid nanoparticles, Pickering emulsions, and bigels. The review further identified the top 10 leading institutions shaping this domain. Technologies like spray-drying, microfluidics, and phase gelation had revolutionized the landscape, resulting in refined sensory experiences, innovative reduced-fat formulations, enriched beverages, tailor-made infant nutrition, and nuanced release mechanisms for flavors. The review also spotlighted current research frontiers, notably Pickering emulsions, bigels, and multiple emulsions. These emerging technologies not only exemplified the ongoing innovation in the field but also underscored their potential in reshaping the future landscape of value-added functional foods. [ABSTRACT FROM AUTHOR]

Summary: Polyunsaturated fatty acids (PUFAs), which are abundant in fish oil, easily oxidise. Therefore, stabilisation is necessary, preferably through encapsulation and the addition of antioxidants. This research looked on multiple emulsification for PUFA‐rich fish oil by utilising a wall material (whey protein and chitosan) and an antioxidant (betalain) combination. Spray‐dried, microparticles filled with PUFA were successfully created (80% yield) and characterised. It was determined that the emulsion droplet size was 0.917 μm. Good oxidative stability was observed after 4 weeks of storage, as evidenced by a moderate (4%) drop in EPA and DHA content and a low peroxide value (PV) of 4.8 ± 0.23 meq/kg oil in microparticles. Microencapsulation of PUFA‐rich fish oil was successfully accomplished using multiple emulsion technology, as evidenced by encapsulation efficiency values of 87.73 ± 0.21% and loading efficiency values of 67 ± 0.11%. These results suggest that structurally stabilised healthful lipids could be added to foods using these innovative emulsions, which provide greater stability and versatility for a wide variety of uses. [ABSTRACT FROM AUTHOR]

The development of the modern market for food functional ingredients involves the search for new raw materials, increasing efficiency and developing innovative technological processes for their production and introduction into fortified products, and the development of marketing promotion strategies. Considering this, we have conducted the research to assess physical, chemical and technological properties of secondary resources for the production of black caviar of sturgeon fish grown in the conditions of sturgeon farms in the Krasnodar Territory. It has been shown that ovarian fluid (caviar sol) has a high biological value, which is confirmed by the presence of all essential amino acids in caviar proteins. Caviar sol also contains a complex of basic macro- and micronutrients. The results obtained confirm that this product is a physiologically functional ingredient for the production of new generation food products. A technology has been developed for disinfecting caviar sol to increase its shelf life and of the products obtained from it. The processing of ovarian fluid (caviar sol) in the anode zone during electrolysis of an aqueous solution of table salt was carried out followed by its placement in the structure of a multiple emulsion sauce. Analysis of microbiological indicators has indicated that the processing of caviar sol and the production of sauce in the form of a multiple emulsion makes it possible to ensure microbiological indicators of the finished product that meet the requirements of TR CU 021/2011.

This study aimed to optimize the preparation of multiple oil–water–oil (O/W/O) emulsions using varying amounts of Tween 20 emulsifier, different homogenization methods, and optimal preparation temperatures as carriers for encapsulated curcumin. Following the optimization process, the optimal preparation temperature was found to be 25 °C, with a homogenization speed of 10,000 RPM and an emulsifier concentration of 0.5% Tween 20. Subsequently, the effects of physicochemical and viscoelastic properties on the different types of oils used in the outer phase, as well as the impact of storage time, were monitored. The novelty of this work lies in its comprehensive analysis of the stability and encapsulation efficiency of multiple emulsions using various oils, an area that has not been extensively explored before. After identifying the optimal preparation procedure, all samples with different edible oils demonstrated excellent stability and encapsulation efficiency, showing minimal variation in results. The most stable multiple emulsion was found to be the one with coconut oil in the outer phase, exhibiting half the particle size compared to other samples and the lowest encapsulation efficiency losses over 50 days of storage. This study provides new insights into the formulation of stable multiple emulsions for the effective delivery of curcumin and similar bioactive compounds.

Multiple emulsions can dissolve some substances with different properties, such as hydrophilicity and lipophilicity, into different phases. They play an important role in protection, controlled release and targeted release of the encapsulated substances. However, it’s poor stability has always been one of the main problems restricting its application in the food industry. For this reason, a heat-induced aggregate (HIA) of Maillard graft product of isomalto-oligosaccharides (IMO), as well as egg white protein (EWP), was used as hydrophilic emulsifier to improve the stability of W1/O/W2 emulsions. Moreover, gelatin was added into the internal aqueous phase (W1) to construct W1/O/W2 emulsion-gels system. The encapsulation efficiency of HIA-stabilized W1/O/W2 emulsions remained nearly unaltered, dropping by only 0.86%, significantly outperforming the conjugates and physical mixture of IMO and EWP in terms of encapsulation stability. The emulsion-gels system was constructed by adding 5% gelatin in the W1, and had the highest EE% and good salt and heat stability after 30 days of storage. This experiment provides guidance for improving the stability of W1/O/W2 emulsions system and its application in the package delivery of functional substances in the food field.

Self-emulsifying drug delivery systems (SEDDSs) are lipid-based systems that are superior to other lipid-based oral drug delivery systems in terms of providing drug protection against the gastrointestinal (GI) environment, inhibition of drug efflux as mediated by P-glycoprotein, enhanced lymphatic drug uptake, improved control over plasma concentration profiles of drugs, enhanced stability, and drug loading efficiency. Interest in dermal spontaneous emulsions has increased, given that systems have been reported to deliver drugs across mucus membranes, as well as the outermost layer of the skin into the underlying layers. The background and development of a double spontaneous emulsion incorporating four anti-tubercular drugs, clofazimine (CFZ), isoniazid (INH), pyrazinamide (PZY), and rifampicin (RIF), are described here. Our methods involved examination of oil miscibility, the construction of pseudoternary phase diagrams, the determination of self-emulsification performance and the emulsion stability index of primary emulsions (PEs), solubility, and isothermal micro calorimetry compatibility and examination of emulsions via microscopy. Overall, the potential of self-double-emulsifying drug delivery systems (SDEDDSs) as a dermal drug delivery vehicle is now demonstrated. The key to success here is the conduct of preformulation studies to enable the development of dermal SDEDDSs. To our knowledge, this work represents the first successful example of the production of SDEDDSs capable of incorporating four individual drugs. [ABSTRACT FROM AUTHOR]

In view of the common problems of conventional water shutoff agent, such as "Either not injected or not plugged, can not deep profile control and flooding, and poor effect of increasing oil and dewatering", a novel terpolymer was prepared from acrylamide（AM）,2-acrylamide-2-methylpropanesulfonic acid（AMPS） and N-（3-dimethylaminopropyl） methacrylamide（DMAPMA）, at the same time, multiple emulsions were prepared to encapsulate the crosslinking agent. The results showed that the cross-linking time of the multi-emulsion system could be delayed more than 1 times to 5～15 d, and the optimal gel system had good temperature and salt resistance, it is suitable for reservoirs with salinity less than 100 000 mg/L and temperature between 70 ℃ and 90 ℃. The gel system has the advantages of low initial viscosity, easy injection into low permeability formation, controllable cross-linking time and high gelling strength, and the hypertonic channel is effectively blocked. [ABSTRACT FROM AUTHOR]

It has long been established that the equilibrium properties of a water–oil–surfactant system governs the morphology of the emulsion formed—an inherently non-equilibrium system. In this work, we reinforce this concept and bring forward additional insights. Two types of 3-phase emulsions are examined, one obtained from suspension polymerization of silicone and acrylate in an aqueous phase and another obtained from mechanical dispersion of a silicone oil and a sunflower seed oil into an aqueous phase. We show that the specific emulsification process has an impact on the detailed structure of the final multiple droplets. In suspension polymerization, the complete miscibility of silicone with acrylate monomers prior to polymerization renders uniformity in the composition of the starting droplets; hence the final droplets after polymerization all have identical equilibrium tensions as well as relative volume ratios between the separated phases. Consequently, the final droplets have uniformly the same structure as predicted based on thermodynamics. On the other hand, the 3-phase emulsion formed from mechanical dispersion of two immiscible oils in water shows an overall morphology that is predicted by equilibrium tensions, however, a wide variation in the specific geometry is observed. This latter aspect reflects the randomness in drop break-up-and-recombination associated with the homogenization process, which results in variable volume ratio between the two immiscible oils among different droplets. [ABSTRACT FROM AUTHOR]

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM. [ABSTRACT FROM AUTHOR]

Due to their nested structure, double emulsions have the potential to encapsulate value-adding substances until their application, making them of interest to various industries. However, the complex, nested structure negatively affects the stability of double emulsions. Still, there is a lack of suitable measurement technology to fundamentally understand the cause of the instability mechanisms taking place. This study presents a novel measurement method to continuously track filling degree changes due to water diffusion in a water-in-oil-in-water (W1/O/W2) double emulsion droplet. The measurement method is based on the Raman effect and provides both photometric and spectrometric data. No sample preparation is required, and the measurement does not affect the double emulsion droplet. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (1001-1803) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In water-in-oil-in-water (W1/O/W2) double emulsions several irreversible instability phenomena lead to changes. Besides diffusive processes, coalescence of droplets is the main cause of structural changes. In double emulsions, inner droplets can coalesce with each other (W1–W1 coalescence), inner droplets can be released via coalescence (W1–W2 coalescence) and oil droplets can coalesce with each other (O–O coalescence). Which of the coalescence pathways contributes most to the failure of the double emulsion structure cannot be determined by common measurement techniques. With monodisperse double emulsions produced with microfluidic techniques, each coalescence path can be observed and quantified simultaneously. By comparing the occurrence of all possible coalescence events, different hydrophilic surfactants in combination with PGPR are evaluated and discussed with regard to their applicability in double emulsion formulations. When variating the hydrophilic surfactant, the stability against all three coalescence mechanisms changes. This shows that measuring only one of the coalescence mechanisms is not sufficient to describe the stability of a double emulsion. While some surfactants are able to stabilize against all three possible coalescence mechanisms, some display mainly one of the coalescence mechanisms or in some cases all three mechanisms are observed simultaneously. [ABSTRACT FROM AUTHOR]

Self-emulsifying drug delivery systems (SEDDSs) are lipid-based systems that are superior to other lipid-based oral drug delivery systems in terms of providing drug protection against the gastrointestinal (GI) environment, inhibition of drug efflux as mediated by P-glycoprotein, enhanced lymphatic drug uptake, improved control over plasma concentration profiles of drugs, enhanced stability, and drug loading efficiency. Interest in dermal spontaneous emulsions has increased, given that systems have been reported to deliver drugs across mucus membranes, as well as the outermost layer of the skin into the underlying layers. The background and development of a double spontaneous emulsion incorporating four anti-tubercular drugs, clofazimine (CFZ), isoniazid (INH), pyrazinamide (PZY), and rifampicin (RIF), are described here. Our methods involved examination of oil miscibility, the construction of pseudoternary phase diagrams, the determination of self-emulsification performance and the emulsion stability index of primary emulsions (PEs), solubility, and isothermal micro calorimetry compatibility and examination of emulsions via microscopy. Overall, the potential of self-double-emulsifying drug delivery systems (SDEDDSs) as a dermal drug delivery vehicle is now demonstrated. The key to success here is the conduct of preformulation studies to enable the development of dermal SDEDDSs. To our knowledge, this work represents the first successful example of the production of SDEDDSs capable of incorporating four individual drugs.

Double emulsions arouse great interest in various industries due to their ability to encapsulate value-adding ingredients. However, they tend to be unstable due to their complex structure. Several measurement techniques have already been developed to study and monitor the stability of double emulsions. Especially for the measurement of the filling degree of double emulsions, so far there is no reliable method available. In this paper, a measurement system is presented that can measure the filling degree of water-in-oil-in-water (W/O/W) double emulsions by both spectrometrical and photometrical means. The method is based on the Raman effect and does not require any sample preparation, and the measurement has no negative influence on the double emulsion. It is shown that both spectrometric and photometric Raman techniques can reliably distinguish between double emulsions with filling degrees that have a 0.5% difference. Additionally, oil droplet sizes can be photometrically measured. Furthermore, the measurement system can be integrated into both inline and online emulsification processes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Water‐in‐oil‐in‐water (W1/O/W2) emulsions stabilized by protein–carbohydrate complexes were prepared from an inner water phase (W1), an oil phase (O) and an outer water phase (W2). The complexes consisted of heat‐induced aggregates (HIAs) of isomalto‐oligosaccharide/egg white protein Maillard conjugates. The effects of polyglycerol ester of polyricinoleic acid (PGPR) concentration, HIA concentration, W1‐to‐O volume ratio and W1/O‐to‐W2 volume ratio on the properties of the W1/O/W2 emulsions were systematically investigated. RESULTS: At sufficiently high PGPR concentrations (>2%), the emulsions possess a high negative charge (≈−44 mV). The encapsulation efficiency of the emulsions, which was determined by incorporating a hydrophilic yellow dye in the inner water phase prior to homogenization, was relatively high (up to 93%) and did not change significantly during 14‐day storage at 4 °C. All emulsions were fluids that exhibited shear thinning behavior. CONCLUSION: Overall, this study shows that nature‐derived emulsifiers can be used to create W1/O/W2 emulsions suitable for application in the food industry. In addition, we provided a viable strategy to encapsulate water‐soluble nutrients. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The droplet dynamic model under an electric field is established in this paper by coupling electric equations, multiphase flow equations, and isoAdvector interface capture method, accurately predicting the deformation and rupture characteristics of multiple emulsion droplets affected by an electric field. The evolutions of the flow field and electric field during the deformation and breakup processes of multiple emulsion droplets subjected to an electric field are elucidated and the effects of the electric capillary number Ca and the radius ratio R ∗ of the inner and outer droplets on the characteristics of droplet deformation and rupture are analyzed. The results show that in the silicone oil/water emulsion system, the inner droplet is difficult to induce charge since the electrostatic shielding effect of the outer droplet, and it has no impact on the equilibrium deformation of the outer droplet; whereas in the castor oil/silicone oil emulsion system, the charge is induced on the interfaces of both the internal and external droplets and the internal droplet has a remarkable impact on the equilibrium deformation of the external droplet. Furthermore, deformation-breakup phase diagrams of multiple emulsion droplets exposed to the electric field are obtained. As R ∗ increases, the Ca c for droplet breakup decreases, indicating that the internal droplet intensifies the breakup of the external droplet. The results are significant for the promotion and application of electric field-driven droplet manipulation technology. [Display omitted] • The isoAdvector method is developed to precisely predict deformation and breakup. • The inner droplet has no impact on the outer droplet deformation in O/W/O emulsion. • The inner droplet promotes the outer droplet deformation in C/S/C emulsion. • The multiple emulsion droplet is prone to break as R * increases. [ABSTRACT FROM AUTHOR]

Due to their nested structure, double emulsions have the potential to encapsulate value-adding substances until their application, making them of interest to various industries. However, the complex, nested structure negatively affects the stability of double emulsions. Still, there is a lack of suitable measurement technology to fundamentally understand the cause of the instability mechanisms taking place. This study presents a novel measurement method to continuously track filling degree changes due to water diffusion in a water-in-oil-in-water (W1/O/W2) double emulsion droplet. The measurement method is based on the Raman effect and provides both photometric and spectrometric data. No sample preparation is required, and the measurement does not affect the double emulsion droplet.

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM.

The design of biocompatible multiple emulsions is an important challenge in the field of controlled delivery systems for protecting and delivering compounds encapsulated and protected in the innermost phase. In this paper, we use biocompatible water – Miglyol®812 water-in-oil-in-water (W/O/W) emulsions stabilized by a stimuli-responsive diblock copolymer consisting of poly(dimethylsiloxane) (PDMS) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) to design an easy-to-process new delivery W/O/W system. Such emulsions are formed in a single emulsification step. They present a high encapsulation yield and are shown to be stable over months. As such, the encapsulation of a hydrophilic dye (Alexa fluor) in the innermost water phase is successfully demonstrated over months. These emulsions are stimulable either by a shift in pH level or in ionic strength. The former destabilizes the multiple emulsion and leads to a simple one while the latter partly maintains the multiple character. Eventually both stimulations are effective in the dye release and molecular mechanisms are proposed for explaining the observed two-stage kinetics of release.

The global obesity epidemic and increasing incidences of metabolic diseases have been correlated to increased consumption of fat, sugar, and salt. In response, many food scientists are developing food products with reduced levels of sugar, fat and/or salt. However, knowledge of composition-structure-property relationships of foods is critical to create high-quality products that are well accepted by consumers. Moreover, food processing may increase the digestion rates of nutrients by breaking down food structures, thereby making them more readily digestible and absorbable. This review provides an overview of the mechanisms and expected effects of using structural design approaches to reduce the levels or retard the digestibility of nutrients associated with negative health impacts (especially fats, carbohydrates and salt) in processed foods. There are a number of design approaches that may be applied to food in order to make them less energy-dense or with reduced digestion rates of key nutrients, while not affecting much their sensory appeal to consumers. • Health problems have resulted from increased consumption of fat, sugar, and salt. • Structural food design depends on knowledge of food composition-structure-properties. • Macronutrients (eg starch and fat) may have their contents or digestibility reduced. • Structurally designed foods may be healthier while still well accepted by consumers. [ABSTRACT FROM AUTHOR]

Evaluations have been made about the physicochemical stability in water-in-oil-in-water (W/O/W) emulsion loaded with resveratrol under different pH, NaCl concentration, temperature, and storage time. The in vitro digestion and Caco-2 cell transport were also investigated. Results showed W/O/W emulsion remained stable at pH 2–8, temperatures of 25–70 °C and could be stable storage for 77 days. With an increase in NaCl concentration from 1 to 500 mM, the zeta potential changed from −40 mV to −10 mV, but the droplets size didn’t show any significant change. The in vitro digestion showed W/O/W emulsion could maintain the structure until small intestine which could give higher protecting for resveratrol. Meanwhile, W/O/W emulsion could reduce the efflux rate of resveratrol across the Caco-2 cell monolayers and special complex of W/O/W emulsion could delay resveratrol release. Results indicated that W/O/W emulsion was suitable vehicle for resveratrol and could improve its bioavailability considering those complicated influence factors.

The present study aimed to optimize insulin-loaded chitosan-coated W/O/W multiple emulsions (MEs) by investigating the effect of process variables on the response using Box–Behnken design. Effect of three independent factors, which are, the concentration of the lipophilic surfactant (Span 80) in the primary emulsion, the concentration of the hydrophilic surfactant (Tween 80) in the secondary emulsion, and phase volume ratio (W/O) in the primary emulsion, was studied on three dependent responses, which are particle size, zeta potential, and entrapment efficiency. The optimized ME showed particle size of 193.7 nm and −64.58 mV zeta potential with maximum entrapment efficiency of 91.84%. The in vitro drug release profile from W/O/W ME was studied under two simulated physiological conditions. In vitro drug release behavior followed the Peppas–Sahlin model and showed an initial and rapid release followed by a slower release. The results of the present investigation suggest the potential of the chitosan-coated W/O/W MEs as a promising oral drug delivery system for insulin. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (1001-1803) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Double emulsions arouse great interest in various industries due to their ability to encapsulate value-adding ingredients. However, they tend to be unstable due to their complex structure. Several measurement techniques have already been developed to study and monitor the stability of double emulsions. Especially for the measurement of the filling degree of double emulsions, so far there is no reliable method available. In this paper, a measurement system is presented that can measure the filling degree of water-in-oil-in-water (W/O/W) double emulsions by both spectrometrical and photometrical means. The method is based on the Raman effect and does not require any sample preparation, and the measurement has no negative influence on the double emulsion. It is shown that both spectrometric and photometric Raman techniques can reliably distinguish between double emulsions with filling degrees that have a 0.5% difference. Additionally, oil droplet sizes can be photometrically measured. Furthermore, the measurement system can be integrated into both inline and online emulsification processes.

Lidocaine is a primary local anesthesia that blocks the ionic fluxes required for the beginning and operation of impulses in the neuronal membrane. The benefits of local anesthetics, such as enhancing patient acceptance, prohibiting systemic toxicity and delivering continuous drug delivery, make them the attracting field for pharmaceutical researchers. The nanoparticles were prepared by solvent evaporation W1/O/W2 emulsion method and in the ratios of 1 to 1, 1 to 2 and 1 to 3 drug to polymer. The production yield, loading efficiency, particle size, poly dispersity index and zeta potential of selected formulation were 84.30%, 80.60%, 192 nm, 0.18 mV and + 4 2. 8 mV, respectively. DSC and FTIR studies showed that no chemical interactions between drug and polymer Formulations showed an initial burst release, which is a reason for the good capacity of the polymer to maintain the drug in it and lead to a primary slow release. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (1001-1803) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In present study, we have developed W/O/W microemulsion (ME) containing piperine (PiP) as a permeation enhancer and albumin (Alb) serving as a stabilizer for oral delivery of insulin (INS). The resultant formulation, ME(INS)-PiP-Alb exhibited droplet size of 3.35 ± 0.25 μm along with polydispersity index (PDI) of 0.30 ± 0.10. The formulation process employed for developing ME(INS)-PiP-Alb showed no effect on INS's chemical and conformational stability. Further, ME(INS)-PiP-Alb was able to maintain desired attributes (size & PDI) along with INS stability in simulated gastrointestinal fluids. Also, ME(INS)-PiP-Alb rendered higher protection to INS in presence of pepsin and trypsin than ME(INS)-PiP. In qualitative Caco-2 cell uptake, INS loaded ME's showed higher uptake in comparison to free INS. Whereas, in permeability studies ME(INS)-PiP-Alb showed ~4 and ~1.5-fold enhanced permeation than free INS and ME(INS) without PiP groups respectively. Also, in ex vivo intestinal permeation studies similar fold increment in permeation were observed. Interestingly, the pharmacodynamic studies revealed ~3.2-fold higher hypoglycemic effect in animals treated with ME(INS)-PiP-Alb in comparison to ME(INS)-PiP. Similarly, the pharmacokinetic studies also revealed ~1.6 fold higher AUC for ME(INS)-PiP-Alb than ME(INS)-PiP. Thus, in vivo results suggested that Alb as a stabilizer can assist in improving the hypoglycemic effect of the developed ME with PiP. Hence, this strategy can also be extrapolated for delivering other bio-macromolecules orally. Unlabelled Image • The developed formulation is relatively less complex and beholds high scale-up potential. • The insulin (INS) loaded ME with permeation enhancer and albumin as stabilizer showed spherical morphology with narrow PDI. • The developed formulation exhibited in-process and biological stability. • In vitro and ex vivo studies showed 4 fold higher permeation of formulation than free INS. • Formulation revealed ~1.4 and ~1.3 fold higher cumulative hypoglycemia and AUC than SC injected INS respectively. [ABSTRACT FROM AUTHOR]

In contrast to when polyglycerol polyricinoleate (PGPR) is used as lipophilic emulsifier, the used oil phase and phospholipid composition have a strong influence on the characteristics of water-in-oil (w/o) emulsions prepared using lecithin. These parameters are also expected to influence the characteristics of the corresponding water-in-oil-in-water (w/o/w) emulsions. Moreover, a hydrophilic emulsifier is typically added to the external water phase of w/o/w emulsions and is also expected to influence the characteristics of the w/o/w emulsions. Lecithin with a varying phospholipid composition was used to prepare w/o emulsions with medium chain triglyceride (MCT) oil as well as long chain triglyceride (LCT) oil. In case the w/o emulsion was stable, w/o/w emulsions were produced as well. Hereby, the w/o/w emulsions were prepared using different hydrophilic emulsifiers. Each of the lecithin samples could be used to produce a stable w/o emulsion in MCT-oil. In contrast, a stable w/o emulsion could only be produced in LCT-oil with phosphatidylcholine depleted lecithin. The storage stability of the w/o/w emulsions was also higher in case MCT-oil was used as compared to LCT-oil. Finally, a remarkable influence of the high-HLB emulsifier on the resulting enclosed water volume fraction in the w/o/w emulsions was observed. [ABSTRACT FROM AUTHOR]

The analysis of drops and rheological measurements of the emulsion produced were presented in the article. The influence of stirring time and rotation frequency on the drops size of the emulsion produced in the propeller of diameter D = 0.1 m and liquid height H = 0.5D equipped with four standard flat dividers was defined. The Smith turbine stirrer was used to stir the emulsion produced. The drop size was defined for three different propeller rotation frequencies, 500 rpm, 1000 rpm and 1500 rpm. The stirring time, after which the samples were collected, was accordingly 15 min and 45 min. To produce the emulsion, sunflower oil was used in the oil phase and distilled water in the water phase. There were 6 measurement series all together, and they were presented as the diameter size distribution. The mean arithmetic diameter da, median dm and the mean Sauter diameter d32 were determined. The rheological measurements of the produced emulsions were presented in graphics as a function τ = f(γ) and were described as Herschel–Bulkley and Bingham models presented in Table 3. [ABSTRACT FROM AUTHOR]

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Background: Cosmetics are the products used to beautify the skin. Emulsion is a fine dispersion of two or more immiscible liquids. Sphaeranthus indicus is claimed to be used for skin beautification in folk medicine. Multiple emulsion was formulated containing the extract of S indicus flowers. Aims: This research study indicates that extract of S indicus flowers contains sufficient amount of polyphenols and also possess good antioxidant activity with mushroom tyrosinase inhibition activity. Method: Further, stable multiple emulsion was developed and stability testing was performed for 180 days by keeping the multiple emulsion at 8°C ± 1, 25°C ± 1, 40°C ± 1, and 40°C ± 1 with 75% ± 1 RH. Parameters checked were color change, phase distribution, viscosity, droplet size and size distribution, pH determination, and electrical conductivity. Sun protection factor (SPF) was determined which also showed promising results. Skin testing on human volunteers was done for 3 months after biosafety profiling of the most stable multiple emulsion. Results: This also showed remarkable effects. Skin erythema, melanin, and sebum were reduced. Skin hydration and elasticity were increased. There was also reduction in the number of skin large and small skin pores. Skin spot area was also reduced by the use of multiple emulsion loaded with S indicus flower extract. ANOVA test showed that all the effects produced on skin were significant, ie, P ≤.05. Conclusion: A stable multiple emulsion was developed which produced significant cosmetic effects on human skin. [ABSTRACT FROM AUTHOR]

Multiple liquid emulsions of the water in oil in water (W1/O/W2) type are used in a variety of consumer or technical applications, for instance in the encapsulation of certain active ingredients. The encapsulation process and release mechanisms of the inner phase of the carrier drops are important in order to properly process and formulate such liquid‐liquid systems. In this work the stability and breakage of multiple W1/O/W2 emulsions under mechanical shear stress are investigated for emulsions with different surfactants and surfactant concentrations of the internal emulsion. Stressing the emulsions in a mechanical stirring process is compared to the membrane emulsification process. The membrane emulsification process results in higher encapsulation efficiencies than the stirring process. The emulsion droplets were subjected to shear stress below and above the critical capillary number for drop breakup. The results show that stable inner emulsions with sufficient surfactant concentrations increase the overall encapsulation efficiency for multiple emulsions subjected to shear stress, although the effect is not prominent. The depletion of the carrier oil droplets could be achieved for Ca numbers below the critical limit, reducing the encapsulation efficiency below 10 %. This shows that even a low shear stress can result in content release from the internal droplet phase. The experimental emulsion release study is supported by a numerical simulation of drop deformation and break‐up under shear stress. [ABSTRACT FROM AUTHOR]

Continuous contact of air pollutants on human skin has produced early ageing and led to roughness, dryness, poor elasticity, increased wrinkling and irregular pigmentation of the skin. The present study was carried out to fabricate an anti-pollution cosmetic-based w/o/w multiple emulsion containing D-biotin, prepared by a one-step formation as protection for the skin against the effects of air pollutants and further used for in vitro and in vivo evaluation. A similar multiple emulsion without D-biotin was also prepared in the same way. Each of the tested multiple emulsions (CB2 and CF2) was applied to the cheeks of 15 human volunteers for a testing period of 90 days. Both emulsions were assessed for skin melanin, erythema, hydration and elasticity values. The droplet sizes of CB2 and CF2 stored in the dark were 10.92 ± 0.23 and 15.4 ± 0.12 μm, respectively. The size distributions of CB2 and CF2 ranged from 4.55 ± 0.1 to 26.056 ± 0.34 μm and from 1.97.16 ± 1.2 to 45.13 ± 2.17 μm, respectively. The rheological parameters showed non-Newtonian, pseudo-plastic and shear thinning behaviour, while pH remained within an acceptable range. No considerable physical changes were observed. The skin irritation testing indicated that CB2 and CF2 were safe after application and did not cause any skin irritation. The skin melanin, erythema, moisture and elasticity values of both the right and left cheeks of the volunteers were measured at baseline visits: 15, 30, 45, 60, 75 and 90 days of time intervals. While CB2 showed insignificant effects, therefore, it was demonstrated that CF2 decreased skin erythema content and increased skin elasticity and hydration significantly but had an insignificant effect on skin melanin content with respect to time. Good sensory attributes were also achieved. Therefore, CF2 is a promising new approach for protection of the skin from the deleterious effects of air pollutants. [ABSTRACT FROM AUTHOR]

The present paper introduces a numerical approach based on the level-set framework to simulate multiphase flow in the context of multiple emulsion formation. The present technique, designed for the flow of n-phases, is applicable for the production of multiphase emulsions and also for the modeling of two and three-dimensional systems. This method is utilized to simulate the formation of single, double, and triple emulsions in a microfluidic cross-junction. The accuracy of the findings is confirmed by conducting an investigation of a single emulsion at home, as well as by referencing experimental and numerical literature on multiple emulsions. Until recently, the prospect of a shift in the double droplet formation regime at a constant capillary ratio between phases had not been taken into account. The present study yielded a flow regime mapping diagram that exhibits a transition in the double droplet formation regime under a constant capillary number ratio between the inner and middle phases. Using a morphological diagram, our method takes into consideration the effect of varying values of interfacial tension between the phases on the formation of double droplets. A comparison of two-dimensional and three-dimensional modeling strategies for double emulsion is also conducted, with the aim of clarifying the dissimilar results obtained from these two techniques. [Display omitted] • A level-set-based numerical method is used to explore multiphase flow. • Using this method, multiple emulsion formation in a microfluidic device is simulated. • Phase-morphological interactions are included. • Simulations of 2-D and 3-D higher-order emulsion generation are incorporated. [ABSTRACT FROM AUTHOR]

The multiple W/O/W emulsion supplemented with the extracts of Rosmarinus officinalis L., Avena sativa L. and Linum usitatissimum L. was prepared in the study, its active compounds were determined by HPLC and its safety was evaluated in vitro by the means of reconstituted human skin model EpiDerm™ for the assessment of its irritation, phototoxicity and early skin inflammation effects and by the 48 h human skin patch test for its skin irritation and allergenic potential. The microbiological challenge test of W/O/W emulsion was performed to ensure its preservation efficiency. The results showed that the W/O/W emulsion loaded with self-preserving plant-based bio-actives had no irritant potential, was not phototoxic and did not provoke skin inflammation or sensitization and thus could be used as a safe base for cosmetic products. Furthermore, our results demonstrate that the safety evaluation of cosmetic ingredients of natural or organic origin could be easily performed using reconstructed human skin model EpiDerm™ similar to the well-defined chemicals used in the cosmetics industry.

Background: The ability to preserve living cells or stem cells is critical for their use in cell therapy, especially for regenerative, reproductive, and transfusion medicine. This article addresses the low survival rates of cells and their loss of function during traditional freezing and banking (cells in a liquid medium with cryoprotectants). Aim: In this article, we developed multiple emulsions (water-in-oil-in-water type) for the effective encapsulation and cryopreservation of cells. In multiple emulsions, the oil drops, acting as a protective membrane, contain even smaller water droplets with encapsulated living cells, dispersed in the continuous water phase. Materials and Methods: The multiple emulsions with HEK293 cells encapsulated in the internal alginate droplets were successfully prepared in a Couette-Taylor flow biocontactor. The cryoprotectants (sucrose/dimethyl sulfoxide-DMSO) were located within the internal or external or both water phases of the emulsions. Encapsulated and non-encapsulated cells were frozen to −80°C (cooling rate: −1°C/min) and then transferred to liquid nitrogen (−196°C) for 24 hours. The standard rapid warming procedure was applied to thaw samples. Cell proliferation and viability were measured by using the AlamarBlue™ assay after recovery of cells. Results: The results showed that the viability of cells encapsulated in the internal droplets of multiple emulsions, and then cryopreserved, was significantly higher, up to 27.9%, than that observed for cells conventionally cryopreserved (non-encapsulated cells in water). Moreover, the effective cell-loaded multiple emulsions-based banking method allowed DMSO—toxic cryoprotectant—to be eliminated from the cryopreservation system. Conclusion: The proposed approach of the cryoprotection of cells encapsulated in multiple emulsions could minimize cell damage, degradation, and their loss during freezing–thawing processes. [ABSTRACT FROM AUTHOR]

Results of drops dimension and rheological properties of the produced multiple emulsion are presented in this paper. Sunflower oil (oil phase), distilled water (liquid phase), and lecithin from soya beans were used as materials to produce emulsion. Emulsions were produced in vessel with inner diameter D = 0.1 m and liquid height H = 0.5D. Smith turbine has been used to stir the emulsions. Examination of the drops dimension and rheological properties were conducted for emulsions collected after 15 min and 45 min of stirring as well as after the 3rd and 30th day. There were 6 measurements altogether. To do the analysis of drops dimension, in each series 700–800 inner oil-phase drops were taken. The results were presented in a form of graphics as a distribution of drops. The dimensions of the drops obtained d were also presented as a minimal diameter dmin, arithmetic mean diameter da, median dm, and Sauter mean diameter d32. The results of the research of rheological emulsions were presented graphically as a viscosity curve and they were described by Herschel–Bulkley model (Eq. 4) [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Multiple W/O/W emulsion for topical application of clotrimazole has been developed. • Sphericalspherical droplets with negative charge and optimal pH were obtained. • Formulation showed pseudoplastic behavior with hysteresis areas and low viscosities. • Improved release and permeation profiles than commercial references were shown. • Higher antimycotic efficacy than commercial references were also achieved. Abstract Clotrimazole (CLT) was formulated in a multiple W/O/W emulsion (ME) with the aim of evaluating its potential as topical anticandidal agent and comparing with marketed products. A previously evaluated CLT-ME was selected and physicochemically characterized. The in vitro release behavior and the ex vivo permeation profiles were assessed using Franz diffusion cells using three different types of biological membranes: human skin and porcine buccal, sublingual and vaginal mucosae. The antifungal activity against Candida strains was also tested. Results showed CLT-MEs sizes of 29.206 and 47.678 μm with skin compatible pH values of 6.47 and 6.42 exhibiting high zeta potential values of -55.13 and -55.59 mV with dependence on the pH variation. The physicochemical stability was kept for a period of 180 days of storage at room temperature. CLT-MEs exhibited pseudoplastic behavior with hysteresis areas and viscosities of 286 and 331 mPa⋅s showing higher spreadability properties than commercial counterparts. An improved CLT release pattern was supplied by the ME system following a hyperbolic model. Likewise, ME system gave higher skin permeation flux of CLT than commercial reference. CLT amounts retained in the skin and mucosae were also higher than commercial references, which coupled with the higher antimycotic efficacy make CLT-MEs a great tool for clinical investigation of topical candidiasis treatments. [ABSTRACT FROM AUTHOR]

Abstract Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21 ± 0.18) and Alg-HMP (70.60 ± 0.68) were obtained with CX initial concentration of 11 and 18 μg/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX 18 microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent. [ABSTRACT FROM AUTHOR]

Ferulic acid is a derivative of cinnamic acid showing efficacious anti-oxidant activity. It catalyzes the stable phenoxy radical formation, upon absorption of ultraviolet light, giving the strength to ferulic acid for terminating free radical chain reactions. Ultraviolet rays are one of the most dangerous factors that daily assault the skin, causing excessive generation of reactive oxygen species (ROS), which are regarded to be important contributors to a variety of cutaneous alterations. The skin possesses endogenous antioxidant defense systems, but the excess of ROS leads to an oxidant–antioxidant imbalance. Although ferulic acid is daily introduced in human organism with the diet, its bioavailability after oral administration is poor, particularly in the skin. The aim of this investigation was to evaluate three types of emulsions (W/O/W multiple emulsions and two simple emulsions) as suitable formulations for topical application of the active compound. In vitro studies were performed to investigate the stability and release profiles of these systems. Multiple emulsions showed great stability and the best ability to carry and release ferulic acid. In vivo evaluations highlighted their best capability to treat UV-B-induced erythema. These findings suggested multiple emulsions as an innovative and more efficient vehicle for topical application of ferulic acid.