Behavior of vitamin E acetate delivery systems under simulated gastrointestinal conditions: lipid digestion and bioaccessibility of low-energy nanoemulsions

The effect of physical stability and modified gastrointestinal tract behaviour of resveratrol-loaded NLCs encapsulated alginate beads

Nanostructured lipid carriers (NLC) have low storage and gastrointestinal stability, limiting their applicability. The work aimed to elevate the stability and behaviour of NLC in the alimentary tract by creating an alginate bead. Through the extrusion dropping procedure, Resveratrol (RES)-loaded NLC were efficiently integrated into alginate beads. The incorporation had no significant impact on the particle size, morphology, or inner structure of NLC, as assessed using DLS (Dynamic Light Scattering), SEM (Scanning Electron Microscopy), Differential Scanning Calorimetry (DSC) and FT-IR (Fourier Transform Infra-Red). Incorporating NLC into alginate beads improves its physical stability compared to dispersion of NLC as well as NLC-Sol. An in vitro release investigation found that the NLC-alginate beads released RES more slowly than optimized NLC formulation (RES-NLCs-opt) and NLC-alginate sol. Research on simulated in vitro digestive models revealed that just a small amount of integrated NLC may permeate stomach fluid due to its tiny size. The slow diffusion of NLC from alginate to intestinal fluid prevented aggregation and allowed for gentle hydrolysis of the lipid matrix. Incorporating NLC in alginate beads shows promise for improving stability, modifying gastrointestinal behaviour, and controlling release throughout the process of digestion.

W/O/W emulsion-filled sodium alginate hydrogel beads for co-encapsulation of vitamins C and E: Insights into the fabrication, lipolysis, and digestion behavior

In this study, vitamins C and E were simultaneously encapsulated in water-in-oil-in-water (W/O/W) emulsion-filled sodium alginate (SA) hydrogel beads, as well as the effects of SA concentrations (0.5%, 1.0%, 1.5%, and 2.0%) on the structures and lipolysis the of hydrogel beads were investigated. With increasing SA concentration, the beads showed larger sizes, denser structures and better textures. The droplets tightly penetrated the gel network at high SA concentrations. Digestion behavior revealed the disintegrated intramolecular structure at low SA concentrations. The beads with 0.5% SA were fragmented, losing the initial shape during digestion in the intestinal fluid. Additionally, lipid phases were released as W/O/W and O/W emulsion droplets after digestion. However, the high SA concentration-containing beads exhibited a well-preserved morphological structure after digestion, and the release profiles of lipid phase were mainly O/W emulsion droplets. Furthermore, vitamins C and E encapsulated in the beads exhibited high bioaccessibility (vitamin C: 90.20% and vitamin E: 95.19%).

Emulsification and stabilisation technologies used for the inclusion of lipophilic functional ingredients in food systems

Food industry is increasingly using functional ingredients to improve the food product quality. Lipid-containing functional ingredients are important sources of nutrients. This review examines the current state of emulsification and stabilisation technologies for incorporating lipophilic functional ingredients into food systems. Lipophilic functional ingredients, such as omega-3 fatty acids, carotenoids, and fat-soluble vitamins, offer numerous health benefits but present challenges due to their limited solubility in water-based food matrices. Emulsification techniques enable the dispersion of these ingredients in aqueous environments, facilitating their inclusion in a variety of food products. This review highlights recent advances in food emulsion formulation, emulsification methods and stabilisation techniques which, together, improve the stability and bioavailability of lipophilic compounds. The role of various emulsifiers, stabilizers, and encapsulation materials in enhancing the functionality of these ingredients is also explored. Furthermore, the review discusses different stabilisation techniques which can yield in emulsion in a solid or liquid state. By providing a comprehensive overview of current technologies, this review aims to guide future research and application in the development of functional foods enriched with lipophilic ingredients.

Physical properties and in-vitro gastrointestinal digestion of oil-in-water emulsions stabilized by single- and dual-modified cassava starches with cross-linking and octenylsuccinylation

The different modified cassava starches (MCS) obtained by either single or dual modifications with cross-linking (CL) and octenylsuccinylation (OS), including 2%CL, 3%OS, 2%CL-3%OS, and 3%OS-2%CL, were used to stabilize soybean oil-in-water emulsions (oil content 10% (w/w)) at a concentration of 4.5% (w/w) compared to native cassava starch (NCS) and their physical properties and in-vitro gastrointestinal digestion were investigated. The emulsions stabilized with NCS and 2%CL-MCS had larger oil droplet sizes, higher viscosity, and lower negative charge than the emulsions stabilized by single- or dual-MCS with 3%OS. All MCS-stabilized emulsions showed a higher emulsion stability against creaming than the NCS-stabilized emulsion. Under a simulated gastrointestinal tract, all 3%OS-MCS promoted droplet flocculation, while the less ionic NCS and the 2%CL-MCS showed a decrease in droplet size after passing through the mouth and stomach stages. The lipid digestion rate of emulsions stabilized with different MCS and NCS followed the following order: 3%OS >2%CL-3%OS > 3%OS-2%CL > 2%CL > NCS. The NCS- and 2%CL-stabilized emulsions had a lower lipid digestion rate, possibly due to the larger droplet sizes and higher viscosity of the initial emulsions, which delays access of lipase enzymes to lipid droplet surfaces, compared to all 3%OS-MCS-stabilized emulsions.

Plant-based essential oil encapsulated in nanoemulsions and their enhanced therapeutic applications: An overview

In recent years, studies on the formulation of nanoemulsions have been the focus of attention due to their potential applicability in food, pharmaceuticals, cosmetics, and agricultural industries. Nanoemulsions can be formulated using ingredients approved by the Food and Drug Administration (FDA), which assures their safety profiles to a great extent. Bioactive compounds such as essential oils although have strong biological properties and antimicrobial compounds, their usage is restricted due to their high volatility, instability, and hydrophobic nature. Therefore, nanoemulsion as carrier vehicle can be used to encapsulate essential oils to obtain stable and enhanced physicochemical characteristics of the essential oils. This review details the structure, formulation, and characterization techniques used for nanoemulsions, with a focus on the essential oil-based nanoemulsions which have the potential to be used as antimicrobial and anticancer therapeutics.

Carboxymethyl konjac glucomannan-chitosan complex nanogels stabilized emulsions incorporated into alginate as microcapsule matrix for intestinal-targeted delivery of probiotics: In vivo and in vitro studies

In this study, we developed a novel delivery system using carboxymethyl konjac glucomannan-chitosan (CMKGM-CS) nanogels stabilized single and double emulsion incorporated into alginate hydrogel as microcapsule matrix for intestinal-targeted delivery of probiotics. Through in vitro experiments, it was demonstrated that alginate hydrogel provided favorable biocompatible growth conditions for the proliferation of Lactobacillus reuteri (LR). The alginate hydrogel containing single (ASE) or double emulsions (ACG) enhanced the resistance of LR to various adverse environments. Simulated gastrointestinal digestion experiments revealed that the survivability of LR in free, CON, ASE and ACG group decreased by 6.45 log CFU/g, 4.21 log CFU/g, 1.26 log CFU/g and 0.65 log CFU/g, respectively. In vivo studies conducted in mice showed that ACG maintained its integrity during passage through the stomach and released the probiotics in the targeted intestinal area, whereas the pure alginate hydrogels (CON) were prematurely released in the gastrointestinal tract. Moreover, the viable counts of ACG in different intestinal segments (jejunum, ileum, cecum, and colon) were increased by 1.11, 1.42, 1.68, and 1.89 log CFU/g, respectively, after 72 h of oral administration compared to the CON group. This research contributed valuable insights into the development of an effective microbial delivery system with potential applications in the biopharmaceutical and food industries.

Assessing the nutritional quality of lipid components in commercial meal replacement shakes using an in vitro digestion model

This study aimed to investigate the nutritional value of five commercial meal-replacement shakes, and mainly focused on the lipid digestion fates and fat-soluble vitamin bioavailability. Four out of five samples exhibited a low lipolysis level (37.33-61.42%), aligning with the intended objectives of these products. Although the remaining sample rich in diacylglycerol (DAG) had a higher lipolysis level (80.83%), the inherent low-calorie nature of DAG might compensate for this drawback. The release level of individual fatty acid was largely determined by the glycerolipid composition. Moreover, the strong positive correlation between lipid hydrolyzed products amounts and the fat-soluble vitamin bioavailability was observed. Surprisingly, one out of five samples can provide enough vitamin A and vitamin E for consumers as a total replacement of one or two regular meals. Consequently, the meal-replacement shakes hold the potential to emerge as healthy products for this fast-paced era if the composition and structure were carefully designed and calculated.

Augmented Oral Bioavailability and Prokinetic Activity of Levosulpiride Delivered in Nanostructured Lipid Carriers

The present study is aimed to develop and optimize levosulpiride-loaded nanostructured lipid carriers (LSP-NLCs) for improving oral bioavailability and prokinetic activity of LSP. LSP-NLCs were optimized with D-optimal mixture design using solid lipid, liquid lipid and surfactant concentrations as independent variables. The prepared LSP-NLCs were evaluated for physicochemical properties and solid-state characterization. The in vivo oral pharmacokinetics and prokinetic activity of LSP-NLCs were evaluated in rats. LSP-NLCs formulation was optimized at Precirol® ATO 5/Labrasol (80.55/19.45%, w/w) and Tween 80/Span 80 concentration of 5% (w/w) as a surfactant mixture. LSP-NLCs showed a spherical shape with a particle size of 152 nm, a polydispersity index of 0.230 and an entrapment efficiency of 88%. The DSC and PXRD analysis revealed conversion of crystalline LSP to amorphous state after loading into the lipid matrix. LSP-NLCs displayed a 3.42- and 4.38-flods increase in AUC and Cmax after oral administration compared to LSP dispersion. In addition, LSP-NLCs showed enhanced gastric emptying (61.4%), intestinal transit (63.0%), and fecal count (68.8) compared to LSP dispersion (39.7%, 38.0% and 51.0, respectively). Taken together, these results show improved oral bioavailability and prokinetic activity of LSP-NLCs and presents a promising strategy to improve therapeutic activity of LSP for efficient treatment of gastric diseases.

Application of Curcumin Emulsion Carrier from Ultrasonic-Assisted Prepared Octenyl Succinic Anhydride Rice Starch

The emulsification of ultrasonic-assisted prepared octenyl succinic anhydride (OSA) rice starch on curcumin was investigated in the present study. The results indicated that the encapsulation efficiency of curcumin in emulsions stabilized by OSA-ultrasonic treatment rice starch was improved, from 81.65 ± 0.14% to 89.03 ± 0.09%. During the in vitro oral digestion, the particle size and Zeta potential of the curcumin emulsion did not change significantly (p > 0.05). During the in vitro digestive stage of the stomach and small intestine, the particle size of the curcumin emulsion continued to increase, and the absolute potential continued to decrease. Our work showed that OSA-pre-treatment ultrasonic rice starch could improve curcumin bioavailability by increasing the encapsulation efficiency with stronger stability to avoid the attack of enzymes and high intensity ion, providing a way to develop new emulsion-based delivery systems for bioactive lipophilic compounds using OSA starch.

Improving the in vitro and in vivo bioavailability of pterostilbene using Yesso scallop gonad protein isolates-epigallocatechin gallate (EGCG) conjugate-based emulsions: effects of carrier oil

This study investigated the influence of carrier oils on the in vitro and in vivo bioavailability of PTE encapsulated in scallop gonad protein isolates (SGPIs)-epigallocatechin gallate (EGCG) conjugate stabilized emulsions. The SGPIs-EGCG stabilized emulsions were subjected to an in vitro simulated digestion, and the resulting corn oil and MCT micelles were used to evaluate the PTE transportation using the Caco-2 cell model. Both emulsions remarkably improved the bioaccessibility of PTE in the micelle phase. Nevertheless, corn oil emulsions increased trans-enterocyte transportation of PTE more efficiently than MCT emulsions. Furthermore, the maximum plasma concentrations of PTE and its metabolites in mice fed with PTE emulsions were prominently higher than those in mice fed with PTE solution, while the in vivo metabolic patterns of PTE in different oil-stabilized emulsions were different. Therefore, SGPIs-EGCG stabilized emulsions could enhance the bioavailability of PTE through controlled release, in which corn oil is more suitable than MCT.

Soy and whey protein isolate mixture/calcium chloride thermally induced emulsion gels: Rheological properties and digestive characteristics

We present the preparation and physicochemical properties of thermally induced emulsion gels of a soy protein isolate-whey protein isolate (SPI-WPI)/calcium chloride composite, and the analysis of their nutrient release behaviors using fat-soluble vitamin E as a model system by simulating its digestion in vitro. In general, the SPI-WPI composite emulsion gel was found to have better water-holding capacity and texture than the emulsion gels formed by the single protein. The microstructure and rheological properties of the gel suggested that the CaCl₂ concentration significantly influences the fundamental structure and mechanical properties of the SPI-WPI gel. The in vitro digestion experiments revealed that the mixed protein emulsion gel improves the bioavailability of vitamin E. This study is of great significance in the utilization of these natural emulsifiers, as they can be used in the development of emulsion delivery systems for lipophilic nutrients and other health products.

Design and development of essential oil based nanoemulsion for topical application of triclosan for effective skin antisepsis

The skin acts as physical barrier to protect the body from external physical and chemical environment. When skin is infected, the outer epidermal barrier is compromised and colonized with microbial growth. Wound infection presents an immense burden in healthcare costs and decreased quality of life for patients. Topical application of nanoemulsions (NE) at pathological sites offers the potential advantage of direct drug delivery to the skin including potential for follicular targeting. This may have application in the improvement of skin antisepsis. In this study, NEs of triclosan (TSN) were prepared using hot high shear homogenization followed by ultrasonication. The oil phases comprised eucalyptus oil (EO) and olive oil (OO) and pseudo-ternary phase diagrams used to select optimum concentrations of surfactant. EO-based NEs had smaller droplet size and higher entrapment efficiency compared to OO-based NEs. Skin permeation was higher for EO-containing formulations, likely due to higher solubility of TSN in EO, smaller droplet size, low viscosity, and permeation enhancement effects of EO. Significantly, TSN was retained within the skin, demonstrating the potential of NEs for targeting hair follicular delivery within the skin, which may help improve the success of topical antisepsis.

Effect of hydrocolloids on physicochemical properties, stability, and digestibility of Pickering emulsions stabilized by nanofibrillated cellulose

In this study, the effect of hydrocolloids with different electrostatic characteristics, namely negatively charged xanthan gum (XG), positively charged chitosan (CH), and non-ionic guar gum (GG), on the physicochemical properties, stability, and lipid digestibility of 10% (w/w) soybean oil-in-water Pickering emulsions stabilized by nanofibrillated cellulose (NFC) was investigated. Addition of XG and CH to the NFC-stabilized emulsions significantly increased the oil droplet sizes and apparent viscosity at high shear rates as compared with the addition of GG. The XG added emulsion showed the lowest rate and extent of creaming, whereas the CH added emulsion gave the highest extent of creaming. The addition of XG and CH led to a more pronounced effect on in vitro lipid digestion, i.e. changes in droplet sizes, surface charges, microstructure, and free fatty acid (FFA) release, than the addition of GG. The XG added emulsion showed the lowest rate and extent of lipid digestion possibly due to the high viscosity of the aqueous phase, large oil droplet sizes, and interaction of XG and calcium, resulting in the reduction of lipase activity. The CH added emulsion exhibited the highest extent of lipid digestion possibly due to binding between CH and FFAs and move away from the droplet surfaces, thereby facilitating the lipase activity. In summary, it can be concluded that ionic hydrocolloids exerted more influence on NFC-stabilized Pickering emulsions than non-ionic ones. These results may facilitate the design of highly stable emulsion-based functional food products with added hydrocolloids to promote health and wellness.

The vaping product use associated lung injury: is this a new pulmonary disease entity?

In the summer of 2019, an epidemic of e-cigarette or vaping product use associated lung injury (EVALI) broke out in the United States of America. EVALI is a lung disease that can be severe and life-threatening. It should be emphasized that EVALI is not a clinical diagnosis, but surveillance case definition. Due to the profile of users of such devices, the pathology mainly affects young adults, although cases of EVALI have been reported in almost all age groups, from teenage children to seniors. The worst prognosis is in patients over 35 years of age, with accompanying diseases. A significant number of patients declared the use of products containing tetrahydrocannabinol (THC). The most likely factor responsible for the occurrence of EVALI is vitamin E acetate, which is sometimes added to liquids necessary for the use of electronic cigarette type devices, especially those liquids that contain THC. Nevertheless, it is possible that other substances used in liquids may also be a causative factor. Typical for EVALI are respiratory, gastrointestinal and systemic symptoms, while in imaging tests, a characteristic feature of EVALI is the presence of opacities on the chest radiogram and ground-glass clouds on computed tomography scans. In the course of this disease, respiratory failure often occurs (58%). In the vast majority of cases oxygen substitution is necessary. Currently, the best treatment of EVALI is considered to be the administration of systemic glucocorticosteroids. Over 90% of patients with EVALI required hospitalization, while the mortality rate was about 2.42%. Median age of the fatalities was 51 years. The aim of this review is to summarise the available information on EVALI and to consider possible causative factors and pathomechanism.

Nanoemulsion-based delivery approaches for nutraceuticals: fabrication, application, characterization, biological fate, potential toxicity and future trends

In the modern food industry, people are paying more and more attention to the use of edible nanoemulsions to encapsulate, protect and deliver lipophilic functional ingredients, such as volatile additives, polyphenols, aromas, pigments, proteins, vitamins, oil-soluble flavors, preservatives, etc., which are the current global needs. Nanoemulsions are constructed with droplets of nano range size and they offer many potential advantages over conventional emulsions including the delivery of both hydrophilic and hydrophobic compounds, higher stability, better antibacterial properties, good taste experience, higher affinity, longer shelf-life and improvement of the bioavailability of components. Moreover, they are highly capable of improving the wettability and/or solubility of poorly water-soluble compounds, which may result in better pharmacokinetic and pharmacodynamic properties of nutraceutical compounds. On the other hand, oral nanoemulsions also have certain risks, such as their ability to change the biological fate of biologically active ingredients in the gastrointestinal tract and the potential toxicity of certain ingredients used in their production. This review article summarizes the manufacturing, application, characterization, biological fate, potential toxicity, and future challenges and trends of nanoemulsions, and focuses on nanoemulsion-based nutraceutical delivery approaches suitable for the food industry.

Review of Health Consequences of Electronic Cigarettes and the Outbreak of Electronic Cigarette, or Vaping, Product Use-Associated Lung Injury

Electronic cigarettes (e-cigarettes) are battery-operated devices to insufflate nicotine or other psychoactive e-liquid aerosols. Despite initial claims of e-cigarettes as a nicotine-cessation device, aggressive marketing of e-cigarettes has led to an explosion in adolescents' and young adults' use over the last few years. Coupled with a lack of adequate investigation and regulation of e-cigarettes, the USA is facing an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) starting in mid-2019. While little long-term health hazard data are available, the components and constituents of e-cigarettes may adversely impact health. Propylene glycol and glycerin are humectants (water-retaining excipients) that generate pulmonary irritants and carcinogenic carbonyl compounds (e.g., formaldehyde, acetaldehyde, and acrolein) when heated in e-cigarettes. Metals contained in heating coils and cartridge casings may leach metals such as aluminum, chromium, iron, lead, manganese, nickel, and tin. Flavoring agents are considered safe for ingestion but lack safety data for inhalational exposures. Diacetyl, a common buttery flavoring agent, has known pulmonary toxicity with inhalational exposures leading to bronchiolitis obliterans. In 2019, clusters of lung injury associated with e-cigarette use were identified in Wisconsin and Illinois. Patients with EVALI present with a constellation of respiratory, gastrointestinal, and constitutional symptoms. Radiographically, patients have bilateral ground glass opacifications. As of February 18, 2020, the Centers for Disease Control has identified 2807 hospitalized patients diagnosed with either "confirmed" or "probable" EVALI in the US. Currently, vitamin E acetate (VEA) used as a diluent in tetrahydrocannabinol vape cartridges is implicated in EVALI. VEA cuts tetrahydrocannabinol oil without changing the appearance or viscosity. When inhaled, pulmonary tissue lacks the mechanism to metabolize and absorb VEA, which may lead to its accumulation. While most EVALI patients were hospitalized, treatment remains largely supportive, and use of corticosteroids has been associated with clinical improvement. The outbreak of EVALI highlights the need for regulation of e-cigarette devices and e-liquids. Clinicians need to be aware of the health hazards of e-cigarettes and be vigilant in asking about vaping.

Therapeutic bullfrog oil-based nanoemulsion for oral application: Development, characterization and stability

The aim of this study was to develop, optimize, and characterize a stable therapeutic bullfrog oil based nanoemulsion for oral application using a rational experimental design approach. The optimized oral nanoemulsion contained 0.2 % sodium benzoate and 0.02 % propyl-paraben as preservatives; 0.1 % sucralose and 0.4 % acesulfam K as sweeteners and 0.1 % tutti-frutti as flavoring to mask the unpleasant organoleptic characteristics of bullfrog oil. The oral O/W-nanoemulsion showed the droplet size, PDI, zeta potential, and pH of 410 ± 8 nm, 0.20 ± 0.02, -38 ± 2.5 mV, and 6.43 ± 0.05, respectively. The optimized oral nanoemulsion showed a milky single-phase and optimal physical stability at 25 °C for 90 days. Indeed, higher oxidation induction time and lower formation of peroxides in the oral nanoemulsion were responsible for improving its stability. A therapeutic delivery system containing bullfrog oil for oral application was successfully developed and optimized with ideal thermo-oxidative stability.

Low-Energy Encapsulation of α-Tocopherol Using Fully Food Grade Oil-in-Water Microemulsions

Encapsulation of active agents, such as vitamins and antioxidants, is one of the possibilities that allow their incorporation in beverages, food, or in pharmaceutical products. Simultaneously, encapsulation protects these active agents from oxidation, producing more stable active compounds. Formation of nanodroplets by spontaneously formed microemulsion (ME) offers, on one hand, a low-energy technology of encapsulation and, on the other hand, because of a small size of the droplets, it assures long-term stability even in harsher environments. In this study, oil-in-water MEs allowed the low-energy encapsulation of α-tocopherol (αToc) into an aqueous medium with the aid of fully food-grade ingredients, using isoamyl acetate as the dispersed oil phase, which was selected between three different types of oils. Both cosurfactant-free and cosurfactant-holder ME systems were formulated, in which Tween 20 and glycerol were employed as the surfactant and the cosurfactant, respectively. The ME monophasic area was determined through the construction of pseudoternary phase diagrams. The encapsulated αToc within 10-20 nm nanocapsules showed radical scavenging activity dependent on the encapsulated amount of αToc, as it was demonstrated by electron paramagnetic resonance spectroscopy. The radical scavenging activity slightly increased within the time investigated, indicating a slow release of the active compound from the nanodroplets, which is a promising result for their application, especially in pharmaceuticals.

Gypenosides as natural emulsifiers for oil-in-water nanoemulsions loaded with astaxanthin: Insights of formulation, stability and release properties

The formulation, physicochemical stability and bioaccessibility of astaxanthin (AST) loaded oil-in-water nanoemulsions fabricated using gypenosides (GPs) as natural emulsifiers was investigated and compared with a synthetic emulsifier (Tween 20) that is commonly applied in food industry. GPs were capable of producing nanoemulsions with a small volume mean diameter (d_4,3 = 125 ± 2 nm), which was similar to those prepared using Tween 20 (d_4,3 = 145 ± 6 nm) under the same high-pressure homogenization conditions. GPs-stabilized nanoemulsions were stable against droplet growth over a range of pH (6-8) and thermal treatments (60-120 °C). Conversely, instability occurred under acidic (pH 3-5) and high ionic strength (25-100 mM CaCl₂) conditions. In comparison with Tween 20, GPs were more effective at inhibiting AST from degradation during 30 days of storage at both 5 and 25 °C. However, GPs led to lower lipid digestion and AST bioaccessibility from nanoemulsions than did Tween 20.

Physicochemical and Antimicrobial Characterization of Beeswax-Starch Food-Grade Nanoemulsions Incorporating Natural Antimicrobials

Nanoemulsions are feasible delivery systems of lipophilic compounds, showing potential as edible coatings with enhanced functional properties. The aim of this work was to study the effect of emulsifier type (stearic acid (SA), Tween 80 (T80) or Tween 80/Span 60 (T80/S60)) and emulsification process (homogenization, ultrasound or microfluidization) on nanoemulsion formation based on oxidized corn starch, beeswax (BW) and natural antimicrobials (lauric arginate and natamycin). The response variables were physicochemical properties, rheological behavior, wettability and antimicrobial activity of BW-starch nanoemulsions (BW-SN). The BW-SN emulsified using T80 and microfluidized showed the lowest droplet size (77.6 ± 6.2 nm), a polydispersion index of 0.4 ± 0.0 and whiteness index (WI) of 31.8 ± 0.8. This BW-SN exhibited a more negative ζ-potential: -36 ± 4 mV, and Newtonian flow behavior, indicating great stability. BW-SN antimicrobial activity was not affected by microfluidization nor the presence of T80, showing inhibition of the deteriorative fungi R. stolonifer, C. gloeosporioides and B. cinerea, and the pathogenic bacterium S. Saintpaul. In addition, regardless of emulsifier type and emulsification process, BW-SN applied on the tomato surface exhibited low contact angles (38.5° to 48.6°), resulting in efficient wettability (-7.0 mN/m to -8.9 mN/m). These nanoemulsions may be useful to produce edible coatings to preserve fresh-produce quality and safety.

Development of a carboxymethyl chitosan functionalized nanoemulsion formulation for increasing aqueous solubility, stability and skin permeability of astaxanthin using low-energy method

In this research, firstly astaxanthin (ASX)-loaded nanoemulsions (NEs) were produced using a convenient low-energy emulsion phase inversion method. The optimised ASX-NEs were prepared in the presence of Cremophor^® EL and Labrafil^® M 1944 CS, with a surfactant-to-oil ratio of 4:6. The ASX-NE droplets were spherical with a mean droplet diameter below 100 nm and a small negative surface charge. The system was stable without alteration of mean droplet diameter for three months. Then, the ASX-NE was functionalised with carboxymethyl chitosan (CMCS) through direct CMCS (0.02%) incorporation during the preparation process. The ASX chemical stability and skin permeability increased in the following order: ASX solution control < ASX-NE < CMCS-ASX-NE. Cell viability assays on L929 cells revealed low cytotoxicity of blank NE, ASX-NE and CMCS-ASX-NE in the range from 5 to 500 μg mL^-1. In conclusion, the CMCS-ASX-NE might be a promising delivery vehicle in dermal and transdermal products.

Fish oil based vitamin D nanoencapsulation by ultrasonication and bioaccessibility analysis in simulated gastro-intestinal tract

Recently, nanoemulsions have been employed for different applications including food and drug industries for efficient nutrient delivery system. In this study, vitamin D (a lipophilic molecule) was encapsulated in fish oil for higher oral bioavailability. The oil-in-water nanoemulsion was formulated by ultrasonication technique with a droplet size range of 300-450nm and a shelf life of more than 90days. The influence of oil, water and surfactant concentration was investigated by phase diagram. The formulated nanoemulsion had encapsulation efficiency in the range of 95.7-98.2%. Further, nanoemulsion passed through simulated gastro-intestinal tract revealed an increased bioavailability than non-encapsulated vitamin. Thus, the formulation can be used as a drug delivery vehicle for various lipophilic compounds. Till date, no one have fabricated an efficient nano-vehicle for the delivery of vitamin D as well as analyzed the efficient delivery system in simulated GI-tract, this is first of its kind study in this regard. This can be scaled up further after analyzing the safety aspects.

Formulation and physiochemical study of α-tocopherol based oil in water nanoemulsion stabilized with non toxic, biodegradable surfactant: Sodium stearoyl lactate

The unique properties such as high optical clarity, stability and enhanced bioavailability of nanoemulsion make them useful for food, cosmetic and pharmaceutical industries. In this work, sodium stearoyl lactate and Tween 80 surfactants were collectively used to fabricate alpha tocopherol based oil in water nanoemulsion using high energy ultrasonication method. The spherical nature of pure and drug loaded nanoemulsion has been confirmed with transmission electron microscopy (TEM). The influence of pH, dilution, surfactant concentration and ionic strength on average particle size of pure and nutraceutical (benzylisothiocyanate and curcumin) encapsulated emulsion was examined. The prepared emulsion exhibited good stability up to 90days in salt solution (50-200mM) and different pH conditions. The cumulative release % of benzylisothiocyanate and curcumin was found to be 50.29% in 36h and 89.15% in 150h respectively. The antioxidant activity of pure, benzylisothiocyanate, curcumin and cocktail (benzylisothiocyanate and curcumin) nanoemulsion was calculated with 2,2-diphenyl-1-picrylhydrazyl radical. The IC₅₀ value of different antioxidant showed that benzylisothiocyanate nanoemulsion acted as better antioxidant as compared to pure and curcumin encapsulated nanoemulsion. Also the cell viability of pure nanoemulsion was found to be 24% on hep G2 cell. The effect of UV light irradiation on curcumin and benzylisothiocyanate stability was carried out in different solvent conditions (water/ethanol and nanoemulsion). The degradation of curcumin by the impact of UV light was successfully controlled by trapping in NEm.

Edible Nanoemulsions as Carriers of Active Ingredients: A Review

There has been growing interest in the use of edible nanoemulsions as delivery systems for lipophilic active substances, such as oil-soluble vitamins, antimicrobials, flavors, and nutraceuticals, because of their unique physicochemical properties. Oil-in-water nanoemulsions consist of oil droplets with diameters typically between approximately 30 and 200 nm that are dispersed within an aqueous medium. The small droplet size usually leads to an improvement in stability, gravitational separation, and aggregation. Moreover, the high droplet surface area associated with the small droplet size often leads to a high reactivity with biological cells and macromolecules. As a result, lipid digestibility and bioactive bioavailability are usually higher in nanoemulsions than conventional emulsions, which is an advantage for the development of bioactive delivery systems. In this review, the most important factors affecting nanoemulsion formation and stability are highlighted, and a critical analysis of the potential benefits of using nanoemulsions in food systems is presented.

Phase Transitions of Isotropic to Anisotropic Biocompatible Lipid-Based Drug Delivery Systems Overcoming Insoluble Benznidazole Loading

Previous studies reported low benznidazole (BNZ) loading in conventional emulsions due to the weak interaction of the drug with the most common oils used to produce foods or pharmaceuticals. In this study, we focused on how the type of surfactant, surfactant-to-oil ratio w/w (SOR) and oil-to-water ratio w/w (OWR) change the phase behavior of different lipid-based drug delivery systems (LBDDS) produced by emulsion phase inversion. The surfactant mixture composed of soy phosphatidylcholine and sodium oleate (1:7, w/w, hydrophilic lipophilic balance = 16) stabilized medium chain triglyceride in water. Ten formulations with the clear aspect or less turbid dispersions (five with the SOR ranging from 0.5 to 2.5 and five with the OWR from 0.06 to 0.4) were selected from the phase behavior diagram to assess structural features and drug-loading capacity. The rise in the SOR induced the formation of distinct lipid-based drug delivery systems (nanoemulsions and liquid crystal lamellar type) that were identified using rheological measurements and cross-polarized light microscopy images. Clear dispersions of small and narrow droplet-sized liquid-like nanoemulsions, Newtonian flow-type, were produced at SOR from 0.5 to 1.5 and OWR from 0.12 to 0.4, while clear liquid or gel-like liquid crystals were produced at SOR from 1.5 to 2.5. The BNZ loading was improved according to the composition and type of LBDDS produced, suggesting possible drug location among surfactant layers. The cell viability assays proved the biocompatibility for all of the prepared nanoemulsions at SOR less than 1.5 and liquid crystals at SOR less than 2.5, demonstrating their promising features for the oral or parenteral colloidal delivery systems containing benznidazole for Chagas disease treatment.

Simulated gastrointestinal fate of lipids encapsulated in starch hydrogels: Impact of normal and high amylose corn starch

The influence of starch type (resistant starch (RS) versus native (NS) starch) and concentration (10 and 35wt.%) on the potential gastrointestinal fate of digestible lipid (corn oil) droplets encapsulated within starch hydrogels was studied using a simulated gastrointestinal tract (GIT). The NS used was a normal corn starch, whereas the RS used was a high amylose corn starch. Changes in morphology, organization, size, and charge of the particles in the delivery systems were measured as they passed through each stage of the GIT model: mouth, stomach, and small intestine. The GIT fates of three types of delivery system were compared: free lipid droplets; lipid droplets in RS-hydrogels; and, lipid droplets in NS-hydrogels. Encapsulation of the lipid droplets in the hydrogels had a pronounced influence on their GIT behavior, with the effect depending strongly on starch type. The starch granules in the RS-hydrogels remained intact throughout the simulated GIT because their compact structure makes them resistant to enzyme digestion. The initial rate of lipid digestion in the small intestine phase also depended on delivery system type: emulsion>RS-hydrogels>NS-hydrogels. However, the lipid phase appeared to be fully digested at the end of the digestion period for all samples. These results provide useful information for designing functional foods for improved health. For example, food matrices could be developed that slowdown the rate of lipid digestion, and therefore prevent a spike in serum triacylglycerols in the blood, which may be advantageous for developing functional foods to tackle diabetes.