Formulation of oil-in-water β-carotene microemulsions: effect of oil type and fatty acid chain length

Preparation, characterization, and release properties of Rosa roxburghii Tratt seed oil and β-carotene-coloaded proliposomes

Rosa roxburghii Tratt seed oil (RSO) and β-carotene (βC) were chosen to prepare proliposomes by the thin-film dispersion method. The characteristics of unloaded proliposome, RSO proliposome (L-R), βC proliposome (L-β), and RSO/βC proliposome (L-R-β) were analyzed, and their antioxidant activity, storage stability, and release properties were investigated. The proliposomes had an encapsulation efficiency (RSO, βC) higher than 83.10%, nanometer size, smooth surface, and irregular structure. L-R-β showed better dispersibility, stability, and antioxidant activity than L-R and L-β. Simultaneous encapsulation of RSO and βC reduced the phospholipid oxidation of proliposomes and improved the retention rate of RSO in storage environments of 4, 25, and 40°C. Moreover, the RSO and βC release kinetics of proliposomes in the simulated saliva fluid and gastric fluid phases can be described by the first-order model, and the Korsmeyr-Peppas method was applied to describe their release mechanism in the simulated intestinal fluid phase.

Effect of wall material on lipophilic functional compounds of high oleic palm oil emulsions encapsulated by Refractance Window drying

High-oleic palm oil is a food-grade oil with desirable properties, as it is characterised by having an oleic acid concentration above 50 % and a high vitamin E and provitamin A content. This study investigated the effect of different combinations of two wall materials (whey protein (WP) and Capsul®, a commercial octenyl succinic anhydride modified starch (OSA-MS)) on the concentration of provitamin A, vitamin E and oleic acid, and the physical properties of high oleic palm oil emulsions encapsulated by Refractance Window drying technology. Wall material composition significantly affected (p < 0.05) all response variables, and R2 values were above 0.75 for all responses. Phytonutrient preservation showed its highest at an OSA-MS: WP concentration ratio of 1: 3. Optimal results were achieved (minimum moisture content, water activity and hygroscopicity, and maximum encapsulation efficiency and phytonutrient preservation) at an OSA-MS concentration of 8.13 % and WP concentration of 91.87 %. Flakes were obtained as a solid structure that protects oil's phytonutrients with 94 %, 75 % and 87 % of preservation of oleic acid, vitamin E and carotenoids, respectively. It shows that the wall material combination and encapsulation technique are suitable for obtaining lipophilic functional compounds.

Recent progresses in the delivery of β-carotene: From nano/microencapsulation to bioaccessibility

Beta-carotene (BC) as an efficient pro-vitamin is effective in improving vision, immune system and cognitive function as well as preventing coronary diseases and cancer. However, besides its poor chemical stability, the high lipophilic nature of BC reduces its dispersibility and consequently bioavailability which limits its application into food, pharmaceutical and nutraceuticals. Different carriers with vesicular or particulate structures have been studied and utilized for promoting BC solubility, dispersibility, and protection against diverse operational or environmental stresses and also controlling BC release and subsequent bioaccessibility. The current study, therefore reviews different micro/nanocarriers reported on BC encapsulation with special focusing on its bioavailability. Liposomal structures have been successfully used for enhancing BC stability and bioavailability. Besides, emulsion-based carriers including Pickering emulsions, nanoemulsions and microemulsions have been widely evaluated for BC encapsulation and protection. In addition, lipid-based nanoparticles and nanostructural carriers have also been applied successfully for this context. Moreover, gel structures including emulgels, hydrogels and oleogels are studied in some researches. Most of these delivery systems led to higher hydro-solubility and dispersibility of BC which consequently increased its bioavailability; thereupon could promote its application into food, cosmetic and nutraceutical products. However, for remarkable incorporation of BC and other bioactive compounds into edible products, the safety and toxicological aspects of these delivery system especially those designed in nano scale should be addressed in the further researches.

Ex vivo permeation parameters and skin deposition of melatonin-loaded microemulsion for treatment of alopecia

Background

Melatonin (MEL) is a powerful antioxidant molecule with anti-androgenic property. A microemulsion (ME) system loaded with MEL was designed for treatment of androgenic alopecia. Pseudo-ternary phase diagram was constructed, and ME formulae were developed using coconut oil, Tween 80 and PEG 400. In the present study, MEL ME was characterized and evaluated for droplet size, polydispersity index, zeta potential, morphology using TEM imaging. MEL ex vivo permeation study through rat skin followed by tape stripping for stratum corneum (SC) was performed for different ME formulae, to determine skin permeation parameters and detect SC-MEL deposition.

Results

Spherical and uniform particles of MEL-loaded microemulsion were formulated with high stability. In ex vivo permeation study, MEL ME exhibited low steady-state skin flux along with pronounced SC deposition which prevailed a controlled release manner.

Conclusion

The results suggested that MEL ME could be a promising candidate for further permeation and in vivo studies for androgenic alopecia treatment.

Vitamin A fortification: Recent advances in encapsulation technologies

Vitamin A is an essential micronutrient whose deficiency is still a major health concern in many regions of the world. It plays an essential role in human growth and development, immunity, and vision, but may also help prevent several other chronic diseases. The total amount of vitamin A in the human diet often falls below the recommended dietary allowance of approximately 900-1000 μ $ \umu $ g/day for a healthy adult. Moreover, a significant proportion of vitamin A may be degraded during food processing, storage, and distribution, thereby reducing its bioactivity. Finally, the vitamin A in some foods has a relatively low bioavailability, which further reduces its efficacy. The World Health Organization has recommended fortification of foods and beverages as a safe and cost-effective means of addressing vitamin A deficiency. However, there are several factors that must be overcome before effective fortified foods can be developed, including the low solubility, chemical stability, and bioavailability of this oil-soluble vitamin. Consequently, strategies are required to evenly disperse the vitamin throughout food matrices, to inhibit its chemical degradation, to avoid any adverse interactions with any other food components, to ensure the food is palatable, and to increase its bioavailability. In this review article, we discuss the chemical, physical, and nutritional attributes of vitamin A, its main dietary sources, the factors contributing to its current deficiency, and various strategies to address these deficiencies, including diet diversification, biofortification, and food fortification.

Developing Eco-Friendly Skin Care Formulations with Microemulsions of Essential Oil

With the rising public awareness of environmental issues, consumers are increasingly demanding skin care products that create less environmental impact but still provide the same or even greater efficacy. In the skin care arena, microemulsions have been receiving increased attention as the promising delivery technology of skin care actives. Essential oils such as peppermint oil, lavender oil and eucalyptus oil are purported to have excellent antioxidant and antimicrobial properties that could be used as the eco-friendly alternatives for synthetic antioxidants and preservatives in the skin care formulations. This work therefore seeks to develop eco-friendly skin care formulations based on microemulsions of essential oil. Peppermint oil, lavender oil and eucalyptus oil were used as the oil phase to formulate naringin-loaded microemulsions, which demonstrated similar or better antioxidant and antimicrobial properties compared to the synthetic ones. When formulated into gel form, naringin-loaded microemulsion-gel formulations showed enhanced stability and release profile over their unformulated counterpart. Hence, microemulsions of essential oil developed in this work conferred a 4-fold benefits to the skin care formulations: (1) improved release (membrane permeation) of skin care active, (2) improved stability of skin care active, (3) as an eco-friendly alternative to synthetic antioxidant, and (4) a self-preserving system.

Intranasal delivery of Clozapine using nanoemulsion-based in-situ gels: An approach for bioavailability enhancement

Limited solubility and hepatic first-pass metabolism are the main causes of low bioavailability of anti-schizophrenic drug, Clozapine (CZP). The objective of the study was to develop and validate nanoemulsion (NE) based in-situ gel of CZP for intranasal administration as an approach for bioavailability enhancement. Solubility of CZP was initially investigated in different oils, surfactants and co-surfactants, then pseudoternary phase diagrams were constructed to select the optimized ratio of oil, surfactant and co-surfactant. Clear and transparent NE formulations were characterized in terms of droplet size, viscosity, solubilization capacity, transmission electron microscopy, in-vitro drug release and compatibility studies. Selected NEs were incorporated into different in-situ gel bases using combination of two thermosensitive polymers; Pluronic® F-127 (PF127) and F-68 (PF68). NE-based gels (NG) were investigated for gelation temperature, viscosity, gel strength, spreadability and stability. Moreover, selected NGs were evaluated for ex-vivo permeation, mucoadhesive strength and nasal ciliotoxicity. Peppermint oil, tween 80 and transcutol P were chosen for NE preparation owing to their maximum CZP solubilization. Clear NE points extrapolated from tween 80:transcutol P (1:1) phase diagram and passed dispersibility and stability tests, demonstrated globule size of 67.99 to 354.96 nm and zeta potential of −12.4 to −3.11 mV with enhanced in-vitro CZP release (>90% in some formulations). After incorporation of the selected N3 and N9 formulations of oil:Smix of 1:7 and 2:7, respectively to a mixture of PF127 and PF68 (20:2% w/w), the resultant NG formulations exhibited optimum gelation temperature and viscosity with enhanced CZP permeation and retention through sheep nasal mucosa. Ciliotoxicity examinations of the optimum NGs displayed no inflammation or damage of the lining epithelium and the underlying cells of the nasal mucosa. In conclusion, NE-based gels may be a promising dosage form of CZP for schizophrenia treatment.

Hypericin-loaded oil-in-water nanoemulsion synthesized by ultrasonication process enhances photodynamic therapy efficiency

Hypericin (Hy) is a hydrophobic photosensitizer used in photodynamic therapy for cancer therapeutic. In this study, Hy-loaded oil-in-water (O/W) nanoemulsions (NEs) were produced by the ultrasonication method combing different biocompatible oils and surfactants to enhance Hy aqueous solubility and bioavailability. Experimental parameters were optimized by the characterization of droplet size, zeta potential, and physicochemical properties. In vitro studies based on the release profile, cytotoxicity, cell morphology, and Hy intracellular accumulation were assayed. Hy at 100 mg L^-1 was incorporated into the low viscosity (~0.005 Pa s) NEs with spherical droplets averaging 20-40 nm in size and polydispersity index <0.02. Hy release from the NE was significantly higher (4-fold) than its suspension (p < 0.001). The NEs demonstrated good physical stability during storage at 5 °C for at least six months. The Hy-loaded NEs exhibited an IC50 value 6-fold lower than Hy suspension during PDT against breast cancer cell lines (MCF-7). Cell microscopy imaging confirmed the increased cytotoxic effects of Hy-loaded NEs, showing damaged and apoptotic cells. Confocal laser scanning microscopy evidenced greater Hy delivery through NE into MCF-7 cells followed by improved intracellular ROS generation. Our results suggest that the Hy-loaded NEs can improve hypericin efficacy and assist Hy-PDT's preclinical development as a cancer treatment.

Citrus processing by-products: an overlooked repository of bioactive compounds

Citrus fruits contain plethora of bioactive compounds stored in edible as well as inedible part. Since, citrus fruits are processed mainly for juice, the residues are disposed in wastelands, hence, plenty of nutritional potential goes in vain. But if utilized wisely, the bioactive phytochemicals in citrus by-products have the ability to revolutionize the functional food industry. In the present review, the composition of citrus by-products in terms of bioactive components and their health benefits has been reviewed. Various extraction techniques used to extract these bioactives has been discussed and a brief overview of purification and utilization of the extracted compounds, in food and nutraceutical industry is also presented. Bioactives in citrus by-products are higher than the peeled fruit, which can be extracted, isolated and incorporated into food systems for development of health foods. From the studies reviewed, it was observed that research reported on utilization of citrus by-products is limited to mainly research labs; proper scale-up process and its adequate research commercialization is the need of hour to transform these bioactives into economical functional ingredients.

Novel Gel Microemulsion as Topical Drug Delivery System for Curcumin in Dermatocosmetics

Gel microemulsion combines the advantages of the microemulsion, which can encapsulate, protect and deliver large quantities of active ingredients, and the gel, which is so appreciated in the cosmetic industry. This study aimed to develop and characterize new gel microemulsions suitable for topical cosmetic applications, using grape seed oil as the oily phase, which is often employed in pharmaceuticals, especially in cosmetics. The optimized microemulsion was formulated using Tween 80 and Plurol^® Diisostearique CG as a surfactant mix and ethanol as a co-solvent. Three different water-soluble polymers were selected in order to increase the viscosity of the microemulsion: Carbopol^® 980 NF, chitosan, and sodium hyaluronate salt. All used ingredients are safe, biocompatible and biodegradable. Curcumin was chosen as a model drug. The obtained systems were physico-chemically characterized by means of electrical conductivity, dynamic light scattering, polarized microscopy and rheometric measurements. Evaluation of the cytotoxicity was accomplished by MTT assay. In the final phase of the study, the release behavior of Curcumin from the optimized microemulsion and two gel microemulsions was evaluated. Additionally, mathematical models were applied to establish the kinetic release mechanism. The obtained gel microemulsions could be effective systems for incorporation and controlled release of the hydrophobic active ingredients.

Fate of β-Carotene within Loaded Delivery Systems in Food: State of Knowledge

Nanotechnology has opened new opportunities for delivering bioactive agents. Their physiochemical characteristics, i.e., small size, high surface area, unique composition, biocompatibility and biodegradability, make these nanomaterials an attractive tool for β-carotene delivery. Delivering β-carotene through nanoparticles does not only improve its bioavailability/bioaccumulation in target tissues, but also lessens its sensitivity against environmental factors during processing. Regardless of these benefits, nanocarriers have some limitations, such as variations in sensory quality, modification of the food matrix, increasing costs, as well as limited consumer acceptance and regulatory challenges. This research area has rapidly evolved, with a plethora of innovative nanoengineered materials now being in use, including micelles, nano/microemulsions, liposomes, niosomes, solidlipid nanoparticles, nanostructured lipids and nanostructured carriers. These nanodelivery systems make conventional delivery systems appear archaic and promise better solubilization, protection during processing, improved shelf-life, higher bioavailability as well as controlled and targeted release. This review provides information on the state of knowledge on β-carotene nanodelivery systems adopted for developing functional foods, depicting their classifications, compositions, preparation methods, challenges, release and absorption of β-carotene in the gastrointestinal tract (GIT) and possible risks and future prospects.

Nanoemulsion Stabilized by Safe Surfactin from Bacillus Subtilis as a Multifunctional, Custom-Designed Smart Delivery System

The developing field of bio-nanotechnology aims to advance colloidal research via the introduction of multifunctional nanoparticles to augment the dermal effectiveness of active substances. Self-emulsifying drug delivery systems (SEDDS)-isotropic mixtures of oils, surfactants, solvents and co-solvents or surfactants-are attracting interest in the cosmeceutical field. As part of this study, SEDDS systems containing vitamin C or vitamin E and curcumin were developed, whereby the bioavailability of the active compounds increased by enhancing their permeability to deeper layers of the skin. A composition consisting of 50% surfactin from Bacillus subtilis, 30% Transcutol and 20% oil phase was designed to encapsulate the active substances, i.e., vitamin C or vitamin E and curcumin, contained in the oil phase. The developed carriers were characterized by average particle sizes of 69-183 nm. The formulations with the vitamins were found to be physically and chemically stable for 6 months. Transdermal tests were carried out, showing that the carriers enable the transport of active substances deep into the skin, stopping at the dermis border. The formulations with vitamin C and vitamin E reduced the discoloration, the vascular lesions, and the depth of the wrinkles on the tested skin, which can be useful in cosmetics in the treatment of problem skin, including capillary and sensitive skin.

Interactions of β-carotene with WPI/Tween 80 mixture and oil phase: Effect on the behavior of O/W emulsions during in vitro digestion

This study investigated the impact of adding β-carotene on the structure of fresh O/W emulsions with different oil phase (sunflower oil-LCT or NEOBEE®1053-MCT) and emulsifiers (WPI, Tween 80 - T80 or WPI/T80 mixture). In this sense, the behavior of emulsions through the gastrointestinal tract, the stability and bioaccessibility of β-carotene were also assessed. The β-carotene reduced the interfacial tension of the LCT/MCT-water systems. The addition of β-carotene promoted an increase of viscoelasticity of LCT/MCT-T80 (0.5%WPI/0.5%T80 and 1%T80 w/w) interfaces, but an increase of WPI content reduced the viscoelasticity of interfacial layers (LCT/MCT-1% WPI). These changes in the interface properties influenced the mean droplet size and ζ-potential of the fresh emulsions. LCT systems presented similar bioaccessibility/stability of β-carotene. However, β-carotene entrapped within protein-coated MCT droplets was more stable than within T80-MCT systems. Our results show that β-carotene interacted with other ingredients of emulsions changing their properties and behavior under gastrointestinal tract as well as the stability/bioaccessibility of β-carotene.

Microemulsions as nano-reactors for the solubilization, separation, purification and encapsulation of bioactive compounds

Bioactive components possess various functionalities and are most interested for different food, nutraceutical and pharmaceutical formulations. The current review will discuss the preparation methods and fabrication techniques to design microemulsions (MEs) for the solubilization, separation, encapsulation and purification of various agro-food bioactive compounds. ME systems have shown suitable potential in enhancing oil recovery, protein extraction, and isolation of bioactive compounds. Moreover, the capability of ME based systems as drug and nutraceutical delivery cargos, and synthesis of various organic and inorganic nanoparticles, especially using biopolymers, will be investigated. ME liquid membranes are also developed as nano-extractor/nano-reactor vehicles, capable of simultaneous extraction, encapsulation or even synthesis of hydrophilic and lipophilic bioactive compounds for food, nutraceutical and drug applications.

Factors affecting the fate of β-carotene in the human gastrointestinal tract: A narrative review

Carotenoids and their metabolites play crucial roles in human health such as in immunity, cell differentiation, embryonic development, maintenance of plasma membrane integrity, and gastrointestinal functions, in addition to counteracting night blindness and other eye-related diseases. However, carotenoid bioavailability is highly variable and often low. The bioavailability of β-carotene, among the most frequently consumed carotenoid from the diet, is determined by food matrix related factors such as carotenoid dose, its location in food the matrix, the physical state in food, the presence of other food compounds in the matrix such as dietary fiber, dietary lipids, other micronutrients present such as minerals, and food processing, influencing also the size of food particles, and the presence of absorption inhibitors (fat replacers and anti-obesity drugs) or enhancers (nano-/micro-formulations). However, also host-related factors such as physiochemical interactions by gastrointestinal secretions (enzyme and salts) and other host-related factors such as surgery, age, disease, obesity, and genetic variations have shown to play a role. This review contributes to the knowledge regarding factors affecting the bioavailability of β-carotene (food and host-relegated), as well as highlights in vitro models employed to evaluate β-carotene bioavailability aspects.

A Green Enzymatic Extraction Optimization and Oxidative Stability of Krill Oil from Euphausia Superba

Krill oil enriched with polyunsaturated fatty acids is in the form of phospholipid. However, its application as a dietary supplement is limited, because of its rapid deterioration. Thus, this study aims to investigate the oxidative stability of krill oil extracted from Euphausia superba. Under optimal conditions (enzyme concentration 0.16%, enzymolysis time 2.9 h, and enzymolysis temperature of 45 °C) designed by response surface methodology, the extraction yield of krill oil is 86.02%. Five assays, including peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), pH value, and turbidity were used to determine the oxidative stability of krill oil nanoliposomes during storage. Carboxymethyl chitosan (CMCS) nanoliposomes showed a significant reduction in POV and TBARS values, a prevention of pH value decrease and turbidity increase. This study indicated that CMCS nanoliposome can effectively improve the oxidative stability of krill oil during storage. Furthermore, the release profile in vitro illustrated that the controlled release of krill oil carried out by CMCS nanoliposomes is feasible.

Pickering stabilized nanocellulose-alginate: A diosgenin-mediated delivery of quinalizarin as a potent cyto-inhibitor in human lung/breast cancer cell lines

The current study explores the facile fabrication of multilayer self-assembled electrostatic oil-in-water Pickering emulsions (PEs) using quaternized nanocellulose (Q-NC) and diosgenin-conjugate alginate (DGN-ALG) particles as stabilizers to form hydrocolloid nanocarriers. The conditions of formulation such as storage time, pH, temperature and salt effect on the emulsion stability were evaluated. The results deduced showed good emulsion droplet stability over a period of 30 days. Morphological analysis revealed the hydrodynamic sizes of the PE droplets to be spherically shaped with an average diameter of 150 ± 3.51 nm. Creaming index, wettability and critical aggregation concentrations (CAC) as well as chemical characterization of the PEs were examined. In vitro release kinetics of encapsulated quinalizarin as a model drug was investigated with a determined cumulative drug release (CDR) of 89 ± 1.21% in simulated pH blood medium of pH 7.4. In addition, cellular internalization of the PEs was studied via confocal microscopy imaging and showed high cellular uptake. Also, evaluated in vitro cytotoxicity by MTT assay demonstrated excellent anticancer activity in human lung (A549) and breast (MCF-7) cancer cell lines.

Development of microemulsion of tamsulosin and dutasteride for benign prostatic hyperplasia therapy

Benign prostatic hyperplasia (BPH) is a condition characterized by a benign enlargement of the prostate that interferes with the normal flow of urine. This disease is treated with the oral administration of combination therapy comprising α-blockers (tamsulosin) and 5α-reductase inhibitors (dutasteride). However, these compounds have low bioavailability. Thus, transdermal microemulsions aimed at promoting permeation and efficient targeted drug delivery through the skin are used. The objectives of this study were to obtain microemulsions of the combined doses of dutasteride and tamsulosin and evaluate their anti-hyperplastic activity in vivo. A phase diagram (4:1) was obtained for the choice of microemulsions. The microemulsions were characterized in terms of the droplet size, rheology, pH, conductivity, refractive index, in vitro release profile, and antihyperplastic effect in vivo. A method for the simultaneous quantification of drugs was developed using UV-vis spectroscopy. The microemulsions had an average size less than 116 nm, an acidic pH and low viscosity. The conductivity ranged from 6.18 to 185.2 μS/cm. The in vitro release profile was sustained for 6 h. Microemulsions promoted the reduction in the size of testosterone-dependent organs (prostate and seminal vesicles). Transdermal formulations for the treatment of BPH were obtained as a therapeutic alternative to conventional treatments.

Development of Oral Delivery Systems with Enhanced Antioxidant and Anticancer Activity: Coix Seed Oil and β-Carotene Coloaded Liposomes

Fortifying food and beverage products with combinations of bioactive agents is a major initiative within the food industry because of their potentially additive or even synergistic benefits for human health. Coix seed oil (CSO) has been reported to possess anticancer activity, whereas β-carotene (βC) is a natural antioxidant that may also exhibit anticancer activity. However, both of these bioactives are insoluble in water and have poor oral bioavailability. The aim of this study was to overcome these obstacles by encapsulating both βC and CSO into liposomes (L-βC-CSO). The effect of different combinations of these two bioactive agents on the physiochemical properties, stability, release, antioxidant activity, and anticancer activity of the liposomes was then determined. Increasing the CSO level decreased the βC entrapment efficiency, increased the particle size, reduced the polydispersity, and raised the magnitude of the surface potential of the bioactive-loaded liposomes. Moreover, the βC and CSO levels affected their orientation within the lipid bilayer, which also influences the physiochemical properties, stability, and in vitro release behavior of the system. Compared to liposomes containing single bioactive types, the combined systems exhibited higher bioavailability and increased anticancer and antioxidant activity. These results suggest that the combined bioactive-loaded liposomes could be an efficient formulation for potential applications in functional foods and supplements.

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.

Preparation and evaluation of spirulina polysaccharide nanoemulsions

The aim of the present study was to prepare spirulina polysaccharide (PSP) into an oral nanoemulsion (NE) with the aim of improving its oral bioavailability and prolonging its sustained release effect. The PSP-NE was prepared through a phase transformation method, and its formulation components were screened through the use of a pseudo-ternary phase diagram. The optimal formulation of PSP-NE was determined to be: 11.9% Span 80, 6.0% Tween-80, 9.0% ethanol, 62.8% soybean oil, and 10.3% PSP aqueous solution. The prepared PSP-NE was clear and transparent, had a uniform color and spherical morphology, exhibited stability and no adhesion. The average particle size was 79.93±19 nm, the polydispersity index was 0.185±0.04 (n=3), and the entrapment rate was 62%. Small-animal imaging results showed that the prepared PSP-NE exhibited a sustained release and tissue effect in contrast to the PSP aqueous solution. The present study showed that the prepared PSP-NE not only exhibited a sustained release and tissue effect in contrast to the PSP aqueous solution, but also had superior performance in terms of antitumor and antioxidant effects.

Development of β-Carotene-Loaded Organogel-Based Nanoemulsion with Improved In Vitro and In Vivo Bioaccessibility

β-Carotene (BC), a naturally occurring lipophilic carotenoid, is beneficial for human health. However, its water solubility and bioavailability are low. In this study, organogel-based nanoemulsion was successfully prepared to improve the loading amount, solubility, and bioavailability of BC. Corn oil was selected as the oil phase for the organogel as a result of the greatest release amount of BC. Tween 20 was optimized as the emulsifier based on the highest extent of lipolysis and BC bioaccessibility. The nanoemulsion was a better alternative than the organogel according to both the extent of lipolysis and BC bioaccessibility. Cellular uptake of BC was significantly improved through organogel-based nanoemulsion compared to BC suspension. Caveolae-/lipid-raft-mediated route was the main endocytosis pathway. Pharmacokinetic results confirmed that the in vivo bioavailability of BC in nanoemulsion was 11.5-fold higher than that of BC oil. The information obtained suggested that organogel-based nanoemulsion may be an effective encapsulation system for delivery of insoluble and indigestible bioactive compounds.

Enhancement of the solubility and antioxidant capacity of α-linolenic acid using an oil in water microemulsion

The applications of α-linolenic acid (ALA) in the food industry are restricted due to its poor water solubility and antioxidant stability. This study concentrates on developing an ALA-loaded microemulsion (ALA-ME) to enhance its solubility and antioxidant capacity. The formulation of the microemulsion was investigated based on pseudoternary phase diagrams. The ALA-ME was characterized by using electrical conductivity, viscosity and transmission electron microscopy (TEM). The microstructure of the ALA-ME was probed using nuclear magnetic resonance (¹H-NMR). The results proved that ALA-ME consisted of spheroidal droplets with 20-40 nm diameter. A structural transformation from water in oil (W/O) to oil in water (O/W) occurred, as seen from the electrical conductivity determination. The ¹H-NMR results revealed a transition of the ALA position encapsulated from the core area of the microemulsion to the lipophilic layer of the surfactant. Furthermore, two microstructural models of ALA-ME were proposed. The antioxidant evaluation demonstrated that the ALA antioxidant capacity in microemulsions was enhanced to about 80% compared with that of ALA in oil solution.