Highly Active, Entirely Biobased Antimicrobial Pickering Emulsions.

We present the development of surfactant-free, silica-free and fully biobased oil-in-water antimicrobial Pickering emulsions, based on the self-assembly of ß-cyclodextrin and phytoantimicrobial oils (terpinen-4-ol or carvacrol). Undecylenic acid (UA), derived from castor oil, can be used as bio-based drug to treat fungal infection, but is less effective than petroleum-based drugs as azole derivatives. To maximize its antifungal potential, we have incorporated UA in fully biobased Pickering emulsions. These emulsions are effective against fungi, Gram-positive and Gram-negative bacteria. The carvacrol emulsion charged with UA is +390 % and +165 % more potent against methicillin-resistant S. aureus (MRSA), compared to UA and azole-based commercial formulations. Moreover, this emulsion is up to +480 % more efficient that UA ointment against C. albicans. Finally, remarkable eradication of E. coli and MRSA biofilms was obtained with this environmental-friendly emulsion.

Application of Nanoemulsions (W/O) of Extract of Opuntia oligacantha C.F. Först and Orange Oil in Gelatine Films.

Over the past decade, consumers have demanded natural, completely biodegradable active packaging serving as food containers. Bioactive plant compounds can be added to biopolymer-based films to improve their functionality, as they not only act as barriers against oxidation, microbiological, and physical damage, they also offer functionality to the food they contain. A water-in-oil (W/O) nanoemulsion was produced by applying ultrasound to xoconostle extract and orange oil, and was incorporated into gelatine films in different proportions 1:0 (control), 1:0.10, 1:0.25, 1:0.50, 1:0.75, and 1:1 (gelatine:nanoemulsion). The nanoemulsions had an average size of 118.80 ± 5.50 nm with a Z-potential of -69.9 ± 9.93 mV. The presence of bioactive compounds such as phenols, flavonoids, and betalains in the films was evaluated. The 1:1 treatment showed the highest presence of bioactive compounds, 41.31 ± 3.71 mg of gallic acid equivalent per 100 g (GAE)/100g for phenols, 28.03 ± 3.25 mg of quercetin equivalent per 100 g (EQ)/100g flavonoids and 0.014 mg/g betalains. Radical inhibition reached 72.13% for 2,20-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 82.23% for 1,1-diphenyl-2-picrylhydrazyl (DPPH). The color of the films was influenced by the incorporation of nanoemulsions, showing that it was significantly different (p < 0.05) to the control. Mechanical properties, such as tensile strength, Young's modulus, and percentage elongation, were affected by the incorporation of nanoemulsified bioactive compounds into gelatine films. The obtained films presented changes in strength and flexibility. These characteristics could be favorable as packaging material.

Effects of zein stabilized clove essential oil Pickering emulsion on the structure and properties of chitosan-based edible films.

Clove essential oil (CLO) Pickering emulsions were prepared with zein colloid particles as stabilizer, and the effects of CLO Pickering emulsion incorporation on the structure, mechanical, barrier and antimicrobial properties of chitosan-based edible films were explored. CLO Pickering emulsions with 3% w/v zein and 50% v/v CLO had smaller particle size and more even distribution. Incorporation of CLO Pickering emulsion in the films decreased the water vapor permeability and tensile strength, but the elongation at break firstly increased then decreased with the maximum value of 19.2% when the content of emulsion was 0.4%. Scanning electron microscopy revealed the formation of microstructure-sized holes in the films by the addition of CLO Pickering emulsion. The emulsified oil droplets were uniformly distributed, due to the good compatibility between oil phase and chitosan matrix. The antimicrobial properties of the films were strengthened by CLO Pickering emulsion incorporation and mainly depended on its concentration.

Compatibility of sodium alginate and konjac glucomannan and their applications in fabricating low-fat mayonnaise-like emulsion gels.

In this study, the compatibility of alginate (Alg) and konjac glucomannan (KGM) in aqueous solutions was evaluated by dilute solution viscometry (DSV). It was found that when Alg: KGM ratio was lower than 6:4 (w/w), Alg and KGM were compatible, which was subsequently confirmed by SEM, AFM and TEM. Moreover, by dispersing emulsified oil droplets into Alg gel matrix, followed by addition of KGM to thicken the system, where the ratio of Alg: KGM was 5:5, a class of emulsion gels with significant thixotropy and viscoelasticity could be obtained. The prepared emulsion gels displayed good thermal stability and freeze-thaw stability, with no oil droplet coalescence observed after heating at 100°C for 30 min or freezing the gels at -18°C for 24 h. Overall, the mixed Alg/KGM system is expected to provide a template for designing low-fat mayonnaise-like food emulsions.

Development of nanoemulsions containing Physalis peruviana calyx extract: A study on stability and antioxidant capacity.

The aim of this study was to develop and evaluate the physicochemical and antioxidant stability of nanoemulsions containing a Physalis peruviana calyx extract (CPp-NE) and free extracts under different storage conditions (7 and 25 °C) and with absence or incidence of light for 120 days. The calyx extracts were prepared with ethanol 60% and characterized for later preparation of the nanoemulsions by spontaneous emulsification. The formulations presented nanometric sizes, low polydispersity index, negative zeta potential, acid pH, rutin content (11 µg·mL-1), and encapsulation efficiency of 85%. Regarding the stability, the droplet size and PdI of the CPp-NE stored at refrigeration temperature in the dark, room temperature in the dark, and refrigeration temperature with light incidence were stable for 120 days and with no visible changes in the formulations. The antioxidant capacity was related to the reducing capacity, and the best results were found for nanoemulsions stored at room temperature and in absence of light. In addition, CPp-NE presented higher antioxidant and reducing capacity in relation to the free extracts.

Preparation, Optimization, and Evaluation of Hyaluronic Acid-Based Hydrogel Loaded with Miconazole Self-Nanoemulsion for the Treatment of Oral Thrush.

Miconazole nitrate (MZ) is a BCS class II antifungal poorly water-soluble drug with limited dissolution properties and gastrointestinal side effects. Self-nanoemulsifying delivery system-based gel of MZ can improve both solubility and oral mucosal absorption with enhanced antifungal activity. The study aims to formulate MZ self-nanoemulsion (MZ-NE) and combine it within hyaluronic acid-based gel. MZ solubility in various oils, surfactants, and cosurfactant used in NE formulations were evaluated. Mixture design was implemented to optimize the levels of NE components as a formulation variable to study their effects on the mean globule size and antifungal inhibition zones. Further, the optimized MZ-NE was loaded into a hyaluronic acid gel base. Rheological behavior of the prepared gel was assessed. Ex vivo permeability of optimized formulation across buccal mucous of sheep and inhibition against Candida albicans were examined. Mixture design was used to optimize the composition of MZ-NE formulation as 22, 67, and 10% for clove oil, Labrasol, and propylene glycol, respectively. The optimized formulation indicated globule size of 113 nm with 29 mm inhibition zone. Pseudoplastic flow with thixotropic behavior was observed, which is desirable for oral gels. The optimized formulation exhibited higher ex vivo skin permeability and enhanced antifungal activity by 1.85 and 2.179, respectively, compared to MZ-SNEDDS, and by 1.52 and 1.72 folds, respectively, compared to marketed gel. Optimized MZ-NE hyaluronic acid-based oral gel demonstrated better antifungal activity, indicating its potential in oral thrush pharmacotherapy.

A solid lipid nanoparticle formulation of 4-(N)-docosahexaenoyl 2', 2'-difluorodeoxycytidine with increased solubility, stability, and antitumor activity.

Previously, we synthesized 4-(N)-docosahexaenoyl 2', 2'-difluorodeoxycytidine (DHA-dFdC), a novel lipophilic compound with a potent, broad-spectrum antitumor activity. Herein, we report a solid lipid nanoparticle (SLN) formulation of DHA-dFdC with improved apparent aqueous solubility, chemical stability, as well as efficacy in a mouse model. The SLNs were prepared from lecithin/glycerol monostearate-in-water emulsions emulsified with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and Tween 20. The resultant DHA-dFdC-SLNs were 102.2 ±â€¯7.3 nm in diameter and increased the apparent solubility of DHA-dFdC in water to at least 5.2 mg/mL, more than 200-fold higher than its intrinsic water solubility. DHA-dFdC in a lyophilized powder of DHA-dFdC-SLNs was significantly more stable than the waxy solid of pure DHA-dFdC. DHA-dFdC-SLNs also showed an increased cytotoxicity against certain tumor cells than DHA-dFdC. The plasma concentration of DHA-dFdC in mice intravenously injected with DHA-dFdC-SLNs in dispersion followed a bi-exponential model, with a half-life of ~44 h. In mice bearing B16-F10 murine melanoma, DHA-dFdC-SLNs were significantly more effective than DHA-dFdC in controlling the tumor growth. In addition, histology evaluation revealed a high level of apoptosis and tumor encapsulation in tumors in mice treated with DHA-dFdC-SLNs. DHA-dFdC-SLNs represents a new DHA-dFdC formulation with improved antitumor activity.

Pickering emulsion stabilized by amphiphilic pH-sensitive starch nanoparticles as therapeutic containers.

In this paper, we report the use of amphiphilic crosslinked starch nanoparticles (CSTNs) as biocompatible, biodegradable and effective stabilizer for Pickering emulsion formulation. The nearly monodispersed CSTNs (˜140 nm) were synthesized through alkali-freezing method followed by crosslinking using citric acid. The prepared nanoparticles were characterized by field emission scanning electron microscopy, zeta-potential measurements, dynamic light scattering, and Fourier transform infrared spectroscopy. The efficacy of the CSTNs toward the stability, the oil droplet size distribution and the surface area moment mean diameter (d3,2) of sunflower oil-in-water emulsions were then assessed as a function of pH. Increase in pH from 3 to 5 and 7.4 led to an enhance in the emulsion stability, decrease in d3,2 and narrowing of the size distribution of emulsions droplets. Moreover, the abundance of nanoparticles increased with pH so that the surface coverage for pH 3, 5 and 7.4 were calculated 10.6, 14.8 and 22.2%, respectively. In vitro controlled release studies showed that the encapsulated curcumin, as a lipophilic and therapeutic compound, into the Pickering emulsion can be tuned by pH of the release media; drug release increases with pH. Collectively, the facile preparation of emulsions stabilized by solid particles derived from biocompatible and renewable resources along with the pH responsivity of these emulsions make them promising drug carriers to treat gastrointestinal tissue disorders via oral drug delivery.

Comparison of natural and synthetic surfactants at forming and stabilizing nanoemulsions: Tea saponin, Quillaja saponin, and Tween 80.

HYPOTHESIS: This study compared the interfacial and emulsification properties of tea saponins, quillaja saponins, and Tween 80. We hypothesized that tea saponins are an effective and sustainable source of plant-based emulsifiers that could replace synthetic or animal-based emulsifiers in many commercial applications. EXPERIMENTS: Interfacial tension measurements were used to characterize the behavior of the three surfactants at an oil-water interface. The emulsifying properties of the surfactants were determined by preparing oil-in-water emulsions containing 10 wt% medium chain triglycerides (MCT) and varying surfactant levels (0.1-2 wt%) using high-pressure homogenization (pH 7). The impact of surfactant type on emulsion formation and stability was determined by measuring particle size, zeta-potential, microstructure, and creaming stability. FINDINGS: The tea saponins were capable of producing nano-scale droplets (d32 < 200 nm) at low surfactant-to-oil ratios (SOR < 0.1). Emulsions containing tea saponins remained stable to droplet aggregation when exposed to various temperatures (30-90 °C), salt levels (0-200 mM NaCl), and pH values (3-9). However, droplet flocculation and/or coalescence occurred under highly acidic (pH 2) and high ionic strength (300-500 mM NaCl) conditions. Tea saponin-coated oil droplets appeared to be mainly stabilized by a combination of electrostatic and steric repulsion. The tea saponins behaved similarly or better than the other two emulsifiers under most conditions. These results suggest that tea saponins are effective plant-based surfactants that may have applications in commercial products.

Getting the Jump on the Development of Bullfrog Oil Microemulsions: a Nanocarrier for Amphotericin B Intended for Antifungal Treatment.

Amphotericin B (AmB), a potent antifungal drug, presents physicochemical characteristics that impair the development of suitable dosage forms. In order to overcome the AmB insolubility, several lipid carriers such as microemulsions have been developed. In this context, the bullfrog oil stands out as an eligible oily phase component, since its cholesterol composition may favor the AmB incorporation. Thus, the aim of this study was to develop a microemulsion based on bullfrog oil containing AmB. Moreover, its thermal stability, antifungal activity, and cytotoxicity in vitro were evaluated. The microemulsion formulation was produced using the pseudo-ternary phase diagram (PTPD) approach and the AmB was incorporated based on the pH variation technique. The antifungal activity was evaluated by determination of minimal inhibitory concentration (MIC) against different species of Candida spp. and Trichosporon asahii. The bullfrog oil microemulsion, stabilized with 16.8% of a surfactant blend, presented an average droplet size of 26.50 ± 0.14 nm and a polydispersity index of 0.167 ± 0.006. This system was able to entrap AmB up to 2 mg mL-1. The use of bullfrog oil as oily phase allowed an improvement of the thermal stability of the system. The MIC assay results revealed a growth inhibition for different strains of Candida spp. and were able to enhance the activity of AmB against T. asahii. The microemulsion was also able to reduce the AmB toxicity. Finally, the developed microemulsion showed to be a suitable system to incorporate AmB, improving the system's thermal stability, increasing the antifungal activity, and reducing the toxicity of this drug.

Preparation and Pharmacokinetics Evaluation of Solid Self-Microemulsifying Drug Delivery System (S-SMEDDS) of Osthole.

The study was performed aiming to enhance the solubility and oral bioavailability of poorly water-soluble drug osthole by formulating solid self-microemulsifying drug delivery system (S-SMEDDS) via spherical crystallization technique. Firstly, the liquid self-microemulsifying drug delivery system (L-SMEDDS) of osthole was formulated with castor oil, Cremophor RH40, and 1,2-propylene glycol after screening various lipids and emulsifiers. The type and amount of polymeric materials, good solvents, bridging agents, and poor solvents in S-SMEDDS formulations were further determined by single-factor study. The optimal formulation contained 1:2 of ethyl cellulose (EC) and Eudragit S100, which served as matrix forming and enteric coating polymers respectively. Anhydrous ethanol and dichloromethane with a ratio of 5:3 are required to perform as good solvent and bridging agent, respectively, with the addition of 0.08% SDS aqueous solution as poor solvent. The optimized osthole S-SMEDDS had a high yield (83.91 ± 3.31%) and encapsulation efficiency (78.39 ± 2.25%). Secondly, osthole L-SMEDDS was solidified to osthole S-SMEDDS with no significant changes in terms of morphology, particle size, and zeta potential. In vitro release study demonstrated a sustained release of the drug from osthole S-SMEDDS. Moreover, in vivo pharmacokinetic study showed that the Tmax and mean residence time (MRT(0-t)) of osthole were significantly prolonged and further confirmed that osthole S-SMEDDS exhibited sustained release effect in rabbits. Comparing with osthole aqueous suspension and L-SMEDDS, osthole S-SMEDDS increased bioavailability by 205 and 152%, respectively. The results suggested that S-SMEDDS was an effective oral solid dosage form, which can improve the solubility and oral bioavailability of poorly water-soluble drug osthole.

Cornus mas L. extract as a multifunctional material for manufacturing cosmetic emulsions.

Dogwood fruits are a valuable source of active ingredients, such as phenolic compounds, vitamin C, iridoids, flavonoids and anthocyanins. Plant extracts and substances derived from latin Cornus mas L. exhibit not only strong antibacterial but also antioxidant and tonicity properties, effectively preventing the development of inflammation in living organisms. In the present study, we attempted to obtain the innovative, multi-functional plant extract from the fruit of dogwood (Cornus mas L.). During the extraction process a mixture of water, glycerol, and vegetable oil were used as an extractant. The usage of such mixtures of solvents enabled us to extract a variety of active substances, soluble in both water and oils. The obtained extracts were analyzed for their physicochemical and biochemical properties, in order to apply the extract in a body nutrient lotion. The results clearly showed that such extract could be an innovative and multi-functional raw material used in cosmetics industry.

Water-in-oil-in-water emulsion obtained by glass microfluidic device for protection and heat-triggered release of natural pigments.

Anthocyanins and norbixin are natural pigments used in food; however, they are unstable. The aim of this study was to evaluate the microencapsulation technique to protect these pigments. Elderberry extract (source of anthocyanins) and norbixin were encapsulated using a microfluidic device with palm oil as middle phase in a water-in-oil-in-water emulsion. The formulations were characterized for morphology, particle size, encapsulation efficiency, zeta potential, color release under heating, Fourier transform infrared spectrophotometry, and color stability under different conditions. Spherical, mononucleated microcapsules, with particle size of 187-190 µm (elderberry) and 164-184 µm (norbixin), and with encapsulation efficiencies values of 47.80-54.87% (elderberry) and 49.18-74.73% (norbixin) were obtained. The formulations showed high color retention, with the encapsulated elderberry extract stored at pH 3.0 being the most stable. This study shows that the microencapsulation of these pigments using a microfluidic device provided protection, and represents a new method for anthocyanins and norbixin delivery in foods.

Tragacanth nanocapsules containing Chamomile extract prepared through sono-assisted W/O/W microemulsion and UV cured on cotton fabric.

Encapsulation is the best method to protect the plant extracts against volatility and instability in the presence of air, light, moisture and high temperatures. Nevertheless, application of encapsulated plant extracts on the textiles requires a low-temperature and high rate processing to avoid from breaking or destroying of capsules. The present paper represents application of nanocapsules prepared by ultrasound irradiation assisted W/O/W microemulsion method on the cotton fabric through UV curing method. The surface and structure of nanocapsules and treated cotton fabric using FESEM and FT-IR indicated the spherical nanocapsules with size of 60-80nm stabilized on the fabric surface in a film layer feature. Also, the treated cotton fabric showed a good release behavior of 96h, a high stability against washing and rubbing tests and a relative good antimicrobial activity with 91, 89 and 94% reduction against S. aureus, E. coli and C. albicans, respectively.

Preparation and therapeutic evaluation of (188)Re-thermogelling emulsion in rat model of hepatocellular carcinoma.

Radiolabeled Lipiodol(®) (Guerbet, Villepinte, France) is routinely used in hepatoma therapy. The temperature-sensitive hydrogel polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol triblock copolymer is used as an embolic agent and sustained drug release system. This study attempted to combine the polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol hydrogel and radio-labeled Lipiodol to form a new radio-thermogelling emulsion, rhenium-188-N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride-Lipiodol/hydrogel ((188)Re-ELH). The therapeutic potential of (188)Re-ELH was evaluated in a rodent hepatoma model. Rhenium-188 chelated with N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride was extracted with Lipiodol to obtain rhenium-188-N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride-Lipiodol ((188)Re-EL), which was blended with the hydrogel in equal volumes to develop (188)Re-ELH. The (188)Re-ELH phase stability was evaluated at different temperatures. Biodistribution patterns and micro-single-photon emission computed tomography/computed tomography images in Sprague Dawley rats implanted with the rat hepatoma cell line N1-S1 were observed after in situ tumoral injection of ~3.7 MBq (188)Re-ELH. The therapeutic potential of (188)Re-EL (48.58±3.86 MBq/0.1 mL, n=12) was evaluated in a 2-month survival study using the same animal model. The therapeutic effects of (188)Re-ELH (25.52±4.64 MBq/0.1 mL, n=12) were evaluated and compared with those of (188)Re-EL. The responses were assessed by changes in tumor size and survival rates. The (188)Re-ELH emulsion was stable in the gel form at 25°C-35°C for >52 hours. Biodistribution data and micro-single-photon emission computed tomography/computed tomography images of the (188)Re-ELH group indicated that most activity was selectively observed in hepatomas. Long-term (188)Re-ELH studies have demonstrated protracted reductions in tumor volumes and positive effects on the survival rates (75%) of N1-S1 hepatoma-bearing rats. Conversely, the 2-month survival rate was 13% in the control sham group. Therapeutic responses differed significantly between the two groups (P<0.005). Thus, the hydrogel enhanced the injection stability of (188)Re-EL in an animal hepatoma model. Given the synergistic results, direct (188)Re-ELH intratumoral injection is a potential therapeutic alternative for hepatoma treatment.

Characterization of rice bran wax policosanol and its nanoemulsion formulation.

Policosanol, a mixture of long-chain alcohols found in animal and plant waxes, has several biological effects; however, it has a bioavailability of less than 10%. Therefore, there is a need to improve its bioavailability, and one of the ways of doing this is by nanoemulsion formulation. Different droplet size distributions are usually achieved when emulsions are formed, which solely depends on the preparation method used. Mostly, emulsions are intended for better delivery with maintenance of the characteristics and properties of the leading components. In this study, policosanol was extracted from rice bran wax, its composition was determined by gas chromatography mass spectrophotometry, nanoemulsion was made, and the physical stability characteristics were determined. The results showed that policosanol nanoemulsion has a nanosize particle distribution below 100 nm (92.56-94.52 nm), with optimum charge distribution (-55.8 to -45.12 mV), pH (6.79-6.92) and refractive index (1.50); these were monitored and found to be stable for 8 weeks. The stability of policosanol nanoemulsion confers the potential to withstand long storage times.

Development of a nanoemulsion of Phyllanthus emblica L. branch extract.

For potential topical administration, we formulated a nanoemulsion containing phenolic constituents of Phyllanthus emblica branch extract. The nanoemulsion has high entrapment efficiency, small particle size, is stable, and can release its main chemical components. Branches of P. emblica were extracted with 50% ethanol (EPE) with 5.4% yield. HPLC analysis indicated several phenolic compounds, including gallic acid, vanillic acid, epigallocatechin (EGC), epigallocatechin gallate (EGCG) and ellagic acid. These were selected as chemical markers of EPE in the nanoemulsion development. The nanoemulsion was prepared by microemulsion techniques with hot high pressure homogenization. A ternary phase diagram was constructed to obtain the optimized nanoemulsion. The obtained transparent EPE nanoemulsion is composed of isopropyl myristate (0.6% w/w), Brij® 78 (0.35% w/w), and 0.15% (w/w) EPE. The optimized EPE nanoemulsion had a median particle size of 191.63 ± 4.07 nm with a narrow particle size distribution, a zeta potential of -10.19 ± 0.54 mV, high entrapment efficiency at 67.99 ± 0.87% and good stability at 4 °C after 90 d of storage. The release of active ingredients from the EPE nanoemulsion was slower than that of the EPE aqueous formulation. The loading ratios of the five phenolic compounds were high, with relative order of EGC > EGCG > vanillic acid > gallic acid > ellagic acid, resulting in slow release profiles of EGC and EGCG in the EPE nanoemulsion. In conclusion, the obtained EPE nanoemulsion has good characteristics for future clinical trials.

Nanoemulsion improves the oral bioavailability of baicalin in rats: in vitro and in vivo evaluation.

Baicalin is one of the main bioactive flavone glucuronides derived as a medicinal herb from the dried roots of Scutellaria baicalensis Georgi, and it is widely used for the treatment of fever, inflammation, and other conditions. Due to baicalin's poor solubility in water, its absolute bioavailability after oral administration is only 2.2%. The objective of this study was to develop a novel baicalin-loaded nanoemulsion to improve the oral bioavailability of baicalin. Based on the result of pseudoternary phase diagram, the nanoemulsion formulation consisting of soy-lecithin, tween-80, polyethylene glycol 400, isopropyl myristate, and water (1:2:1.5:3.75:8.25, w/w) was selected for further study. Baicalin-loaded nanoemulsions (BAN-1 and BAN-2) were prepared by internal or external drug addition and in vivo and in vitro evaluations were performed. The results showed that the mean droplet size, polydispersity index, and drug content of BAN-1 and BAN-2 were 91.2 ± 2.36 nm and 89.7 ± 3.05 nm, 0.313 ± 0.002 and 0.265 ± 0.001, and 98.56% ± 0.79% and 99.40% ± 0.51%, respectively. Transmission electron microscopy revealed spherical globules and confirmed droplet size analysis. After dilution 30-fold with water, the solubilization capacity of BAN-1 and BAN-2 did not change. In vitro release results showed sustained-release characteristics. BAN-1 formulation was stable for at least 6 months and was more stable than BAN-2. In rats, the area under the plasma drug concentration-time curve value of BAN-1 was 1.8-fold and 7-fold greater than those of BAN-2 and free baicalin suspension after oral administration at a dose of 100 mg/kg. In conclusion, these results demonstrated that the baicalin-loaded nanoemulsion formulation, in particular BAN-1, was very effective for improving the oral bioavailability of baicalin and exhibited great potential for future clinical application.

Interfacial behaviour of sodium stearoyllactylate (SSL) as an oil-in-water pickering emulsion stabiliser.

The ability of a food ingredient, sodium stearoyllactylate (SSL), to stabilise oil-in-water (O/W) emulsions against coalescence was investigated, and closely linked to its capacity to act as a Pickering stabiliser. Results showed that emulsion stability could be achieved with a relatively low SSL concentration (≥0.1 wt%), and cryogenic-scanning electron microscopy (cryo-SEM) visualisation of emulsion structure revealed the presence of colloidal SSL aggregates adsorbed at the oil-water interface. Surface properties of SSL could be modified by altering the size of these aggregates in water; a faster decrease in surface tension was observed when SSL dispersions were subjected to high pressure homogenisation (HPH). The rate of SSL adsorption at the sunflower oil-water interface also increased after HPH, and a higher interfacial tension (IFT) was observed with increasing SSL concentration. Differential scanning calorimetry (DSC) enabled a comparison of the thermal behaviour of SSL in aqueous dispersions with SSL-stabilised O/W emulsions. SSL melting enthalpy depended on emulsion interfacial area and the corresponding DSC data was used to determine the amount of SSL adsorbed at the oil-water interface. An idealised theoretical interfacial coverage calculation based on Pickering emulsion theory was in general agreement with the mass of SSL adsorbed as predicted by DSC.

Preparation and physicochemical properties of surfactant-free emulsions using electrolytic-reduction ion water containing lithium magnesium sodium silicate.

Surfactant-free emulsions by adding jojoba oil, squalane, olive oil, or glyceryl trioctanoate (medium chain fatty acid triglycerides, MCT) to electrolytic-reduction ion water containing lithium magnesium sodium silicate (GE-100) were prepared, and their physiochemical properties (thixotropy, zeta potential, and mean particle diameter) were evaluated. At an oil concentration of 10%, the zeta potential was ‒22.3 ‒ ‒26.8 mV, showing no marked differences among the emulsions of various types of oil, but the mean particle diameters in the olive oil emulsion (327 nm) and MCT emulsion (295 nm) were smaller than those in the other oil emulsions (452-471 nm). In addition, measurement of the hysteresis loop area of each type of emulsion revealed extremely high thixotropy of the emulsion containing MCT at a low concentration and the olive emulsion. Based on these results, since surfactants and antiseptic agents markedly damage sensitive skin tissue such as that with atopic dermatitis, surfactant- and antiseptic-free emulsions are expected to be new bases for drugs for external use.