Droplet Size Of Nanoemulsions Research Articles

Development and Characterization of Aerosol Nanoemulsion System Encapsulating Low Water Soluble Quercetin for Lung Cancer Treatment

Palm-based nanoemulsion containing low water soluble drug quercetin for lung cancer via aerosol delivery was prepared in this study. Formulation of quercetin nanoemulsion having the desirable criteria was 1.5 % of palm oil ester:ricinoleic acid (1:1 ratio), 1.5 % of lecithin, 1.5 % of Tween 80, 1.5 % of glycerol, and 93.95% of water. The formulation was carried out using low and high energy emulsification method. The characterization of zetasizer analysis showed the droplet size and zeta potential of quercetin nanoemulsion were 106.1 ± 0.44 nm and -43.7 ± 3.57 mV, respectively. In addition, the particle size measured in TEM is consistent with the size obtained using Zetasizer and confirmed that the nanoemulsion droplets of formulations were spherical. Medium mass aerodynamic diameter, fine particle fraction (% FPF < 5 μm) and geometric standard deviation (GSD) value of nanoemulsion were 4.25 ± 0.38 μm, 70.56 ± 66.33 and 1.96 ± 0.07, respectively. The formulation exhibited good viscosity, conductivity, osmolality and pH values as well as stability against phase separation and storage at temperature 4 °C for 3 months. These results suggest that palm oil -based nanoemulsion in this study could be successful nanocarrier system of quercetin as pulmonary delivery for lung cancer treatment

Novel Approaches for Colloidal Drug Delivery System: Nanoemulsion

An advanced mode of drug delivery system has been developed to overcome the major drawbacks associated with conventional drug delivery systems. Nanoemulsions are submicron sized emulsion that is under extensive investigation as drug carriers for improving the delivery of therapeutic agents and drug targeting. These are the thermodynamically stable isotropic system in which two immiscible liquid (water and oil) are mixed to form a single phase by means of an appropriate surfactants or it mixes with a droplet diameter approximately in the range of 0.5–100 um. Nanoemulsion droplet size falls typically in the range of 20–200 nm and shows a narrow size distribution. Nanoemulsion show great promise for the future of cosmetics, diagnostics, drug therapies and biotechnologies. These are the thermodynamically stable isotropic system in which two immiscible liquids are mixed to form a single phase by means of an emulsifying agent, i.e., surfactant and co-surfactant. The droplet size of nanoemulsion falls typically in the range 20–200 nm. The main difference between emulsion and nanoemulsion lies in the size and shape of particles dispersed in the continuous phase. In this review, the attention is focused to give a basic idea about its formulation, method of preparation, characterization techniques, evaluation parameters, and various applications of nanoemulsion.

Effect of high pressure homogenization on the structure and the interfacial and emulsifying properties of β-lactoglobulin

The effect of high pressure homogenization (HPH) on the structure of β-lactoglobulin (β-lg) was studied by combining spectroscopic, chromatographic, and electrophoretic methods. The consequences of the resulting structure modifications on oil/water (O/W) interfacial properties were also assessed. Moderated HPH treatment (100 MPa/4 cycles) showed no significant modification of protein structure and interfacial properties. However, a harsher HPH treatment (300 MPa/5 cycles) induced structural transformation, mainly from β-sheets to random coils, wide loss in lipocalin core, and protein aggregation via intermolecular disulfide bridges. HPH-modified β-lg displayed higher surface hydrophobicity leading to a faster adsorption rate at the interface and an earlier formation of an elastic interfacial film at Cβ-lg = 0.1 wt%. However, no modification of the interfacial properties was observed at Cβ-lg = 1 wt%. At this protein concentration, the prior denaturation of β-lg by HPH did not modify the droplet size of nanoemulsions prepared with these β-lg solutions as the aqueous phases. A slightly increased creaming rate was however observed. The effects of HPH and heat denaturations appeared qualitatively similar, but with differences in their extent.

Optimization and characterization of the formation of oil-in-water diazinon nanoemulsions: Modeling and influence of the oil phase, surfactant and sonication

ABSTRACTNanoemulsions are particularly suitable as a platform in the development of delivery systems for lipophilic functional agents. Current research describes the formation of oil-in-water (O/W) diazinon nanoemulsions using synthetic and natural additives by adopting a high-energy (ultrasound) emulsification method. The diazinon nanoemulsions were spontaneously formed by adding dropwise a mixture of diazinon, solvent and co-solvent in an aqueous solution containing a surfactant (tween or lecithin) with continuous stirring. The nanoemulsions were then formed by ultra-sonication. The effects of three levels of active ingredient, solvent, co-solvent, surfactant, sonication time and sonication cycle and power were performed by Minitab software to design the experiment. Effects of these factors on droplet size, polydispersity index (PDI), viscosity and pH of nanoemulsions were investigated. The results of the modeling showed that the experimental data could be adequately adapted in a second-order polynomial model with a multiple regression coefficient r2 of 0.821 for the prediction of particle size, PDI and viscosity. The long-term and thermodynamic stability of the prepared nanoemulsions were tested. The droplet size and morphology of the nanoemulsions were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). On this basis, a water-insoluble insecticide diazinon was incorporated into 26 optimized nanoemulsion systems to demonstrate potential applications in pest control. The results of DLS and TEM measurements showed that most of prepared nanoemulsions had an almost monodisperse droplet size distribution (PDI < 200 nm). Incorporation of diazinon had no significant effect on the size and stability of the nanoemulsions and the formulated nanoemulsion remained stable after four months of storage.

In vitro bioaccessibility of ergocalciferol in nanoemulsion‐based delivery system: the influence of food‐grade emulsifiers with different stabilising mechanisms

SummaryThe effect of emulsifier type on the in vitro bioaccessibility of ergocalciferol‐loaded nanoemulsions was examined (mouth, stomach and small intestinal phases). Oil‐in‐water nanoemulsions were prepared using emulsifiers with different stabilising mechanisms: decaglycerol monooleate (MO7S; steric), modified lecithin (ML; electrostatic), sodium caseinate (SC; electrosteric) and ML‐MO7S (combined electrostatic and steric). The droplet size, size distribution, ζ‐potential and microstructure of nanoemulsions during digestion depended on the emulsifier type. The fate of lipid in the small intestinal phase also relied on the emulsifier type, with the free fatty acids release rate decreasing in the following order: MO7S &gt; ML‐MO7S &gt; ML &gt; SC. The ergocalciferol bioaccessibilities in nanoemulsions prepared using MO7S (62%), ML (64%) and ML‐MO7S (65%) were similar and significantly higher than that stabilised by SC (12%). No significant loss of ergocalciferol was observed in all nanoemulsions after full digestion; they were chemically stable against digestion conditions, regardless of the emulsifier type.

Experimental Study of Nanofluids Applied in EOR Processes

AbstractNanoemulsions are small droplet‐sized systems that have low surface tension and a small percentage of active material in their composition. In this study, low oil content nanoemulsion systems were developed for the use in enhanced oil recovery (EOR). The experiments were performed on a device capable of simulating petroleum reservoir conditions using sandstone rock cores. Nanoemulsions were obtained from a pre‐selected microemulsion system composed of: RNX95 as surfactant, isopropyl alcohol as cosurfactant, kerosene as oil phase, and distilled water as aqueous phase. Different percentages of polyacrylamide were added to the systems obtained to evaluate the influence of viscosity in EOR results. The nanoemulsion droplet sizes ranged from 9.22 to 14.8 nm. Surface tension values were in the range of 33.6–39.7 dyn/cm. A nanoemulsion system with 2.5 wt% surfactant was used in EOR assays. The oil recovery was directly proportional to polymer percentage in the nanoemulsion, ranging from 39.6 to 76.8%. The total oil in the place recovery ranged from 74.5 to 90%.

Influence of polymer concentration on the properties of nano-emulsions and nanoparticles obtained by a low-energy method

This study concerns the effect of polymer content on the properties of nano-emulsions formulated by the PIC low-energy method and on the nanoparticles prepared from nano-emulsions by solvent evaporation. The region of nano-emulsion formation, droplet size and stability as a function of polymer content were investigated. Nano-emulsions were formed in a wide range of oil-to-surfactant weight ratios (Ros) and water contents higher than 45%. For nanoparticles, droplet size, stability, encapsulation efficiency, pH, drug release and cytotoxicity effect were evaluated as a function of polymer content. Nano-emulsion droplet size (Rh=8–75nm) and nanoparticle size (Rh=8–55nm) increase with the polymer content. No desestabilization process such as creaming or sedimentation was observed by light transmittance/backscattering neither in nano-emulsions nor in nanoparticle dispersions. The morphology and size of nano-emulsions and nanoparticles were comfirmed by Cryo-TEM and TEM techniques, respectively. The pH of nanoparticle dispersions was in the range of 5–6.5 during the studied experimental time (7days), an indication of no polymer degradation. Moreover, Dexamethasone (DXM) encapsulated in the polymeric nanoparticles (0.18wt% DXM in the oil phase of the template nano-emulsion) did not modify the nanoparticle size. No effect of polymer concentration was found in the encapsulation efficiency (close to 90%) of DXM. In vitro drug release studies indicated Fick’s diffusion as the main drug release mechanism from the nanoparticle to the receptor solution. DXM loaded and non-loaded nanoparticles showed cell viability higher than 70%. This study reports a promising system to be used as template for polymeric nanoparticle preparation suitable for biomedical applications.

Natural herbicide activity of Satureja hortensis L. essential oil nanoemulsion on the seed germination and morphophysiological features of two important weed species

The aim of the present study was to obtain an oil/water (O/W) nanoemulsion (NE) containing garden savory (Satureja hortensis) essential oil (EO) and evaluating its herbicidal activity against Amaranthus retroflexus and Chenopodium album. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the chemical composition of the EO. Carvacrol (55.6%) and γ-terpinene (31.9%) were the major EO components. Low energy method was applied, allowing achievement of EO nanodroplets. The NE also presented low polydispersity, and the mean droplet was below 130nm even after storage for 30d. Laboratory tests showed that the NE at different concentrations (100, 200, 400, 800, and 1000μL.L−1) significantly (P≤0.05) reduced the germination indices and the seedling's growth in dose-response. The inhibitory effect was the greatest at 800μL.L−1 NE. Overall, root length was more inhibited as compared to shoot length. Post-emergence application of NE at different concentrations (1000, 2000, 3000, 4000 and 5000μL.L−1 of EO) on 2–4 true leaves' stage of the weeds caused significant (P≤0.05) decrease in the growth factors in dose-dependent manner. Complete lethality was observed by 4000μL.L−1 NE sprayed on the weeds. Spraying of NE significantly (P≤0.05) reduced chlorophyll content in the tested weeds. Increasing in relative electrolyte leakage (REL) 1 and 5d after treatment represented significant cell membrane disruption and increased cell membrane permeability. Transmission electron microscope (TEM) pictures confirmed NE droplet size and demonstrated membrane destruction. The study approved that the NE of S. hortensis EO has herbicidal properties as it has high phytotoxic effect, and interferes with the germination, growth and physiological processes of the weeds. The production of NE from S. hortensis EO is a low energy method that offers a promising practical natural herbicide for weed control in organic agricultural systems.

Importance of crystallinity of anchoring block of semi-solid amphiphilic triblock copolymers in stabilization of silicone nanoemulsions

Polymer emulsifiers solidified at the interface between oil and water can provide exceptional dispersion stability to emulsions due to the formation of unique semi-solid interphase. Our recent works showed that the structural stability of paraffin-in-water emulsions highly depends on the oil wettability of hydrophobic block of methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) (mPEG-b-PCL). Here we investigate the effects of the crystallinity of hydrophobic block of triblock copolymer-based emulsifiers, PCLL-b-PEG-b-PCLL, on the colloidal properties of silicone oil-in-water nanoemulsions. The increased ratio of l-lactide to ε-caprolactone decreases the crystallinity of the hydrophobic block, which in turn reduces the droplet size of silicone oil nanoemulsions due to the increased chain mobility at the interface. All of the prepared nanoemulsions are very stable for a month at 37°C. However, the exposure to repeated freeze-thaw cycles quickly destabilizes the nanoemulsions prepared using the polymer with the reduced crystallinity. This work demonstrates that the anchoring chain crystallization in the semi-solid interphase is critically important for the structural robustness of nanoemulsions under harsh physical stresses.

Virgin Coconut Oil as Oil Phase in Tretinoin Nanoemulsion

This study was aimed to determine the characteristic and tretinoin release in nanoemulsion using virgin coconut oil (VCO) as oil phase compared with emulsion. The characteristics of the tretinoin nanoemulsion (TN) were observed in terms of droplet morphology by Transmission Electron Microscopy (TEM) and droplet size by particle analyzer and light microscope and the pH value by pH meter. The release rate of tretinoin in nanoemulsion and emulsion was measured by Franz diffusion cell using cellophane membrane. Result of this research showed the droplet morphology of tretinoin nanoemulsion and emulsion were spherical. The droplet size of tretinoin nanoemulsion (72.57 ± 18.16 nm) was smaller than tretinoin emulsion (10.54 ± 0.61 m). The pH value of tretinoin nanoemulsion and tretinoin emulsion was 6.24 ± 0.01 and 6.21 ± 0.02. In interval times 5 – 60 minutes the tretinoin release rate (flux) in nanoemulsion was 0.158 ± 0.016 µg/cm2 /minute higher than in emulsion which was 0.048 ± 0.016 g/cm2 /minute. In interval times 60 – 180 minutes, tretinoin release rate (flux) in nanoemulsion was 0.046 ± 0.005 g/cm2 /minute lower than in emulsion which was 0.090 ± 0.016 g/cm2 /minute. In interval times 180 – 720 minutes the tretinoin release rate (flux) in nanoemulsion was 0.025 ± 0.001 g/cm2 /minute which had no significant different compared to in emulsion which was 0.022 ± 0.002 g/cm2 /minute. The statistical analysis of the tretinoin release rate value using independent T-test result was known that there were significant different between nanoemulsion (TN) and emulsion (TE). Conclusion: The droplet size of tretinoin nanoemulsion was below 100 nm, pH value 6.24 ± 0.01 and the tretinoin release rate in nanoemulsion using VCO was higher than in emulsion

Characterization of basil seed gum-based edible films incorporated with Zataria multiflora essential oil nanoemulsion

Direct introduction of essential oils (EOs) into biopolymer-based packaging materials faces various challenges such as insolubility and loss of activity. The aim of this study was increasing the bioactivity of Zataria multiflora essential oil (ZMEO) through first making a nanoemulsion and then immobilizing within basil seed gum (BSG)-based film network. ZMEO (nano)emulsions were prepared using high intensity ultrasound approach at 150W and various sonication times (0, 2.5, 5 and 10min). An increase in the antibacterial activity of ZMEO nanoemulsion was observed by decreasing the nanoemulsion droplet size. Increasing nanoemulsion concentration in BSG film matrix improved the mechanical properties. Scanning electron micrographs showed that the presence of ZMEO nanoemulsions resulted in significant changes in the microstructure of BSG films. Antimicrobial films were effective against potential foodborne pathogens. This innovative incorporation of EOs into biopolymer-based films may have implications in extending the shelf life of food products through retarding the release of volatile constituents.

Penetration of Ubiquinone (Q10) Nanoemulsion Using Olive Oil Through Rat Skin

Ubiquinon (Q10) is an endogenous antioxidant. It is lipophilic and practically insoluble in water. To improve its solubility and penetration, it was formulated into O/W nanoemulsion. The resulting Q10 nanoemulsion was then physically characterized for its droplet size, morphology, and viscosity. In addition, it was conducted a penetration test of Q10 in nanoemulsion delivery system compared to Q10 in emulsion using male Wistar rats. From the characterization results, it was found that the droplet size of Q10 nanoemulsion (70.07 ± 12.42 nm) less than Q10 emulsion (21.063 ± 3,57μm), the morphology of droplet Q10 nanoemulsion and Q10 emulsion that are spherical, and that the viscosity of Q10 nanoemulsion (10.5 CPa.s) less than Q10 emulsion (16 CPa.s). The penetration rate of Q10 in nanoemulsion and emulsion was observed at 2 hours, 4 hours, and 6 hours after treatment. The result was known that the penetration rate of Q10 in nanoemulsion (174.49 μm/h) &gt; Q10 in emulsion (20.429 μm/h).

Citral stabilization and characterization of nanoemulsions stabilized by a mixture of gelatin and Tween 20 in an acidic system.

Citral is one of the most important flavor compounds in fresh juice and lemon oil. Unfortunately, citral is chemically unstable and degrades over time in aqueous solutions. Here, citral nanoemulsions including a mixture of gelatin and Tween 20 as emulsifiers were produced in an effort to maintain the stability of citral in an acidic system. The mean droplet size and polydispersity index of the citral nanoemulsion were 467.83 nm and 0.259 respectively when the mass ratio of gelatin/Tween 20 was 3:1 and the total emulsifier concentration of the emulsion system was 10 g kg-1 . The citral nanoemulsion remained stable during storage for 14 days at 30 °C. Therefore this nanoemulsion system effectively protected citral from degradation and decreased the formation of off-flavor compounds (e.g. p-cymene, p-cresol and p-methylacetophenone) relative to a single emulsifier. The mixture of gelatin and Tween 20 enhanced the stability of citral under acidic conditions and could be used as an effective emulsifier to protect citral from degradation under acidic environments in the food industry. © 2016 Society of Chemical Industry.

The effect of a lipophilic drug, felodipine, on the formation of nanoemulsions upon phase inversion induced by temperature variation

The correlation between a dispersed phase/dispersion medium interfacial tension σ at a storage temperature of 22°C and the dispersity and stability of oil-in-water miniemulsions, which result from temperature-induced phase inversion, has been revealed for hydrocarbon/polyoxyethylene(4)lauryl ether/water systems (in the presence and absence of felodipine) with the help of conductometry, tensiometry, and dispersion analysis. At σ < 3.5 × 10–6 N/m, oil-in-water nanoemulsions, which have narrow monomodal particle size distributions and are stable for a month, are a fortiori formed. Felodipine has been shown to serve as a cosurfactant, which is incorporated into the adsorption layer of a basic stabilizing nonionic surfactant. Therewith, σ values increase and the temperature of phase inversion decreases, while the concentration of the basic surfactant in an optimal composition must be substantially reduced. A heptane/water nanoemulsion (droplet size of 75 nm) stabilized with a basic nonionic surfactant and Tween 80 exhibits a high solubilization capacity with respect to felodipine and ensures its efficient mass transfer through a model membrane.

커큐민 나노에멀젼의 특성에 미치는 바이오폴리머 유화제의 영향

Curcumin is a natural polyphenolic phytochemical, which has a number of potential benefits in biological activities. However, curcumin has extremely low water solubility and low bioavailability, which makes it difficult to incorporate into many food products. In this study, we investigated the effects of biopolymer emulsifier type and environmental stress on the physical stability of nanoemulsions containing curcumin. Nanoemulsion containing curcumin stabilized by sodium caseinate (SC), whey protein isolate (WPI), modified starch (MS), and gum arabic (GA) were prepared using microfludizer. The droplet size of nanoemulsions decreased significantly from 1028 nm to 169 nm as emulsifier concentration increased (p&lt;0.05). The optimum concentration of emulsifiers for stable curcumin nanoemulsions were determined to be 1% of SC and 1% of WPI, respectively. The storage study showed that the nanoemulsions were physically stable for 5 weeks at 25°C. In addition, nanoemulsions were physically stable against heat, freeze-thaw, pH, and NaCl solution. However, extensive droplet aggregation occurred in protein-stabilized nanoemulsions at CaCl2 solution, which was attributed to hydrophobic interaction between droplets.

Ultrasonic assisted formation and stability of mustard oil in water nanoemulsion: Effect of process parameters and their optimization

The present work reports the ultrasound assisted preparation of mustard oil in water nanoemulsion stabilized by Span 80 and Tween 80 at different operating conditions. Effects of various operating parameters such as HLB (Hydrophilic Lipophilic Balance) value, surfactant volume fraction (φS), oil volume fraction (φO) and power amplitude were investigated and optimized on the basis of droplet size and stability of nanoemulsions. It was observed that minimum droplet size of about 87.38nm was obtained within 30min of ultrasonication at an optimum HLB value of 10, φS of 0.08 (8%, v/v), φO of 0.1 (10%, v/v) and ultrasonic power amplitude of 40%. The stability of the nanoemulsion was measured through visual observation and it was found that the unstable emulsions got separated within 24h whereas, stable emulsions never showed any separation until 90days. In addition to that, the kinetic stability of the prepared nanoemulsions was also assessed under centrifuge and thermal stress conditions. The emulsion stability was found to be unaffected by these forces as the droplet size remained unchanged. The ultrasound prepared emulsion was found to be long term stable even after 3months of storage at ambient conditions without any visual evidence of creaming and phase separation and also remained kinetically stable. FTIR analysis of the emulsions at different sonication conditions was carried out to examine the possible impact of ultrasonically induced chemical effects on oil structure during emulsification and it was found that the oil molecular structure was unaffected by ultrasonication process. The present work illustrates the formation and stability of mustard oil in water nanoemulsion using ultrasound cavitation which may be useful in food and cosmetic based applications.

Design Expert® supported optimization and predictive analysis of selegiline nanoemulsion via the olfactory region with enhanced behavioural performance in Parkinson’s disease

Selegiline is a monoamine oxidase B (MAO-B) inhibitor and is used in the treatment of Parkinson’s disease. The main problem associated with its oral administration is its low oral bioavailability (10%) due to its poor aqueous solubility and extensive first pass metabolism. The aim of the present research work was to develop a nanoemulsion loaded with selegiline for direct nose-to-brain delivery for the better management of Parkinson’s disease. A quality by design (QbD) approach was used in a statistical multivariate method for the preparation and optimization of nanoemulsion. In this study, four independent variables were chosen, in which two were compositions and two were process variables, while droplet size, transmittance, zeta potential and drug release were selected as response variables. The optimized formulation was assessed for efficacy in Parkinson’s disease using behavioural studies, namely forced swimming, locomotor, catalepsy, muscle coordination, akinesia and bradykinesia or pole test in Wistar rats. The observed droplet size, polydispersity index (PDI), refractive index, transmittance, zeta potential and viscosity of selegiline nanoemulsion were found to be 61.43 ± 4.10 nm, 0.203 ± 0.005, 1.30 ± 0.01, 99.80 ± 0.04%, −34 mV and 31.85 ± 0.24 mPas respectively. Surface characterization studies demonstrated a spherical shape of nanoemulsion which showed 3.7 times enhancement in drug permeation as compared to drug suspension. The results of behaviour studies showed that treatment of haloperidol induced Parkinson’s disease in rats with selegiline nanoemulsion (administered intranasally) showed significant improvement in behavioural activities in comparison to orally administered drug. These findings demonstrate that nanoemulsion could be a promising new drug delivery carrier for intranasal delivery of selegiline in the treatment of Parkinson’s disease.

Wound healing effects of nanoemulsion containing clove essential oil

The aim of this study was to investigate the wound healing effects of clove oil (CO) via its encapsulation into nanoemulsion. Optimized nanoemulsion (droplet size of 29.10 nm) was selected for wound healing investigation, collagen determination, and histopathological examination in rats. Optimized nanoemulsion presented significant would healing effects in rats as compared to pure CO. Nanoemulsion also presented significant enhancement in leucine content (0.61 mg/g) as compared to pure CO (0.50 mg/g) and negative control (0.31 mg/g). Histopathology of nanoemulsion treated rats showed no signs of inflammatory cells. These results suggested that nanoemulsion of CO was safe and nontoxic.

Exotic Vegetable Oils for Cosmetic O/W Nanoemulsions: In Vivo Evaluation.

Oil-in-water nanoemulsions are stable systems with droplet sizes in the 20–200 nm range. The physicochemical properties of these systems may be influenced by the addition of additives. Thus, the influence of ethoxylated (EL) and acetylated lanolin (AL) addition on the droplet size, pH values, electrical conductivity and stability of nanoemulsions was investigated. Then, effect of nano-emulsions additives with EL (NE-EL) or AL (NE-AL) in hydration, oiliness and pH of the skin were evaluated. Nanoemulsion safety was evaluated through the observation of no undesirable effects after skin formulation application. Both additives caused changes in droplet size and electrical conductivity, but not in pH values. Nanoemulsions containing up to 6.0% ethoxylated lanolin and 2.0% acetylated lanolin remained stable after centrifugation tests. Higher concentrations of the additives made the nanoemulsions unstable. Stability tests showed that ethoxylated lanolin produced more stable nanoemulsions then acetylated lanolin and that the major instability phenomenon occurring in these systems is coalescence at elevated temperatures. Nanoemulsion-based lanolin derivatives increased skin hydration and oiliness and did not change cutaneous pH values. These formulations are non-toxic since they did not cause any irritation on the skin surface after nanoemulsion application, showing potential as carriers for pharmaceuticals and cosmetic applications.

Formulation and characterization of self-nanoemulsifying drug delivery systems containing monoacyl phosphatidylcholine

The study investigated the use of monoacyl phosphatidylcholine (MAPC) in self-nanoemulsifying drug delivery system (SNEDDS). A D-optimal design was used to generate two sets of formulations containing long-chain (LC) or medium-chain (MC) glycerides, caprylocaproyl macrogol-8 glycerides (Labrasol), Lipoid S LPC 80 (LPC) (80% MAPC) and ethanol. The formulations were characterized using dynamic light scattering, microscopy, in vitro lipolysis and viscometric measurements. All LC formulations within the investigated range were predicted to generate polydisperse emulsions while MC formulations generated nanoemulsions with droplet sizes from 23 to 167nm. Using LPC in MC formulations reduced the nanoemulsion droplet sizes in simulated gastric and intestinal media. The nanoemulsion droplet size of MC SNEDDS containing LPC was not affected by gastrointestinal pH, while the zeta potentials increased at low pH. During in vitro lipolysis, less fatty acids were released when LPC was incorporated into the formulations (2.05±0.02mmol reduced to 1.76±0.05mmol when incorporating 30% LPC). Replacing Labrasol by LPC increased the formulation dynamic viscosity from 57±1mPas (0% LPC) to 436±8mPas (35% LPC) at 25°C, however, this did not considerably prolong the formulation dispersion time. In conclusion, MC SNEDDS containing LPC are promising formulations when desiring to reduce the amount of synthetic surfactants and possibly modify the digestion rate.