Oil Microemulsion Research Articles

Microemulsion of Medicago marina Essential Oil: In Vitro Evaluation of Antimicrobial, Antibiofilm, Anticoagulant Effects, and In Silico Studies Involving Molecular Docking and ADME Prediction

This work characterizes microemulsions of Medicago marina essential oil and evaluates their antimicrobial, antibiofilm, and anticoagulant effects. Medicago marina L. aerial parts essential oil was hydro-distilled and analyzed by gas chromatography-FID and gas chromatography/mass spectrometry (GC/MS) for the first time from the Tunisian chemotype. The microemulsion was prepared using an oil/water formulation with a biopolymer (Arabic gum) and surfactant (Tween 20). Antibacterial and antifungal activities were evaluated using the microbroth dilution method, while anticoagulant activity was tested in vitro using prothrombin time (PT) and aPTT tests. Eventually, the binding affinities and molecule’s interactions of the main chemicals with the operational locations of C (30) carotenoid dehydrosqualene synthase and cytidine deaminase were explored. The essential oil contained 71 compounds of which 87.6% were identified. Major compounds were [Formula: see text]-ionone (17.67%), 1-methyleugenol (10.75%), eugenol (8.86%), [Formula: see text]-damascenone (4.33%), and [Formula: see text]-humulene (4.32%). A microemulsion with a diameter of 1.63 [Formula: see text] m, a polydispersity index of 0.17, a zeta potential of –40.8 mV and a pH of 6 was obtained and it showed the highest antibacterial potential against a multitude of microbes, with low MICs varying between 0.406 mg/mL and 3.25 mg/mL. Significant antibiofilm activity was observed with over 80% inhibition at 4 × MIC concentration. It showed better anticoagulant activity than heparin, with PT and aPTT values of 19.5 s and 57 s, respectively, at 10 mg/mL. Molecular docking showed that “([Formula: see text]-[Formula: see text]-ionone” had the highest binding scores. Notable pharmacokinetic and drug-like qualities were found in the obtained molecules after establishing ADME profiling. As a result, Medicago marina L. Essential oil microemulsion can be used in food processing as a preservative.

Antimicrobial and acaricide sanitizer tablets produced by wet granulation of spray-dried soap and clove oil-loaded microemulsion

A novel sanitizer tablet containing clove essential oil (CO) microemulsion was developed. A preformulation study using nuclear magnetic resonance and thermal analyses showed component compatibility. The main components of the samples remained intact despite a color change, probably due to a strong acid-base interaction between eugenol and diethanolamine. The CO microemulsion showed acaricidal and larvicidal activities superior to the commercial product, with product efficacy of 99.9% and larvae mortality of 94%. Optimal spray-drying conditions were achieved with inlet and outlet temperatures of 50°C and 40°C, respectively, an aspiration rate of 1 m3 min⁻1, and a 0.25 L h⁻1 injection flow. The feed suspension comprised 50% (v/v) liquid soap, 37.5% (v/v) water, 12.5% (v/v) ethanol, and 5.0% (w/v) silica. This formulation and processing parameters allowed for successful free-flow powder formation, providing a suitable matrix for incorporating the CO microemulsion via wet granulation without heating. Finally, sanitizer tablets produced from such granules resulted in a uniform product with low weight variation (coefficient of variation of 0.15%), eugenol content of 95.5% ± 3.3, and friability of 0.58%. Furthermore, the tablets showed rapid aqueous dispersion, forming a colloidal system with particle sizes of 221 nm and a zeta potential of -17.2 mV. Antimicrobial activity tests demonstrated the effectiveness of the sanitizer tablet against bacteria and fungi, exhibiting comparable antimicrobial potency to isolated CO. Hence, the sanitizer tablet developed represents a promising candidate as a practical and efficient solution for pest control, offering strong antimicrobial and acaricidal activity.

Microemulsion containing Kaffir lime oil using photo-crosslinkable bio-based copolymer

The research aimed to prepare a microemulsion of Kaffir lime oil (KLO) using photocrosslinkable bio-based copolymers as polymer shells. First, cinnamyl alcohol was used as a biomonomer, which was functionalized with methacrylic anhydride via an esterification reaction to contain a double bond named cinnamyl methacrylate. Then, it was copolymerized with methacrylic acid by solution iodine transfer polymerization, resulting in polymethacrylic acid-block-polycinnamyl methacrylate-block-poly methacrylic acid (PMAA-b-PCMA-b-PMAA) with a molecular weight of 2700 g/mol and a chain length of PMAA-b-PCMA-b-PMAA equals 7: 6: 7 units. After that, PMAA-b-PCMA-b-PMAA (BioSurf) was used as the polymer shell to encapsulate KLO in a microemulsion system cooperative with Tween 80 (surfactant; Surf) and ethanol (co-surfactant; CoSurf). The ratio of kaffir lime oil: Surf-CoSurf was varied from 1: 9 to 9: 1 (wt) where Surfmix was BioSurf: Surf: Co-Surf ratio of 1: 1: 1 (wt) dispersed in water at 400 rpm for 5 min. The optimal contents of oil, Surfmix, and water were 6 %, 24 %, and 70 %, respectively, with the nanocapsule size at about 68 nm. After UV curing at 254 nm for 120 min, the dimerization of cinnamyl groups in PCMA was confirmed by UV spectroscopy, where the absorbance peaks of cinnamyl groups at 283 and 294 nm significantly decreased. The encapsulated KLO was slowly permeating skin which was only 10 % after 1 h, with the anti-inflammatory percentage of inhibited nitric oxide production in macrophage cells at 19.24 ± 1.63. Moreover, nanocapsules did not show toxicity to human skin cells at concentrations less than or equal to 1 v/v%. Moreover, the microemulsion is thermodynamically stable at 4 °C, 30 °C, and 45 °C. The encapsulation of KLO in microemulsion might be an alternative candidate for cosmetic products and related applications.

DES/O microemulsion for solubilizing and delivering curcumin via the nasal administration to treat acute asthma

As a natural small molecule drug derived from turmeric, curcumin is known for its good biosafety and a range of beneficial effects, including anti-inflammatory, anti-spasmodic, antioxidant, antibacterial, anti-tumor, and neuroprotective effects. Even though, its insolubility in water and instability severely limit its bioavailability and clinical applications. The present study developed a deep eutectic solvent (DES) in oil microemulsion (DES/O-ME) system loaded with Cur for intranasal administration, aiming to enhance both the solubility and permeability of Cur to significantly increase its bioavailability. The project first constructed and screened the optimal choline chloride-based DES. Subsequently, the DES/O-ME system was prepared and optimized to achieve uniform particle size and stability using a pseudo-ternary phase diagram and electrical conductivity measurements. The resulting DES/O-ME system was thoroughly evaluated for its solubilization efficacy, permeability, mucosal cytotoxicity, and stability. Additionally, the therapeutic efficacy of the Cur-DES/O-ME was assessed in vivo using a murine model of allergic asthma. This comprehensive evaluation highlights the potential of the DES/O-ME system as a promising intranasal drug delivery platform to overcome the limitations of curcumin’s bioavailability and clinical application.

Effect of chitosan films containing clove essential oil-loaded microemulsions combined with deep learning on pork preservation and freshness monitoring

In this study, chitosan (CS) films with different concentrations of clove essential oil (CEO) microemulsions were prepared. The composite film with a 0.8% microemulsion concentration exhibited the highest DPPH free radical clearance (77.44 ± 1.10%). When applied to six types of pork with different n-3 polyunsaturated fatty acid (PUFA) content stored at 4 °C, the composite films with 0.6% and 0.8% CEO microemulsions effectively preserved the pork and extended its shelf life by 9 days. Additionally, the deep-learning model successfully monitored the freshness levels of different n-3 pork samples. The CS/CEO microemulsion composite films, in conjunction with deep learning, demonstrate significant potential for pork preservation and freshness monitoring.

Studies on the Preparation of a Microemulsion Formulation of Matricaria Recutita Essential Oil and the Treatment of 2,4-Dinitro-Chlorobenzene- Induced Eczema in Mice by Inhibiting Inflammation.

Eczema, an inflammatory skin disease causing intense itching, is a function of a range of internal and external factors, impacting individuals of all ages and leading to economic loss. Inflammation is the most important manifestation of eczema, and Matricaria recutita essential oil (MREO) extracted from Matricaria recutita possesses excellent antibacterial and anti-inflammatory properties. In this study, Matricaria recutita microemulsions were prepared by the trans-phase emulsification method and their stability was determined by evaluating the relevant indexes. Establishment of 2,4-dinitro-chlorobenzene-induced AD model in mice. Detection of serum indexes of IL-6, IL-17, and TNF-α, and on pathological tissue sections, the HE staining, toluidine blue staining, immunohistochemistry, and observation were performed. The study obtained optimal conditions for the preparation of microemulsion formulations of Matricaria recutita. Through quality evaluation, it was found that the microemulsion increased stability, reduced irritation, and retained anti-inflammatory activity and therapeutic effects on eczema compared to Matricaria recutita essential oil (MREO). Studies have demonstrated that microemulsion formulations of Matricaria recutita and Matricaria recutita significantly down regulate the proinflammatory factors TNF-α, IL-17, and IL-6. It was shown by hematoxylin-eosin (HE) staining that both Matricaria recutita essential oil (MREO) and Matricaria recutita microemulsion (MRME) improved the inflammatory status of eczematous skin tissues in mice. The number of mast cells expressed in the tissues was decreased in the surface-treated group, as shown by toluidine blue staining. Additionally, the number of mast cells expressed in the tissues in the surface-treated group was reduced, as demonstrated by immunohistochemistry. Furthermore, immunohistochemistry revealed that MREO and MRME have immunomodulatory effects on the tissues. The study showed that microemulsion formulations of Matricaria recutita may serve as a novel remedy for eczema.

Propellant-free foam formulation with tamanu oil microemulsion and nanocurcumin for enhanced burn healing

Several commercial topical formulations are currently available to treat burns, including ointments, gels, and creams. However, these options come with a major drawback as they require a strong dispersing force to apply the drug to large areas of the skin, which can cause pain and discomfort to already sensitive burns. Conversely, foam is a soft, porous, easy-to-spread dosage form that does not require direct contact with the wound, making it an excellent option for treating sensitive, painful, and extensive burns. In this study, we aimed to develop a novel non-propellent foamed microemulsion-based system of tamanu oil and nanocurcumin for effective, safe, and fast-acting treatment of burns. We successfully formulated a stable and homogeneous microemulsion containing tamanu oil, nanocurcumin, and Labrasol/Plurol Oleique CC 497 (6:1) as surfactant/cosurfactant. The final formulation resulted in a stable, transparent, pale-yellow, and homogeneous microemulsion with a pH value of 5.05 and a density of 1.01 g/cm3. The foam generated by the non-propellent foam dispenser had a density of 0.08 g/cm3 and the foam completely broke after 30 min. In the third-degree burn mice model, the percentage of wound area reduction after 21 days of treatment was 86.67 ± 2.89% for the novel non-propellent foamed system, which was comparable to Silvirin cream (positive control) and significantly higher than saline (negative control). We believe that our propellant-free foam containing tamanu oil and nanocurcumin exhibits a promising candidate for wound healing, especially burn injuries.

Preparation of preservation paper containing essential oil microemulsion and its application in maintain the quality of post-harvest peaches

Post-harvest peaches are highly susceptible to fungal infections leading to spoilage. This study investigates the utilization of three edible plant essential oils (EOs) with antifungal properties for the preservation of peaches, along with an evaluation of their preservative efficacy. Initially, GC-MS was employed to identify the primary constituents of the EOs, revealing a predominance of phenols, alcohols, hydrocarbons and aldehydes. Principal component analysis was conducted to compare the chemical compositions of the EOs from the plants used in this study with those obtained from other regions. This analysis facilitates the quality assessment of the plant materials in the later stages of the research. In vitro antimicrobial assays indicated that the three EOs independently exhibited their respective antifungal activities against 7 fungi responsible for peach spoilage. The Response Surface Methodology was then applied to optimize the blend ratio of the composite EOs (CEOs) for maximum antifungal efficacy. Concurrently, this study validated the rationality of a second-order polynomial model that correlates the peach decay index with the concentration of the CEOs. To enhance the bioavailability of the CEOs, a pseudo-ternary phase diagram was employed to formulate the CEOs into a microemulsion. Based on the RSM optimization results for the CEOs, the optimal mass ratio of the components within the microemulsion was determined. Using this microemulsion as a base, preservative films were developed that demonstrated a significant preservation effect on peaches, highlighting the immense potential of this research in the food industry.

Rhamnolipids stabilized essential oils microemulsion for antimicrobial and fruit preservation

Essential oils, well-known for their antifungal properties, are widely utilized to combat fruit decay. However, their application faces big challenges due to their high volatility and hydrophobic traits, which leads to strong odor, short effective time and poor dispersivity. This study aimed to address these challenges by formulating microemulsions consisting of essential oils and rhamnolipids. The optimized microemulsion, featuring a small particle size of 6.8 nm, exhibited higher stability and lower volatility than conventional emulsion. Notably, the prepared microemulsions demonstrated remarkable antimicrobial efficacy against E. coli, S. aureus, C. albicans, S. cerevisiae, and A. niger. The application of these microemulsions proved to be highly effective in preventing blueberry decay while preserving fruit's quality, particularly by minimizing the loss of essential nutrients such as anthocyanins. Consequently, essential oil microemulsions emerge as a highly effective postharvest preservative for fruits, offering a promising solution to extend their shelf life and enhance overall quality.

Development and Characterization of a Microemulsion Containing a Cannabidiol Oil and a Hydrophilic Extract from Sambucus ebulus for Topical Administration.

Cannabidiol (CBD) is a safe and non-psychotropic phytocannabinoid with a wide range of potential therapeutic anti-inflamatory and antioxidant activities. Due to its lipophilicity, it is normally available dissolved in oily phases. The main aim of this work was to develop and characterize a new formulation of a microemulsion with potential anti-inflammatory and antioxidant activity for the topical treatment of inflammatory skin disorders. The microemulsion system was composed of a 20% CBD oil, which served as the hydrophobic phase; Labrasol/Plurol Oleique (1:1), which served as surfactant and cosurfactant (S/CoS), respectively; and an aqueous vegetal extract obtained from Sambucus ebulus L. (S. ebulus) ripe fruits, which has potential anti-oxidant and anti-inflammatory activity and which served as the aqueous phase. A pseudo-ternary phase diagram was generated, leading to the selection of an optimal proportion of 62% (S/CoS), 27% CBD oil and 11% water and, after its reproducibility was tested, the aqueous phases were replaced by the vegetal hydrophilic extract. The defined systems were characterized in terms of conductivity, droplet size (by laser scattering), compatibility of components (by differential scanning calorimetry) and rheological properties (using a rotational rheometer). The designed microemulsion showed good stability and slight pseudo-plastic behavior. The release properties of CBD from the oil phase and caffeic acid from the aqueous phase of the microemulsion were studied via in vitro diffusion experiments using flow-through diffusion cells and were compared to those of a CBD oil and a microemulsion containing only CBD as an active substance. It was found that the inclusion of the original oil in microemulsions did not result in a significant modification of the release of CBD, suggesting the possibility of including hydrophilic active compounds in the formulation and establishing an interesting strategy for the development of future formulations.

Water in nigella oil microemulsion for enhanced oral bioavailability of linagliptin.

Linagliptin is hydrophilic antidiabetic with poor oral bioavailability due to poor permeability and pre-systemic metabolism. The objective was to assess w/o microemulsion for enhanced oral bioavailability of linagliptin. Nigella oil was used as oily phase based on its reported antidiabetic effect. Isopropyl myristate (IPM) or capryol were combined with nigella oil to impart intestinal membrane permeabilizing abilities. Pseudoternary phase diagrams were constructed utilizing nigella oil in presence and absence of isopropyl myristate or capryol as oily phase using Tween 60 as surfactant. W/O microemulsion formulations were selected from the constructed phase diagrams and linagliptin was loaded in the internal aqueous phase at a concentration of 0.5mg/ml. The prepared formulations were physically evaluated and linagliptin in vitro release was monitored. Eventually, the in vivo hypoglycemic effect was assessed using diabetic rats. The developed microemulsions were of w/o type and exhibited Newtonian flow behavior with nigella/capryol microemulsion recording the lowest viscosity. The recorded droplet size values were 104.9, 121.2 and 86.4nm for nigella, nigella/IPM and nigella/capryol microemulsions, respectively. All microemulsion formulations showed slower drug release rate compared with aqueous suspension with nigella/capryol microemulsion showing the highest release rate compared to other microemulsions. Release data from microemulsion best fitted to Higuchi model. In vivo oral hypoglycemic activity measurement reflected a more intensified hypoglycemic effect with rapid onset after oral ingestion of microemulsion compared to linagliptin dispersion. Nigella oil/IPM-based microemulsion was ranked as the most effective. The investigation highlighted the feasibility of w/o microemulsion for enhanced oral bioavailability of hydrophilic drugs like linagliptin.

Blends of Salvinia molesta oil microemulsion with diesel in an unmodified diesel engine for the simultaneous reduction of nitrogen oxide and smoke

In this study, microemulsion synthesized from chemically extracted Salvinia molesta oil with diesel was evaluated as fuel in stationary unmodified diesel engine. The microemulsions from S. molesta oil was prepared using the best combinations of 67% S. molesta oil, 15% ethanol, 13% water and 5% surfactant (span 80) and its properties were compared with that of diesel. The engine test conducted with M10, M20 and M30 blends and reported a brake thermal efficiency of 29.76% and brake specific fuel consumption of 0.3239 kg/kWh with M20. The emissions like NO and smoke reduced by 18.07% and 7.37%, respectively, with marginal increase in CO, CO2 and unburned hydrocarbon by 3.8%, 3.4% and 16.66% respectively, with M20 compared to diesel at maximum engine load of 3.73 kW. At lower engine loads with M10, M20 and M30 slightly lower CO2 emission than diesel. A drop in peak pressure and heat release rate was found to be 1.73% and 8.40%, correspondingly with M20, as that of diesel. Even though a slight reduction in brake thermal efficiency observed with M20 as compared to M10 and diesel by considering the lowest emissions of NO and smoke, it is feasible to use as promising fuel for unmodified diesel engines.

Properties of an active film based on chitosan/silk fibroin loaded with an essential oil microemulsion and its application in preservation of strawberries

This study aimed to enhance the weak antibacterial activity of silk fibroin (SF) by creating a composite edible coating film. The film was composed of chitosan (CS), SF, and a 3% (v/v) cinnamon essential oil microemulsion (CEOM), which showed excellent inhibition rates of over 99% against two bacteria and four fungi. The resulting film had a transparency of 84.6% and a contact angle of 61.85° on hydrophobic surfaces. In addition, it exhibited a low water vapor permeability of 1.09 × 10−12 g·cm−1·s−1·Pa−1. These properties make it ideal for use in food coating applications. To assess the preservation capabilities of the composite films, strawberries were coated with different films: CS, SF, SF-CEOM, and SF-CS-CEOM. The results showed that the SF-CS-CEOM film had a similar effect to the SF-CEOM film in suppressing the deterioration of strawberries, when compared to the untreated group, and the shelf life of the strawberries was extended from 2 days to 8 days. The SF-CS-CEOM film inhibits oxidation and metabolism by reducing gas exchange, thereby protecting the integrity of cell membranes, maintaining firmness, and reducing weight loss, while delaying the onset of spoilage by inhibiting microbial growth.

Preparation and physicochemical evaluation of phytosterol‐enriched sesame oil microemulsions

AbstractSesame oil, known for its nutritional benefits, was selected as source for phytosterol extraction. Optimal conditions of 40°C, oil‐to‐solvent ratio of 1:25, and a saponification duration of 150 min were employed to separate the phytosterols from sesame oil. The extracted phytosterols were encapsulated using microemulsion method. Various variables, such as percent of sesame oil, surfactant‐to‐cosurfactant ratio, and presence of phytosterols, were evaluated to determine their impact on particle size, polydispersity, pH, viscosity, surface tension, and stability. The particle size and PDI demonstrated significant increase with increasing oil and addition of phytosterols. A higher S:C ratio resulted in the formation of smaller microemulsion droplets. The viscosity and surface tension of the microemulsions increased significantly with an increase in the oil percent. In conclusion, the optimal composition of the microemulsion was found to be 10 wt% sesame oil with an S:C ratio of 3:1. FESEM micrographs revealed a microstructure consisting of cylindrical micelles.Practical applicationsResearch has shown that consuming 2–3 g of plant sterols and stanols can lower blood cholesterol levels by 10% and LDL levels by 15%. However, incorporating phytosterols into food products is challenging due to oxidation, insolubility, and high melting point. Most phytosterols are esterified to enrich low‐fat foods but they can be expensive and impure. The synthesis of phytosterols often involves carcinogenic chemicals and requires additional purification. Extracting phytosterols from plant sources has been proposed as a solution. However, incorporating phytosterols into food products is challenging due to their susceptibility to oxidation, particularly during processing and storage at high temperatures, their insolubility in water, and their limited solubility in fats and oils. The main aim of this study was to enrich sesame oil microemulsions with phytosterols through encapsulation. Phytosterols were extracted from sesame seed oil, followed by purification, and finally, enriched microemulsions were prepared. The optimal formulation was determined based on the evaluation of several parameters, including the mean volume diameter of particles, polydispersity index, pH, viscosity, surface tension, and physical stability.

Optimization of an onion oil microemulsion by response surface methodology for enhanced physicochemical stability and biological activity

Onion oil (OO) containing propyl-propane thiosulfinate (PTS) and propyl-propane thiosulfonate (PTSO) is known for various therapeutic properties. However, its industrial use in hydrophilic matrices is challenging due to the lack of physicochemical stability. Applying Box-Behnken design (BBD), we developed an optimal OO microemulsion (OOME) with a minimum droplet size and maximum chemical stability. The OOME comprised 2 % w/w oily phase (high oleic acid sunflower oil), 120 mg/L of OO containing PTS+PTSO, 1.47 % w/w emulsifier (Diacetyl tartaric acid ester of mono-diglycerides, DATEM), 0.25 % stabilizer (xanthan gum) and 573 mM phosphate buffer. Turbidimetry as well as laser and dynamic light scattering over 30 days was used to characterize physical stability of the OOME, assessing chemical stability by HPLC. Cytotoxicity and quantification of cytokines (IL-4 and IL-8) were evaluated in colorectal cancer cells (HT-29, T-84 and SW-837) culture supernatants. After 30 days of storage, OOME remained stable, with no flocculation or coalescence phenomena. It achieved a PTS+PTSO amount of 98 mg/L, a droplet size of 329 nm, a particle size dispersal coefficient of 0.89, and Z-potential was −40.17 mV. The OOME improved the antitumor effect of OO in lines HT-29 and SW-837, as well as its influence on the inflammatory response.

Curcumin Encapsulation in Geranium Oil Microemulsion Elevates Its Antibacterial, Antioxidant, Anti-Inflammatory, and Anticancer Activities.

One of the major challenges with curcumin is its poor solubility in water, which limits its absorption and bioavailability in the body. This study aimed to develop and characterize stable microemulsions (MEs) as MEs increase the dispersibility of curcumin in water and aid its absorption in the body. Curcumin-loaded MEs were developed with the goal of enhancing topical delivery and its pharmacological activity (antioxidant, antibacterial, anticancer activity, and anti-inflammatory). The pseudoternary phase diagram was constructed to find out the desired microemulsion region. The prepared MEs (ME1-ME5) were evaluated for pH, viscosity, size of the particle, electrical conductivity, zeta potential, and ex vivo permeation of the drug. The optimized ME formulation was selected based on particle size and was further evaluated for biological activity (in vitro/vivo). In vitro cytotoxic effects of formulations were checked on the human liver cancer cell line, HEPG2 (a cell line exhibiting epithelial-like morphology that was isolated from a hepatocellular carcinoma). Geranium oil, Tween 80 (as a surfactant), and propylene glycol (as a cosurfactant) were screened out based on solubility to formulate MEs. The optimized ME formulation (ME5), with a composition of 20:50:30 (geranium oil:Tween 80:propylene glycol), exhibited pH 4.36 ± 0.057, conductivity of 40.06 ± 0.05 μS/cm, viscosity of 165 ± 0.37 mPa·s, and droplet diameter of 199.39 ± 0.017 nm. The ex vivo permeation study demonstrated a significant cumulative amount of curcumin permeated in 24 h and had a flux of 130.91 ± 0.02 μg/cm2/h. Antioxidant activity demonstrated that curcumin-loaded microemulsion (ME5) exhibited higher scavenging activity (99.27 ± 0.021%) than blank microemulsion (94.67 ± 0.001%). Optimized curcumin-loaded microemulsion (ME5) exhibited zones of inhibition of 25.18 and 28.37 mm against Escherichia coli and Staphylococcus aureus, respectively. Among the cell lines tested, a higher concentration of ME5 showed the greatest cytotoxicity with a % viability of 8.22 ± 1.09%. Evidently, it also revealed significant in vivo anti-inflammatory effects with 93.29 ± 0.030% inhibition by the carrageenan-induced paw edema model (6 h study) and 88.39 ± 0.002% inhibition by the formalin-induced paw edema model (14 day study). In conclusion, microemulsion was safe and effective for effective delivery of curcumin with the potential for antioxidant, antibacterial, cytotoxic, and in vivo anti-inflammatory activities.

A Bibliometric approach for Analyzing the Potential Essential Oil Microemulsions

Essential oils are bioactive compounds consisting of various pharmacological or therapeutic activities capable of causing changes in color and odor with unstable characteristics. Several studies have been conducted to overcome these problems by developing essential oil into microemulsion dosage forms. However, none have been conducted to identify the trends and patterns quantitatively through a collection of research publication documents. Therefore, this study identified the developments and areas of focus on essential oil microemulsions using bibliometric methods. Data was collected from PubMed from 2000 to 2021 and analyzed using R-studio and VOSviewer software. The results showed that 2020 had the largest number of publications, with 114 documents widely published in China. The most productive author, Oknologi S, used the keywords “Essential oils” and “microemulsions” 47 and 21 times, respectively. The trend of publications related to essential oil microemulsions is expected to increase with its continuous development.

Microemulsion of essential oil of Citrus aurantium var. dulcis for control of Aleurocanthus woglumi and evaluation of selectivity against Aschersonia aleyrodis and Ceraeochrysa cornuta

The aim of this study was to develop a microemulsion from the essential oil of Citrus aurantium var. dulcis (EOCA) as an alternative to synthetic pesticides, and to evaluate its efficacy against Aleurocanthus woglumi and selectivity towards the natural enemies Aschersonia aleyrodis and Ceraeochrysa cornuta. Chemical composition of the essential oil determined by gas chromatography coupled with mass spectrometry revealed limonene, myrcene, linalool and α-pinene as major components. The microemulsion was prepared using a ternary diagram illustrating the composition of water, essential oil, surfactant (procetyl AWS) and co-surfactant (ethanol). Selected microemulsions were characterized by polarized light microscopy, revealing to be isotropic with a Newtonian behaviour when measuring the shear stress against shear rate. The mean droplet size of microemulsions ranged from 53.69 nm to 2.22 μm. The insecticidal activity was evaluated by assessing three application routes, namely, contact, systemic and translaminar. Selectivity of microemulsions was determined by the percentage of growth inhibition (PGI) of fungi on A. aleyrodis and by contact on eggs and larvae of C. cornuta. The oil (LC50 = 36.07 mg/mL) in its pure form had a lower insecticidal effect on A. woglumi than the microemulsions (LC50 = 18.65 mg/mL). The microemulsions showed systemic insecticidal activity with approximately 90% mortality at 72 h (LC90 = 55.50 mg/mL). On A. aleyrodis, the microemulsion interfered with biomass production, which was concentration dependent. At a concentration of 15.68 mg/mL, a 91% inhibition of biomass production were observed. In the selectivity experiments against C. cornuta, the microemulsions were selective for eggs and larvae, and did not interfere with its predatory capacity.

Functional efficacy of tempeh oil microemulsion containing omega 3 for Alzheimer’s protection

Alzheimer’s disease (AD) is associated with ageing symptoms due to stress oxidative, neuroinflammation, acetylcholinesterase and butyrylcholinesterase activation, and Tau hyperphosphorylation. Tempeh has been recognized as one of the Indonesian traditional fermented foods made from soybean fermentation with a microbial consortium. Our previous study demonstrated that tempeh oil contains polyunsaturated fatty acids (PUFAs) and antioxidants for ageing prevention. Tempeh oil rich in PUFAs may be developed as a modern functional supplement for AD protection. This study aimed to extract tempeh oil, formulate a tempeh oil microemulsion supplement, and determine its functional efficacy towards Alzheimer's protection via AD-related enzymatic inhibition, antioxidant capability, and AD-related gene regulation in Schwann neuronal cell model in vitro. Tempeh oil microemulsion contained omega 3 and exerted acetylcholinesterase inhibitory and antioxidant activities. Tempeh oil microemulsion also had the capability of gene regulation related to AD in the lipopolysaccharide-induced Schwann neuronal cells model. These findings indicated that tempeh oil microemulsion effectively suppressed the gene expression of BACE, APP, and TNF-α, and increased the NTrK and BDNF gene expression in Schwann neuronal cells induced by lipopolysaccharide. Therefore, tempeh oil microemulsion containing omega 3 could be offered as an alternative modern functional food supplement for ageing protection in particular AD.

Application possibilities of triple-layer furcellaran film with hazelnut oil microemulsion for packing cod liver oil

Triple-layer films based on furcellaran were successfully produced, where the middle layer was enriched with a hazelnut oil microemulsion. SEM images showed good embedding of the emulsion in the furcellaran layer. The addition of microemulsions significantly decreased the thermal and mechanical properties of the films, where the tensile strength values decreased, while the elasticity values of the film were improved. The presence of the emulsion increased the hydrophilicity of the film surface. The developed films in the form of sachets were used for packaging and storing cod liver oil. Fish oil was stored in refrigerated conditions without access to light and at room temperature (22 °C ± 1 °C) with access to light for 3 months. The acid (AV), iodine (IV) and peroxide values (PV), as well as the profile of fatty acids, were determined for the cod liver oil samples. It was shown that the cod liver oil samples had a similar value of the acid number during storage, however, over time, the IV and PV values increased statistically significantly, which indicates the ongoing process of fat rancidity. Furthermore, 23 compounds were identified in the fatty acid profile. It was shown that the profile of fatty acids in the stored fish oil changed, and the direction of these changes varied and generally, significantly depended on the film type and conditions in which the fat was stored. This study shows the possibility to obtain biodegradable packaging based on furcellaran enriched with a hazelnut oil microemulsion but also underline how important it is to check the presented packaging material in terms of its potential application.