Ovarian Accumulation of Nanoemulsions: Impact of Mice Age and Particle Size.

Nanotechnology in the field of drug delivery comes with great benefits due to the unique physicochemical properties of newly developed nanocarriers. However, they may come as well with severe toxicological side effects because of unwanted accumulation in organs outside of their targeted site of actions. Several studies showed an unintended accumulation of various nanocarriers in female sex organs, especially in the ovaries. Some led to inflammation, fibrosis, or decreasing follicle numbers. However, none of these studies investigated ovarian accumulation in context to both reproductive aging and particle size. Besides the influences of particle size, the biodistribution profile may be altered as well by reproductive aging because of reduced capacities of the reticuloendothelial system (RES), changes in sex steroid hormone levels as well as altering ovarian stromal blood flow. This systematic investigation of the biodistribution of intravenously (i.v) injected nanoemulsions revealed significant dependencies on the two parameters particle size and age starting from juvenile prepubescent to senescent mice. Using fluorescent in vivo and ex vivo imaging, prepubescent mice showed nearly no accumulation of nanoemulsion in their uteri and ovaries, but high accumulations in the organs of the RES liver and spleen independently of the particle size. In fertile adult mice, the accumulation increased significantly in the ovaries with an increased particle size of the nanoemulsions by nearly doubling the portion of the average radiant efficiency (PARE) to ~10% of the total measured signal of all excised organs. With reproductive aging and hence loss of fertility in senescent mice, the accumulation decreased again to moderate levels, again independently of the particle size. In conclusion, the ovarian accumulation of these nanocarriers depended on both the age plus the particle size during maturity.

Development, characterisation and efficacy evaluation of biochemical fungicidal formulations for postharvest control of anthracnose (Colletotrichum gloeosporioides Penz) disease in mango.

The objectives of the study are to develop and characterise formulations with volatile molecules in an emulsifiable concentrate form, for their antimicrobial properties and to evaluate their efficacies against Colletotrichum gloeosporioides Penz., to control anthracnose in mangoes after harvest. Results showed EC39 and EC40 among formulations were characterised for their excellent emulsification properties, the droplet size of 192.34 ± 0.48 nm and 227.4 ± 0.71 nm and Zeta potential of -52.5 ± 2.76 mv and -48.84 ± 2.62 mv, respectively, with better storage stability at 10 ± 20 °C and RH 80 ± 5%. In vitro assay, 100% inhibition of visual spore germination by 0.15% and 0.2% MIC value for EC39 and EC40, respectively Studies on the efficacy of their fungicide properties also indicated the IC50 value of 0.161% and 0.162% for EC39 and EC40 respectively for mycelial growth inhibition. In vivo testing too, EC39 and EC40 effectively controlled anthracnose incidence in mango in a dosage-dependent manner.

Determination of Mycoplasma hyopneumoniae-Specific IgG, IgG1, and IgG2a Titers in BALB/c Mice Induced by Mineral Oil-Based Oil-in-Water Emulsion Adjuvants Prepared Using a Self-Emulsifying Drug Delivery System.

We prepared mineral oil-based emulsion adjuvants by employing simple self-emulsifying drug delivery system (SEDDS). Mineral oil emulsions (3%, 5%, and 7%) were prepared using deionized water and C-971P NF and C-940 grade carbomer solutions with concentrations 0.01% (w/v) and 0.02% (w/v). In total, 15 emulsions were prepared and mixed with a solution containing inactivated Mycoplasma hyopneumoniae (J101 strain) antigen and porcine circovirus type 2 antigen to prepare vaccines. Droplet sizes in the submicron range and zeta potential values between - 40 and 0 mV were maintained by most emulsion adjuvants for a period of 6 months. Emulsion adjuvants were regarded safe, and their M. hyopneumoniae-specific IgG, IgG1, and IgG2a titers were either better or comparable to those of aluminum gel.

Evaluation of the efficacy and toxicity of massoia oil nanoemulsion.

In order to enhance essential oil's stability and water insolubility, Massoia aromatica oil nanoemulsion was formulated and tested on the planktonic growth and biofilm formation of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans; macrophage phagocytosis and on Vero cells viability. Oil in water nanoemulsion formula was optimized by using several solvents and co-solvents composition. The stability test of the formula was conducted by using a six cycle's freeze-thaw technique. Particle size and morphology were analyzed using a particle size analyzer and transmission electron microscopy. Microbial growth, biofilm formation inhibition, and cytotoxicity assays were performed on the optimized formula by using micro dilution methods. Mice macrophage phagocytosis activities against latex and C. albicans in the presence of samples were evaluated. Massoia nanoemulsion was obtained as a transparent yellowish emulsion having 99.6-99.9% of transmittance; physically and chemically stable; showed stronger antibacterial and antibiofilm on P. aeruginosa and S. aureus, moderate to C. albicans; no significant different on phagocytic activities. The IC50 of massoia oil nanoemulsion and massoia oil towards Vero cells were 35.9µg/mL and 107.5µg/mL respectively. Massoia oil nanoemulsion can protect the stability and decreases the hydrophobicity of the oil, conserve the antimicrobial and immunomodulatory activities, but increases its cytotoxicity.

Pterodon emarginatus oleoresin-based nanoemulsion as a promising tool for Culex quinquefasciatus (Diptera: Culicidae) control.

BACKGROUND: Preparation of nanoformulations using natural products as bioactive substances is considered very promising for innovative larvicidal agents. On this context, oil in water nanoemulsions develop a main role, since they satisfactorily disperse poor-water soluble substances, such as herbal oils, in aqueous media. Pterodon emarginatus, popularly known as sucupira, has a promising bioactive oleoresin. However, to our knowledge, no previous studies were carried out to evaluate its potential against Culex quinquefasciatus, the main vector of the tropical neglected disease called lymphatic filariasis or elephantiasis. Thus, we aimed to investigate influence of different pairs of surfactants in nanoemulsion formation and investigate if a sucupira oleoresin-based nanoemulsion has promising larvicidal activity against this C. quinquefasciatus. We also evaluated morphological alteration, possible mechanism of insecticidal action and ecotoxicity of the nanoemulsion against a non-target organism. RESULTS: Among the different pairs of surfactants that were tested, nanoemulsions obtained with polysorbate 80/sorbitan monooleate and polysorbate 80/sorbitan trioleate presented smallest mean droplet size just afterwards preparation, respectively 151.0 ± 2.252 and 160.7 ± 1.493 nm. They presented high negative zeta potential values, low polydispersity index (<0.300) and did not present great alteration in mean droplet size and polydispersity index after 1 day of preparation. Overall, nanoemulsion prepared with polysorbate 80/sorbitan monooleate was considered more stable and was chosen for biological assays. It presented low LC50 value against larvae (34.75; 7.31-51.86 mg/L) after 48 h of treatment and some morphological alteration was observed. The nanoemulsion did not inhibit acetylcholinesterase of C. quinquefasciatus larvae. It was not toxic to green algae Chlorella vulgaris at low concentration (25 mg/L). CONCLUSIONS: Our results suggest that optimal nanoemulsions may be prepared with different surfactants using a low cost and low energy simple method. Moreover, this prototype proved to be effective against C. quinquefasciatus, being considered an ecofriendly novel nanoproduct that can be useful in integrated control programs of vector control.

Comparing in vivo biodistribution with radiolabeling and Franz cell permeation assay to validate the efficacy of both methodologies in the evaluation of nanoemulsions: a safety approach.

The Franz cells permeation assay has been performed for over 25 years. However, the advent of nanotechnology created a whole new world, especially with regard to topical products. In this new global scenario an increasing number of nanostructure-based delivery systems (NDSs) have emerged and a global warning relating to the safety of these NDSs is arising. This work studied the efficacy of the Franz cells assay, comparing it with the radiolabeling biodistribution test. For this purpose a formulation of sunscreen based on an NDS was developed and characterized. The results demonstrated both that the NDS did not present in vitro cytotoxicity and that the radiolabeling biodistribution test is more precise for the evaluation of NDS cosmetics than the Franz cells assay, since it detected the permeation of the NDS at a picogram order. Due to this fact, and considering all the concerns related to NDSs and nanoparticles in general, more precise methods must be used in order to guarantee the safe use of these new classes of products.

Novel POSS-PCU Nanocomposite Material as a Biocompatible Coating for Quantum Dots.

Quantum dots (QDs) are fluorescent nanoparticles with unique photophysical properties that enable them to potentially replace traditional organic dyes and fluorescent proteins in various bioimaging applications. However, the inherent toxicity of their cores based on cadmium salts limits their widespread biomedical use. We have developed a novel nanocomposite polymer emulsion based on polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) that can be used to coat quantum dots to nullify their toxicity and enhance photostability. Here we report the synthesis and characterization of a novel POSS-PCU nanocomposite polymer emulsion and describe its application for coating QDs for biological application. The polymer was synthesized by a process of emulsion polymerization and formed stable micelles of ∼33 nm in diameter. CdTe/CdS/ZnS QDs were efficiently stabilized by the polymer emulsion through encapsulation within the polymer micelles. Characterization studies showed no significant change in the unique photophysical properties of QDs after coating. The polymer was biocompatible to HepG2, HUVECs, and mouse skeletal muscle cells at 2.5% after 24 h exposure on in vitro testing. Polymer encapsulated QDs showed enhanced photostability on exposure to high degrees of UV irradiation and air as well as significantly reduced cytotoxicity on exposure to HepG2 cells at 30 µg/mL for 24 h. We have therefore concluded that the POSS-PCU polymer emulsion has the potential to make a biocompatible and photostable coating for QDs enabling a host of biomedical applications to take this technology to the next level.

Propofol (Diprivan®) and Intralipid® exacerbate insulin resistance in type-2 diabetic hearts by impairing GLUT4 trafficking.

BACKGROUND: The IV anesthetic, propofol, when administered as fat emulsion-based formulation (Diprivan) promotes insulin resistance, but the direct effects of propofol and its solvent, Intralipid, on cardiac insulin resistance are unknown. METHODS: Hearts of healthy and type-2 diabetic rats (generated by fructose feeding) were aerobically perfused for 60 minutes with 10 µM propofol in the formulation of Diprivan or an equivalent concentration of its solvent Intralipid (25 µM) ± insulin (100 mU•L). Glucose uptake, glycolysis, and glycogen metabolism were measured using [H]glucose. Activation of Akt, GSK3ß, AMPK, ERK1/2, p38MAPK, S6K1, JNK, protein kinase Cθ (PKCθ), and protein kinase CCßII (PKCßII) was determined using immunoblotting. GLUT4 trafficking and phosphorylations of insulin receptor substrate-1 (IRS-1) at Ser307(h312), Ser1100(h1101), and Tyr608(hTyr612) were measured. Mass spectrometry was used to determine acylcarnitines, phospholipids, and sphingolipids. RESULTS: Diprivan and Intralipid reduced insulin-induced glucose uptake and redirected glucose to glycogen stores in diabetic hearts. Reduced glucose uptake was accompanied by lower GLUT4 trafficking to the sarcolemma. Diprivan and Intralipid inactivated GSK3ß but activated AMPK and ERK1/2 in diabetic hearts. Only Diprivan increased phosphorylation of Akt(Ser473/Thr308) and translocated PKCθ and PKCßII to the sarcolemma in healthy hearts, whereas it activated S6K1 and p38MAPK and translocated PKCßII in diabetic hearts. Furthermore, only Diprivan phosphorylated IRS-1 at Ser1100(h1101) in healthy and diabetic hearts. JNK expression, phosphorylation of Ser307(h312) of IRS-1, and PKCθ expression and translocation were increased, whereas GLUT4 expression was reduced in insulin-treated diabetic hearts. Phosphatidylglycerol, phosphatidylethanolamine, and C18-sphingolipids accumulated in Diprivan-perfused and Intralipid-perfused diabetic hearts. CONCLUSIONS: Propofol and Intralipid promote insulin resistance predominantly in type-2 diabetic hearts.

Development and Evaluation of Nanoemulsions Containing Phthalocyanines for Use in Photodynamic Cancer Therapy.

This work reports the development of oil in water (o/w) nanoemulsions containing poly(ethylene oxide)-poly(propylene oxide) block copolymer surfactant for the formulation of a delivery system for endovenous zinc and chloroaluminum phthalocyanines. A solubility study suggested clove oil and its combination with ethanol as the best candidates for the oil phase composition. The nanoemulsions were obtained using a high-pressure homogenizer and analyzed for droplet size to determine their short- and long-term stability. Formulations containing 7 and 10% oil phase and 12% surfactant presented higher stability and allowed the incorporation of a bigger amount of phthalocyanines in the formulation. Rheological analyses showed the prevailing Newtonian behavior of the nanoemulsions. Studies of toxicity and phototoxicity determined that the nanoemulsions produced were capable of inhibiting the growth of adenocarcinoma tumor cells. The nanoemulsions proved to be a good alternative for use in photodynamic therapy.

Study on antimicrobial potential of neem oil nanoemulsion against Pseudomonas aeruginosa infection in Labeo rohita.

Presence of several biochemical constituents in neem makes it an efficient antimicrobial agent for pathogenic diseases. The current investigation was aimed to assess the therapeutic potential of neem nanoemulsion as a control measure for Pseudomonas aeruginosa infection in freshwater fish Labeo rohita. The median lethal concentration (LC50) for the neem oil and neem nanoemulsion was 73.9 and 160.3 mg/L, respectively. The biomarker enzymes of treated fish tissues showed a significant difference in the level of glutathione reductase, catalase, and lipid peroxidation in neem oil-treated samples than in neem nanoemulsion-treated samples at P<0.05. The results were corroborative with histopathology and ultrastructural analysis. The bacterial infection of P. aeruginosa treated using neem nanoemulsion was more effective in both in vitro and in vivo methods. Present findings suggest that neem-based nanoemulsion has negligible toxicity to Rohu fishes. This makes neem-based nanoemulsion as an efficient therapeutic agent against P. aeruginosa infection, leading to its possible usage in the aquaculture industry.

Development of an insecticidal nanoemulsion with Manilkara subsericea (Sapotaceae) extract.

BACKGROUND: Plants have been recognized as a good source of insecticidal agents, since they are able to produce their own defensives to insect attack. Moreover, there is a growing concern worldwide to develop pesticides with low impact to environment and non-target organisms. Hexane-soluble fraction from ethanolic crude extract from fruits of Manilkara subsericea and its triterpenes were considered active against a cotton pest (Dysdercus peruvianus). Several natural products with insecticidal activity have poor water solubility, including triterpenes, and nanotechnology has emerged as a good alternative to solve this main problem. On this context, the aim of the present study was to develop an insecticidal nanoemulsion containing apolar fraction from fruits of Manilkara subsericea. RESULTS: It was obtained a formulation constituted by 5% of oil (octyldodecyl myristate), 5% of surfactants (sorbitan monooleate/polysorbate 80), 5% of apolar fraction from M. subsericea and 85% of water. Analysis of mean droplet diameter (155.2 ± 3.8 nm) confirmed this formulation as a nanoemulsion. It was able to induce mortality in D. peruvianus. It was observed no effect against acetylcholinesterase or mortality in mice induced by the formulation, suggesting the safety of this nanoemulsion for non-target organisms. CONCLUSIONS: The present study suggests that the obtained O/A nanoemulsion may be useful to enhance water solubility of poor water soluble natural products with insecticidal activity, including the hexane-soluble fraction from ethanolic crude extract from fruits of Manilkara subsericea.

Castor oil and mineral oil nanoemulsion: development and compatibility with a soft contact lens.

CONTEXT: The non-invasive ophthalmic therapy has a drawback: low residence time in the eye socket. Nanoparticles and contact lenses have been studied as promising ocular drug delivery systems. OBJECTIVE: To develop a nanoemulsion and evaluate its compatibility with a soft contact lens as a potential strategy for ocular delivery. MATERIALS AND METHODS: The formulations were developed by spontaneous emulsification and fully characterized. Two drops of nanoemulsion were instilled on the surface of a commercial contact lens and its transparency was measured using a UV-Vis spectrophotometer. Before and after the instillation of the drops, the morphology (scanning electron microscopy - SEM) and ion permeability of the lenses were analyzed. RESULTS: The formulations had a mean particle size of 234 nm, polydispersity below 0.16, zeta potential of -8.56 ± 3.49 mV, slightly acid pH, viscosity ≈1.2 mPa s(-1) and spherical-shaped particles. Nanoemulsion was non-irritant (hen's egg test-chorioallantoic membrane), which was confirmed by the cytotoxicity studies in the SIRC cell cultures. After instillation, SEM analysis showed nanodroplets inside and on the surface of the lenses, although their transparency remained near 100%. No significant differences were found between lens ion permeability coefficients before and after instillation. CONCLUSIONS: Formulations presented appropriate physicochemical characteristics and suitability for ocular application. The contact lens remained transparent and ion-permeable after association with the formulation.

Lipid emulsions attenuate the inhibition of carnitine acylcarnitine translocase induced by toxic doses of local anesthetics in rat cardiomyoblasts.

The aim of this study was to examine the effects of lipid emulsions on carnitine palmitoyltransferase I (CPT-I), carnitine acylcarnitine translocase (CACT), carnitine palmitoyltransferase II (CPT-II), and the mitochondrial dysfunctions induced by toxic doses of local anesthetics in H9c2 rat cardiomyoblasts. The effects of local anesthetics and lipid emulsions on the activities of CPT-I, CACT, and CPT-II, and concentrations of local anesthetics were examined. The effects of lipid emulsions, N-acetyl-L-cysteine (NAC), and mitotempo on the bupivacaine-induced changes in cell viability, reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), and intracellular calcium levels were examined. CACT, without significantly altering CPT-I and CPT-II, was inhibited by toxic concentration of local anesthetics. The levobupivacaine- and bupivacaine-induced inhibition of CACT was attenuated by all concentrations of lipid emulsion, whereas the ropivacaine-induced inhibition of CACT was attenuated by medium and high concentrations of lipid emulsion. The concentration of levobupivacaine was slightly attenuated by lipid emulsion. The bupivacaine-induced increase of ROS and calcium and the bupivacaine-induced decrease of MMP were attenuated by ROS scavengers NAC and mitotempo, and the lipid emulsion. Collectively, these results suggested that the lipid emulsion attenuated the levobupivacaine-induced inhibition of CACT, probably through the lipid emulsion-mediated sequestration of levobupivacaine.

Biodegradable Poly(lactic acid) Stabilized Nanoemulsions for the Treatment of Multidrug-Resistant Bacterial Biofilms.

Biofilm infections caused by multidrug-resistant (MDR) bacteria are an urgent global health threat. Incorporation of natural essential oils into biodegradable oil-in-water cross-linked polymeric nanoemulsions (X-NEs) provides effective eradication of MDR bacterial biofilms. The X-NE platform combines the degradability of functionalized poly(lactic acid) polymers with the antimicrobial activity of carvacrol (from oregano oil). These X-NEs exhibited effective penetration and killing of biofilms formed by pathogenic bacteria. Biofilm-fibroblast coculture models demonstrate that X-NEs selectively eliminate bacteria without harming mammalian cells, making them promising candidates for antibiofilm therapeutics.

Multi-Encapsulation Combination of O/W/O Emulsions with Polyurea Microcapsules for Controlled Release and Safe Application of Dimethyl Disulfide.

Dimethyl disulfide (DMDS), a promising alternative fumigant, has been highly desirable for excellent management of soil pests and diseases. However, high volatility and moderate toxicity of this sulfide limit its application. To address these issues, a novel controlled release formulation of DMDS was proposed employing multiple emulsions and polyurea microcapsules (DMDS@MEs-MCs). The successful combination of the two technologies was revealed by confocal laser scanning microscopy, scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared. According to the multiple encapsulation structure, the encapsulation efficiency decreased by only 3.13% after thermal storage, compared with a 15.21% decrease of microcapsules made with only a monolayer film. DMDS@MEs-MCs could effectively control the release of active ingredient, which increased applicator and environmental safety during application. Moreover, it could be facilely used by spraying and drip irrigation instead of a special fumigation device. The innovative formulation exhibited better control efficacy on soil pathogens (Fusarium spp. and Phytophthora spp.) and root-knot nematodes (Meloidogyne spp.) than DMDS technical concentration (DMDS TC). In addition, it did not inhibit seed germination after 10 days when the plastic film was removed from the fumigated soil. This method appears to be of broad interest for the development of safe and handy fumigant application.

Nanostructured oleic acid/polysorbate 80 emulsions with diminished toxicity in NL-20 cell line: Insights of potential drug carriers.

Nanoemulsions (NE) are nowadays required drug nanocarriers. We have selected i) oleic acid (OA) as oil (O), ii) polysorbate 80 (PS80) as surfactant (S), and iii) water (W) in a prototype NE. Our best formulation had O:S ratio [OA]/[PS80] = 0.0708/0.0382 = 1.85 [mol·L-1], implying 1.85 parts of OA covered/stabilized by 1 part of PS80, giving 71.86 nm and 0.42 polydispersity index (PDI) in NE, determined by DLS and TEM. These nanosystems stored at room temperature/darkness stabilized up to 12 months (measured by DLS and TEM) maintaining very similar particle sizes and sometimes decreasing PDI. NE stability was determined by DSC, evidencing reversibility upon heating from 25 to 100 °C, increasing to 125 °C (sealed systems) produced more attenuated heating profiles in second and third cycles, compared with first, indicating partial but enough stability for storage means. NE cytotoxicity tests were conducted on immortalized normal lung epithelial cells (NL-20), as reference. The results show 50 % inhibitory concentrations (IC50,µM) of 1100, OA, and 2.6, PS80. The IC50 was 20.5, PS80 (PS80@NE) and 37.9, OA (OA@NE) clearly indicating that components changed their toxicities upon nanostructuring, OA exhibited 30-fold increase (IC50(OA) 1100.0→37.9) while PS80, decreased 7.9-fold (IC50(PS80) 2.6→20.5). PS80 is the most toxic component but when is included in PS80@NE, less toxic nanocarriers were generated.

Synthesis, characterization and toxicity assessment of a new polymeric nanoparticle, l-glutamic acid-g-p(HEMA).

The toxic effects of poly(HEMA)-based polymeric nanoparticles must be analyzed before their biomedical applications as drug delivery systems. The aim of the study was to characterize and evaluate the toxicity for its biocompatibility of a newly synthesized l-glutamic acid-g-p(HEMA) polymeric nanoparticle The nanoparticle was synthesized with surfactant-free emulsion polymerization and grafting techniques. Grafting efficiency was estimated at 58%. The nanoparticle shape was verified as nearly spherical by scanning electron microscopy. Atomic force microscopy images showed a rough surface topography. The nanoparticle had an average size of ~194.6 nm on zeta analysis, and the zeta potential value was -18 mV. Fourier transformed infrared spectroscopy revealed spectra from 750 to 4000 cm-1 and characteristic peaks of stretching bands. The swelling ratio was 46%. With 24-h exposure, p(HEMA) and l-glutamic acid-g-p(HEMA) did not have cytotoxic effects on a human bronchial epithelial cell line (16HBE) and human monocyte cell line by water-soluble tetrazolium salt 1 (WST-1) assay and lactate dehydrogenase assay (LDH). It did not show genotoxic potential by comet assay and did not have mutagenic effects on Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains by Ames test. The nanoparticle at 160 µg/ml showed 2% hemolytic activity on erythrocytes. On cell migration assay, the percentage closure difference between exposed and control cells was estimated at 21%. We found no irritation effect on Hen's egg test-chorioallantoic membrane test. We determined that the polymeric nanoparticle l-glutamic acid-g-p(HEMA) was biocompatible and has potential for use in a drug delivery system.

Transdermal delivery enhancement of carvacrol from Origanum vulgare L. essential oil by microemulsion.

Carvacrol has been reported for analgesic and anti-inflammatory activity by cyclooxygenase inhibition but it could induce gastrointestinal toxicity because of its non-selective inhibition. Therefore, the present study aimed to develop transdermal microemulsion from Origanum vulgare essential oil to deliver carvacrol into and through the skin which would overwhelm the gastrointestinal problems. O. vulgare essential oil was extracted by hydrodistillation and its carvacrol content was determined using high performance liquid chromatography. Pseudoternary phase diagrams were constructed using water dilution method to investigate the suitable microemulsion components. Microemulsions were then characterized for external appearance, particle size, size distribution, zeta potential, electrical conductivity, refractive index, viscosity, transmittance, pH, and stability. Additionally, the irritation property of microemulsions were investigated by hen's egg on the chorioallantoic membrane assay. The release profile, percutaneous absorption, and skin retention were investigated using dialysis bag and Franz diffusion cell, respectively. The interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were investigated using the enzyme-linked immunosorbent assay. The results remarked that carvacrol was a major component of O. vulgare essential oil with high concentration of 83.7%. The most suitable microemulsion (ME 1), composing of 5% w/w O. vulgare essential oil, 25%w/w Tween 60, 25%w/w butylene glycol, and 45%w/w deionized water, had the smallest internal droplet size (179.5 ± 27.9 nm), the narrowest polydispersity index (0.30 ± 0.07), the highest transmittance (93.13 ± 0.04%), and Newtonian flow behavior with low viscosity of 0.30 ± 0.07 Pas. ME 1 could reduce the irritation effect of O. vulgare essential oil since ME 1 (IS = 3.1 ± 0.10) exhibited significantly lower irritation effect than its blank formulation (IS = 4.8 ± 0.02) and O. vulgare oil solution (IS = 5.0 ± 0.01) (p < 0.05). Furthermore, ME 1 sustain released carvacrol from the formulation, remarkedly deliver more carvacrol through the skin layer (2.6 ± 2.2%) and significantly retained carvacrol in the skin layer (2.60 ± 1.25%). Additionally, ME 1 significantly enhanced IL-6 inhibition of O. vulgaris oil and carvacrol (p < 0.05). Therefore, O. vulgaris oil microemulsion was suggested to be used for the transdermal delivery and anti-inflammatory activities enhancement of carvacrol.

Emulsifiers' composition modulates venous irritation of the nanoemulsions as a lipophilic and venous irritant drug delivery system.

In this study, a nanoemulsion (NE) system was investigated for intravenous delivery of lipophilic and venous irritant drugs. NEs were prepared to deliver diallyl trisulfide (DT) for systemic therapy of bacterial and fungal infection, egg phospholipid was chosen as the main emulsifier, and two co-emulsifiers were also incorporated, including Poloxamer 188 (P188) and Solutol HS 15 (S15). Soybean oil was used as the dispersed phases, forming stable DT NEs with small particle sizes. The venous irritation of DT NEs was evaluated by in vitro human umbilical cord endothelial cells (CRL 1730) compatibility model with the intracellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations as the indices. The intracellular ATP and GTP reduction changed with the incorporation of a variety of co-emulsifiers, which varied in a free DT concentration-dependent manner. It was deduced that the free DT concentrations of NEs containing co-emulsifiers were determined by the partition coefficient of DT between oil and surfactant buffer solution. In conclusion, NE was an appropriate delivery system for lipophilic and venous irritant drug, and optimization of the composition of emulsifiers was an effective method to alleviate the venous irritation of DT NEs.

Cytotoxicity and permeability enhancement of Capmul®MCM in nanoemulsion formulation.

This study aimed to investigate the following factors affecting the cytotoxicity of Capmul®MCM (C8/10MD) in self-emulsified nanoemulsions (SENs): concentration, triglycerides, and droplet size, and how these factors influence permeability of lipid droplets. Two triglycerides (C8T and C18T) and six formulations were used: SEN1(C18T:C8/10MD:Kolliphor®RH40 = 7:3:10, 257 nm), SEN2(C8T:C8/10MD:Kolliphor®RH40 = 1:1:2, 30 nm), SEN3(C18T:Kolliphor®RH40 = 1:4, 26 nm), SEN4(C8T:Kolliphor®RH40 = 1:4, 27 nm), SEN5(C8/10MD:Kolliphor®RH40 = 1:1, 120 nm) and SEN6(C8/10MD:Kolliphor®RH40 = 1:4, 15 nm). There was no cytotoxicity from SEN3-4 (5% preconcentrate), but there was concentration-dependent cytotoxicity from the SENs containing C8/10MD. The presence of triglycerides in SEN1-2 reduced the toxicity of C8/10MD as compared to SEN5-6. SEN2 and SEN6 showed higher toxicity than SEN1 and SEN5, respectively, due to the smaller size. 14C-Triolein-loaded droplets from SEN1 (0.45-0.6% C8/10MD) and SEN2 (0.3-0.6% C8/10MD) could permeate across the MDCK monolayer, resulted in intact droplets and radioactivity in the receiver chamber. The TEER was reduced as the C8/10MD concentration increased, and not recovered after 24 h from SEN1 (0.6% C8/10MD) and SEN2 (0.45-0.6% C8/10MD), resulted in significantly higher (p < 0.05) permeability of 14C-mannitol and 3H-propranolol compared to the treatment by the medium. In conclusion, Capmul®MCM caused concentration-dependent cytotoxicity and permeation enhancement, which were reduced with the presence of triglycerides and increase in droplet size.