Blank Nanoemulsion Research Articles

Larvicidal and insecticidal effect of Cinnamomum zeylanicum oil (pure and nanostructured) against mealworm (Alphitobius diaperinus) and its possible environmental effects

The aim of this study was to evaluate the in vitro susceptibility of larva and adult forms of Alphitobius diaperinus treated with cinnamon (Cinnamomum zeylanicum) essential oil on its free form, nanoemulsion (NE), and nanocapsule (NC), as well as the effect of these treatments on the edaphic fauna using springtails of Folsomia candida (ISO) as a model. The tests with larvae and adults were performed using 1, 5, and 10% of the cinnamon essential oil, and 0.5, 1, and 5% of NE and NC containing 5% of cinnamon essential oil. To validate the test, three controls were used: only oil diluent (Triton), blank nanoemulsion (without oil) and blank nanocapsule (without oil). Cinnamon essential oil at 5 and 10% caused mortality in larva and adult forms of A. diaperinus. The NE (1%) and NC (5%) caused mortality in both phases of A. diaperinus life cycle. After these promising findings, more studies were conducted to verify the ecotoxicological effect of the cinnamon oil. For this, a Tropical Artificial Soil (TAS) was used with different doses of cinnamon oil, NE and NC, using springtails of F. candida. The use of cinnamon oil, even in very low concentrations (25mgkg−1), on its original form significantly affected springtails survival and reproduction. However, the nanostructuring process seemed to minimize this toxic effect without affecting its insecticidal action. In summary, the pure oil and NE containing cinnamon oil showed effect against A. diaperinus, and may be considered an alternative to control this infestation.

Separation of external aqueous phase from o/w nanoemulsions

The aim of this study is to develop a simple, reliable, timesaving and cost-effective method for separation of the external aqueous phase from o/w nanoemulsions. The method is based on centrifugation through a hydrophilic membrane. Five o/w nanoemulsions (droplet size of 20–200nm) with radio-labeled C18 triglyceride were prepared. These nanoemulsions were placed in tubes with cellulose membranes (10–50K molecular weight cut-off) and centrifuged at 250–3000g for 5–15min. The filtrates were analyzed for the presence of lipid droplets and radioactivity. The applicability of this method was tested on FITC-dextran-loaded nanoemulsion (FITC-dextran was expected to be in the lipid droplets) and a blank nanoemulsion mixed with FITC-dextran (FITC-dextran was expected to be in the external aqueous phase). The results show that no droplets were detected in the filtrate. The radioactivity in the filtrate was in the range of 0.3–2.9%. The volume of the filtrate increased with increase in the membrane pore size, centrifugal force and time, and decrease in droplet size. There was 41.6±4.2% and 98.4±0.8% FITC-dextran in the aqueous phase of the FITC-dextran-loaded nanoemulsion and the blank nanoemulsion mixed with FITC-dextran, respectively. In conclusion, centrifugation with hydrophilic membrane is an efficient and convenient method for the separation of the external aqueous phase from o/w nanoemulsions with droplet sizes in the range of 20–200nm.

Antitumor activity of doxorubicine-loaded nanoemulsion against Ehrlich ascites carcinoma-bearing mice

Purpose: To evaluate the antitumor activity of doxorubicine (DOX) loaded nanoemulsion (NE) on Ehrlich ascites carcinoma (EAC)-bearing Swiss albino mice. Methods: The mice were divided into five groups ( n = 20) according to the administered drug. Groups I - V were labeled as negative control (normal), positive control of the untreated EAC bearing mice (EAC control), blank nanoemulsion (BI-NE), DOX-loaded-NE (DOX/LNE) and free DOX (DOX-Sol), respectively. Cardiotoxicity was assessed by measuring changes in body and organ weight, analyzing serum enzymes and lipids, and examining histological changes in heart tissues by light microscopy. In addition, mean survival time (MST), increase in life span (ILS) and survival (S) of the mice were determined. Results: DOX/LNE group reduced levels of serum enzymes and lowered damage to heart tissues relative to DOX-Sol group. The MST of the DOX/LNE group (80 ± 0.0 days) was significantly greater than that for DOX-Sol group (34.6 ± 8.9 days), while ILS of DOX/LNE (265.30 days) was higher than that of DOX-Sol (57.99 days) by 4.6-fold. Conclusion: Administration of DOX/LNE to EAC-bearing mice improves the efficacy of DOX and reduce its side effects on the heart. Keywords: Doxorubicine, Anti-tumor activity, Mean survival time, Heart histology, Nanoemulsion, Lipid profile

Pomegranate seed oil nanoemulsions improve the photostability and in vivo antinociceptive effect of a non-steroidal anti-inflammatory drug

The combination of pomegranate seed oil and ketoprofen in nanoemulsions aiming to improve the antinociceptive effect was evaluated according to the writhing test and Complete Freud’s Adjuvant induced paw inflammation in mice. The formulations showed adequate characteristics and improved ketoprofen’s photostability against UVC radiation exposure. The dialysis bag technique showed that 100% of the drug was released from the nanoemulsions after 3h and the oil amount had no influence on the releasing. Furthermore, time- and dose-response curves were obtained to determine the antinociceptive effect of the formulations. In the post-test, the nanoemulsion containing ketoprofen significantly reduced abdominal constrictions in time-response curve, showing effect up to 12h while the free ketoprofen showed effect up to 3h. In addition, the blank nanoemulsion presented a reduction of abdominal constriction up to 1h of pre-treatment. Regarding the dose-response curve, the free ketoprofen presents effect at 0.5mg/Kg dose and nanoemulsion at 1.0mg/Kg dose. Time- and dose-response curves were performed to determine the antinociceptive effect in inflammatory pain. After the evaluation of mechanical allodynia testing at the Von Frey Hair, the free ketoprofen showed effect up to 6h while nanoemulsions presented effect up to 10h. Moreover, acute toxicity was performed with ALT and AST activity evaluations and urea levels. After 7 days of treatment, no toxic effects for nanoemulsions were found. In conclusion, ketoprofen-loaded pomegranate seed oil nanoemulsions presented adequate characteristics and a high antinociceptive activity in the animal models tested.

Immunotherapeutic vitamin E nanoemulsion synergies the antiproliferative activity of paclitaxel in breast cancer cells via modulating Th1 and Th2 immune response

Paclitaxel (PTX) is used as first line treatment for metastatic breast cancer but the relief comes at a heavy cost in terms of accompanying adverse effects. The pharmaceutical credentials of PTX are further dampened by the intrinsically low aqueous solubility. In order to sideline such insidious tendencies, PTX was incorporated in a vitamin E nanoemulsion using high pressure homogenization. The encapsulation efficiency of PTX in nanoemulsion was 97.81±2.7% and a sustained drug release profile was obtained. PTX loaded nanoemulsion exhibited higher cytotoxicity in breast cancer cell line (MCF-7) when compared to free PTX and marketed formulation (Taxol). Cell cycle arrest study depicted that MCF-7 cells treated with PTX loaded nanoemulsion showed high arrest in G2-M phase. Moreover blank nanoemulsion induced additional apoptosis in breast cancer cells through G1-S arrest by disrupting mitochondrial membrane potential. Cytokine estimation study in macrophages showed that both PTX loaded nanoemulsion and blank nanoemulsion enhanced secretion of IL-12 and downregulated secretion of IL-4 and IL-10. Results suggest that inclusion of vitamin E in nanoemulsion opened multiple complementary molecular effects which not only magnified the principle antiproliferative activity of PTX but also independently showcased potential in restoring the proactive nature of the breast cancer slackened chronic immune response. In-vivo anticancer activity showed significantly improved efficacy of PTX loaded nanoemlsion compare to Taxol and free PTX. The list of plausible advantages of PTX nanoemulsification was further substantiated by acceptable haemolytic potential, reduced in-vivo toxicity and conveniently modified pharmacokinetic profile in which the AUC and MRT were extended considerably. Overall, there were strong evidences that developed formulation can serve as a viable alternative to currently available PTX options.

Anti-inflammatory and analgesic activity of novel oral aspirin-loaded nanoemulsion and nano multiple emulsion formulations generated using ultrasound cavitation

The present study investigated the anti-inflammatory and analgesic activities of novel aspirin oil-in-water (O/W) nanoemulsion and water-in-oil-in-water (W/O/W) nano multiple emulsion formulations generated using ultrasound cavitation techniques. The anti-inflammatory activities of nanoemulsion and nano multiple emulsion were determined using the λ-carrageenan-induced paw edema model. The analgesic activities of both nanoformulations were determined using acetic acid-induced writhing response and hot plate assay. For comparison, the effect of pretreatment with blank nanoemulsion and reference aspirin suspension were also studied for their anti-inflammatory and antinociceptive activities. The results showed that oral administration of nanoemulsion and nano multiple emulsion containing aspirin (60mg/kg) significantly reduced paw edema induced by λ-carrageenan injection. Both nanoformulations decreased the number of abdominal constriction in acetic acid-induced writhing model. Pretreatment with nanoformulations led to a significant increase in reaction time in hot plate assay. Nanoemulsion demonstrated an enhanced anti-inflammatory and analgesic effects compared to reference suspension while nano multiple emulsion exhibited a mild inhibitory effects in the three experimental animal model tests. The results obtained for nano multiple emulsion were relatively lower than reference. However, administration of blank nanoemulsion did not alter the nociceptive response significantly though it showed slight anti-inflammatory effect. These experimental studies suggest that nanoemulsion and nano multiple emulsion produced a pronounced anti-inflammatory and analgesic effects in rats and may be candidates as new nanocarriers for pharmacological NSAIDs in the treatment of inflammatory disorders and alleviating pains.

Ocular antisense oligonucleotide delivery by cationic nanoemulsion for improved treatment of ocular neovascularization: An in-vivo study in rats and mice

The efficacy of an antisense oligonucleotide (ODN17) cationic nanoemulsion directed at VEGF-R2 to reduce neovascularization was evaluated using rat corneal neovascularization and retinopathy of prematurity (ROP) mouse models. Application of saline solution or scrambled ODN17 solution on eyes of rats led to the highest extent of corneal neovascularization. The groups treated with blank nanoemulsion or scrambled ODN17 nanoemulsion showed moderate inhibition in corneal neovascularization with no significant difference with the saline and scrambled ODN17 control solution groups, while the groups treated with ODN17 solution or Avastin® (positive ODN17 control) clearly elicited marked significant inhibition in corneal neovascularization confirming the results reported in the literature. The highest significant corneal neovascularization inhibition efficiency was noted in the groups treated with ODN17 nanoemulsion (topical and subconjunctivally). However, in the ROP mouse model, the ODN17 in PBS induced a 34% inhibition of retinal neovascularization when compared to the aqueous-vehicle-injected eyes. A significantly higher inhibition of vitreal neovascularization (64%) was observed in the group of eyes treated with ODN17 nanoemulsion. No difference in extent of neovascularization was observed between blank nanoemulsion, scrambled ODN17 nanoemulsion, vehicle or non-treated eyes. The overall results indicate that cationic nanoemulsion can be considered a promising potential ocular delivery system and an effective therapeutic tool of high clinical significance in the prevention and forthcoming treatment of ocular neovascular diseases.

Nanoemulsions of an anti-oxidant synergy formulation containing gamma tocopherol have enhanced bioavailability and anti-inflammatory properties

The present study investigated whether MicroFluidizer Processor ®-based nanoemulsions of an antio-xidant synergy formulation (ASF), containing delta, alpha and gamma tocopherol influenced inflammation and bioavailability in CD-1 mice. Croton oil was applied to all animals’ right ear lobe to induce inflammation. Auricular thickness was measured after 2 and 6 h after the various treatments. The animal plasma and ear lobes were collected and frozen for bioavailability and cytokine analyses. The ASF nanoemulsions of alpha, delta, or gamma tocopherol significantly reduced auricular thickness compared to control (57, −57, and −71%, respectively) and blank nanoemulsion (−50, −50, −67%, respectively). Relative to the suspensions of ASF, only the nanoemulsion of ASF containing gamma tocopherol significantly reduced auricular thickness (−60%), whereas the 40% reduction with nanoemulsions of delta tocopherol compared to suspension was not statistically significant. Auricular concentrations of cytokines TNF-alpha and IL-1 alpha were significantly reduced in mice treated only with ASF nanoemulsions of gamma tocopherol compared to control (−53, −46%, respectively) and blank nanoemulsion (−52, −46%, respectively). Auricular thickness was significantly associated with tissue TNF-alpha ( r = 0.539, p < 0.001) and IL-1 alpha concentrations ( r = 0.404, p = 0.01). Bioavailability for gamma and delta was dramatically enhanced (2.2- and 2.4-folds) with the nanoemulsion compared to suspensions. Only the plasma gamma tocopherol concentration was significantly associated with auricular thickness ( r = −0.643, P = 0.001). In conclusion, nanoemulsions of ASF containing gamma, alpha, and delta tocopherol, have enhanced anti-inflammatory properties and increased bioavailability, with gamma tocopherol, in particular compared to their suspensions.

The influence of cationic lipid type on in-vitro release kinetic profiles of antisense oligonucleotide from cationic nanoemulsions

Novel formulations of cationic nanoemulsions based on three different lipids were developed to strengthen the attraction of the polyanionic oligonucleotide (ODN) macromolecules to the cationic moieties on the oil nanodroplets. These formulations were developed to prolong the release of the ODN from the nanoemulsion under appropriate physiological dilutions as encountered in the eye following topical application. Increasing the concentration of the new cationic lipid exhibiting two cationic amine groups (AOA) in the emulsion from 0.05% to 0.4% did not alter markedly the particle size or zeta potential value of the blank cationic nanoemulsion. The extent of ODN association did not vary significantly when the initial concentration of ODN remained constant at 10 μM irrespective of the cationic lipid nature. However, the zeta potential value dropped consistently with the low concentrations of 0.05% and 0.1% of AOA in the emulsions suggesting that an electrostatic attraction occurred between the cationic lipids and the polyanionic ODN molecules at the o/w interface. Only the nanoemulsion prepared with N-[1-(2,3-dioleoyloxy)propyl]- N, N, N-trimethylammonium salts (DOTAP) remained physically stable over time. DOTAP cationic lipid nanoemulsion was the most efficient formulation capable of retaining the ODN despite the high dilution of 1:100 with simulated tear solution (STS). Less than 10% of the ODN was exchanged in contrast to 40–50% with the other cationic nanoemulsions. The in-vitro release kinetic behavior of ODN exchange with physiological anions present in the STS appears to be complex and difficult to characterize using mathematical fitting model equations. Further pharmacokinetic studies are needed to verify our kinetic assumptions and confirm the in-vitro ODN release profile from DOTAP cationic nanoemulsions.