Eucalyptus oil (Eucalyptus globulus) nanoemulsion was formulated using lowand high-energy emulsification methods. Development of nanoemulsion was optimized for system parameters such as emulsifier type, emulsifier concentration, and emulsification methods to obtain a lower droplet size with greater stability. The minimized droplet diameter was achieved using the high-energy method of ultrasonication. Tween 80 was more effective in reducing droplet size and emulsion appearance when compared to Tween 20. Stable nanoemulsion was formulated with Tween 80 as a surfactant, and the particle size was found to be 9.4 nm (1:2 v/v). The eucalyptus oil nanoemulsion was impregnated into chitosan (1%) as a biopolymer in varying concentrations. Further, the film was characterized by moisture content, microscopic study, X-ray diffraction, and Fourier transform infrared spectroscopy. Also, the film with and without nanoemulsion was evaluated against Staphylococcus aureus. The nanoemulsion-impregnated chitosan film showed higher antibacterial activity than chitosan film. These results support the inclusion of nanoemulsion-impregnated chitosan film in wound management studies. © 2015 Sugumar et al.

Amitava Mukherjee

Centre for Nanobiotechnology

Vellore Campus

Chandra Sekaran N

Sugumar S

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro.

International Journal of Nanomedicine

Environmental Chemistry Letters

Nanoemulsion ingredients and components

Vitamin deficiency arises when the dietary intake of essential vitamins is too low. Insufficient levels of vitamin weaken the body and induce diseases. Although the dietary intake of essential vitamins has increased through food fortification, there are still major issues of vitamin deficiency. Moreover, consumption of vitamins in classical food supplements presents drawbacks such as poor bioavailability and low stability, notably in the gastrointestinal tract conditions. To overcome such issues, vitamin nanoemulsions have been recently developed. Here, we review the design of vitamin nanoemulsions with various oils to meet specific needs; actual research and markets for vitamin nanoemulsions; and techniques for nanoemulsion characterization. © 2019, Springer Nature Switzerland AG.

Food-grade nanoencapsulation of vitamins

Objective: Azithromycin (AZM), an azalide drug is used to treat bacterial infections. It is poorly water-soluble, with low human bioavailability due to partial absorption. This can be improved using a microemulsion drug delivery system using essential oil.Methods: Microemulsion system was prepared with AZM solubilized lemongrass oil (Cymbopogon citratus), Tween 20 and water containing 1% (v/v) 10 mmol sodium hydroxide. In vitro drug release was determined using a 14KDa semipermeable dialysis membrane. The kinetics of bacterial killing was done at MIC concentrations, and viable counts were determined hourly for 24 h. Bacterial cell viability was determined by differential staining with acridine orange and ethidium bromide. In vitro toxicity was determined by the MTT assay, while in vivo toxicity was determined in male Wistar rats.Results: The optimized formulation (5:20:75 %) was thermodynamically stable with drug solubility of 366.90 mg/ml and a droplet diameter of 12.4±3.9 nm, which do not show in vivo or in vitro toxicity. In vitro drug release study in simulated body fluids revealed a controlled drug release from microemulsion-based formulation. The MIC was 1μg/ml and 2μg/ml against Staphylococcus aureus and Escherichia coli respectively. In vitro kill kinetics showed&gt;2 log10 killing by 8 h. Bacterial cell viability assay and scanning electron microscopy analysis further confirmed substantial morphological changes due to alteration in the cell membrane.Conclusion: The reduced droplet size and the inherent antibacterial property of lemongrass oil enhanced the efficacy of the AZM loaded ME system in comparison with the bulk drug, against the bacterial pathogens.

International Journal of Applied Pharmaceutics

DEVELOPMENT OF AZITHROMYCIN LOADED LEMONGRASS OIL BASED MICROEMULSION AND DETERMINATION OF ANTIBACTERIAL POTENTIAL

AbstractFilariasis is a mosquito-borne disease that causes lymphedema and the main vector is Culex quinquefasciatus. A simple measure was taken to eradicate the vector using nanoemulsion. Eucalyptus oil nanoemulsion was formulated in various ratios comprising of eucalyptus oil, tween 80 and water by ultrasonication. The stability of nanoemulsion was observed over a period of time and 1:2 ratios of eucalyptus oil (6%) and surfactant (12%) was found to be stable. The formulated eucalyptus oil nanoemulsion was characterized by transmission electron microscopy and dynamic light scattering. The nanoemulsion droplets were found to have a Z-average diameter of 9.4 nm and were spherical in shape. The larvicidal activity of eucalyptus oil nanoemulsion and bulk emulsion was tested and compared. Our nanoemulsion showed higher activity when compared to bulk emulsion. The histopathology of larvae-treated and untreated nanoemulsion was analyzed. Furthermore, biochemical assays were carried out to examine the effect of nanoemulsion on biochemical characteristics of larvae. The treated larval homogenate showed decrease in total protein content and a significant reduction in the levels of acetylcholinesterase. The levels of acid and alkaline phosphatase also showed reduction as compared to control larval homogenate.

Bulletin of Entomological Research

Nanoemulsion of eucalyptus oil and its larvicidal activity against Culex quinquefasciatus

The plant derived essential oil nanoemulsion was prepared using a mixture of components containing eucalyptus oil as organic phase, water as continuous phase, and non ionic surfactant, Tween 80, as emulsifier at a particular proportion of 1:1 v/v%. The ultrasonication was applied for varied processing time from 0 to 30 min to study the effect of time on the formation of nanoemulsion and physical stability of formulation by this method. The transparency and stability of emulsion was enhanced when the sonication time was increased compared to hand blender emulsion. The most stable nanoemulsion was obtained in 30 min sonication having the mean droplet diameter of 3.8 nm. The antibacterial studies of nanoemulsion against Staphylococcus aureus by time kill analysis showed complete loss of viability within 15 min of interaction. Observations from scanning electron microscopy of treated bacterial cells confirmed the membrane damage compared to control bacteria. Furthermore, the wound healing potential and skin irritation activity of the formulated nanoemulsion in Wistar rats, suggested non-irritant and higher wound contraction rate with respect to control and neomycin treated rats. These results proposed that the formulated system could be favourable for topical application in pharmaceutical industries. © 2013 Elsevier B.V. All rights reserved.

Ultrasonics Sonochemistry

Ultrasonic emulsification of eucalyptus oil nanoemulsion: Antibacterial activity against Staphylococcus aureus and wound healing activity in Wistar rats

The current study deals with the formulation and characterization of bio-based oil in water nanoemulsion and its potential antibacterial activity. A typical v/v% of eucalyptus oil (16.66%), Tween 80 (16.66%), and water (68.68%) was prepared by ultrasonication method. The mean droplet size was 17.1nm as confirmed by dynamic light scattering. Different concentrations of the formulation ranging from undiluted to 10-, 100-, and 1000-fold dilutions were used to check the antibacterial activity in three different microorganisms, namely, Bacillus cereus, Staphylococcus aureus (Gram-positive), and Escherichia coli (Gram-negative). All three species showed a 100% bactericidal at the 10-fold dilution of the nanoemulsion formulation in the following order: B. cereus at 0th min, S. aureus at 15min and E. coli at 1h, respectively. A 10-fold dilution of the nanoemulsion showed that, the cytoplasmic content leakage from the bacterial species was high for S. aureus when compared to B. cereus and E. coli as determined by UV-Vis spectroscopic method. Fluorescence microscopic technique further confirmed this study. © 2013.

Journal of Basic Microbiology

Bio-based nanoemulsion formulation, characterization and antibacterial activity against food-borne pathogens

Cinnamon oil (extracted from Cinnamomum zeylanicum) nanoemulsion was formulated using Tween 80 and water by ultrasonic emulsification. Process of nanoemulsion formulation was optimized for parameters such as surfactant concentration, oil-surfactant mixing ratio and emulsification time. Surfactant concentration was found to be inversely related to droplet size and directly related to stability. Increase in emulsification time resulted in decrease in droplet diameter. Stable cinnamon oil formulation (CF3) having droplet diameter of 65 nm was formulated after sonication for 30 min. Formulated nanoemulsion was evaluated for bactericidal efficacy against Bacillus cereus. Time and concentration dependent killing of B. cereus cells was observed upon treatment with nanoemulsion. Even at a higher dilution of CF3, significant reduction in bacterial population was observed. Alteration in membrane permeability of interacted samples was suggested by quantifying the release of UV absorbing materials. Bacterial staining with acridine orange/ethidium bromide supported kinetics of killing data and also substantiated the above findings of alteration in membrane permeability. FTIR illustrated disappearance of peak corresponding phosphate vibration at 1078 cm-1 and 536 cm-1, and peak associated with vibration of acyl chains of lipid at 2852 cm-1 was shifted to 2854 cm-1 which suggested deformation of membrane phospholipids in nanoemulsion treated cells. SEM observations demonstrated membrane distortion leading to cell lysis. These results propose the potential use of cinnamon oil nanoemulsion for preservation of minimally processed food. Copyright © 2013 American Scientific Publishers All rights reserved.

Journal of Nanoscience and Nanotechnology

Cinnamon Oil Nanoemulsion Formulation by Ultrasonic Emulsification: Investigation of Its Bactericidal Activity

Basil oil (Ocimum basilicum) nanoemulsion was formulated using non-ionic surfactant Tween80 and water by ultrasonic emulsification method. Process of nanoemulsion development was optimized for parameters such as surfactant concentration and emulsification time to achieve minimum droplet diameter with high physical stability. Surfactant concentration was found to have a negative correlation with droplet diameter, whereas emulsification time had a positive correlation with droplet diameter and also with intrinsic stability of the emulsion. Stable basil oil nanoemulsion with droplet diameter 29.3 nm was formulated by ultrasonic emulsification for 15 min. Formulated nanoemulsion was evaluated for antibacterial activity against Escherichia coli by kinetics of killing experiment. Fluorescence microscopy and FT-IR results showed that nanoemulsion treatment resulted alteration in permeability and surface features of bacterial cell membrane. © 2012 Elsevier B.V. All rights reserved.

Journal	International Journal of Nanomedicine
Publisher	Informa UK Limited
ISSN	11769114
Open Access	Yes