Chapter 3 - Nanoemulsion-based antimicrobial systems

Abstract

Microbial infection is a threat in the healthcare sector. Administration of different antibiotics in different dosages is being carried out to prevent and/or treat bacterial infections. Most of the antibiotics are administered in the form of tablet to be consumed orally. The drug molecules after entering the host system begin to disintegrate and enter into the blood stream. The drug is then circulated throughout the body except for the brain. This dilution results in a very low concentration of drug reaching the target site. On the other hand, nontargeted regions of the human body are needlessly exposed to the drug. Besides, the tablets come along with the filler molecules to give the size, shape, color, sweetness and shiny appearance to the tablet. These components pose an additional unreasonable workload to the liver and kidneys. To combat the situation, targeted drug delivery vehicles are essential. Nanoemulsions were identified to possess such property that can efficiently transport and deliver the drug to the target site. Nanoemulsions are generally tiny oil droplets containing the drug molecules suspended in the aqueous media. Nanoemulsions could be oil-in-water type, water-in-oil type, or biphasic type. To enhance the stability of the nanoemulsions components such as “surfactants” and “co-surfactants” are added. Nanoemulsions could be prepared using either high energy methods or low energy methods. Nanoemulsions are stable molecules and are nonirritant. Nanoemulsions are good carriers of both lipophilic and hydrophilic drug components. Several drugs were reported to have shown higher efficacy when administered in the form of nanoemulsions than as pure drug. This chapter deals with the components of nanoemulsion, their classification, preparation, and characterization. In addition, the mechanism of the antibacterial property of nanoemulsion is also explained.