Nanoemulsions: Preparation, Stability and Application in Biosciences

Abstract

Nanoencapsulation is being thoroughly investigated for the encapsulation and delivery of actives and/or contrast agents. Our approach allows for better solubilization, protection, transportation, and delivery of encapsulated molecules to their biological site of action. This is expected to increase treatment efficiency while reducing possible side effects through dose reduction and/or targeted delivery. Among other nanocarriers, lipid nanoparticles are biocompatible, biodegradable, can be easily produced by up-scalable processes and, depending on the lipid physical state, may allow control of the release of encapsulated molecules. This chapter will explain how nanoemulsions can be efficiently used as nanocarriers for drug delivery and imaging. We will first emphasize the importance of specific formulation to reach long-term physical stability of the nanoparticles in simple and more complex formula. We will then highlight how the lipids' physical state dramatically impacts the actives encapsulation and release behaviors. Finally, we will explore the interaction of nanoemulsion with biological media in terms of biocompatibility and targeting possibilities. Differences between the two main application domains envisaged, namely pharmaceutics and cosmetics, are detailed, and implications for nanoemulsion preparation are discussed.

Evaluation of transdermal delivery of nanoemulsions inex vivoporcine skin using two-photon microscopy and confocal laser-scanning microscopy

“…Since relatively large micron-sized droplets tend to flocculate and coalesce into larger droplets, nanoemulsions whose drop sizes are less than hundreds of nanometers have been both theoretically and experimentally investigated in order to prevent such irreversible destabilization. 11 Nanoemulsions not only have a better penetrating ability compared with micro-or macroemulsions due to small droplet sizes, but can also target specific cells by incorporating various ligands in the droplets. Such targeting ability of droplets within nanoemulsions can be exploited in targeted tumor therapy 12,13 or topical application of drugs targeting specific cells in the skin.…”