ATR-FTIR Characterization of Janus Nanoparticles. Part I: Implementation of Spectroscopic Descriptors

The present work deals with original bicompartmental lipid Janus nanoparticles (JNPs), which are characterized by the presence of an oily compartment associated with an aqueous compartment delimited by a phospholipid-based bilayer. The size of JNP varies between 150 and 300 nm. As JNP are promising candidates for cutaneous application, the purpose of this study was to implement reliable infrared descriptors over time of JNP, to follow the physical stability of JNP in open air and over time. Therefore, a comparative study with the nanoemulsion and the physical mixture formulations was conducted by attenuated total reflection by FTIR spectroscopy. We defined herein spectroscopic descriptor reflecting the integrity of the JNP. Principal component analysis and orthogonal partial least square-discriminant analysis were used to validate the relevant descriptor and permitted to extract relevant and useful information from the spectral data. Dynamic light scattering measurements were also carried and gave supporting data for our conclusion on the fate of JNP over time.