Estimating the Analytical Performance of Raman Spectroscopy for Quantification of Active Ingredients in Human .

Confocal Raman microscopy (CRM) has become a versatile technique that can be applied routinely to monitor skin penetration of active molecules. In the present study, CRM coupled to multivariate analysis (namely PLSR-partial least squares regression) is used for the quantitative measurement of an active ingredient (AI) applied to isolated (ex vivo) human (SC), using systematically varied doses of resorcinol, as model compound, and the performance is quantified according to key figures of merit defined by regulatory bodies (ICH, FDA, and EMA). A methodology is thus demonstrated to establish the limit of detection (LOD), precision, accuracy, sensitivity (SEN), and selectivity (SEL) of the technique, and the performance according to these key figures of merit is compared to that of similar established methodologies, based on studies available in literature.

Confocal Raman Spectroscopic Imaging for Evaluation of Distribution of Nano-Formulated Hydrophobic Active Cosmetic Ingredients in Hydrophilic Films.

Film-forming systems are highly relevant to the topical administration of active ingredients (AI) to the body. Enhanced contact with the skin can increase the efficacy of delivery and penetration during prolonged exposure. However, after the evaporation of volatile solvents to form a thin film, the distribution of the ingredient should remain homogenous in order to ensure the effectiveness of the formula.

Nanoscale investigation of human skin and study of skin penetration of Janus nanoparticles.

Janus nanoparticles (JNP) are innovative nanocarriers with an interesting pharmaceutical and cosmetic potential. They are characterized by the presence of a lipid compartment associated with an aqueous compartment delimited by a phospholipid bilayer containing phospholipids and non-ionic surfactants. The hydrodynamic diameter of JNP varies between 150 and 300 nm.

ATR-FTIR Characterization of Janus Nanoparticles-Part II: Follow-Up Skin Application.

Attenuated total reflection by Fourier transform infrared (ATR-FTIR) was used to implement reliable infrared descriptors over time of Janus nanoparticles (JNP), to follow their behavior before and after cutaneous application. In the last study, ATR-FTIR spectroscopic analysis allowed us to identify the evolution of intensity ratio of ν(C=O) at 1739 cm and δ(H-O-H) at 1639 cm as a spectroscopic descriptor, for JNP before cutaneous application (on the CaF window). This descriptor can be used to follow the physical stability (presence) of nanoparticles over time.

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.