Infrared spectroscopic study of lipid interaction in stratum corneum treated with transdermal absorption enhancers.

To develop a transdermal drug delivery system, it is necessary to search for effective modulators to act as permeation enhancers and evaluate its mechanisms of action. It has been suggested that attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a useful tool for evaluating the functional group interaction of the intercellular lipids in the stratum corneum. The purpose of this study is elucidation of the effect of the transdermal permeation enhancers on the intercellular lipid in hairless rat stratum corneum using the ATR-FTIR.

An accurate quantitative analysis of polymorphic content by chemometric X-ray powder diffraction.

Data from X-ray powder diffraction (XRD) were subjected to a partial least-squares regression analysis (PLS) to build a calibration model for predicting the polymorphic content of carbamazepine (CBZ). The effectiveness of the PLS method in the construction of calibration models was analyzed by a scientific approach based on a regulation vector. CBZ forms I and III were characterized by differential scanning calorimetry (DSC) and XRD.