Permeation of dimyristoylphosphatidylcholine into skin-Structural and spatial information from IR and Raman microscopic imaging

DMPC-d54 permeated ∼25-35 μm, with most of the exogenous lipid residing in the stratum corneum, a result generally in accord with literature values. In addition, the state of the DMPC-d54 (intact vesicles or molecularly dispersed with skin constituents) was evaluated from the spatial dependence of the perdeuterated myristate chain conformational order. Uncertainties in the measurement of permeation distances by vibrational spectroscopy are noted.