Determination of penetration profiles of topically applied substances by means of tape stripping and optical spectroscopy: UV filter substance in sunscreens.
Penetration profiles of topically applied drugs and cosmetic products provide important information on their efficacy. The application of tape stripping in combination with UV/VIS spectroscopy is checked to determine the local position of topically applied substances inside the stratum corneum, the penetration profile. The amount of corneocytes removed with each tape strip is quantified via the particle-dependent absorption, the pseudoabsorption, in the visible spectral range. The concentration of a typical UV filter substance, 4-methylbenzylidene camphor, is determined by optical spectroscopy using the tape strips removed originally. In this case, a time-dependent increase in the absorbance must be taken into account. Laser scanning microscopic investigations confirm that the nonhomogeneous distribution of the filter substance, on the strips, can explain this spectroscopic behavior. When reaching a homogeneous distribution, the UV spectroscopic signal reflects the correct concentration. These spectroscopic values are compared with high performance liquid chromatography (HPLC) data. The values obtained with both methods for the concentrations of 4-methylbenzylidene camphor are in good agreement. The data obtained are used to illustrate the determination of a penetration profile of a UV filter substance. The results demonstrate that the described protocol is well suited to characterize, in a simple manner, topically applied substances that have a characteristic UV/VIS absorption band.
Weigmann
Hans-Jürgen
HJ
Medical Faculty Charité, Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, 10098 Berlin, Germany.
Jacobi
Ute
U
Antoniou
Christina
C
Tsikrikas
George N
GN
Wendel
Volker
V
Rapp
Claudius
C
Gers-Barlag
Heiner
H
Sterry
Wolfram
W
Lademann
Jürgen
J
D000279:Administration, Cutaneous; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D006801:Humans; D055095:Optics and Photonics; D010539:Permeability; D012867:Skin / Q000187:drug effects* / Q000378:metabolism*; D012869:Skin Absorption; D013057:Spectrum Analysis; D013473:Sunscreening Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D013997:Time Factors; D014466:Ultraviolet Rays
D013473:Sunscreening Agents