title: Pathways of lateral spreading.
abstract: In the case of topically applied substances, usually both lateral spreading and competitive penetration into the skin occur in parallel. In the present study, the pathways of lateral spreading were studied quantitatively and visually. The local distribution and lateral spreading of the UV filter substance butyl methoxydibenzoylmethane applied in an o/w emulsion was studied on the forearm and the back. The tape stripping procedure was used to determine the recovery rates inside and outside the area of application. The skin characteristics of transepidermal water loss, pH value, hydration of the stratum corneum and sebum rate were determined at both anatomic sites. Photography and laser scanning microscopy were used to visually investigate the lateral spreading of topically applied dyes. On the back, a preferred direction of lateral spreading parallel to the body axis was observed. This result was caused by differences in the network of furrows. The furrows functioned as a pathway for lateral spreading, whereas the follicles formed a reservoir for the topically applied substance.
authors: Department of Dermatology, Center of Experimental and Applied Cutaneous Physiology, Charité - Universitätsmedizin Berlin, Germany.
authors: U
authors: U
authors: Jacobi
authors: S
authors: S
authors: Schanzer
authors: H-J
authors: HJ
authors: Weigmann
authors: A
authors: A
authors: Patzelt
authors: T
authors: T
authors: Vergou
authors: W
authors: W
authors: Sterry
authors: J
authors: J
authors: Lademann
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000473:Alkanes / Q000008:administration & dosage / Q000032:analysis; D001415:Back; D047188:Chalcones / Q000008:administration & dosage / Q000032:analysis; D004655:Emulsions; D005260:Female; D005542:Forearm; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D011427:Propiophenones; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D013057:Spectrum Analysis; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D053832:Surgical Tape; D014870:Water Loss, Insensible; D055815:Young Adult
chemical_list: D000473:Alkanes; D047188:Chalcones; D004655:Emulsions; D011427:Propiophenones; D013473:Sunscreening Agents; C049935:avobenzone