Methodology to measure the transient effect of occlusion on skin penetration and stratum corneum hydration in vivo.
Ryatt KS; Mobayen M; Stevenson JM; Maibach HI; Guy RH
Departments of Pharmacy, Pharmaceutical Chemistry and Dermatology, Schools of Pharmacy and Medicine, University of California, San Francisco, California, 1987 Dec; :1-17
The absorption of hexyl-nicotine (HN) to the ventral forearm surface of the skin of human volunteers was examined following random assignment to one of three pretreatments: protocol 1, no pretreatment; protocol 2, occlusion for 30 minutes using a small polypropylene chamber; and protocol 3, 30 minutes occlusion as before plus subsequent exposure to ambient conditions for 1 hour. The effect of these treatments on percutaneous absorption and skin hydration were made using laser Doppler velocimetry (LDV) and the dielectric probe technique. The 30 minute period of occlusion shortened significantly both the time of onset of LDV detected response to HN and the time to peak response when compared to the no treatment control. The magnitude of the LDV response to HN and the area under the response versus time curve were significantly increased. Under treatment where the occluded site was exposed to ambient conditions for 1 hour post occlusion before NH dosing, blood flow responses were not significantly different from controls. The stratum corneum water content values showed the same pattern of behavior. Protocol 3 was indistinguishable from control levels whereas protocol 2 caused the horny layer water content to be significantly elevated. These findings probably reflect different intersubject skin dehydration rates following a period of occlusion. The authors suggest that extending the period of ambient exposure would reduce to some extent the variability in the results.
NIOSH-Grant; Dermatitis; Skin-absorption; Skin-exposure; Physiological-measurements
Pharmacy University of California 926 Medical Sciences Building San Francisco, Calif 94143
Final Grant Report
NTIS Accession No.
Departments of Pharmacy, Pharmaceutical Chemistry and Dermatology, Schools of Pharmacy and Medicine, University of California, San Francisco, California
University of California San Francisco, San Francisco, California