Conference Contribution Details
LI Ciortea, RE Imhof, P Xiao and G Kramer
Poster Presentation, SCC Annual Scientific Meeting & Technology Showcase, New York 2009.
The importance of TEWL measurements in cosmetics and pharmaceuticals product testing and claims support is well recognised. However, some formulations applied to the skin may contain volatile materials whose vapours may interfere with TEWL measurements, leading to false readings. We are therefore studying the effects of a number of common vapours on TEWL measurements using a condenser-chamber AquaFlux™ instrument [1,2].
The in-vitro measurement protocol used is similar to the recently developed droplet calibration technique for TEWL . For liquids, we use a micro-syringe to dispense a droplet of 0.5mL volume into a purpose-designed cap that can be tightly coupled to the measurement chamber of the TEWL instrument. For solids, we dispense a small quantity, typically less than 1mg into the cap. The instrument is then set to record a time-series of flux density readings as the cap is coupled to the instrument, thus trapping the volatile components within the closed TEWL measurement chamber.
We will present measurements on a range of common materials, including Thymol, DMSO, Transcutol, isopropyl alcohol, propylene glycol and glycerol. Apart from these in-vitro measurements, we will also present the results of an in-vivo study, where changes of TEWL through a Menthol patch applied to the volar forearm was measured over a period of several hours.
|1.||Imhof, R.E., Berg, E.P., Chilcott, R.P., Ciortea, L.I. and Pascut, F.C. New instrument for measuring water vapour flux density from arbitrary surfaces. IFSCC Magazine. 5(4):297-301 (2002).|
|2.||Imhof, R.E., De Jesus, M.E.P., Xiao, P., Ciortea, L.I. and Berg, E.P. Closed-chamber Transepidermal Water Loss Measurement: Microclimate, Calibration and Performance. International Journal of Cosmetic Science. 31:97-118 (2009).|
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