In vitro and In vivo percutaneous absorption of 14C-octamethylcyclotetrasiloxane (14C-D4) and 14C-decamethylcyclopentasiloxane (14C-D5)

Evaporation of decamethylcyclopentasiloxane (D5) from selected cosmetic products: Implications for consumer exposure modeling

“…5 min vs. 15 min observed in our experiments with porcine skin and 20 min attained in the second modeling approaches), possibly due to a significantly higher air turbulence augmenting advection in the examination room compared to the test chamber. Jovanovic et al (2008) also report that after 24 h more than 90% of D5 applied on human skin in vitro had volatilized, which we consider similar to our results if measurement uncertainties and differences in the experimental setup are taken into account. The use of porcine ear skin is not expected to significantly affect the modeling results, since its histological, physiological and biochemical properties were repeatedly shown to be similar to those of human skin (Dick and Scott, 1992;Jacobi et al, 2007;Wester et al, 1998).…”

“…aluminum, silica) D5 is still the major constituent (45% w/w), so that it can be expected that the evaporation kinetics of the principal component resemble that of the pure compound. Similarly, the study of Jovanovic et al (2008) with deodorant on dermatomed human skin in vitro did not reveal any significant differences in neither the absorption nor the evaporation of neat and formulated D5. In contrast, for the investigated face cream the initial evaporation rate is 2-fold lower compared to that of the pure substance.…”

“…2b) its evaporation is controlled by the first-order rate constant, k −1 [min −1 ]. An additional input parameter, describing the steady state flux of neat D5 from the skin into the receptor fluid (k −2 [mg cm −2 min −1 ]), was acquired from an absorption study with dermatomed human skin in vitro (Jovanovic et al, 2008). Here, we assume that the concentration of D5 in the receptor fluid remains low relative to the amount of substance in the skin at the exposed site so that transport from the receptor fluid back into the skin can be neglected.…”

“…Acknowledging the fact that consumer products designed for topical applications are usually complex and often non-aqueous systems containing multiple ingredients, researchers attempted to investigate the influence of the formulation on dermal absorption (Reifenrath and Robinson, 1982;Saiyasombati and Kasting, 2003) and evaporation (Nihi et al, 2009;Vuilleumier et al, 1995) for a range of VOCs. Several studies were also conducted for decamethylcyclopentasiloxane (D5) (Jovanovic et al, 2008;Koini et al, 1999;Reddy et al, 2007;Wang et al, 2011), a highly lipophilic (logK ow = 8.0) and volatile (P = 33 Pa at 25°C) compound that is incorporated into a variety of C&PCPs as a carrier solvent and emollient (Dudzina et al, 2014;Horii and Kannan, 2008;Wang et al, 2009). However, despite the fact that the respective experiments were all designed to mimic realistic application of C&PCPs, their results vary largely, indicating the need of more consistent research.…”

A survey of cyclic and linear siloxanes in indoor dust and their implications for human exposures in twelve countries

“…A few studies have reported exposure of humans to siloxanes through dermal absorption from the use of personal care products in the USA and China (Horii and Kannan, 2008;Jovanovic et al, 2008;Lu et al, Fig. 1.…”