IN VITRO STUDIES FURTHER DETAILS
In Vitro Study No: 1071
METHODS
Chemical
Conc. (mg/ml)
Volume (ml)
Loading (mg/cm2)
Vehicle
Species
Membrane
Site
Area (cm2)
Cell Type
Receptor Fluid
Temp. (oC)
Temp. Measured
Exposure Time (h)
Study Length (h)
Occluded
Analytical Method
Benzo[a]pyrene
0.582
0.01
0.0091
Acetone
Testskin TM
Full Thickness Skin (0.3mm)
cultured human foreskin
0.64
Flow-through
HHBSS, BSA, NaHCO3 and gentamycin sulphate
37
Incubator
24
48
2
Radiolabelled (14C)
RESULTS
% Recovery
+/-
% In Stratum Corneum
+/-
% in Viable Skin
+/-
% Penetrated
+/-
% Absorbed
+/-
s-s-flux (mcrg/cm2/h)
+/-
kp (cm/h)
n
Lag Time (h)
97.4
2.93
0.35
0.6
0.8
0.2
0.05
4
NOTES
The testskin was cultured human foreskin from Organogenesis Inc, Cambridge MA. % Penetrated was calculated from adding together the amount found in the receptor fluid to the amount found in the skin digest at the end of the experiment. The skin was washed with an aqueous radiac soap solution at 24 hours and immediately after that there was an increase in absorption. Further experimental detail was gained from Ref. No 90. They do a methanol wash at 48 hours which they take to be the amount found in the stratum corneum. This yielded 33.5%. I have not included it as I don't feel that there is enough evidence that this is in fact just the chemical bound to the stratum corneum. For example they don't do another radiac soap wash to remove any chemical that may have sloughed off over the 24h period.
REFERENCE
In Vivo And In Vitro Dermal Absorption Of Benzo[a]pyrene In Rat, Guinea Pig, Human And Tissue Cultured Skin (1995) J. Dermatol. Sci., 9 :48-58
