Although it is accepted that frogs have highly-permeable skin, little is known how the physicochemical characteristics of chemicals, or skin region of chemical application, influence percutaneous absorption in frogs. Additionally, frog species from different primary habitats have different skin composition, thickness and vascularisation, and this is also likely to influence percutaneous absorption. This dataset provides in vitro absorption kinetics for three model chemicals - benzoic acid, caffeine, and ibuprofen - through excised skin of two frog species: the arboreal frog Litoria caerulea and the terrestrial toad Rhinella marina. Franz-type diffusion cells were used to measure absorption, and chemical content was quantified using validated HPLC methods.
Each chemical was formulated as a saturated solution (infinite dose) in Amphibian Ringer’s solution and applied to the external skin surface. Diffusion through the skin was measured over a period of six hours for benzoic acid and caffeine, and for 24 hours for ibuprofen. Chemical flux was determined from the steady-state slope of the cumulative absorption vs time plot.
Data includes a spreadsheet (comma-separated values / .csv file) providing individual animal information (including animal ID, species, sex, weight, and from which body regions each skin sample was obtained), chemical information including name, concentration, logP and molecular weight, and absorption data including chemical content at each sample time and calculated flux and Kp values.
Column headings are explained below:
AnimalID: individual animal identifier
Conc: concentration of chemical applied (microgram/ml)
Chemical: chemical applied to the skin (caffeine/benzoic acid/ibuprofen)
LogP: logarithm of the partition coefficient for chemical investigated
MW: molecular weight of the chemical investigated
Species: frogs species used (L. caerulea or Rh. marina)
Sex: frog sex
Weight: frog weight in grams
Region: primary skin region (dorsal=D/ ventral=V) of skin sample
SubRegion: For Rh. marina, identifies if ventral samples are thoracic (T) or pelvic (P) in origin. Otherwise same as Region (Dorsal=D, Ventral=V)
LeftRightMid: identifies if samples taken from left (L), right (R) or on the midline (M)
Flux: steady-state flux of the chemical
logFlux: logarithm of flux
Kp: permeability coefficient of the chemical (Kp=Conc/Flux)
t=0 through t=24: concentration (microgram/ml) of chemical in receptor fluid at each sampling time (hr)