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In Vivo Study No: 757

METHODS

ChemicalMembraneConcentration mg/mlConcentration mg/mlloading (mg/cm2)SpeciesSiteArea (cm2)Occluded?Exposure Time (h)Analytical Method
DHEANot Given 0.0576995% aq. EthanolRatDorsal120.5Radiolabelled (3H)

RESULTS

Length of Study (h)% Recovery+/-Dose remaining on surface (mg)% remaining on SurfaceDose remaining in stratum corneum (mg)% remaining in stratum corneumDose remaining in the viable skin% remaining in the viable skinAmount Absorbed (mg)% Absorbed+/-% Absorbed
96      6E-050.10.001522.640.12.64
Maximal Flux (mcrg/cm2/h)Average Flux (mcrg/cm2/h)+/-Time Plasma/Blood Levels Peaked (h)Peak Blood Concentration (mg/l)nkp (cm/h)Lag Time (h)
     6  

NOTES

Female Hairless Sprague-Dawley Rats were used. The application area was delimited by an open circular cel fixed by silicone glue.After 30mins the excess product on the application site was removed by 2 washings with the vehicle solvent followed by 2 rinsings with water and light drying with cotton wool. The animals were equipped with collars to prevent licking. The % absorption was determined by adding the amounts found in the excreta (urine and faeces), epidermis and dermis of treated area and the animal carcass. The amount applied was given as 200nmol/cm2. I have converted this for the database. In a separate study, they found how much was in the stratum corneum after 30mins. They found that this was 1.95nmol. They think that there is a correlation between the amount recovered in the SC after 30mins and the amount that is absorbed after 96h.

REFERENCE

In Vivo Correlation Between Stratum Corneum Reservoir Function And Percutaneous Absorption (1983) J. Investig. Dermatol., 81 :275-278