In Vivo Dermatopharmacokinetic Approach

Skin Segmentation Studies — Tape Stripping Method 

Comparative studies on the bioavailability of three different tretinoin gel formulations showed that the dimensions of the sampling area may play a critical role in determining the extent of dermal drug uptake [33, 34], If, by lateral spreading, a substance is distributed over an area sufficiently larger than the sampling area, significant proportions of compound will not be recovered and hence permeability will be underestimated. 

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