Which of the following aspects affecting skin bioavailability are primarily affected by the chemical structure of the permeant such as its octanol/water partition coefficient and molecular weight? (More than one correct answer)

Group of answer choices

1. Evaporation of the non-volatile vehicle components of the product.

2. Partitioning of the permeant from the product residue into the stratum corneum.

3. Uniform application and retention of the product on the skin.

4. Diffusion of the permeant through the stratum corneum.