The doctor wanted an oily lotion with keratolytic properties. Salicylic acid 10% urea 10% ethanol 10 polyethylene lenglycol 10 oleum arachidis AD 100 g

I don't think the different substances you specify are to be processed together. Without doubt, you may delete urea because this is certainly not soluble in oil; It is soluble (not good) in alcohol but then you will have to add a lot of alcohol. In addition, alcohol is not soluble in oil and vice versa.

In The Galensich Formularium you can find the improved Oleum Salicylatum under LOTIONS. Why not recommend this preparation? Perhaps it is possible to increase the concentration of salicylic acid, but this has to be tried.