Following preparation does not succeed: Saponin Coaltar 15 ml salicylic acid 15 g Cetomacrogol 1000 30 g shampoo simplex AD 300 cc

The cause of your problem is the change in the composition of Shampo Simplex by the company Certa. The new composition differs severely from the original also called Shampoo herdies. Topical, the shampoo simplex consists of Plantapon 611 C, NaCl, Bronidox and purified water. Plantapon 611 C is itself a mixture of sodium laurylethersulfate (Texapon), Cocamidopropylbetaine (Dehyton) and Alkylpolyglucoside (Plantapon). This shampoo does not contain cocamide diethanolamide, which with Bronidox can lead to the formation of certain carcinogens depending on a number of factors including the pH.

the solubilizing properties of alkyl polyglucosides are no less than of the laurylethersulfates. The only difference can be in the concentration of tensides in the formulation. Plantapon 611C has a synergistic effect for cleaning and foam. So you need much less Tenside to get the same cleaning and foam as a formulation using only Ether sulfate and Cocamide DEA. It is possible that the manufacturer now has fewer tensides in the formulation than in the old recipe which makes the solubilizing properties less. So the solution will have to be sought in the increase in the concentration of Solubilizer. Following formula (obtained thanks to Apoth. P. Perdieus) gives satisfaction:

salicylic acid 15g
saponione coaltar 15ml
cetomacrogol 1000 45g
Cremophor EL 15g
Shampoo simplex ad 300ml