Following preparation schift: Burow 15 g, chlorobutanol 15 g, salicylic acid 15 g, lactic acid 15 g, zinc sulfate 800 mg dexamethasone 480 mg, betamethasone dipropionate 180 mg, cetyl alcohol 51 g, Vaseline 63 g, glycerol 45 g, cetomacrogol ether 12 g, water AD 300

The large amount of salicylic acid will inevitably give an incompatibility with Cetomacrogol 1000. These should be replaced by either nalauryl sulfate or after cetylsteryl sulfate. You can also use Lanette SX or N. Count the hemultiplicity of cetyl alcohol with the amount of cetomacrogol.  

But then we are confronted with the incompatibility of laurylsulfates with two-and trivalent (AL from Burow) ions.  

So best on a small amount of hydrophilic anionic cream to try the compatibility with a reduced adjusted amount of Burow and znsulfate. It is possible that the complexed does not already interact. So best to test the interaction of both substances individually in a preview.  

This composition is really not ideal! I suspect an acidic pH (how sour??). This is certainly detrimental to betamethasone dipropionate!  

If the above incompatibilities do not continue, you can leave the hydrophilic anionic cream. Dexamethasone and Betamethasondiprop. You can mix with salicylzur powder and finely rubbed zinc sulfate and then mix with a part hydrophilic anionic cream. You then dilute with the remaining about hydrophilic anionic cream. Is Chlorbutanol possibly soluble in lactic acid? This solution adds, under stirring,   to the contents of the mortar and most recently the Burow solution.