(r)-11b,16a,17,21-tetrahydroxypregna-1,4-diene-3,20-dione cyclic 16,17-acetal with cyclohexanecarboxaldehyde 21-isobutyrate Ciclesonide (11β,16α)-16,17-[[(R)-CyclohexylMethylene]bis(oxy)]-11-hydroxy-21-(2-Methyl-1-oxopropoxy)-pregna-1,4-diene-3,20-dione Ciclesonide(RPR251526) Ciclesonide containing impurity A CRS Ciclesonide CRS Zetonna Pregna-1,4-diene-3,20-dione, 16,17-[[(R)-cyclohexylmethylene]bis(oxy)]-11-hydroxy-21-(2-methyl-1-oxopropoxy)-, (11β,16α)-