Forced degradation study to develop and validate stability-indicating RP-LC method for the determination of ciclesonide in bulk drug and metered dose inhalers

► A validated stability-indicating assay is proposed for ciclesonide. ► The mobile phase consisted of ethanol-water, simpler than that in literature. ► Degradation behavior of ciclesonide under different conditions was studied. ► Desisobutyryl-ciclesonide was proved to be the main degradation product. ► It was easily degraded in alkaline and to a lesser extent in acidic conditions.