Estimation and characterisation of budesonide tablets impurities

Budesonide is the 16α,17α-acetal of 16α-hydroxyprednisolone with n-butyraldehyde, endowed with anti-inflammatory activity. In a sample of budesonide tablets, kept for 3 years at 25 °C and 60% RH unknown impurities, not reported in European Pharmacopoiea, were present. Their identification was achieved by means of chemical and spectroscopic methods.