[Studies on the analysis of nifedipine considering in particular transformation products formed by light exposition (author's transl)].

Under the influence of light (VIS and UV) on thin-layer plates and in liquid solutions, 1,4-dihydro-2,6-dimethyl-4-(0-nitro-phenyl)-pyridine-3,5-carboxylic acid dimethylester (nifedipine, Adalat) is converted to the nitroso compound 4-(2-'nitrosophenyl)-2,6-dimethyl-3,5-dicarbomethoxy-pyridine. The article also describes TLC-, GLC-, UV-, IR- and MS-data of nifedipine, the nitroso and the nitro derivative.