chemical and spectroscopic analysis of a phenobarbitalephedrine complex a complex of phenobarbital and ephedrine was prepared and characterized the complex was differentiated from physical mixtures of the two drugs by tlc and ir spectroscopy nmr spectroscopy was used to verify the proportion of each drug in the complex and to confirm the existence of intermolecular binding mass spectrometry was employed to establish that all fragments characteristic of the individual drug entities could be isolated from the complex elemental analysis confirmed the chemical composition of the complex a possible chemical structure for the complex was hypothesized on the basis of the chemical and spectroscopic data