Identification of some interferences in the analysis of clorazepate

Clorazepate presents several problems in identification. In addition to rapid acid decarboxylation to N-desmethyldiazepam, a noncontrolled substance often confused with clorazepate, extracts of the pharmaceutical forms (Tranxene and Azene capsules) contain substances that interfere with isolation of intact and unaltered clorazepate. These substances have been identified and have been found to be quite dependent on both capsule type and, especially, on capsule age. The cause of the conversion of dipotassium clorazepate to the monopotassium salt, following solution, has also been identified. An infrared analysis method, which removes all of the interferences, is presented.