Detectability of drug tablets and capsules by plain radiography

This study was undertaken to determine the detectability of drugs in tablet or capsule form by plain radiography. A total of 459 drugs in tablet or capsule form were radiographed in water with parameters commonly used in routine upper abdominal films. Detectability was judged subjectively by radiologist's readings and objectively by the use of a densitometer. Of the total, 6.3% were as radiopaque as a ferrous sulfate control tablet, 29.6% were moderately radiopaque, but less than control values, and 64% were essentially nondetectable. Potential benefits of this information in the clinical setting are discussed.