The effect of formulation on oesophageal transit.

The oesophageal transit of barium sulphate in small or large, heavy or light capsules or film coated and plain oval tablets was measured during fluoroscopy in five separate studies involving 175 subjects. Transit of large, but not small capsules was significantly faster than plain oval tablets in both erect and supine subjects (P less than 0.05). Heavy large capsules entered the stomach in all subjects within 20 s, whereas in all other studies some subjects retained dosage forms in the oesophagus for over 5 min. The transit of heavy capsules was significantly faster than light capsules in erect subjects (P less than 0.0005). Light capsules tended to have faster transit times than heavy capsules in the supine position. Film coating significantly enhanced oval tablet transit in erect (P less than 0.00003) and supine subjects (P less than 0.05). When large capsules of equal weight but less dense than film coated oval tablets were directly compared, the tablet transit was significantly superior in the erect subjects (P less than 0.0001). In supine subjects the transit of the light capsule was significantly faster (P less than 0.005). It is concluded that different drug formulations can have significant effects on oesophageal transit, and hence on the development of drug induced oesophageal ulceration.