AbstractFendosal(200 mg) was given orally to each of two separate groups of twelve healthy male volunteers on separate occasions to assess the influence of food or antacid on the bioavailability of fendosal. Blood samples (20ml) were drawn during 12 hours postdosing and fendosal plasma concentrations were quantitated by a validated fluorescence technique. Food was shown to have no significant effect (p>0.05) on fendosal bioavailability. However, the bioavailability of fendosal in the presence of an antacid was reduced by 80 per cent.In vitrostudies suggested that a complexation between unionized fendosal and the metal ions contained in the antacid may be responsible for the decrease in the rate and extent of absorption observedin vivo.