Study of the bioavailability of different formulations of 8-methoxypsoralen in the dog

The absolute bioavailability of 8-methoxypsoralen in gelatin capsules and as a solution was studied in dogs. A dose of 2 mg kg-1 was given. Both for the solution and the gelatin capsules, a large variation in bioavailability was found between the different dogs. For the gelatin capsules in 1 dog out of 4 an absolute bioavailability of more than 100 per cent was found; for the solution a bioavailability of more than 100 per cent was found in all 4 dogs. Resorption was more rapid and bioavailability higher for the solution than for the gelatin capsules. Relative bioavailability of an emulsion and of a solution of 8-methoxypsoralen was studied in 2 dogs. A faster resorption and a higher bioavailability were found for the solution.