Didanosine is the second antiretroviral drug marketed and, in the last decade, the presentation and dosage form of this drug have improved remarkably, from bags with buffered powder for twice daily administration, with dispersible tablets with buffer, to the current dosage form which is a gastroresistant capsule (capsule-CT) which allows for administration in once daily doses and that, since it has no buffer, has improved substantially the gastric tolerance to the drug.