The present invention provides solid oral dosage forms and methods of treating subjects in need thereof. The solid oral dosage forms of the present invention provide a mixture including at least one compound classified as BCS Class II, BCS Class III or BCS Class IV, where the compound does not include a peptide bond in the compound's molecular structure; an absorption enhancer; and coated organic acid particles; an enteric coating; and a water soluble barrier positioned between the mixture and the enteric coating.