An oral drug must be:
except

The drug must go into solution to pass through the gastrointestinal mucosa.

Even drugs administered as true solutions may remain in solution

being the situation for many of the sustained- action products

example is ______ administered sodium phenytoin

sodium phenytoin it is widely used in the treatment of epilepsy

Chemical modification is also used to facilitate a drug reaching its desired target,

Olsalazine, used in the treatment of ulcerative colitis.

Mesalamine is effective orally

Chloramphenicol is water—-

To mask this intense bitter taste, the palmitic acid moiety is added as an ester of chloramphenicol’s primary alcohol

ester linkage is hydrolyzed by the digestive esterase to the active antibiotic

chloramphenicol

chloramphenicol palmitate

2.5 mg/mL)- bitter taste
(1.05 mg/mL)- suspension

prodrug approach is used to enhance the absorption of a drug from GIT . Ex: Enalapril = (ACE-I)

Much more readily absorbed orally

poorly abs. orally active pharmacologically