4.2 mechanisn by which bile salts enhance drug absorption

• bile salts increase drug solubility

bile salts increase the solubility of lipophilic drugs by incorporating them into micelles making absorption into the bloodstream easier

• enhancing drug bioavailability

promotes drub solubility improving its ability to cross the intestinal barrier

• enterohepatic circulation and drug recirculation

bile salts under enterhepatic circulation, where they are reabsorbed in the ileum and returned to the liver for reuse. certain drugs experience this too extending their presence in the body and prolonging their therapeutic effect

drugs excreted into bile may be reabsorbed in the small intestine along with bile salts

prolonging their half life and allowing them to act over a more extended period

• impand of dietary fats on drug absorption

presence of fats in the diet stimulates the release of bile salts from the gallbladder increasing the intake of fat soluble drugs via increasing the amount of bile salts present in the intestine promoting efficient drug absoprtion

This is especially important for drugs like griseofulvin and cyclosporine,

where absorption is greatly enhanced when taken with food.

drugs that depend on dietary fats for absorption:

Griseofulvin (an antifungal medication):

Cyclosporine (an immunosuppressant):

Fat-Soluble Vitamins (A, D, E, K):

Atorvastatin and Other Statins:

Griseofulvin (an antifungal medication):

1. griseofulvin is a classic example of a drug with poor water solubility. Bile salts improve the solubility of griseofulvin by incorporating it into micelles, allowing it to be absorbed through the intestine.

Cyclosporine (an immunosuppressant):

cyclosporine is a lipophilic drug used in organ transplantation to prevent rejection. Its absorption is greatly enhanced by bile salts, which increase its solubility and facilitate absorption.

Fat-Soluble Vitamins (A, D, E, K):

these vitamins require bile salts for proper absorption. Without bile salts, these vitamins would remain unabsorbed and pass through the gastrointestinal tract.

Atorvastatin and Other Statins:

statins, which are used to lower cholesterol levels, are lipophilic and rely on bile salts for absorption. Taking statins with food, particularly foods that contain fat, improves their absorption due to increased bile salt secretion