The intestine absorbs approximately 10 litres of water a day from the diet and digestive secretions, and only 100-200 ml of water is lost in the stools. The question of whether the water flux influences drug absorption has been raised by many authors. Rat perfusion experiments have shown that the disappearance of the drugs sulphanilamide, sulphisoxazole and metoclopramide from the lumen increases with increasing fluid absorption and decreases when the tonicity of the perfusate increases, which causes intestinal secretion61. In a slight variation of the technique which measured appearance of drug in the plasma, the absorption of both acidic (benzoic, salicylic) and basic drugs (amidopyrine, antipyrine) increased with increasing water absorption62 63. This phenomenon is known as solvent drag. It is proposed that it will affect paracellular drug absorption and may affect the absorption of small and hydrophilic drugs. In humans the intestinal steady state perfusion technique using a triple lumen tube passed into the small intestine, combined with simultaneous measurement of drug plasma concentration, has shown that transmucosal water fluxes affect the absorption of paracetamol and ranitidine64 65.
Was this article helpful?
Tired of Trying To Loose Weight And It Never Works or You Have To Starve Yourself Well Here's A Weight Loss Plan That takes Care of Your Weight Problem And You Can Still Eat. In This Book, You’ll Learn How To Lose Weight And Not Feel Hungry! In An Easy Step-By-Step Process That Enables You To Feel Good About Loosing Weight As Well As Feeling Good Because Your Stomach Is Still Full.