Acetyl salicylate & phenobarbitone are better absorbed from stomach because they are-
Ans. is 'a' i.e., Weak acids remain non-ionic at gastric pH Remember simple funda : When the medium is same drugs can cross the membrane: i) Acidic drugs can cross the membrane in acidic medium, i.e., acidic drugs are unionized at acidic pH and are lipid soluble --> so, in stomach acidic drugs are absorbed. ii) Basic drugs can cross the membrane in basic medium, i.e., basic drugs are unionized at alkaline pH and are lipid soluble --> so, in intestine basic drugs are absorbed.
Weak acids remain non-ionic in gastric pH
Weak acids remain ionic in gastric pH
Strong acids fully ionised in gastric pH
Weak bases which are ionised at gastric pH