Pharmacovigilance and Drug Safety

Drug absorption

Drugs may be either weak acids or bases that exist in both ionized and non-ionized forms in the body. Drug in the non-ionized form is adequately soluble in membrane lipids and can cross cell membranes. The rate of absorption depends upon the ratio of the 2 forms at a particular site and is also a factor in circulation and elimination. Absorption takes place across the biological membrane by two methods.