Factors that affect the rate of drug absorption

Wikis > Pharmacology > Pharmacokinetics > Absorption > Factors that affect the rate of drug absorption

Factors that affect the rate of drug absorption:
• rate that the drug dissolves (drug must first dissolve before it can be absorbed)
• surface area available for absorption
• drug concentration (tends to be greater absorption if drug is administered in a high concentration)
• blood flow at administration site (ie a richer blood supply, such as sublingual, increases absorption)
• nature of absorbing surface (ie absorption is faster through a single layer if cells such as the intestinal epithelium compared to the multilayered skin)
• lipid solubility (generally the more lipid soluble  more rapidly absorbed)
• pH differences (absorption generally faster when pH of plasma and site of administration is different  greater tendency to be ionised in plasma)

Comments are closed.