When the weak acid is given orally, the concentration gradient for un-ionized drug between stomach and plasma tends to be large, favoring diffusion through the gastric mucosa.

• 当这种弱酸性药物经口服给药时，胃与血浆之间的非解离型药物浓度梯度很大，从而有利于透过胃粘膜扩散。