Table 3.

Physicochemicals properties of some antimicrobial classes

Antimicrobials	Lipophilicity	Acido/basic properties
β‐Lactams	Low	Acidic	Strong
Aminoglycosides	Low	Basic	Strong
Macrolides	Moderate	Basic	Weak
Fluoroquinolones 1st generation	High	Acidic	Weak
Fluoroquinolones 2nd/3rd generation	High	Amphoteric	–
Tetracyclines	Moderate	Amphoteric	–
Sulfonamides	Moderate	Acidic	Weak

Table adapted from Toutain (1984) and Milhaud (1985).