Antibiotic development is mainly focused on demonstrating clinical efficacy and setting susceptibility breakpoints. However, several issues cannot be addressed at the premarketing stage. Any ecological effects on human microbiota, as well as effects on mixed inocula selecting bacterial populations in species, strains within species, or subpopulations within strains, need to be addressed and can be explored in the laboratory using pharmacodynamic simulator devices as predictors of resistance selection. From the social perspective, relationships between the consumption of a compound and resistance can only be performed postmarketing. Specific resistance phenotypes/genotypes that could not be isolated in enough numbers in clinical trials can be examined in pharmacodynamic devices in the laboratory for comparison with other antibiotics and thereby for determination of the compound that best fits the need to counter the development/emergence and further spread of resistance.