The brain is one of the least accessible organs of the body due to the presence of the blood-brain barrier (BBB), thus making drug delivery to the brain quite a challenge. Various strategies have been explored to circumvent this physiological barrier, including the use of colloidal carriers. These carriers hold great promise as they may increase the delivery of drugs into the brain by protecting them from degradation and prolonging their circulation in the blood, as well as promoting their transport through the BBB. Moreover, functionalisation of these carriers with various ligands allows specific targeting of the central nervous system compartment. Additionally, various in vitro BBB models have been developed and are increasingly useful for screening of drug delivery systems, especially cell-based models that provide mechanistic information. In fact, this paper specifically reviews selected in vitro BBB models as a screening tool for drug delivery colloidal systems.