ODDL hosts a strong expertise and excellent track record in drug delivery system research. Drug delivery systems can be tested using physical, chemical and biological experiments (including cell studies, in vivo animal experiments; see other chapters about the available study methods). The laboratory has experience on liposomes, polymeric nano- and microparticles, polymeric conjugates and implants. The relevant methods include, for instance, binding and diffusion in the ocular components, retention of the formulations on the ocular surface, drug release studies, particle distribution to ocular tissues and cell studies (uptake, effects, toxicity). Drug release and retention values can also be used as inputs in computational models that can help in further optimization of the drug delivery systems.