Review of the pharmacokinetics of nanodrugs

Abstract Nanodrug delivery systems (NDDSs) are a hotspot of new drug delivery systems with great development potential. They provide new approaches to fighting against diseases. NDDSs are specially designed to serve as carriers for the delivery of active pharmaceutical ingredients to their target sites, and their unique physicochemical characteristics allow for prolonged circulation time, improved targeting, and avoidance of drug resistance. Despite remarkable progress achieved in the preparation and efficacy evaluation of NDDSs, the understanding of the in vivo pharmacokinetics of NDDSs is still insufficient. Analysis of NDDSs is far more complicated than that for small molecular drugs; thus, almost all conventional techniques are inadequate for accurate profiling of their pharmacokinetic behaviour in vivo. In this article, we systematically reviewed the absorption, distribution, metabolism, and excretion of NDDSs and summarized the advanced bioanalytic techniques for tracing the in vivo fate of NDDSs. We also reviewed the physiologically based pharmacokinetic model of NDDS, which has been a useful tool in characterizing and predicting the systemic disposition, target exposure, and efficacy/toxicity of various types of drugs when coupled with pharmacodynamic modelling. We hope that this review will be helpful in improving the understanding of NDDS pharmacokinetics and facilitating the development of NDDSs.