In vitro dissolution testing strategies for nanoparticulate drug delivery systems: recent developments and challenges

Nanoparticulate systems have emerged as prevalent drug delivery systems over the past few decades. These delivery systems (such as liposomes, emulsions, nanocrystals, and polymeric nanocarriers) have been extensively used to improve bioavailability, prolong pharmacological effects, achieve targeted drug delivery, as well as reduce side effects. Considering that any unanticipated change in product performance of such systems may result in toxicity and/or change in vivo efficacy, it is essential to develop suitable in vitro dissolution/release testing methods to ensure product quality and performance, and to assist in product development. The present review provides an overview of the current in vitro dissolution/release testing methods such as dialysis, sample and separate, as well as continuous flow methods. Challenges and future directions in the development of standardized and biorelevant in vitro dissolution/release testing methods for novel nanoparticulate systems are discussed.