Controlled Nanonization of Poorly Water-Soluble Drugs for Reliable Bioavailability Beom-Jin Lee Abstract Solid dispersions (SD) can be utilized to improve the dissolution rate of poorly water-soluble drugs and further to modulate the release pattern by selecting an appropriate hydrophilic polymer. SD overcomes the many solubility issues of various types of poorly water-soluble drugs, providing the medical benefits to obtain a reliable bioavailability. Controlled release (CR) systems offer several medical advantages, such as reducing the adverse effects, dosing frequency and ultimately enhancing the patient compliance. Thus, SD-loaded CR (SD-CR) systems provide some privileges in drug delivery by taking into consideration of solubilization and controlled release of poorly water soluble drugs for optimal therapy. Keywords Poorly water-soluble drugs Á Controlled release solid dispersion Á Solubilization mechanism Á Classification of solid dispersions Á Nanonization 1 Introduction The poorly water soluble drugs have major problems which hides the potency of therapeutic usefulness. Their low aqueous solubility have inherently attributed to molecular structure and properties. The drugs with low solubility often trigger to a low and non-constant bioavailability, resulting in large inter-subject variability [1]. Recently, there are many strategies for solubilizing techniques of poorly water soluble drugs such as particle size reduction, salt formation, pH adjustment, solid dispersion system, etc. Solid dispersion (SD) is known to be one of good solution for improving solubility of poorly water sol- uble drugs. Depending on physiochemical properties of drugs, the solubilization mechanism including drug crys- tallinity, powder properties [2], microenvironmental pH [3] and intermolecuar interaction [4] could be differently described. Many researches on SD have been published and have showed a number of advantages in improving disso- lution rate of poorly water soluble drugs and reliable bioavailability [5]. The SD technologies have been evolved and the four types of SD, depending on physiochemical of drugs are classified by Vo et al. [6] (Fig. 1). However, only a few marketed drug products utilizing SD have been launched upon till this time (Table 1). This low number of marketed SD products reflects some issues such as scale-up manufacturing and physicochemical instability to be overcome. In addition, SD has great potentials both for modulating bioavailability of poorly water soluble drugs with a short half-life when CR systems are combined. In order to achieve an ensured drug product, numerous formulation parameters such as physicochemical properties of pharmaceutical excipient, preparation method, solubilization mechanism and releasing patterns of drug and carrier from SD-loaded CR matrix system should be considered. The aim of this presentation is to address solubilization mechanism of SD via nanonization process and its B.-J. Lee (&) College of Pharmacy, Ajou University, Suwon, Republic of Korea e-mail: beomjinlee@gmail.com © Springer Nature Singapore Pte Ltd. 2018 T. Vo Van et al. (eds.), 6th International Conference on the Development of Biomedical Engineering in Vietnam (BME6), IFMBE Proceedings 63, https://doi.org/10.1007/978-981-10-4361-1_140 827