Strategies for the formulation development of poorly soluble drugs via oral route

Poor aqueous solubility, slow dissolution rate, and low permeability are the key reasons for poor bioavailability and, in turn, therapeutic efficacy of many existing drugs. The scenario is the same in the case of the new chemical entities (NCEs) in the various stages of drug development, and a considerable number of NCEs are dropped from the drug development process due to poor solubility and/or permeability. Over the years, to reduce the attrition of these NCEs, various "enabling" formulation strategies have been developed by the pharmaceutical scientists. In this chapter, we provide an overview of the various "enabling" strategies that are currently preferred by the pharmaceutical industry. We have also included a description of key advantages and limitations, methods of manufacturing on small and large scale, and the characterization techniques available for these "enabling" formulation strategies. The chapter specifically describes strategies such as nanonization (nanosuspensions), solid dispersion, and lipid-based delivery systems that have been successfully utilized by the drug delivery scientists to improve the biological performance of existing drugs, which subsequently led to successful clinical translation of these "enabling formulations." The chapter also provides a brief description about mesoporous silica particles, which is an emerging "enabling" formulation strategy.