Biopharmaceutical and pharmacokinetic aspects of nanocarrier-mediated oral delivery of poorly soluble drugs

Abstract Many new chemical entities have limited water solubility and therefore show low and/or variable oral bioavailability. Among the various strategies to overcome this challenge, nanoformulations have emerged as an attractive strategy to improve the oral permeability and absorption of many hydrophobic drugs. In this paper, we give an overview of the most recent developments of different nanosystems including nanocrystals/nanosuspensions, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), polymeric nanoparticles (PNPs), self-nanoemulsifying drug delivery systems (SNEDDSs), nanoemulsions, liposomes, niosomes, micelles, mesoporous silica nanoparticles (MSNs), dendrimers and cyclodextrin (CD)-based nanosponges currently investigated as the absorption enhancement strategy for the oral route. Various components, characterization, biopharmaceutical and pharmacokinetic (PK) aspects of nanoformulations are also been discussed and compared. An overview of changes in oral bioavailability, maximum plasma concentration (Cmax) and in vivo residence time of a wide range of poorly soluble drugs by nanoformulation strategies is provided. In addition, the mechanisms by which these nanoformulations improved oral absorption are presented. The ability of in vitro release data of nanoformulations to predict the corresponding oral bioavailability data is also evaluated by the correlation approach. The data reviewed here could be used as a guide for choosing appropriate formulations for the increasing number of poorly soluble new chemical entities.