Lipid-based formulations

Abstract

The understanding in design, classification, and characterization of Lipid-Based Formulations (LBFs) has evolved greatly over the last two decades. LBFs include simple lipid solutions, self-emulsifying and self-microemulsifying drug delivery systems (SEDDS and SMEDDS), and surfactant-cosolvent solutions, designated as Type I to IV systems depending on their composition and properties. Notably, this chapter details several mechanistic studies that have helped to elucidate the pathways involved for increased absorption of poorly soluble drugs, which have aided in the design and standardization of LBF in vitro characterization methods. Much of this work has evolved through the recent Lipid Formulations Classification System Consortium, an academic-industrial group of experts and stakeholders that have worked to advance the state of the art. The role of sustained supersaturation, triggered by LBF dilution and digestion, in enhancing drug absorption is discussed along with formulation variables intended for this purpose. Finally, a short review is provided on solidification of LBFs and the benefits and challenges associated with the techniques involved.