Self-emulsifying drug–delivery systems (SEDDS) have been widely employed to ameliorate the oral bioavailability of P-glycoprotein (P-gp) substrate drugs and to overcome multidrug resistance in cancer cells. However, the role of formulation aspects in the reduced P-gp activity is not fully understood. In this review, we first explore the role of various SEDDS excipients in the reduced P-gp activity with the main emphasis on the effective excipient concentration range for excipient-mediated modulation of P-gp activity and then we discuss the synergistic effect of various formulation aspects on the excipient-mediated modulation of P-gp activity. This review provides an approach to develop a rationally designed SEDDS to overcome P-gp-mediated drug efflux.

Self-emulsifying drug delivery systems (SEDDS) have been mainly investigated to enhance the oral bioavailability of drugs belonging to class II of the Biopharmaceutics Classification System. However, in the past few years, they have shown promising outcomes in the oral delivery of various types of therapeutic agents. In this chapter, we discuss the recent progress in the application of SEDDS for oral delivery of protein therapeutics and genetic materials. The role of SEDDS in enhancing the oral bioavailability of P-glycoprotein and cytochrome P450 3A4 substrate drugs is also highlighted. Also, we discuss the most critical evaluation criteria of SEDDS. Additionally, we summarize various solidification techniques employed to transform liquid SEDDS to the more stable solid self-emulsifying drug delivery systems (s-SEDDS) that are associated with high patient compliance. This chapter provides a comprehensive approach to develop high utility SEDDS and their further transformation into s-SEDDS.

Curcumin (CUR) is a nature polyphenolic phytoingredient. CUR showed anti-inflammatory, anti-oxidant, anti-fungal and anti-cancer activities. The therapeutic efficacy of CUR was limited due to its poor aqueous solubility, poor oral bioavailability. Poor solubility of drugs is the major challenge associated with formulation development. Therefore, the aim of present work was to enhance CUR aqueous solubility and dissolution rate using Physical mixture and its solid dispersion. CUR solid dispersions were prepared by solvent evaporation and Freeze drying techniques using different polymers, such as cyclodextrins, polyvinyl pyrrolidone (PVP K30), polyethylene glycol 6000 and Pluronic®F-127. The prepared physical mixtures, solid dispersions were characterized using different techniques such as (DSC), (FTIR) and (XRD). Furthermore, the solubility and the dissolution rate of the drug in its different systems were explored. The results of physical characterization of the different systems show no interaction between them. Dissolution studies of CUR solid dispersions showed that the highest drug dissolution rate was achieved at CUR/ Pluronic®F-127 weight ratio of 1:3. Also, complete drug dissolution was obtained for CUR/Pluronic F-127 solid dispersion after 30 min compared to 35% dissolution for CUR alone after the same time. Also, CUR permeability coefficient through rat skin for Pluronic®F-127 micelles and solid dispersion were two times higher than that of the CUR alone. The obtained results concluded that, the preparation of solid dispersion of Pluronic®F-127 solid dispersions by freeze drying method is a promising one to overcome CUR shortcomings through enhancing its aqueous solubility, dissolution rate and skin permeability.