Lipid-based solubilization technology via hot melt extrusion: promises and challenges

Self-emulsifying drug delivery systems (SEDDS) are a promising strategy to improve the oral bioavailability of poorly water-soluble drugs (PWSD). The excipients of SEDDS enable permeation through the mucus and gastro-intestinal barrier, inhibiting efflux transporters (e.g. P-glycoprotein) of drugs. Poor drug loading capacity and formulation instability are the main setbacks of traditional SEDDS. The use of polymeric precipitation inhibitors was shown to create supersaturable SEDDS with increased drug payload, and their solidification can help to overcome the instability challenge. As an alternative to several existing SEDDS solidification technologies, hot melt extrusion (HME) holds the potential for lean and continuous manufacturing of supersaturable solid-SEDDS. Despite being ubiquitously applied in solid lipid and polymeric processing, HME has not yet been widely considered for the preparation of SEDDS.


  • The major barriers to the bioavailability of the orally administering PWSDs are the solubilization, mucus, permeation and pre-systemic metabolism barrier.
  • Lipid-based delivery systems (LBDS), particularly self-emulsifying drug delivery systems (SEDDS) show high potential in improving oral bioavailability of poorly water-soluble drugs (PWSD) by mimicking the endogenous lipid metabolism pathway.
  • Solid physical state of SEDDS is achieved via spray drying, freeze drying, adsorption on solid carriers, wet or melt granulation and hot melt extrusion (HME).
  • HME is an unexploited way of preparing the new generation of solid SEDDS (S-SEDDS), which could be considered as “amorphous solid dispersions (ASD) with self-emulsification ability upon oral administration“.
  • Formulation (material selection and compatibility, material and final product characterization, storage stability) as well as process considerations (temperature, melt viscosity, HME setup) of developing S-SEDDS via HME are presented in detail.

Areas covered

The review begins with the rationale why SEDDS as the preferred lipid-based delivery systems (LBDS) is suitable for the oral delivery of PWSD and discusses the common barriers to oral administration. The potential of LBDS to surmount them is discussed. SEDDS as the flagship of LBDS for PWSD is proposed with a special emphasis on solid-SEDDS. Finally, the opportunities and challenges of HME from the lipid-based excipient (LBE) processing and product performance standpoint are highlighted.

Read more

Ožbej Zupančič, Martin Spoerk & Amrit Paudel (2022) Lipid-based solubilization technology via hot melt extrusion: promises and challenges, Expert Opinion on Drug Delivery,

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