Impact of a formulation design on resultant dispersions of self-microemulsifying lipid systems

Abstract

There is growing interest in the field of self-emulsifying lipid-based technology (SELBT) as an approach to enhance the bioavailability of poorly water-soluble drugs. As a result, the market has witnessed the introduction of more than 30 commercial products based on SELBT. In this investigation, key elements in the formulation design of oil systems which influence vehicle polarity and thus resultant dispersion profiles were optimized. Self-emulsification studies, particle size analysis, and phase behavior studies were carried out with and without drugs. Profiles were compared with commercial Ibuprofen liquigel capsules. Various factors including type of oil, cosurfactant, surfactant, cosolvent, and amount of loaded drug were found to influence dispersion profiles of the self-emulsifying lipid-based system. Furthermore, a significant correlation between total HLB of oil mix and mean emulsion droplet size of resultant aqueous dispersion was established. Also, emulsification of commercial Ibuprofen liquigel capsules has revealed drug precipitation, while self-microemulsifying lipid systems kept the drug in a dissolved state. In conclusion, despite the in vitro apparent failure of cosolvent-based formulation as in commercial Ibuprofen liquigel, these systems still have valid pharmacokinetic profiles.