Self-microemulsifying drug delivery systems of Moringa oleifera extract for enhanced dissolution of kaempferol and quercetin

Abstract The aim of the present study was to develop self-microemulsifying drug delivery systems (SMEDDS) of the extract of Moringa oleifera , a herbal medicinal plant. Kaempferol and quercetin, the flavonoids present in the leaf extract of M. oleifera , were chosen as markers for quantification. The optimized formulation of SMEDDS consisted of propylene glycol dicaprylocaprate, polysorbate 80, and polyethylene glycol 400 (PEG 400) in a percentage ratio of 20:60:20 ( m / m ). SMEDDS emulsified immediately (within 20 s) after dilution in water, resulting in transparent microemulsions with a droplet size of 49 nm. SMEDDS could increase the solubility of kaempferol and quercetin to nearly 100 % within 15 min, whereas only a 30 % improvement in solubility was achieved in the case of crude extract. These results demonstrated SMEDDS to be a promising strategy to improve the solubility of M. oleifera extract-derived drugs, which, in turn, could prove beneficial to the herbal medicine field.