**7. Nanoemulsions for phytopharmaceuticals**

Recently, considerable attention has been focused on the development of novel drug delivery systems for herbal drugs [198]. However some limitations of plant bioactives like instability in highly acidic pH and liver metabolism led to drug levels below therapeutic concentration in the blood resulting in less or no therapeutic effect [199]. Hence, encapsulation of plant extracts or its bioactives would minimize their degradation or presystemic metabolism, and serious side effects due to accumulation of drugs to the non-targeted areas and improves the ease of administration in the pediatric and geriatric patients [200]. Lipid nanoemulsions containing oil from medicinal plants or hydrophobic drugs have been shown to improve drug solubility, reduce side effects of various potent drugs, increase the bioavailability of drugs, and to prolong the pharmacological effects in comparison to conventional formulations such as conventional emulsions [201]. Formulation of nanoemulsions containing phytoactives have been reported.

The effect of nanoemulsion on intestinal absorption of colchicine was demonstrated *in vivo*. Colchicine nanoemulsion was prepared with isopropyl myristate, eugenol, Tween 80, ethanol and water, with eugenol being the oil phase in the formulation. Result obtained indicated that the intestinal absorption of colchicine was significantly enhanced by the nanoemulsion formulation [202]. Genistein has been shown to possess anticancer activities in different experimental systems, yet the same effects could not be translated in the clinical setting due to its poor bioavailability. Researcher have tried various nano approaches including incorpo‐ ration of genistein into topical nanoemulsion formulations composed of egg lecithin, medium chain triglycerides or octyldodecanol and water by spontaneous emulsification with improved activity [203]. Oil in water nanoemulsion formulation has also demonstrated increased antiinflammatory activity of curcumin [204].
