The present disclosure provides a pharmaceutically acceptable, stable, and optically clear oil- in- water nanoemulsions (intensity-averaged diameter<;100 nm) with an oil phase comprising >;10% w/v of long chain triglyceride, total surfactant and cosurfactant concentration less than that of oil phase and without the use of alcohol as cosolvent in the aqueous phase. The nanoemulsions of this disclosure have extremely favorable particle size distribution, optical clarity, and product stability against Ostwald ripening with high levels of oil concentrations. Poorly water soluble, therapeutically active agents and others can be incorporated in the nanoemulsion systems to improve their solubility/stability in aqueous medium or to enhance their delivery for use in pharmaceutical, food, cosmetic, and other applications by oral, intravenous, subcutaneous, intra muscular, inhalation, nasal, topical, ocular, and transdermal routes.