Formulation design and pharmacokinetic evaluation of docosahexaenoic acid containing self-nanoemulsifying drug delivery system for oral administration

Docosahexaenoic acid is a omega-3-fatty acid which together with other long-chain omega-3-fatty acid known to have protective effect against various diseases including hypertension, myocardial infarction, Alzheimer disease, and cancers. Poor bioavailability owning to limited aqueous solubility limits its effective therapeutic delivery. Self-nanoemulsifying drug delivery systems are known to enhance the systemic absorption of poorly bioavailable lipophilic bioactive/therapeutics compounds. The purpose of this work was to investigate the potential of self-nanoemulsifying drug delivery systems produced by spontaneous nanoemulsification to enhance the oral bioavailability of docosahexaenoic acid. Initially, the screening of oil, surfactant, and cosurfactant was carried out by determining the miscibility and emulsifiability of the component with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems were prepared using Capryol 90, Tween 20, and polyethylene glycol 200 due to their excellent miscibility and emulsifiability with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems’ droplet size, size distribution, and zeta potential were found to be 111.5 ± 4.2 nm, 0.269 ± 0.05 nm, and −23.53 ± 2.9 mV, respectively. The in vitro drug release and ex vivo absorption studies showed better in vitro release and intestinal absorption as compared to docosahexaenoic acid aqueous dispersion. In vivo studies demonstrated a significant increase ( p < 0.001) in the oral bioavailability of docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems in comparison to a docosahexaenoic acid aqueous dispersion. This indicated the potential of self-nanoemulsifying drug delivery systems as an effective unit dosage form for the oral delivery of docosahexaenoic acid.