Instantaneous interaction of mucin with pectin- and carrageenan-coated nanoemulsions.

The efficiency of drug delivery and sensory perception is intertwined with mucoadhesive systems. The physiochemical characteristics of mucus induce flocculation of emulsion droplets, which could significantly influence their sensory perception. In this study, we investigated the interactions between pectin- and carrageenan-coated nanoemulsions with mucin. The size and ζ-potential changes in the nanoemulsions were investigated at pHs 3.0-5.0. The results showed no significant differences (p > 0.05) in size without the addition of gums; however, the ζ-potential decreases from 2.92 mV to -2.51 mV as pH increased. The stability of nanoemulsions over the extended time (15 days) and at elevated temperature (60 °C) resulted in minimal degree of phase separation observed. The mucin particle size method was employed to characterize mucin-nanoemulsion interactions. Results confirmed that mucin-emulsion complexes were formed instantaneously mostly due to electrostatic interactions. The contact angle analysis and UV-Vis spectroscopy confirmed contribution of wetting and absorption mechanisms in the mucin interactions.