Formulation and Characterization of Chitosan-Coated BNN27-Loaded Nanoemulsions

After the identification of the optimal NE composition, BNN27-loaded NEs were formulated by the spontaneous emulsification (titration) method. For this, a saturated solution of BNN27 in Capmul MCM was prepared by adding 40 mg/mL BNN27 in the oil phase and applying magnetic stirring. Then, in the BNN27 Capmul MCM phase, the Smix (containing Tween 80 as surfactant) was added until a clear mixture was produced. Finally, H₂O was added dropwise and stirred to produce clear NEs of BNN27. If all of the BNN27 is loaded with a 10% w/w oil phase, the NEs should contain 4 mg of BNN27 per mL of NE.
Mucoadhesive, chitosan (CHT) or carbopol (CAR) coated BNN27-loaded NEs (BNEs) were also prepared. For this, concentrated BNEs (using the minimum volume of the external phase) were initially prepared, and then mixed with the required volume of CHT or CAR aqueous solution to attain a final CHT or CAR concentration of 0.3% w/w. After the addition of CHT or CAR, the BNEs were allowed to homogenize by continuous stirring for 1 h.