Optimization of chitosan-coated W/O/W multiple emulsion stabilized with Span 80 and Tween 80 using Box–Behnken design

The present study aimed to optimize insulin-loaded chitosan-coated W/O/W multiple emulsions (MEs) by investigating the effect of process variables on the response using Box–Behnken design. Effect of three independent factors, which are, the concentration of the lipophilic surfactant (Span 80) in the primary emulsion, the concentration of the hydrophilic surfactant (Tween 80) in the secondary emulsion, and phase volume ratio (W/O) in the primary emulsion, was studied on three dependent responses, which are particle size, zeta potential, and entrapment efficiency. The optimized ME showed particle size of 193.7 nm and −64.58 mV zeta potential with maximum entrapment efficiency of 91.84%. The in vitro drug release profile from W/O/W ME was studied under two simulated physiological conditions. In vitro drug release behavior followed the Peppas–Sahlin model and showed an initial and rapid release followed by a slower release. The results of the present investigation suggest the potential of the chitosan-coated W/O/W MEs as a promising oral drug delivery system for insulin.