Propolis wax nanostructured lipid carrier for delivery of β sitosterol: Effect of formulation variables on physicochemical properties

Preparation and characterization of novel functional nanostructured lipid carriers containing β sitosterol has been studied. The nanostructured lipid carrires (NLCs) were formulated with propolis wax (PW) alone or in mixture (1:1 w/w) with glyceryl behenate (GB), and pomegranate seed oil (PSO) and produced by a hot melt emulsification method. Response surface methodology was used to optimize formulations with respect to β sitosterol concentration, liquid lipid content and solid lipid composition. The NLCs formulated with less oil and higher drug content showed higher size and lower encapsulation efficiency. Solid state analysis exhibited lower crystallinity of optimal formulations compared to raw lipids and a drug amorphization into the NLC matrix. The compatibility between drug and encapsulating materials was confirmed by Fourier transform infrared spectroscopy. Transmission electron microscopy showed spherical particles ranged around 100 nm confirming the applicability of such formulations for the production of functional foods.