CHITOSAN/CARBOXYMETHYLCELLULOSE POLYELECTROLYTE MICROCOMPLEXES AS AN EFFICIENT MATERIAL FOR CARRYING OF NIACINAMIDE

Biopolymers complexes for carrying and controlled release of compounds have attracted the attention from both industry and academia, as these supramolecular structures improve selectivity, incorporation efficiency and temporal stability of bioactive compounds in formulations. The inclusion of bioactive compounds in such vehicles is applicable in different areas, like agrochemical, pharmaceutical and food. Chitosan (CHS; polycation) and carboxymethylcellulose (CMC; polyanion) are two strategic polysaccharides for this purpose, due to their biodegradability, non-toxicity, and already legally authorized use in foods. This research aimed to propose an inexpensive and efficient strategy for the incorporation of niacinamide in CHS-CMC polyelectrolyte micro-complexes (micro-PECs). A Box-Behnken design was adopted to study the effects of three independent variables – processing time (X1: 60, 120 and 180 min), pH (X2: 3, 4 and 5) and niacinamide concentration, (X3: 0.02, 0.04 and 0.06, g•L-1), on the encapsulation efficiency (Y1) and binding capacity (Y2) of CHS-CMC micro-PECs towards niacinamide. The analysis of all experimental data (p = 0,05) showed that only pH and niacinamide concentration were statistically significant for encapsulation efficiency, which decreased with increasing pH (negative coefficient in the adjusted model) and increased with increasing concentration of niacinamide (positive coefficient in the adjusted model). However, the magnitude of the positive coefficient was smaller than the negative one, indicating that the efficiency of the process is more dependent on the pH than the initial niacinamide concentration. Efficiency and encapsulation of niacinamide ranged from 0.86 to 80.78%, the highest of which was obtained with the following experimental conditions: pH = 3, stirring time = 2 h and initial concentration of niacinamide = 0.06 g/L. Thus, we demonstrated that CHS-CMC micro-PECs represent a simple and effective alternative to carry niacinamide. Studies are now on the way quantitatively characterize niacinamide release kinetics when niacinamide-loaded micro-PECs are exposed to simulated gastrointestinal conditions.