Development of chitosan and methylcellulose films containing natamycina as antimicrobial agent

The aim of this work is to develop and evaluate chitosan and methylcellulose films incorporated natamycin as antimicrobial agent. Chitosan and Methylcellulose films were prepared and antimicrobial agent was added to film solutions at room temperature. Migration of natamycin from chitosan and methylcellulose films wereevaluated at 10°C and 20°C, respectively, in 95% ethanol (v/v). Aliquots of 0,5 ml of the simulant were removed at present time intervals, filtered and analysed by HPLC. All of the films were transparent. The average thickness ranged between 38 to 51 μm, and, 56 to 76 μm, for chitosan and methylcellulose films, respectively. After 6 days methylcellulose films were close to the equilibrium, releasing about 70% of natamycin; on the contrary, chitosan film was far from the equilibrium conditions after 24 days, being released less than 15 % of the initial amount of natamycin in the film. Chitosan maintains its structure in a neutral environment but solubilized and degraded in acidic environment. As 95% ethanol (v/v) solution had neutral pH, chitosan film demonstrated higher stability with compact structure, which will make the natamycin diffusion through the film matrix difficult. Moreover, the presence of ethanol at high concentration in the solution limits the film hydration and the weakening effect of the polymer network4, as demonstrates the slow rates of migration obtained.