Response surface methodology as a predictive tool for determining the effects of preparation conditions on the physicochemical properties of poly(isobutylcyanoacrylate) nanoparticles.

Preparation conditions of nanoparticles greatly influence their physicochemical characteristics. A factorial design was used to evaluate the influence of these conditions on the particle diameter, zeta potential, polydispersity, percentage recovery, and molecular weight of poly(isobutylcyanoacrylate) nanoparticles. The relationship between these responses and the effects of simultaneously varying three preparation factors (monomer concentration, surfactant concentration, pH of the polymerization medium) were modelled by response-surface methodology. Three levels were chosen for each factor, giving 27 trials. The responses obtained in the experimental design were found to be modelled by either a reduced quadratic or second-order model. Particle diameter was found to be a function of the pH, whereas zeta potential depended on pH and to a lesser extent of the monomer concentration. Polydispersity depended on the pH and an interaction term between pH and the surfactant concentration. The particle recovery was significantly influenced by all three factors, whereas the pH was the primary influence on the molecular weight. Thus, response surface methodology gave detailed information on the predicted physicochemical characteristics found on poly(isobutylcyanoacrylate) nanoparticles prepared using a wide range of experimental conditions.