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 physicochem ical characteristics. A factorial design was used to evaluate the influence of these conditions on the particle diameter, zeta potential, polydispersi ty, percentage recovery, and molecular weight of poly(isobutylcyanoacrylate ) nanoparticles. The relationship between these responses and the effects o f 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, gi ving 27 trials. The responses obtained in the experimental design were foun d to be modelled by either a reduced quadratic or second-order model Partic le diameter was found to be a function of the pH. whereas zeta potential de pended on pH and to a lesser extent of the monomer concentration. Polydispe rsity depended on the pH and an interaction term between pH and the surfact ant concentration. The particle recovery was significantly influenced by al l 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(isobutylcyanoacry late) nanoparticles prepared using a wide range of experimental conditions. (C) 1999 Elsevier Science B.V. All rights reserved.