Application of simultaneous multiple response optimization in the preparation of thermosensitive chitosan/glycerophosphate hydrogels

LUCIANO N. MENGATTO; JUAN I. PESOA; NATALIA S. VELÁZQUEZ; JULIO A. LUNA

IRANIAN POLYMER JOURNAL

POLYMER RESEARCH CENTER IRAN

Lugar: Tehran; Año: 2016 vol. 25 p. 897 - 906

1026-1265

The parameters affecting the sol/gel transition of chitosan based thermogelling systems, their final properties and structure have been reported. Nevertheless, equations that describe this relationship for a particular case have not been developed. The aim of this study was to develop these equations for a general formulation without drugs so they could be used for the preparation of delivery systems of different drugs. First, a factorial design was built in order to evaluate the main factors affecting the pH of the gel-forming solution, gelling time at ambient temperature and 37.5 ºC and residual mass after exposure to a buffer solution. The independent factors analyzed were: chitosan concentration, β-Glycerophosphate concentration, mixing temperature and mixing time. Mixing time was the only factor whose effect on the responses was not significant; the other three factors were considered for the optimization study. Then, a central composite design based on response surface methodology was carried out in order to develop statistical models which describe the relationship between active independent factors and the studied responses. The optimized gel was prepared and characterized. FTIR experiments allowed observing that hydrogen bonds and electrostatic attraction were the main type of interactions after sol-to-gel transition. The most important finding of this investigation is that the resulting equations can be used to prepare gel-forming solutions with desired pH, gelling time, and residual mass. Then, the significance of these equations lies in its potential use for the design of hydrogels intended for controlled drug delivery.