Influence of the ionic strength on the physicochemical properties of methotrexate-loaded chitosan polyelectrolyte complexes

Polyelectrolyte complexes (PECs) as drug delivery systems are widely explored since they easily obtained by coacervation and biopolymers can be associated. However, particle distribution is a challenging critical parameter that has been infrequently focused. This work evaluated the effect of NaCl concentration on physicochemical properties PECs based chitosan hypromellose loaded with methotrexate. The size, zeta potential polydispersity index (PdI) were determined DLS, besides entrapment efficiency (EE) in vitro release profile determination. Particle size decreased while rised, achieving narrower (345±79 nm) PdI (0.285±0.067) 200 mmol/L NaCl. higher concentration, lower at acid pH. EE was kept similar ((28.2±4.5) %) from 0 to 300 NaCl, 400 impaired entrapment. addition (200 300) did not affect profile, but it faster (100 or 400) mmol/L. In conclusion, reduced no changes release. Therefore, ionic strength plays an important role development.