Crosslinking of alginic acid/chitosan matrices using polycarboxylic acids and their utilization for sodium diclofenac release.

Three different ratios of alginic acid/chitosan matrices of ratios 3/1, 1/1 and 1/2, respectively, were crosslinked in their dry state using citric acid (CA)/sodium hypophosphite (SHP) at different conditions controlling the crosslinking process such as citric acid concentration, citric acid/sodium hypophosphite molar ratio as well as time and temperature of reaction. Results indicate that such matrices were crosslinked efficiently on curing at 180°C for 9min in presence of CA/SHP ratio 1 and the citric acid concentration of 0.6 based on the weight of any matrices. The crosslinked matrices were characterized by investigating their swelling properties, FT-IR and thermalgravimetric analysis. Furthermore, such crosslinked matrices were tested as drug release for sodium diclofenac.