Ionotropic crosslinking of sodium carboxymethylcellulose and sodium carboxymethylcellulose‐gelatin matrices and their erosion properties

Abstract Hydrophilic sodium carboxymethylcellulose (NaCMC) matrices were chemically modified into hydrophobic gels by ionotropic crosslinking with cupric or ferric ion under ambient temperature and pH. Insoluble matrices were also prepared using an interactive polymer gelatin in combination with NaCMC. These matrices underwent erosion at the crosslinks, followed by matrix erosion when released in water. The matrix erosion in water was influenced by the gelling agent, initial crosslinker density, and gelatin content in the insolubilized matrices. The apparent diffusion coefficients of fenthion ranged from 7.2 × 10 −9 to 175.6 × 10 −9 cm 2 /sec, with matrices prepared under different conditions. These erosion‐controlled matrices can be used for the controlled release of various biologically active agents. © 1993 John Wiley & Sons, Inc.