Effect of the loading method on the drug release from cross-linked carboxymethylcellulose beads

Spherical matrices (beads) of cross-linked carboxymethylcellulose were prepared by the in-liquid curing coating process using AlCl3 as curing agent (cross-linker). The loading process was carried out either by adding the drug to the polymer solutions before the extrusion process or by swelling the cross-linked beads in a drug solution. The energy dispersive X-ray (EDS) analysis showed a homogeneous distribution of both the drug concentration and cross-linking density in the network regardless to the loading procedure. When the loading process was carried out before the extrusion process, a residual amount of AICl3 remained in the beads. The effects of the residual amount of AlCl3 on the matrix swelling and drug release processes were analyzed.