Objective: Interpenetrating polymer network (IPN) hydrogel
beads have been prepared for the controlled release of theophylline.
Method: Theophylline loaded IPN hydrogel beads of casein and sodium
carboxymethyl xanthan (SCMX) were prepared by simple ionotropic
gelation and covalent crosslinking method in an aqueous environment.
Hydrogel beads were characterized by Differential scanning calorimetry
(DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy
(FTIR), and Scanning electron microscopy (SEM). Release of drug from
beads has been investigated in pH 1.2 KCl/HCl buffer and pH 6.8 phosphate
Results: Release of drug from beads has been investigated in pH 1.2 KCl/HCl buffer and pH
6.8 phosphate buffers. All the formulations exhibited slow drug release in pH 1.2 KCl/HCl
buffer and the maximum drug release in 2 h was 20.45±0.31 %. The dissolution profiles of
theophylline in phosphate buffer solutions (pH 6.8) from hydrogel beads also showed retarded
release pattern. Retardation of drug release was observed with increasing casein concentration,
glutaraldehyde (GA) concentration, and drug loading. However, increasing aluminium chloride
(AlCl3) concentration showed a quicker drug release. Drug release from hydrogel beads
followed Fickian and anomalous transport in both the dissolution medium.
Conclusion: Sodium carboxymethyl xanthan and casein cross-linked with Al3+ and GA could
be an appropriate matrix for the preparation of interpenetrating polymer network hydrogel
beads for controlled release of theophylline.