Ionically cross-linked pH-responsive interpenetrating polysaccharide network hydrogel tablets for colon-targeted...

To develop ionically cross-linked pH-responsive interpenetrating polysaccharide network hydrogel tablets for the colon-targeted delivery of budesonide (BUD).

The pH-responsive behaviour ensures protection of the drug during its transit through the stomach and small intestine, limiting drug release to less than 10% over a 5 h period.

We developed a series of BUD loaded pH-responsive single network and interpenetrating double network hydrogel tablets using natural polysaccharides cross-linked with Ca²⁺ ions.

Both the single network hydrogel and the interpenetrating polymer network (IPN) double network hydrogel were unable to restrict drug release during the initial 5 h transit through the gastrointestinal tract (GIT). An important finding of the study was that the semi-interpenetrating polymer network (semi-IPN) hydrogel matrix tablets exhibited acceptable swelling, erosion, and drug release profiles compared to the single network and IPN hydrogels. The optimized semi-IPN hydrogel matrix tablets, prepared with equal amounts of guar gum (GG) and carboxymethyl cellulose (CMC) cross-linked with calcium ions, exhibited no drug release within the first 4 h, and only a small amount of drug of about 9% was released after 5 h of the dissolution study.

This semi-IPN hydrogel matrix was found to be suitable for the effective colon-specific delivery of the hydrophobic drug BUD.