Comparing the performance of two gums for controlled-release pharmaceutical tablets 

Kat Gilmore on October 21, 2026

This is a graphic with the UGA New Materials Institute’s logo in the upper left corner. The bottom center of the graphic contains a QR code that takes you to a story page. The text on the slide reads: Development of sustained-release oral tablets using xanthan and tragacanth gums as release modifiers.

Tablets, the most common form of oral solid dosage, are often formulated with polymers to create extended-release or delayed-release medication. This can be achieved using hydrophilic polymer matrix systems, which absorb water and form a gel layer around the tablet, slowing the release of the active pharmaceutical ingredient. 

In this study, the performances of polysaccharides xanthan gum and tragacanth gum, which are natural polymers, are compared through dissolution testing, kinetic modeling and analyses of complementary gel-layer, swelling and erosion. Caffeine, ibuprofen and 5-aminosalicylic acid were selected as model drugs, representing BCS Classes I, II and IV, to evaluate the effects of polymer type, concentration and drug solubility on release behavior.   

Xanthan gum works by forming a viscous gel layer that limits water penetration into the tablet and slows drug diffusion into the surrounding medium. Its swelling and gel formation vary depending on environmental conditions. Tragacanth gum exhibits both dissolution and swelling properties: its soluble component dissolves in water to form viscous solutions, while its insoluble component absorbs water and swells to form a structured gel network.  

The paper highlights xanthan gum’s ability to facilitate faster diffusion through its thick, highly hydrate gel layers and tragacanth gum’s ability to sustain uniform release over longer periods of time through thinner, less hydrated but more cohesive gel networks that gradually erode over time. Additionally, tragacanth gum was effective at polymer loadings as low as 5% whereas xanthan gum required at least 25% loading for effective release control. Both polymers showed further improvement when blended with other polysaccharides, but ultimately, tragacanth gum outperformed xanthan gum.  

“Development of sustained-release oral tablets using xanthan and tragacanth gums as release modifiers” was coauthored by Nohora P. Manovacia Moreno, Jessica A. Bramhall, Kush G. Patel, Michael Broich II and Jason J. Locklin, all from the Locklin Group, and was published in the International Journal of Pharmaceutics.  

—Written by Leighton Dancy