Swelling Behavior of Calcium–Ions Crosslinked Bipolymeric Sodium Alginate–Lignosulphonic Acid Blends

Abstract

A series of blends based on lignosulfonic acid (LSA) and sodium alginate (NaAlg) were prepared with varying proportions of NaAlg and LSA using a solution-casting method. The swelling /degradation behavior of blends was studied so that they can be used for gastrointestinal drug delivery. Effect of crosslinking, pH, alginate content, and treatment with strong acid on swelling properties of the blends was investigated. It was found that blends show pH-sensitive swelling and show less water uptake due to crosslinking, while crosslinking is reduced in the presence of strong acid. Thus these blends offer their strong candidature for possible use in drug delivery.

Keywords:

• bipolymeric blends
• lignosulphonic acid
• sodium alginate
• swelling

Acknowledgments

The authors thank the Amrita School of Engineering for providing the facilities and giving permission to publish this article. The authors are grateful to the Chair, Department of Chemistry, Mr. Nanjunda Reddy, and Dr. B. L. Baskar for his constructive criticism and guidance. Thanks are also due to all our colleagues in the Department of Chemistry for providing constant support and encouragement.