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

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.