Gastroretentive floating sterculia–alginate beads for use in antiulcer drug delivery

Alginate–sterculia gum gel-coated oil-entrapped alginate beads for gastroretentive risperidone delivery

“…The ionotropic interactions between the negatively charged carboxylic groups of alginate and sterculia gum molecules and the positively charged calcium ions could lead to the formation of crosslinked biopolymeric membrane around the optimized beads. In addition, hydrogen bonding and electrostatic interactions between the two polysaccharides might be responsible for the membrane formation (Singh et al, 2010;Guru et al, 2013).…”

“…Currently, crosslinked alginate-sterculia gum blend matrices are being used for the preparation of various multiple-unit drug delivery systems (Singh et al, 2010;Guru et al, 2013;Kulkarni et al, 2014) including mucoadhesive beads (Krishna et al, 2009;Latheeshjlal et al, 2013). Therefore, a mucoadhesive biopolymeric coating of ionotropically crosslinked alginate-sterculia gum blend gel onto oil-entrapped alginate beads would impart gastroretention by a combined mechanism of floatation and mucoadhesion, which was not investigated earlier.…”

“…It exhibits excellent swelling with high viscosity and acid stability (Singh and Sharma, 2008). Thus, in the past few decades, an increased emphasis has been given on the usage of sterculia gum as a carrier in drug delivery (Deshmukh et al, 2009;Singh et al, 2010).…”

“…Moreover, the usage of natural polysaccharides blends is a current trend to improve desired functional properties like drug encapsulation, swelling, drug release and stability (Ahuja et al, 2010). Sterculia gum is a water-soluble polysaccharide obtained from the stem exudates of Sterculia urens (Singh et al, 2010). It is composed of partially acetylated polysaccharides of the substituted rhamnogalacturonoglycan, with residues of D-glucuronic acid, D-galacturonic acid, D-galactose and L-rhamnose (Singh and Sharma, 2008, Page 5 of 38 A c c e p t e d M a n u s c r i 5 2011).…”

Gastro retention using polymer cocoons

“…Indeed, while the idea of polyelectrolyte complexation is well known, for over half a century, most literature uses polyanion and polycation microcapsules to demonstrate controlled release in laboratory experiments though without any evidence that gastro retention is possible, nor in sizes of capsules which could, reasonably, be retained. Alginate beads, a complex between a polyanion and salt, have been studied in gastro retention (Singh et al 2010) though the liquefaction of alginate is sensitive to certain compounds (e.g., citrate) and an alginate bead would degrade irregularly depending on food intake and pH compared with a polyanion complexed with a polycation.…”