Gum acacia-acrylic acid hydrogels: pH sensitive materials for drug delivery system

• Published in: Asian Journal of Research in Chemistry 2014-04, Vol.7 (4), p.407
• Main Authors: Shaikh, Md Mateen M, Lonikar, Madhubala S, Lonikar, Shrikant V
• Format: Article
• Language: English
• ISSN: 0974-4169; 0974-4150

In this paper, graft copolymer hydrogels that are pH sensitive were synthesized by ceric ion initiated graft copolymerization of acrylic acid onto gum acacia in aqueous medium in the presence of varying amount of N, N-methylene bisacrylamide as a crosslinking agent. As the amount of crosslinker increases, the swelling properties decreases gradually and that the copolymers undergo a sharp volume phase transition with the change in pH of the swelling medium from an acid to an alkaline one. This can be attributed that the -COOH group present within network remains almost intact, moreover there exist strong H- bonding interaction between -COOH groups of acrylic acid and -CONH2 group of MBAm which are present within the network, thus resulting in movement of polymeric segment within the hydrogel. This suggests that the diffusion of the entrapped active agents will be greatly enhanced with a change in pH of the medium, making these copolymers a potential candidate for the use in agriculture, biomedicine, pharmaceutics and controlled delivery of bioactive agents.