Abstract

STARCH-ACRYLIC ACID HYDROGEL: SYNTHESIS, CHARACTERIZATION AND DRUG RELEASE STUDY.

Md. Mateen M. Shaikh*, Nitin. S. Gramopadhye, Anand. A. Wardole,
Shrikant .V. Lonikar*

ABSTRACT

Starch-acrylic acid graft hydrogels were prepared by using ceric ammonium nitrate (CAN) as initiator and methylene bis acrylamide (MBAm) as crosslinker. The hydrogels were prepared by varying the amount of the crosslinker (0.5 mole %, 2 mole %, 5 mole %). The crosslinked hydrogels swelling properties were studied at different pH (1.2 and 7.4). The equilibrium swelling of the hydrogels at pH 1.2 was slow as compared to pH at 7.4. In vitro drug releases from these hydrogels were studied using paracetamol as a model drug. In vitro drug release showed that the drug release from the hydrogel was less at pH 1.2 compared to at pH 7.4. 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. However, in the medium of pH 7.4 the complete ionization of COOH group result in extensive chain relaxation due to repulsion among similarly charged –COO groups present in macromolecule chain. This suggests that diffusion of the entrapped active agents will be greatly enhanced with a change in pH of the medium, thus making these copolymers as a potential candidate for the use in agriculture, biomedicine, pharmaceutics and controlled delivery of bioactive agent.

Keywords: Starch, acrylic acid, pH sensitive hydrogels, swelling, controlled drug delivery.