Experimental investigation and modeling of the anti-cancer drug delivery from poly(N-isopropylacrylamide-co Acrylic acid) copolymeric hydrogels.

The diffusion mechanism of a model anti-cancer drug in cross-linked poly(N-isopropylacrylamide/acrylic acid) (P(NIPAAm/AA) copolymeric hydrogels was studied. The crosslinking ratiowas constant but acrylic acid ratio ranged from 10:1 to 10:3. P(NIPAAm/AA) copolymeric hydrogels were synthesized by redox-initiated free radical polymerization in water at room temperature The presence of poly(ethyleneglycol) in the hydrogel formulation resulted the higher mechanical strength. Use of acrylic acid resulted in higher hydrogel swelling. Drug size was also found to be a significant factor. 5-FU is used as amodel anti-cancer drug. The effect of 5-FU solution on swelling characteristics P(NIPAAm/AA) copolymeric hydrogels have also been studied. The percent swelling, equilibrium swelling, diffusion constant values are evaluated for P(NIPAAm/AA) copolymeric hydrogels at 1.5% of 5-FU solution at room temperature Based on the release kinetic of the 5-FU drug, the hydrogels displayed a non-Fickian diffusion mechanism. According the diffusion kinetic data in hydrogels became clear that diffusion kinetic data were best described by Peppas model. Permeation from P(NIPAAm/AA) copolymeric hydrogels followed a Super Case II transport mechanism, most likely driven by macro molecular chain relaxation and swelling of hydrophilic polymers.