Synthesis and Characterization of Chemically Cross-Linked Acrylic Acid/Gelatin Hydrogels: Effect of pH and Composition on Swelling and Drug Release

Table 6

Effect of different concentrations of acrylic acid on drug release kinetics of AA/Gelatin hydrogels in solutions of different pH values using EGDMA as cross-linking agent (0.70% w/w).

Sample codes	AA contents (%)	pH	Zero-order kinetics		First-order kinetics		Higuchi model
			(h^−1)		(h^−1)		(h^−1)
U4	28	1.2	1.75	0.991	0.020	0.991	0.068	0.958
		5.5	3.945	0.997	0.057	0.990	0.157	0.958
		7.5	5.127	0.991	0.092	0.976	0.204	0.959
U5	32	1.2	2.076	0.992	0.024	0.986	0.081	0.930
		5.5	4.149	0.994	0.063	0.995	0.167	0.979
		7.5	5.177	0.994	0.099	0.951	0.206	0.950
U6	36	1.2	1.948	0.985	0.023	0.980	0.077	0.942
		5.5	4.401	0.995	0.071	0.986	0.177	0.971
		7.5	5.679	0.985	0.119	0.987	0.232	0.997