Table 3 Comparison between current work and relevant previous studies

1

Thermally stable venlafaxine HCl loaded polyethylene glycol-co-poly (acrylic acid) hydrogels were developed using benzyl peroxide as initiator. Equilibrium swelling was investigated at pH 1.2 and pH 7.5. Venlafaxine HCl release was 33% and 91% at pH 1.2 and pH 7.5

[36]

2

Gamma radiation assisted development of polyethylene glycol-co-poly (acrylic acid) hydrogels for site specific delivery at a controlled rate. Optimum swelling i.e. more than 2500% documented at pH 7 instead of pH 1. Significant drug release was recorded in at elevated pH levels

[37]

3

Ultraviolet radiation assisted development of biocompatible polyethylene glycol –co- poly (acrylic acid) interpenetrating network

[38]

4

Aqueous free radical polymerization technique was employed to develop thermally stable PEG based hydrogels for controlled delivery of Ivabradine hydrochloride. Drug release and swelling kinetics were conducted at pH 1.2 and pH 6.8

[39]

5

Thermally stable, biocompatible, mechanically strong and non-cytotoxic PEG-co-poly (acrylic acid) hydrogels developed for diffusion based absorption purposes. Swelling studies were conducted at pH 2, 7 and 10. Pronounced swelling reported at pH 7 and pH 10

[40]

6

PEG-co-poly (acrylic acid) hydrogels developed via free radical solution UV polymerization. Theophylline release was higher at lower crosslinker content. Release was pH dependent

[41]