Stimuli-Sensitive Poly(NIPA-co-APA) Hydrogels for the controlled release of Keterolac Tromethamine

Abstract

The pH sensitive hydrogels composed of N-isopropylacrylamide (NIPA) and acryloyl phenylalanine (APA) were prepared by redox polymerization using N,N'-methylenebisacrylamide (MBA) as a crosslinker. Anti-inflammatory and analgesic agent, Keterolac Tromethamine (KT), was loaded successfully into poly(NIPA-co-APA) copolymeric hydrogels by swelling equilibrium method. To understand the nature of drug in the polymeric matrix, the newly synthesized drug loaded poly(NIPAco- APA) copolymeric hydrogels were characterized by using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. The scanning electron microscopy (SEM) technique result indicates the spherical smooth surface of the hydrogels. The drug (KT) releasing nature of the poly(NIPA-co-APA) hydrogels was studied in pH 1.2 and 7.4. Effects of drug loading, crosslinking agent, pH and the ionic strength of the external medium on swelling of hydrogels were also investigated.