Swelling Kinetics of Poly(N-Isopropylacrylamide)-Based Hydrogel and its Application as Anti-Diabetic Drugs Delivery System

The swelling kinetics of charantin from poly (N-isopropyl acrylamide), PNIPAM–based hydrogel, is accomplished through direct weighing, before soaking the gel in fluid/drug solution at controlled temperatures inside a temperature-controlled water bath. The investigation was carried out for application as anti-diabetic drug delivery system. Charantin was extracted from bitter melon fruit and leaf under a controlled pH of 4.5. The preparation of PNIPAM was done by varying the acrylamide between (3-12)% and show increase in the lower critical solution temperature (LCST) from 32- 43℃ which indicates a direct relationship in distilled water. The effect of changing solution from distilled water, insulin, and charantin solution, shows that the higher the polarity of the solution, the lower the LCST of the hydrogel. Charantin loaded on hydrogels N1, N2, N3, and N4 were found to be (42.51, 44.57, 43.55 and 44.61)μg/mL, respectively, when soaked in charantin solution of 52.61 μg/mL. Characterization of the hydrogels using Fourier transformed infrared (FTIR) spectroscopy shows that there is physical interaction between the hydrogel matrix and the charantin molecules. The diffusivity of the hydrogels ranged from 1.48 x 10-10 to 5.08 x 10-8 M2/s and their release exponents were ≥ 0.5 indicative of non-Fickian difusional release.