Development of amylopectin based polyurethanes for sustained drug release studies.

ABSTRACT

In this research work, the crosslinked structure of polyurethane has been exploited for sustained drug delivery. Polyurethane composites have been prepared by the reaction of isophorone diisocyanate (IPDI) and polycaprolactone diol (PCL), which were further extended by varying the mole ratios of amylopectin (AMP) and 1,4-butane diol (1,4-BDO) chain extenders. The progress and completion of the reaction of polyurethane (PU) were confirmed using Fourier Transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopic techniques. Gel permeation chromatography (GPC) analysis showed that the molecular weights of prepared polymers were increased with the addition of amylopectin into the PU matrix. The molecular weight of AS-4 (Mw ≈ 99,367) was found threefold as compared to amylopectin-free PU (Mw ≈ 37,968). Thermal degradation analysis was done using thermal gravimetric analysis (TGA) and inferred that AS-5 showed stability up to 600 °C which was the maximum among all PUs because AMP has a large number of -OH units for linking with prepolymer resulting in a more cross-linked structure which improved the thermal stability of the AS-5 sample. The samples prepared with AMP showed less drug release (<53 %) as compared to the PU sample prepared without AMP (AS-1).