A Study on Transforming Potato Starch Through Microwave-Assisted Modification with Isopropenyl Acetate and Its Application towards Advancement in Milrinone Drug Delivery

We report on the modification of potato starch using isopropenyl acetate (MIS) under microwave activation and its application towards the enhanced physicochemical properties of milrinone in one of its cocrystals. The modified starch resulting in improved drug release and stability, along with a significant enhancement in the solubility and dissolution of milrinone in the milrinone-3,4,5-trifluorobenzoic acid cocrystal. The solubility study showed that the 10% MIS formulation led to a 2.12-fold increase in solubility compared to the cocrystal and a 3.02-fold increase relative to milrinone. The dissolution study indicated a 27% enhancement compared to the MRN-345-TFBA cocrystal and a remarkable 127% improvement compared to MRN alone. The surface of native starch was altered to an exposed structure observed by FE-SEM and HR-TEM images. ¹H NMR signals at δ value 1.86, 1.97, and 2.07 ppm along with FT IR peak at 1737 cm⁻¹ in MIS ascertained the bonding of isopropenyl acetate with starch. A mass fragmentation pattern obtained at m/z = 205 supported the replacement of ─OH by the acetate group. XRD study indicated broadened crystal plane indexed as (140) for a 2θ value of 14.72 and thermogravimetric studies reflect the enhanced thermal stability of modified starch due to increased hydrophobicity.