ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and evaluation of MDI-based polyurethane matrices from maize grain polyol and a novel saccharide chain extender for gastric delivery of 5-fluorouracil

Sapna Sharma, Kiran Kumar, Ghanshyam S. Chauhan, Sandeep Chauhan, Kriti, Shamsher Singh Kanwar, and Sohini Sharma

Department of Chemistry, Himachal Pradesh University, Shimla, India

E-mail: drkiran@hpuniv.ac.in

Received: 2 December 2025  Accepted: 10 March 2026

Abstract:

Due to severe systemic adverse effects, poor stomach retention, and inadequate bioavailability from premature and uncontrolled drug release, conventional oral administration of 5-fluorouracil (5-FU) is not commercially available. In order to overcome these constraints, biocompatible floating polyurethane (PU) matrices were created employing methylene diphenyl diisocyanate (MDI) as the polyisocyanate and powdered maize grain (M^g) as a sustainable bio-polyol. Enzymatic hydrolysis of M^g produced glucose, which was then dehydrated and acetylated with glycerol to create a new bio-based chain extender (CE). PU matrices were created by an exothermic polyaddition process between M^g, CE, and MDI that produced porous structures through in situ carbon dioxide generation. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) were used to thoroughly characterize the synthesised matrices. The matrices showed pH-responsive swelling, and at acidic pH, their stability and performance were at their best. Matrices with increasing chain extender ratios showed controlled 5-FU release following the first-order kinetics. Sustained delivery over 25 h was made possible by a higher ratio of CE, which produced the slowest rates (lowest k₁). Cytotoxicity studies using the rhabdomyosarcoma cell line confirmed matrix biocompatibility and anticancer efficacy of drug-loaded formulations. The drug-loaded matrix also exhibited antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, and Shigella flexneri. Degradation showed 31.1–34.7% weight loss over 10 days in alkaline medium. The floating capability with sustained release properties positions PU_M^g-3 as a promising candidate for the stomach-specific delivery of 5-FU.

Graphical abstract

Keywords: Gastro-retentive; Anti-cancer; Sustained drug release; 5-Fluorouracil

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04803-8

Chemical Papers 80 (6) 6845–6862 (2026)