Eco‐Friendly Preparation of Porous Starch via Water‐Induced Amylose Solubilization

Starch is a safe and biocompatible excipient in pharmaceutical formulations. Introducing pores into its granules transforms it into a biodegradable carrier suitable for drug delivery. Various strategies have been developed to induce pore formation, including physical methods (e.g., microwave, ultrasound), chemical methods (e.g., solvent exchange), enzymatic methods, and synergistic methods. A novel, low-cost and eco-friendly method for preparing porous starch was developed by exploiting its ability to naturally swell when suspended in water under controlled conditions. Thanks to the coexistence of insoluble (amylopectin) and soluble (amylose) fractions, empty pores may be introduced via amylose solubilization. The influence of (i) starch concentration (1%–5% w/w), (ii) contact time (6–24 h), and (iii) temperature (60°C–80°C) on pore formation was experimentally evaluated. Preparation conditions were optimized at 5% w/w of starch, and 60°C temperature for 6 h; well-defined pores with an average diameter of 118.6 nm were observed while maintaining granule integrity. Paracetamol was used to evaluate the effectiveness of porous starch as a drug carrier. Among the drug loading methods evaluated, spray drying led to more efficient and homogeneous results, with reduced crystallinity confirmed by DSC and Raman analyses.