Phosphorylated Starch‐Enhanced Controlled‐Release Formulations for Agricultural Applications

ABSTRACT This study aims to optimize slow‐release formulations for agricultural use by employing biodegradable materials. The tablet contains salicylic acid (100 mg) as the active ingredient, three excipients: phosphorylated starch (PS), polyvinyl alcohol (PVA), and polyvinyl acetate as a membrane to regulate the release. The findings demonstrate that PS significantly enhances water retention, with water uptake increasing from 253 to 384 mg as PS content rises from 0 to 50 mg per tablet, representing a 52% increase. Experiments conducted at different pH levels (1.64 and 7.1) and with varying numbers of coating layers (1–3) revealed a complex two‐step release mechanism that could not be fully described by traditional kinetic models (Higuchi and Korsmeyer–Peppas). This formulation shows strong potential for agricultural applications, such as slow‐release fertilizers and plant stimulants, offering prolonged activity, reduced environmental impact, and improved plant resistance to stress and pathogens.