Assessment of phenprocoumon stability and excipient compatibility using thermoanalytical techniques and FT-IR spectroscopy

Abstract Phenprocoumon, a widely used anticoagulant in Europe, was assessed for solid-state compatibility with common tablet excipients by FT-IR over time and by thermogravimetric analysis. The excipients investigated included starch, hydroxypropyl methylcellulose, magnesium stearate, lactose, mannitol, talc, silicon dioxide, and polyvinylpyrrolidone, as they are frequently employed in tablet manufacturing as fillers, binders, disintegrants, or lubricants. All excipients proved compatible except magnesium stearate, which showed clear signs of interaction in both FT-IR and thermal analysis, indicating a specific incompatibility that requires caution in formulation. Such compatibility studies are essential in pharmaceutical development, as drug–excipient interactions may compromise stability, bioavailability, and overall therapeutic efficacy.