A Mechanistic PFEP Framework for Stabilizing Peptides in Final Aqueous Formulations

A peptide solution can lose quality through oxidation, deamidation, hydrolysis, epimerization, disulfide exchange, adsorption, oligomerization, aggregation, and particulate formation. PFEP cannot confer permanent stability by changing water alone. This article instead treats electrochemically generated fractions as transient, qualified processing reagents used before final composition lock. A multi-pathway kinetic model combines pH-dependent chemical degradation, oxygen/metal-mediated oxidation, and concentration-dependent aggregation. Synthetic accelerated data predict 91.7% intact monomer after 28 days at 40 °C for a PFEP-preconditioned candidate and 82.4% for a matched static candidate; Arrhenius extrapolation gives planning t90 values of 17.2 and 9.1 months at 25 °C. These are not shelf-life claims and cannot replace real-time final-container studies. A stability-indicating analytical package and ICH-aligned validation programme are proposed. Article type: Formulation theory with synthetic accelerated-stability data. All numerical results labelled synthetic or modelled are hypothesis-illustration and planning outputs, not experimental measurements. No wet-laboratory experiment, validated process, clinical benefit, or shelf life is claimed.