PFEP Preconditioning of Exenatide Solutions: Separating Compounding History from Long-Term Stability

Exenatide is a 39-residue linear peptide whose solution degradation is strongly pH dependent. Published work shows relative stability near pH 4.5, oxidation-dominant loss at pH 5.5–6.5, and increasing deamidation and aggregation at pH 7.5–8.5. This article tests a bounded PFEP proposition: qualified fraction dosing may shorten damaging transient conditions during dissolution and pH adjustment, but cannot replace the stabilizing effect of the final composition. A synthetic kinetic model predicts 89.0% intact monomer after 28 days at 37 °C for a rapid PFEP-conditioned transition to pH 4.5 versus 76.2% for a prolonged neutral-pH compounding history. A chemically reconstructed rapid transition predicts 88.6%, which would refute electrochemical uniqueness while retaining an engineering benefit. The numbers are simulations, not experimental results. Article type: Formulation hypothesis with synthetic degradation 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.