Towards an Understanding of the Adsorption of Vaporized Hydrogen Peroxide (VHP) Residues on Glass Vials After a VHP Decontamination Process Using a Miniaturized Tool

Isolators for aseptic filling of biopharmaceuticals and vaccine products are commonly sanitized by vaporized hydrogen peroxide (VHP). However, remaining traces of H₂O₂ may contaminate the solution and cause oxidative degradation of the pharmaceutical products. The present report aims to establish a thorough understanding of the factors influencing H₂O₂ adsorption on empty glass intended for pharmaceutical product filling. A lab-scale miniaturized set-up that mimics the VHP- based isolator decontamination process was used. A fractional factorial design of experiment (DoE) was performed including relative humidity (RH), VHP concentration and exposure time as variables. The results revealed that VHP concentration and RH both impacts significantly the extent of H₂O₂ adsorption on the surface of glass vials and rubber stoppers. The lower extent of H₂O₂ adsorption at elevated RH implies the existence of competitive co-adsorption. Thus, adsorbed H₂O₂ may be removed more efficiently from the isolator after the decontamination phase by insufflating air with a high %RH rate during the isolator's aeration phase. The understanding gained from the present set-up can be applied to optimize the design of isolator decontamination cycles and evaluate the trade-off between process performance and the resulting product quality.