Barrier properties and hydrothermal aging of amorphous alumina coatings applied on pharmaceutical vials

Abstract

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Silicon Oxynitride Coatings Are Very Promising for Inert and Durable Pharmaceutical Glass Vials

“…The question then arises as to whether the observed barrier performance is due to the coating, to the heat treatment of the vial, or to both. Indeed, heat treatment can improve the densification of the silicate network , and can also induce an interdiffusion zone between the glass and the coating that could act as an efficient barrier on its own . To clarify this effect, we subjected bare Type I vials to a heat treatment reproducing the same thermal conditions that prevail during the application of the coating including the heating and cooling steps and subjected them to the exact same USP <1660> tests utilized for the coated vials.…”

“…Following the tuning of the deposition process and structural and functional characteristics of the films, deposition of SiO x N y coatings on the internal surface of Type I borosilicate pharmaceutical vials was carried out in a dedicated CVD setup, described in detail in ref , and schematized in Figure S8A. Vaporized BMDSD was supplied at 1 sccm with 2221 sccm of N 2 directed to the vial through a stainless steel (SS) nozzle located right above it.…”

“…Indeed, heat treatment can improve the densification of the silicate network 13,14 and can also induce an interdiffusion zone between the glass and the coating that could act as an efficient barrier on its own. 5 To clarify this effect, we subjected bare Type I vials to a heat treatment reproducing the same thermal conditions that prevail during the application of the coating including the heating and cooling steps and subjected them to the exact same USP <1660> tests utilized for the coated vials. The results are illustrated as light green bars of Figure 9 and show an almost systematic decrease of the concentration of the cations extracted from the annealed vials compared to that from the as-received vials.…”

“…3 Nonetheless, silicate glass is chemically reactive vis àvis aqueous phases despite its apparent chemical inertness. 4,5 This extremely slow but inexorable glass surface dissolution can adopt different mechanisms of ion exchange and surface hydration, which leads from alkali-depleted layers, up to hydrolysis of the silicon−oxygen bonds, subsequently inducing thickness loss by network dissolution, especially in basic media. 6−8 These mechanisms depend not only on the glass composition and network structure but also on the solution in contact with the glass surface.…”

“…Recent developments in the pharmaceutical industry highlighted challenges regarding sustainable packaging of drugs derived from new molecular entities and delicate active pharmaceutical ingredients. , A commentary published during the first few months of the COVID-19 pandemic underscored the enormous need for billions of vials to contain coronavirus vaccine doses and praised the appropriateness of glass, the primary packaging of choice, particularly due to its superior long-term storage and low gas permeability . Nonetheless, silicate glass is chemically reactive vis à vis aqueous phases despite its apparent chemical inertness. , This extremely slow but inexorable glass surface dissolution can adopt different mechanisms of ion exchange and surface hydration, which leads from alkali-depleted layers, up to hydrolysis of the silicon–oxygen bonds, subsequently inducing thickness loss by network dissolution, especially in basic media. − These mechanisms depend not only on the glass composition and network structure but also on the solution in contact with the glass surface. Reactive excipient solutions in which molecular entities are conditioned can still interact aggressively with the glass container, altering the glass surface, and ultimately producing a silica-rich gel layer likely to detach from the surface, or precipitate particles from the ions in solution and constituents of the drug product, pitting, or glass flakes (lamellae) through delamination, as exemplified by the photograph of Figure A.…”