Physico-chemical Characterization of Glass Surfaces: New Surface-related Analytical Approaches

Since ancient times glass was used as storage material for ointments, medicinal remedies and cosmetics for its properties of inertness and product protection. Along the centuries the technology has developed dedicated glasses for pharmaceutical use, improving their mechanical and chemical performances up to the modern borosilicate glasses. Meanwhile the technology is trying to meet the needs of new complex and sensitive drugs, the necessity of new analytical approaches has increased for a better overview of the content-material interactions to complement the classical pharmacopoeia analysis. From this perspective a physico-chemical analytical approach, focused on the glass surface as main player of the drug-content interactions, is the main topic of this study. The application of surface dedicated complementary techniques as XPS, SIMS and SEM was investigated, permitting the characterization of the glass surface in terms of morphology, composition and depth elemental overview. As preliminary part of a more complex project, this study focused on the comparison and baseline characterization of the raw materials with the related finished containers, highlighting interesting surface features and glass composition-related peculiarities. This work confirms the suitability of these analytical techniques to pave the way for further studies on long term storage or environmental effects, helping to define a possible correlation with drug interactions phenomena.