Characterization of a Novel Particle in a Pharmaceutical Drug Product

A previously unreported particle type was observed during routine visual vial inspection of a liquid drug product and suspected to be the result of vial delamination. Delamination is the corrosive attack on the interior surface of a glass container resulting in the release of thin flake-like glass particles, lamellae, into solution. It is a major concern for pharmaceutical companies, especially for parenteral solutions, and drug programs with a high risk for delamination are typically monitored for lamellae formation through long-term stability studies. Although these particles observed resembled lamellae (i.e., thin, reflecting light, buoyant) they were not the result of glass delamination. In this study, the authors describe a previously unreported particle type and provide a detailed comparison with known lamellae exposed to the same drug formulation. The chemical, elemental, and morphological characteristics of the particles and respective vials are described in detail. Overall, the particles' high organic and low silica elemental signature, along with no signs of delamination on the glass vial inner surface demonstrate that this lamellae-like observation is a novel particle form that can be distinguished from lamellae formed from vial glass delamination.