Editorial Article: Exclusive Interview: New Method to Ensure Safe Pharmaceutical Glass Packaging – Part 2

02 Jan 2015

Professor Matthew Hall is an Associate Professor and Director of the New York State Center for Advanced Ceramic Technology at Alfred University. In the second installment of this exclusive SelectScience interview, he discusses his work on glass used for pharmaceutical packaging and reveals a novel a UV-Vis methodology for quantifying defects in glass.

What is the aim of your research into pharmaceutical glass packaging?

MH: We are currently studying the various aspects of the glasses used for packaging of pharmaceutical solutions such as glass vials. The borosilicate glasses frequently used in these applications are generally regarded as being chemically inert, although it turns out that specific details of the manufacturing process can render glass vials susceptible to corrosion.

The objectives of our work include understanding how various factors controlled by the producers/users influence the chemical stability of glass packaging; we are also interested in developing better methods for assessing chemical stability.

Why is it important to quantify defects in pharmaceutical glass vials?

MH: Glass vials can exhibit ‘glass delamination’, a phenomenon in which the interior surface of the vial can flake off to produce particles in solution. Due to health concerns, glass delamination in even a small number of vials can result in costly recalls and can mean a significant waste of potentially good product. Defects in pharmaceutical glass packaging can have several consequences. First and foremost, defects can lead to physical and chemical contamination of therapeutic drugs, thereby creating a safety issue. This contamination can potentially compromise the efficacy of the drug (e.g. causing aggregation of protein-based therapeutics) or cause physical damage to the patient through vascular damage, emboli formation, etc.

Can you describe your method of quantifying the defects in glass and what are the advantages of this method?

MH: My laboratory has developed a novel UV-Vis method to quantify methylene blue adsorption to glass vial surfaces. While the approach is straightforward, the use of methylene blue to study glass vials has, until now, been largely qualitative and difficult to interpret. We hope to promote this method as a simple and inexpensive approach to quality control. The UV-Vis spectrometer that we use at the CACT is a PerkinElmer Lambda 950.

Why does the methylene blue adsorb on to the defect but not the normal glass surface?

MH: The methylene blue dye likely does adsorb to the entire surface. However, the amount adsorbed on to a normal surface can be sufficiently low to prevent simple visual detection. The defective areas on the interior surface of the glass vial frequently lead to regions of increased surface area that can increase the local concentration of the dye, much like a sponge.

Could this method be applied to quantify defects in other materials?

MH: Yes – methylene blue dye can be used as a qualitative assessment tool in other settings, particularly to identify cracks at the surface of a material. A quantitative approach may facilitate the process of making relative comparisons among a number of samples under investigation.

Read the first part of this interview here.