About a year ago, Schott set out to elevate pharmaceutical glass quality to a new level with its perfeXion initiative. EPM sat down with Dr Patrick Markschläger, executive vice president, Schott Tubing, to discuss the impact of glass tubing on future packaging challenges.
Next level
Q. Why should the pharmaceutical industry give special consideration to pharma glass?
It’s widely accepted that pharma packaging has become an integral part of the drug product. Yet any primary packaging can only be as good as the basic material it is made of. As the pharma industry is striving to optimise its cost/performance ratio, our goal is to provide a material which is highly inert and comes with a high cosmetic quality from the very beginning.
Q. Are you referring to borosilicate glass?
Indeed. Borosilicate glass has the big advantage of exhibiting excellent characteristics without further treatment, which allows for the reduction of risk and complexity in the process.
Q. Looking at the challenges that lie ahead — what current trends in the pharmaceutical industry can you support on the part of glass tubing?
To give you two examples: We see a strong trend towards highly concentrated drug formulations, which are often more viscous and require high-dosage accuracy. Furthermore, there is an increasing number of higher dosage volumes, which leads to longer administration times. Here, a pharma company would be looking for optimal device integration. Both calls for the container to have very accurate dimensions, especially regarding the inner diameter and length. If you use precise tubing, half the battle is already won. Or vice versa — without accurate tubing it is much less likely to end up with a high-quality container. This is exactly why we have introduced our perfeXion process.
Q. Can you briefly explain the concept of perfeXion?
Dr Patrick Markschläger, executive vice president, Schott Tubing
Dr Patrick Markschläger
perfeXion is a big data approach to reach a zero-defect tubing. We are able to examine 100% of the glass with lasers, cameras and infrared systems on-line during the production process. The data is analysed immediately, and the system precisely allocates imperfections allowing for the differentiation of corresponding individual tubes, which can then be sorted out later. The result is a glass tube that has been completely evaluated. We also use the data to improve our own production process, and we can provide it to customers to support quality requirements down the line.
Q. Conducting automated controls seems logic, why is this not yet a standard in the glass tubing industry given the rising quality demands?
I believe this will definitely become a standard. One has to take into account, though, that the analysis of a curved tube surface at high drawing speeds is difficult to perform. Hence, many still rely on sample-based testing to control the quality of glass tubing. With perfeXion, the cornerstone is set to replace statistical control by 100% on-line analyses.
Q. Can perfeXion also help to eliminate glass breakage?
The basis of the initiative is to provide containers with a flawless surface, and this in turn helps to remain the naturally high breakage resistance of glass.
Q. Can you explain that further?
Glass is a very strong material, unless you weaken the surface by causing scratches or chips. This sometimes happens during production or transport. If this weakened spot then experiences too much stress later on — for example, during the filling process — the glass will break. Using glass with a flawless surface will maintain the natural break resistance of the glass, and this should normally be sufficient for the vast majority of pharmaceutical applications. The key for us is to provide pre-damage free tubing, and we will significantly increase our efforts in this field.
Q. How about cases that call for a higher breakage resistance? Do they require a different type of glass?
I think it is safe to assume that pharmaceutical companies are not explicitly looking for a new glass composition. What they are ultimately interested in are the characteristics of the container — break resistance and a superior extractables & leachables (E&L) profile. Both can be achieved with existing and already authorised type I glass. Breakage resistance can be achieved with an industry-standard ion exchange process, which compresses the glass and makes it more stable. Several packaging providers have such solutions in their portfolio. Superior E&L profiles for biotech applications are sufficiently addressed with highly-functional SiO2 plasma coatings, which do not require a reregistration. We favour this route because it keeps down the regulatory hassle for pharma companies.
Q. Can you explain the difference between borosilicate and aluminosilicate glass?
First, I would like to say that Schott is in a good position to comment on both glass types as they have been part of our portfolio for many years. We supply aluminosilicate glass mainly to the electronics industry, where it is widely used, and this chemical composition also plays a role for glass-ceramic cooktops known under the brand name SCHOTT CERAN.
Glass in general consists of network formers (e.g., silicon, boron, aluminium) as well as network modifiers (e.g., sodium, calcium). A borosilicate glass contains significant amounts of boron, whereas aluminosilicate glass does not contain this element. The presence of boron is known to increase the chemical stability of a glass, hence borosilicate glass bears a high hydrolytic resistance due to its chemical composition, making it a type I glass.
Applying further process steps will alter the E&L profile of any glass type. Yet, after the converting process a borosilicate glass vial is still well below the type I limit, while untreated aluminosilicate glass vial would only meet the type III requirements. Thus, intense further treatment is necessary to produce a container of aluminosilicate glass which meets regulatory requirements. Plus, there is no scientific track record to assess the interaction between drug components and the glass surface.
Of course, we are highly interested in an open discussion, and are ready to adjust to market requirements. However, solid data is needed first to do justice to the complexity of pharmaceutical products.
Q. For companies that experience breakage problems, what do you suggest?
Again, big data comes into play. Normally, there are only few passages on the filling line where the glass is set under stress. If you can identify these crucial spots, this will bring you a major step forward.
A system we think is very interesting is provided by a Canadian company called Smart Skin Technologies. They send drones on the line, which mimic the shape of the container and are equipped with sensors, to measure the movement, forces and stress. We heard from leading pharma companies that they were able to significantly reduce breakage by conducting such analyses and performing simple adjustments to the line afterwards. To us, this is a pretty straightforward approach.
