In cartridges with chemically strengthened glass, life-saving medication can be safely stored and ready for application, says Schott
There are times when the packaging used with a drug has to function perfectly. The movie hero James Bond experienced this in ‘Casino Royale’ when his martini was neither stirred nor shaken, but rather poisoned. He only had a few seconds to inject a life-saving medication into his carotid artery. Bond survived, thanks to an injection pen that was immediately ready for use and his co-star, Vesper Lynd, who miraculously recognised within only fragments of a second where the missing cable was on the defibrillator.
Even if this was Hollywood, the example shows that there are in fact situations in which break-resistant packaging can make the difference between winning and losing. Sometimes, even between life and death. This is true when break-resistant packaging is used in areas of war and natural disaster where the conditions are harsh.
”Pharmaceutical companies are also extremely interested in having break-resistant cartridges for storing drugs that are particularly expensive or highly toxic,” explains Schott product manager Andrea Wesp. Toxic medications? ”Yes, especially for treating cancer. Here, the highest safety precautions must be taken to protect employees on the production lines during the manufacture and packaging of these substances. The same applies during transportation of the drug and when administering it to the patient.”
Cartridges are glass bodies inside pen and auto-injectors that hold the drug. To mechanically harden the glass to suit these types of situations, Schott has now developed chemically hardened cartridges. Two aspects were particularly important here: “We wanted to retain the original geometry to make sure that the new cartridges still work with standard pen systems,” explains Wesp. Simply shaping the walls to be thicker was therefore out of the question. ”Chemically hardening the glass proved to be an alternative that would not affect the integrity of the drug,” she adds. The goal was to avoid an undesirable reaction between the glass surface and the contents that could impair the drug’s effectiveness.
The answer was to further develop a glass hardening process that has been the industry standard for many years. These efforts proved to be successful at the US development lab in Pennsylvania, where Schott researchers optimized a proven ion exchange process for use in pharmaceuticals. The cartridges bathe in a potassium nitrate solution during this process, whereby the sodium ions in the surface layer are exchanged for larger potassium ions from the solution. This gives the glass greater stability. Tests have shown that the cartridges hardened in this manner are three times as resistant to mechanical stresses. They can be used in auto-injectors, needle-free injection devices and pen and pump systems.