Schott doubles up cartridge chambers for drug delivery

Modern drugs often consist of combined active ingredients. Schott has enabled these drugs to be stored separately in a double chamber cartridge and yet be administered very easily

The pharmaceutical industry has made great progress in developing increasingly effective medicines for the chronically ill. These usually have to be injected, some on a weekly basis, others several times a day. This places a burden on patients as well as healthcare systems. Because of this it makes sense to have the patients perform the injections themselves. This in itself is not a problem; however, many new drugs can only be stored stably in freeze-dried form. Prior to injection, they must be liquefied by using water for injection (WFI) or another diluent. The patient needs two vials with different contents and a syringe. First, the diluent must be drawn into the syringe and injected into the second vial. After shaking it, the drug can be drawn into the syringe again and administered. The risk of error, such as a possible contamination of the substances, increases with the number of steps. In addition, there is the risk that the patient could miss the right mixing ratio or inject the wrong dosage.

Schott has developed a solution for these forms of administration – a double chamber cartridge for pen systems. It contains the two drug components in two consecutive chambers that are separated by a plunger. When the pen lock is turned, the plunger will be pushed to the level of the bypass, and the liquid will flow into the anterior chamber where it will mix with the second component. The reconstituted drug can then be injected without any risk of contamination and in the exact dosage by simply triggering the pen.

“Many new drugs are initially made available as lyophilisates because manufacturers are still looking for a way to store the active ingredients in a stable manner,” says Schott product manager Andrea Wesp. “If they opt for a double chamber, they don’t have to accept any compromises because the components can be stored and protected, reconstituted quite easily and then administered in the safest and most convenient way – four advantages at once.”

Schott double chamber cartridges are used in pens and can combine either liquids with liquids or liquids with medications in powder form. The two chambers are separated by a plunger. When the patient or doctor turns the closure of the pen, the back plunger moves forward and presses the medication against the front plunger up into a passageway that is less than 0.1 millimeters in width. The medications stored in the back chamber can pass through this bypass and enter the front chamber where they can mix. To inject the medication, the patient simply places the pen against his skin and presses the release button.

Benefits of a double chamber cartridge

The main advantage this approach offers is how easy it is to use. Instead of deploying two containers to store the lyophilisate in one and the diluent in another, double chamber cartridges carry out mixing and application in one go. The pen system allows for higher dosing accuracy and a lower risk of contamination. This translates into much higher safety for patients, as literally a push of a button is all that is needed.

Schott cartridges are compatible with the most co mmonly used pen systems; therefore pharmaceutical manufacturers do not need to develop these devices on their own.

Quality during the manufacturing process

Schott manufactures the double chamber cartridges at its Center of Excellence in Switzerland, and has optimised the production process based on its many years of experience in cartridge manufacturing.

Today, the bypass of the cartridge is created using compressed air during the hot forming process.

This avoids any traces of tools and particles. Moreover, double chamber cartridges are produced without any glass-to-glass contact just like insulin pen cartridges. The aim here is to avoid cosmetic defects.

The cartridges come in standard dimensions, but can also be customized. The length and position of the bypass as well as the edge can be adjusted to meet individual requirements. “The latter is important if a customer wants to fill the drug directly in powder form,” says Wesp. Alternatively, the active ingredient can also be filled in liquid form and t