Glass has become one of the world’s leading primary packaging materials, yet still needs to be able to meet the growing requirements of the pharmaceutical industry. Sensitive new biomolecules and alternative manufacturing techniques such as lyophilization place incredibly high demands on pharmaceutical containers.
In the pharmaceutical field, lyophilization is frequently being used to extend the shelf life of highly sensitive drugs. However, if this technique means longer and more efficient medications storage; lyophilization still places mechanical and thermal stresses on the packaging, and it requires improved chemical properties of the container to ensure that the lyophilization cake has an attractive appearance.
One way to improve the packaging material is to apply extremely thin hydrophobic coatings to the inside surface of the containers with the help of a pulsed plasma technique. The coating is transparent and only about 40 nanometers thick, yet helps to produce an esthetic cake during the lyophilization process. This lowers the reject rate for pharmaceutical companies. Such coated containers can be filled, sealed and inspected as any other containers and undergo all of the normal pharmaceutical processing steps like washing, autoclaving, sterilization and depyrogenization at temperatures of up to 300° C.
A TECHNIQUE ENHANCED BY SCHOTT IMPROVED GLASS GEOMETRY
Although the coating significantly helps the vials to stand up to the lyophilization process, each step of the process poses further challenges regarding the mechanical stability of the container. For example, there is a high possibility for the glass to break due to the enormous local temperature differences.
For production reasons, the bottom of a glass vial is thinner than the walls and therefore represents the weakest point in a glass vial. It simply breaks more easily. To resolve this weakness, Schott has simulated the geometry of its glass vials using a Finite Element Method (FEM) and improved it based on the results. The new geometric design of the bottom significantly reduces glass breakage, and it also allows for better heat transfer during the lyophilization process.
This is one example how coated vials help to meet the high demands created by highly-sensitive medications and sophisticated production processes. They provide an interesting alternative where conventional packaging has reached its limits. Other coatings provide for reduced ion leaching or a low residual volume when the dosage is removed. The benefit is obvious: a more effective process that incurs lower risks inevitably means lower costs.
If you want to know more about coated vials and where to use them you can register for Schott’s webinar on 16th January 2014 here.