Many of the new drug products in development require primary packaging materials with special properties. Special finishing/coating processes to ensure compatibility of the packaging material with the drug formulation have been developed to prevent interactions and maintain solution stability. These include baking silicone oil on the inside of the syringe barrel to help stabilize sensitive biotech drugs in solution. A particular problem is that silicone oil droplets generated by conventional liquid siliconization can, under specific circumstances, interact with the drug product.

An example of this is silicone oil-induced protein aggregation in biotech-derived drug products, which in the worst case can lead to the rejection of the drug.

Our patented baked-on siliconization (EP 1818069/US 7404278) provides the syringe barrel with a lasting and stable coating so that problem-free application is guaranteed throughout the drug’s entire shelf life.

In general, the contribution of the drug delivery system to product stability should not be underestimated. When glass material (type I) is used, the main factor influencing stability is the resistance of its surface, measured in terms of its alkalinity. Since some drugs cannot be kept stable in solution for long enough using typical borosilicate glass, they can be marketed only as a freeze-dried substance in a glass vial or with a shorter than average shelf life.

A special surface treatment process developed at Gerresheimer Bünde helps to overcome this problem and offers a solution for the long-term storage of non or low-buffered drug solutions or WFI. The treat-ment of the glass container’s inner surface with ammonium sulfate provides a significant improvement in pH stability.

Another option is the use of borosilicate glass with a lower temperature extension coefficient. This glass type composition generally has a lower alkali content, thereby minimizing alkaline leachables.