Effect Of Closure Composition And Processing Parameters On End Product Dryness Over Time

By A. Miller and J. Riter

Residual moisture in elastomeric closures can cause degradation of lyophilized drug product. Prior to packaging the drug product, pharmaceutical manufacturers typically wash, steam sterilize and dry the closures. This sterilization process drives moisture into the closure. If the drying conditions for the closure are not optimized, residual moisture can transfer into the lyophilized drug product over time.

This study evaluates closures subjected to a pharmaceutical- grade wash process, a typical steam sterilization cycle and three drying cycles.

Closures were placed on a vial containing a 5% lactose solution and lyophilized. The amount of moisture in the closure and in the lactose was measured over one year, using a coulometric Karl Fischer titrator with a drying oven.