a) The safety cap must be removed from the closure before testing
b) The flanged cap holds the stopper under pre-load
c) When a suitable compression load is applied to the rim of the flanged cap, it lifts from the neck of the vial. This is displayed as the reduction in force in the force-travel diagram. The inflection point indicates the RSF value.
Source:Guidelines (USP
<1207>, International Standard ISO 8362-2 Anhang C, ISO 3826-1 Anhang C,
ISO 15747 Anhang C, PDA Technical Report Nr. 27, FDA Guidance for Industry:
Container and Closure System Integrity Testing in Lieu of Sterility Testing as
a Component of the Stability Protocol for Sterile Products1207>