Container Closure Integrity Testing (CCIT) is an assay that evaluates the adequacy of container closure systems to maintain a sterile barrier against potential contaminants. Contaminants that could potentially cross a container closure barrier include microorganisms, reactive gases, and other substances (USP <1207>). Container closure systems should maintain the sterility and product quality of sterile final pharmaceutical, biological, and vaccine products throughout their shelf-life. Container closure systems consist of primary packaging components and secondary packaging components (USP <1207>). Primary packaging components are those components that come into direct contact with the product, such as a glass vial or syringe. While, secondary packaging components are those components that are vital to ensure correct package assembly, such as aluminum caps over stoppers (USP <1207>). Container closure integrity testing can be performed in many different ways. All of the testing methods have pros and cons. In addition, some containers, such as ampoules, require 100% integrity testing. Contract Container Integrity Testing laboratories offer numerous state- of-the-art options for leak testing and assessing pharmaceutical package integrity per USP <1207>. Container Closure Integrity test programs have been successfully used to optimize sealing parameters, evaluate container storage temperature impact, replace sterility tests for product stability batches, screen production lots for faulty packages and support regulatory submission applications for product commercialization around the world. Contract Analytical services offers parenteral vial capping and residual seal force (RSF) testing of parenteral package systems. When RSF testing is applied in conjunction with leak test methods such as helium leak detection or vacuum decay testing, it can determine an optimal range of residual seal force values that correlate with a reduced risk of leakage resulting from improper capping force. Residual seal force is not a leak test but an indirect measure of the compressive force exerted by the stopper on the vial’s land surface. Service providers monitor the vial’s resistance to compression to gain an objective measure of residual seal force. A quality seal requires an optimal amount of compressive force during the capping process. Insufficient force may result in leakage, and excessive force may result in cracking and bulging. Both risk the integrity of the closure system. RSF testing is especially valuable if your objective is to establish optimal sealing parameters or implement a sampling procedure during product production. Analytical service providers conduct electrical conductivity / high voltage leak detection (HVLD) testing on a range of package systems, including parenteral vials, prefilled cartridges and syringes, plastic containers and plastic bags or pouches.