Package integrity is necessary to maintain a drug product’s quality throughout its shelf life. Thus, packaging systems must demonstrate satisfactory container-closure integrity. Package moisture permeation is a critical quality attribute for solid oral dosage forms, with moisture uptake being a common cause for product package failures. Current permeation methods in USP Chapter Container—Performance Testing <671> establish equivalence for packaging (cap/bottle and blister packs) based on the USP standards of well-closed or tight containers. The chapter is being revised to include a new permeation method for pharmaceutical manufacturers.