IGMPI India

Pharmacopeial Forum 41(1) publishes a new article “stimulus to the revision process" on pharmaceutical packaging. The article will be published as General Chapter <671> in US Pharmacopeial convention (USP). This article proposes a new method for the determination of the permeability of water vapour in packaging. The determination of the permeability rate for water vapour ("water vapour transmission rate", WVTR) applies for solid dosage forms such as tablets or capsules that are packed in plastic bottles or blister packs.

WVTR can be measured by the weight gain of a desiccant or by the weight loss of water in a packaging system in an environment with constant temperature and relative humidity (RH). Packaging materials to be tested, which are filled with water, show a constant vapour pressure difference along the walls of the containers. This constitutes an improvement in comparison to the current WVTR testing according to <671>, in which the containers are filled with desiccant and where the vapour pressure inside neither starts nor remains at 0% rel. humidity.

When containers are filled with water, many of the challenges can be avoided occurring with the use of desiccants and with the handling of containers which must be filled with desiccants - which is another advantage of the new method.