Blogs

A good elastomer stopper for a vial container system needs to have the right properties. These properties are largely determined by the elastomer formulation, which comprises the base elastomer, fillers, plasticizers, and curing agents. The interplay among these components is crucial, as they determine performance. For example, hardness is affected by filler type and level, as well as by curing agent and level. West understands these issues, and therefore is able to develop formulations to offer maximum performance. An example is the formulation 4040/40, which was designed according to quality-by-design (QbD) principles.

In its 95+ year history, West has developed and marketed a very large number of elastomeric formulations, each designed to address particular market demands. Over this time, various aspects of drug product quality have gained attention – a fact reflected in the numerous regulatory guidances that have been issued. An early focus of these guidances was extractables and leachables, followed closely by particulate matter and container closure integrity. Beyond these regulatory requirements, the market demands product portfolios that enable platforming and predictable, consistent product quality and performance.

With the May 21, 2019 meeting to review the FDA draft guidance governing 503B compounding pharmacies, it has become evident that sterility of drugs produced at such facilities is a major focus of the U.S. Food and Drug Administration (FDA).¹ The meeting discussed the importance of qualifying container closure systems and was aimed at providing more context on what compounding pharmacies need to do.

Rubber components are essential for the safe containment and delivery of parenteral drug products. Many rubber formulations used in the pharmaceutical industry are based on halobutyl rubbers. Halobutyl rubbers, typically bromobutyl or chlorobutyl, are made by the halogenation of butyl rubber, which is a copolymer of isobutylene and isoprene (to a smaller extent). Key features of halobutyl rubbers that make them suitable for the pharmaceutical industry are that they typically have lower levels of extractables compared to other rubbers, and they have excellent resistance to permeation by water and oxygen.

Primary packaging components come in intimate contact with drug products – they can affect both drug product and patient safety. Many elastomer components are offered with a FluroTec^® film that serves as a chemical barrier to minimize the migration of compounds from the elastomer into the drug product. FluroTec film comprises an ethylene-tetrafluoroethylene co-polymer (ETFE) – selected based upon flexibility, ability to be laminated to an elastomer, and of course, permeability resistance.

Recently, the generics pharmaceutical industry in the United States has seen the average time to market decrease significantly as approvals have steadily increased thanks to the introduction of the Generic Drug User Fee Amendments (GDUFA) in October 2012. The reduction in time has led pharmaceutical companies to seek out high-quality elastomer products that provide the regulatory simplicity necessary to bring their products to market quickly, helping to increase a company’s competitiveness and their drug product’s overall sales. The AccelTRA™ elastomer program is built on these features: Quality, Speed, Simplicity.