Self-Sealing Thermoplastic Elastomer Solution for Infusion Therapy Systems

Pharmaceutical Technology spoke to John Voyce, marketing manager at GLS Thermoplastic Elastomers, Europe, PolyOne Corporation.

InnoPack, co-located with CPhI, brings together buyers and suppliers from the pharmaceutical packaging industry. Pharmaceutical Technology had the opportunity to speak to PolyOne, a provider of specialized polymer materials, services and solutions about the company’s product, Versaflex HC, for infusion therapy stoppers and septums.

PharmTech: How does Versaflex HC benefit the pharmaceutical industry?

PolyOne: Versaflex HC is a single step injection molding grade that does not require any pre- or post-production work. This material can be moulded directly onto polypropylene (PP) or polyethylene (PE), providing the ability to reduce part costs, streamline production and increase capacity without jeopardizing seal integrity. This allows users to increase market share and capitalize on market growth with a safe and innovative product.

The advantages of Versaflex HC over traditional vulcanized products include improved processing time and enhanced production efficiency, improved cleanliness and lower total system cost. Additionally, this new solution meets the performance criteria for infusion devices, i.e., resealing after multiple penetrations, low penetration force with excellent coring performance and holding force after autoclaving.

PharmTech: What are the major drawbacks of traditional materials used in thermoplastic elastomers and how does Versaflex HC compare?

PolyOne: Traditional materials used in thermoplastic elastomers could not achieve all of the requirements for infusion stoppers and septums such as low coring during penetration; re-sealing after multiple penetrations; low penetration force and needle retention under-load, all tested after autoclaving. Versaflex HC has been found to achieve all of the requirements in a septum cap for pharmaceutical packaging.

Versaflex HC has been formulated to optimize the performance of thermoplastics elastomers for infusion stoppers and septums. PolyOne configured a septum material that yields septum achieving the required performance for ISO 15759 plastic caps with inserted elastomeric liner for containers manufactured by the blow–fill–seal process.

PharmTech: What about extractables and leachables from Versaflex HC and the risk of it interacting with the pharmaceutical formulation?

PolyOne: Versaflex HC was submitted to an independent laboratory for testing and passed: USP VI; ISO 10993 parts 4 & 5 and USP elastomers closures for injections. USP regulates the extraction in water when subjected to autoclave sterilization at 121°C for 30 minutes. The solution is then tested for turbidity, color, acidity/alkalinity, absorbance, reducing substances, heavy metals, extractable zinc, ammonium and volatile sulfides. The above data can be shared with the pharmaceutical companies to help during their pre-selection process to provide evidence prior to carrying out the extraction & leachable testing in contact with their drug.

PharmTech: How does Versaflex HC reduce manufacturing cost? Can you tell us more about the one step injection molding operation versus the multiple steps required for vulcanized rubber?

PolyOne: Versaflex HC is processable by injection molding, enabling high-speed mass production of components in a highly automated system. The material can be molded directly onto PP or PE, forming a secure bond between rigid and soft products, whereas vulcanized products pass through several processing steps:

1. Pre-blending of curing agents, carbon black and processing aids

2. Two-roll milling to fully disperse and prepare strips for feeding into the molding process

3. Molding process with a long cycle time to include injection and curing times

4. De-flashing of components

5. Washing to remove potential uncured additives from the finished article.

The process for using Versaflex HC to make a septum does not include any assembly associated with bonding the elastomers to the rigid plastic if required, or the removal or recycling of the washing solutions used.