Securing performance in drug delivery devices

The drug delivery device industry is growing worldwide as more countries adopt higher standards of care and the average age of the global population increases with concurrent demand for more medication.

With the advent of the new US healthcare programme there is a combination of increased demand alongside a requirement to cut the costs of treatment, which has reached back into the pharmaceutical and medical manufacturing supply chain. Thus designers, manufacturers and hospitals are all looking for top quality, fail-safe devices at the lowest cost.

To debate these issues and highlight the latest research, AMI is organising the international Polymers in Drug Delivery Devices 2014 conference, to be held on September 16-17 at the Hilton Philadelphia City Avenue in Philadelphia, PA, USA. 

Professor David Jones of Queens University in Belfast has reviewed the issue of drug-polymer interactions and will give the opening address.  Many medical devices are now a combination of drug delivery and another function: Johnson & Johnson has used absorbable polymers in devices and drug delivery. Industry suppliers of degradable polymers for drug delivery include DSM Biomedical and Foster Delivery Science.

The drug delivery device industry works within the constraints of many FDA regulations and EU Directives to ensure patient safety including material qualification, extractables and leachables studies for migrating chemicals and biocompatibility testing. 

Medtronic operates high standards to minimise risk, while the role of NAMSA and UL is to provide testing and assist in ensuring compliance. Toxicon focuses on the toxicological assessment side of device approval. However, pharmaceutical devices face the added challenge of drug-device interactions.

For example, static in the device can prevent full delivery of a particulate drug in an inhaler, on the other hand the chemical components of a drug and the excipient can damage a device to the point of failure. The FDA research team has been studying this topic including the compatibility of drug and infusion pump and the impact on drug stability, while BBraun has expertise in IV infusion bags. Elastomers in closures and seals in pharmaceutical devices are subject to specific test protocols and DuPont has examined these materials and how to optimise reliability. The Eastman Chemical Company has checked the chemical interactions of copolyesters for use with oncology medication.

On top of these considerations, the drug delivery device must work well mechanically and be user-friendly. These characteristics might include low-friction in a device with moving parts, a soft touch panel to improve grip, or an additional lever as a manual aid. The RTP Company has developed a test for plastic friction behaviour to optimise material selection for drug delivery devices with moving parts. Plastics are easily processed into any shape and a wide range has been used safely in healthcare for decades.

Promed Pharma moulds a variety of polymer dosage forms for applications such as women’s health. Contract manufacturing is a common feature of the medical device industry and ASI has advice for pharmaceutical companies on how to work effectively with a supplier.

With plastics processing it is also possible to add design features such as colour and shape to appeal to younger patients and improve compliance in taking medication and carrying devices.  All of these developments are subject to testing and approval as part of the qualification procedure.

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