The range of high performance polymers available from DuPont for use in medical devices, including the new DuPont Delrin SC699 acetal resin forms the focal point of the company’s exhibit at Pharmapack 2012 in Paris.Their use enables the design and manufacture of highly-accurate, reliable, durable and convenient products, as illustrated by the launch last year of the UnoPen, a disposable, variable-dose injector pen for insulin and other therapies by the company Ypsomed AG (Burgdorf, Switzerland).
Ypsomed AG has specified the new, ultra low-friction Delrin SC699 acetal resin for a key component of its UnoPen. The DuPont material, which is supplied with extensive regulatory compliance for use in healthcare applications, is used to mould the pen's dose dial sleeve.
Its low-friction behaviour facilitates use of the pen by diabetes patients who are required to administer daily injections of insulin either by themselves or with the help of a health care professional. Further attributes of this grade of Delrin in the application include its mechanical properties and the compatibility of the material with laser marking when using a masterbatch.
The UnoPen from Ypsomed AG, a leading independent developer and manufacturer of injection systems, is a state-of-the-art disposable pen designed for the manual injection and delivery of insulin or other drugs from a pre-filled glass cartridge.
A principal feature of the device is its ease-of-use based on a well-proven 'dial and inject' handling concept, in which the dose dial sleeve - the component moulded from Delrin SC699 acetal resin and located between the housing and the piston rod - plays a key role. It is used by the patient to set the required dose of insulin to be injected and interacts mechanically with the piston rod to dispense the required dosage.
"The friction properties of Delrin SC699 acetal resin used for the dose dial sleeve are fundamental to the pen's ease of use. If friction between the parts of the pen is kept to its minimum, then the patient will need a minimum of force to dose or inject the drug," explains Stefan Burren, manager product development at Ypsomed. "We tested many polymers that are currently available on the market for this component, but none fulfilled the requirements as well as the DuPont material."
Delrin SC699 acetal resin has been modified for exceptional low friction performance and is suitable for high volume manufacture. It has been specifically developed for parts requiring high precision moulding in the healthcare industry and is supplied with the relevant regulatory compliance (FDA and EU food compliance, production according to GMP standards, testing against USP Class VI and ISO 10993–5 and -11).
Further attributes of the new grade leading to its specification for the dose dial sleeve include its compatibility with laser marking, by use of an appropriate masterbatch, for indication of the dose settings. As with other grades from the Delrin product family, the material also exhibits outstanding properties in terms of strength and stiffness, permitting the snap-fit assembly of the component, as well as ensuring reliable and durable mechanical performance in use.
