Extremely smooth puncturing of the skin for highly sensitive use during childbirth.
Approval in only four months thanks to the use of FDA-registered materials.
One-of-a-kind development and plastics expertise in the MedTech sector.

Neuraxial syringe barrels and plungers (disposable) for epidural anaesthesia (EDA)


Highly sensitive obstetrics thanks to ‘Great Performance Engineering’ – featuring the NRFit® connection, our neuraxial syringe barrels and plungers for epidural anaesthesia (EDA) set a new safety standard.

The task

A disposable syringe for epidural anaesthesia with new ISO SLIP and Lock connectors in accordance with the latest DIN EN ISO 80369-6:2016 standard – GPE came into the fold during pre-development of the syringe’s barrel and plunger components as a development partner and for later mass production.

The challenges

The customer was looking for advice on an optimal production concept and a technological solution using plastic injection moulding to realise the project. The focus was on a component design optimised for injection moulded plastic, taking into account the technical requirements and specifications, including mould concepts for the two new injection moulds that needed to be manufactured for the barrel and plunger.

In the process, the topic of materials played a central role – it was important that the types of plastic that would be used and the pad printing ink for the scale on the syringe barrel were already registered with the FDA (i.e. medical grade). This proved particularly challenging, as the customer wanted the plunger to be manufactured in two colours: plain and yellow. The objective was to meet the requirements of medical device class 1, including the entire production process and further finishing under controlled conditions. An important requirement for neuraxial applications (NRFit®) were new, non-interchangeable connectors. The barrel and plunger need to exhibit tight tolerances to each other. The greatest challenge was the ‘loss of resistance technique’ in order to achieve extreme sensitivity during use – the physician must be able to immediately feel the loss of resistance when the needle penetrates the epidural space through the syringe plunger.

The solution

GPE carried out development optimised for injection moulded plastic, designed and manufactured the 8-cavity mass-production injection moulds for a disposable product solution. The tool concepts included the latest slip and lock connector geometries according to the NRFit® standard. GPE assumed responsibility for the selection of materials with regard to plastic, colour batch and printing ink on the basis of existing FDA registration and, thanks to its extensive network of suppliers, procured the special plastic which is only available from the United States.

This was followed by the reliable mass production and downstream pad printing of the syringe barrels, including quality control in the injection moulding and printing process. The barrels and two plunger versions (plain, yellow) were delivered directly to the contract packager in Italy specified by the customer, where the final siliconisation and assembly of the syringe also takes place.

The added value

In close collaboration with the customer, GPE developed and defined well-engineered and stable manufacturing processes. GPE assumed responsibility for the entire supplier management process relating to the external further processing steps, including smart scheduling, and delivered the pre-finished syringe components, including test documentation, directly to the contract packager, which greatly reduced the customer’s workload. The choice of materials, including the selection of FDA-registered colours, combined with the new connectors in accordance with the DIN EN ISO 80369-6:2016 standard, gives the customer a key competitive advantage. This is because the choice of materials reduced the time required to receive FDA approval of the finished syringe from the usual 7 to 12 months to only 4 months. This allowed the customer to launch the product much faster than major syringe manufacturers and enabled it to enter the European and US markets more quickly. In addition, the customer was able to position itself as a pioneer when it came to replacing the 6% Luer lock connector and introducing the NRFit® version.

The application

During epidural anaesthesia, the transmission of pain via nerve fibres coming from the spinal cord is interrupted. In contrast to spinal anaesthesia, this procedure enables pain to be eliminated without impairing the mobility of the legs. This is used in obstetrics, where women in labour are relieved of pain without any relevant loss of strength. (3742)

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