Sruthi Chirra, associate consultant, polymers & specialty chemicals at ChemBizR, discusses material and design innovations for wearable injection devices.
The advances in Wearable Injection Devices (WID) technology are key attempts conforming to concerns of patient comfort and patient treatment adherence. Chronic diseases, such as Oncology, Parkinson’s, and Congestive heart diseases, require regular injections and maximum patient comfort and a WID can add great value to the patient's life.
There are numerous device options currently available for pharmaceutical companies, with at least 25 current brands of WIDs. The competition by device developers is to construct or optimise a design that is all low-cost, lightweight, and simple-to-use, while also fulfilling the primary objective to administer highly viscous and large dosage biologic drugs.
Despite the clear advantage and specific use-case, the adoption of WIDs by drug developers has been quite cautious until now. This is majorly in view of the possible risks and delays in clinical approvals and consequently, only a few projects with WID combination products are in progress and just 2 or 3 have been approved in the past 5 years. But the scenario is picking-up pace as newer developments are forcing the pharma companies to rethink the aspects of risk vs value-addition to their product.
Designing the device
To tailor the needs of specific therapies, device developers are driving innovations in various device concepts: be it pumping mechanisms, drug filling, primary packaging, or user interface/ data connectivity.
The major directional advancement is observed in three aspects.
The first is the development of robust high volume WIDs in the range of 3.5 - 10 ml, with a few even up to 50 ml dosage considerations. None of the presently approved devices is designed for volumes greater than 3ml. Various therapy segments requiring a large volume injection can benefit from the advantages of WIDs. Correspondingly, a few high-volume WID design projects are underway and expected to reach the market in the coming decade. The requirement for high-strength and precision dosing for such systems drives the need for high-performance polymers. And in this sense, we see a couple of devices developed using medical-grade PC, which are currently in the clinical trial stages.
Next in line is the development of small-sized designs that aid in device discretion, resulting in high acceptance amongst patients. To bring this into effect, innovations are taking place both in the design and material sphere. Various brands are incorporating built-in custom drug containers that aid the small-sized design, by fitting perfectly into the device layout. And one interesting material-wise innovation is the development of an experimental semi-reusable WID using PEEK. It is claimed that the use of PEEK presents a cost-effective way for mass production of lightweight, interactive device designs all while keeping the device size low.
The third driving trend is to reduce the overall cost of the devices which makes them more accessible to the end consumer. This is certainly the target for all device developers as extensive research is put forth for cost reduction. One such example is the use of a non-mechanical pumping system, osmosis, for pushing out the drug. It will significantly reduce the device fabrication cost, by eliminating the need for electromechanical components. In a similar case, LCP material manufacturers have claimed that the material significantly lowers the processing costs compared to PC. This leads to a reduction of the overall cost, enabling higher reproducibility of these devices.
New age demand
The potential for WIDs is well recognised in the medical and pharmaceutical industries. The efforts to enhance its accessibility are steadily yet surely growing. The pandemic has brought a considerable need to reduce the dependency on medical infrastructure. There is a heightened consideration for patient comfort. Pharmaceutical companies need to effectively weigh the risk factors and value-addition for the patients to comply with the new age demand.