Abstract
Many biologics are now self-administered by patients at home. A variety of self-injection devices are available, including vials and syringes, prefilled syringes, and spring-driven prefilled pens or auto-injectors. Each has advantages and drawbacks, and different devices suit different patients. For example, some patients have difficulty achieving consistent and successful self-injection due to poor manual dexterity, or experience anxiety at the prospect of self-injection or injection-site pain. These factors can reduce patients' medication adherence and overall experience. Furthermore, while self-injection brings patients many benefits, the proliferation of single-use injection devices has implications for environmental sustainability, including the reliance on single-use plastics, repeated freighting requirements, and need for incineration as hazardous waste. Recently developed, innovative electromechanical auto-injector devices offer technological enhancements over existing devices to overcome some of these issues. Features include customisable injection speeds or durations, consistent rate of injection, electronic injection logs and reminders, and step-by-step, real-time instructions. Indeed, a growing body of evidence points to higher adherence rates among patients using electromechanical devices compared with other devices. Further, with time, the reusability of electromechanical devices may prove to lighten the environmental impact compared with disposable devices, especially as research continues to optimise their sustainability, driven by increased consumer demands for environmental responsibility. This narrative review discusses the differences between prefilled syringes, spring-driven prefilled pens, and electromechanical devices. It also explores how these features may help reduce injection-associated pain and anxiety, improve patient experience, connectivity and adherence, and drive sustainability of biologic drugs in future.