How a new autoinjector aims to decrease pain and provide optimum delivery

Ian Bolland spoke to Lionel Maritan, associate director – research and development, BD, about the company’s Intevia 2.25ml autoinjector which is set to launch at the end of 2021/start of 2022.

Maritan explained the new product is still in its development phase and will be dedicated to injecting at a higher volume compared to previous devices.

The 2.25ml autoinjector is a combination product – a two-step push-on-skin autoinjector used with pre-fillable syringes. The patient puts the autoinjector on their skin and pushes the button once to deliver the prescribed dose. It is designed for home use and to be easy to hold, as chronic disease patients undergoing biologics treatments often need to inject frequently.

Though designed for home use, it has had the input of healthcare professionals during human factor studies during tests on patients with chronic illnesses.

It is hoped this new autoinjector will be able to provide less painful delivery of any dosage but Maritan admits that delivery has to be considered in combination with the drug itself when it comes to pain level.

“What we are doing is trying to establish specific requirements when we launch this new development to keep reasonable injection, so not too fast and not too long as well, and to find the best compromise between flow rate but also the injection time when you are using an autoinjector.

“We are combining these two limits, and have tried to design between them, to keep a good compromise between the pain and the ability for a patient to inject themselves in a reasonable time.”

Designing a new autoinjector does have challenges as Maritan explains it is a case of replacing manual steps by automatic means. Given the higher volume of medication carried within this device, the challenges can be seen as greater compared to the existing products that BD has in smaller volumes.

Comparing it to a 1ml autoinjector, Maritan said: “The challenges are much higher because you want to inject two times the volume, plus we want afford a broad range of viscosity, accessible with the autoinjector technology.

“Your design is at the limits and you need to find the right combination of component subsistence to maximise the performance without compromising the basic functions.

“If you need to inject higher volumes at higher viscosity you need more power force. The higher the power, the higher the challenges are and the side-effects you need to manage at the system level.

“With an autoinjector you integrate a preferable syringe, you integrate stoppers, so you integrate a lot of well-known components not only used in autoinjectors, but used in other systems, and you need also to select the right components to ensure the system functions.”

Areas to consider when developing the device include selecting specific parts and the materials used to assemble them to form the injector, including the barrel and the stopper.

Maritan explains that any plastic parts will be produced with moulding technology, with the barrel and stoppers produced using a specific forming process.

“We have to specify to make sure these components are correctly manufactured at the right quality level and with the right specification.

“We have a lot of knowledge and management of all the components and sub systems that are part of the autoinjector. Not only the autoinjector components but the syringe plus the stopper, so we are managing all the components. We are specifying all of the components to be sure that the system will operate as it should do in the end with patients.”