The Rise Of Autoinjectors

This article is part of a special feature on injectables that was published in the February issue of PTE Digital, available at http://www.pharmtech.com/ptedigital0211.

The original autoinjectors in the 1980s and 1990s were designed for military emergency applications and for the treatment of migraine and anaphylactic shock. Disposable autoinjectors were mainly introduced for emergency situations where the autoinjector provides an effective and convenient solution, and where the infrequent injections justify the investment per unit.

Ian Thompson. Head of Business Development at Ypsomed.

For biotech drugs, reusable autoinjectors have been provided as an injection aid since the 1990s — mainly for the frequent injection of multiple sclerosis and rheumatoid arthritis drugs. Convenient, fully disposable autoinjectors, including needle safety devices for biotech drugs, have been on the market since 2006. Indeed, it is the infrequent injection of biologic drugs that has been the main driver for the further development of disposable autoinjectors because the lower injection frequency (once weekly or less frequently) justifies investment in a fully disposable autoinjector, which is much more expensive than a bare syringe. This cost, however, can be justified by improved therapy and patient compliance.

With regards to biologics, the main challenges come from their stability. For freeze‑dried drugs, special devices such as devices for dual‑chamber cartridges help simplify the reconstitution and injection processes. Drug viscosity and injection volume also pose challenges for the development of injection devices, and a number of companies are working to improve devices in these areas.

Newer autoinjection devices all include integrated needle safety and provide the patient with enhanced visual and audible injection feedback, which makes handling and the injection process more intuitive for the patient. Today, the main innovation focus is on improving the handling and reliability of disposable autoinjectors and prefillable syringes — now that they have been on the market for a number of years — to reduce patient complaints. At our company, for example, we’re working on making devices easier to use and more reliable, while maintaining cost effectiveness. As the number of autoinjectors on the market increases, economy of scale and lower manufacturing costs are also a clear focus. When designing a new autoinjector, the key factors to consider are patents, development know‑how and manufacturing expertise.

Patients have responded very positively to autoinjectors. For monodose syringe‑based injections, disposable autoinjectors are the gold standard because patients really appreciate the easy handling, and needle hiding and safety features that these devices provide. Pen injectors, particularly insulin pens, which can be described as sophisticated syringes, have also reached a high level of convenience. In fact, the two technologies of disposable autoinjectors and pen injectors are starting to overlap, with new devices such as spring‑driven pens and autoinjectors with manual needle insertion already on or coming to market. These improved devices have been developed with the needs of the patient in mind.

The future

Today, self‑injection devices, both pens and autoinjectors, have a high level of functionality. However, key improvements are still being made in the areas of reducing device size, easier needle attachment, easier dose setting of pens, spring‑driven injection pens, and improved injection status feedback for pens and autoinjectors.

www.ypsomed.com