Autoinjector: Empowering The Healthcare Industry

In the dynamic landscape of the healthcare sector, the evolution of drug delivery systems plays a significant role in transforming the management of chronic diseases. Among the various innovations, self-injection devices (specifically autoinjector) have emerged as a promising solution. Autoinjector are self-injection devices that automatically insert the needle and deliver a particular amount of therapeutic into the skin (via spring driven mechanism).

They are generally used in combination with primary containers, such as prefilled syringes and cartridges. Further, autoinjectors offer various benefits, including compact device (allowing easy portability), high user convenience (particularly for patients with limited dexterity), accurate drug dosing (promoting therapeutic effectiveness) and enhanced control over treatment (resulting in patient empowerment). In addition, various combination products have been approved / are currently under development for the treatment of various therapeutic indications, such as rheumatoid arthritis, diabetes, psoriasis, psoriatic arthritis and multiple sclerosis.

Classification of Autoinjector

Autoinjectors can be classified into different types, based on various parameters, such as usability of autoinjectors, type of dose delivered and type of actuation mechanism.

Classification of Autoinjectors
  1. Classification Based on Usability of Autoinjector:
    • Disposable autoinjector: A disposable autoinjector is designed for single use only and is discarded after the drug is injected into the body. These autoinjectors offer several advantages, including simplified drug administration process, safer injection, reduced risk of contamination and minimized maintenance (due to elimination of cleaning and sterilization steps).
    • Reusable autoinjector: A reusable autoinjector is a type of autoinjector that can be used multiple times (for a single patient only). In such devices, it is the primary container that needs to be replaced with a new one, each time the drug is depleted. Once the primary drug container is changed, the autoinjector is ready to use for the next delivery of medication. These autoinjectors minimize the environmental impact, aligning with sustainability goals.
  2. Classification Based on Type of Dose Delivered:
    • Fixed-dose autoinjectors: Fixed-dose autoinjectors are devices that are capable of delivering a specific amount of medication. Such autoinjectors usually consist of 1mL or 2.5mL drug containers. These allow precise and consistent delivery of a fixed dosage.
    • Variable-dose autoinjector: Variable-dose autoinjector are devices that are designed to administer medications in adjustable amounts, as per their individual requirements (of drug and therapeutic indication); these devices provide flexibility for patients whose medications change over time or patients that require personalized drugs.
  3. Classification Based on Type of Actuation Mechanism:
    • Mechanical autoinjectors: These devices are driven by mechanical force and do not need electronic systems for drug delivery. Mechanical autoinjectors involves the user to push a button / press down on the device to initiate the injection process; this enables the user to proceed at their own comfort and pace.
    • Automatic autoinjectors: The delivery mechanism in these devices have embedded electronics (which include an electrical driving unit powered by a battery) that trigger the injection process automatically (without manual initiation by user). These devices reduce injection anxiety, and are useful for patients who prefer a hands-free drug delivery experience.

Advantages of Autoinjector

Autoinjectors offer a number of benefits over traditional parenteral delivery mechanisms for both patients as well as healthcare professionals and are a popular choice for drug delivery, due to their various advantages.

Advantages of Autoinjector
  • Ease of Use: Autoinjectors are easier to use when compared to conventional syringes, enabling patients to self-administer medications at home. The autoinjectors removes the requirement of manual drawing and measuring of drugs, before administration into the body, making the drug delivery more convenient.
  • Reduce Dosing Errors: The fixed dose autoinjector with pre-measured dosage can reduce dosing errors and ensure accuracy in administration of medications.
  • Minimize Drug Waste: The autoinjectors minimize drug waste, as the exact amount of a deliverable dose is contained in the primary container, unlike vials and syringes.
  • Reduce Risk of Contamination: Since the product is sealed at the production facility, the chances of microbial contamination are reduced significantly. This is extremely important for injectable medications.
  • Home use and Self-Administration: Autoinjectors are convenient for home setting and eliminate the need for costly and frequent visits to clinics / hospitals.
  • Patient Safety: Some autoinjector are integrated with safety features in order to prevent inadvertent needle stick injuries. The connected autoinjector is integrated with various features that remind patients to take their medications, and also helps track their entire treatment regimen.
  • Eliminate Overfills: Autoinjector eliminate the overfilling of drugs in the delivery system, thereby saving the expensive formulations.
  • Long Shelf Life: Since the drugs stored in autoinjectors are safe from exposure to environmental factors, they tend to have a longer shelf life.
  • Improved Patience Compliance: The integration of advanced features like Bluetooth connectivity, and audio and visual indicator and convenience provided by connected autoinjector has increased the patient acceptance towards self-injection devices.

Drug Device Combinations

Autoinjectors are considered as single entity combination product. As a result, they are developed as products comprised of two or more regulated components, which are physically or chemically combined / mixed and then produced as single entities. Such combination product typically consists of an autoinjector with specific drug formulation. One of the most widely recognized autoinjector in the market is EpiPen® (Mylan), which is a prefilled epinephrine autoinjector. Notable examples of other autoinjectors based combination product include Fasenra® Pen (AstraZeneca), Gvoke® Hypopen (Xeris Pharmaceuticals), NUCALA Autoinjector (GlaxoSmithKline), and Vyleesi™ Autoinjector (AMAG Pharmaceuticals® / Palatin Technologies)

Driving Factors for Autoinjector Domain

The benefits of using autoinjector over conventional methods of parenteral drug delivery are widely recognized by healthcare industry professionals as well as end-users. Some of the factors that are anticipated to drive the market are as follows:

  • Autoinjectors have the ability to eliminate dosing errors, since the majority of autoinjectors contain exact dose of medication. Further, a wide variety of molecules, such as antibodies, peptides, proteins and small molecules, can be delivered using autoinjectors, demonstrating their versatility in healthcare domain.
  • The use of autoinjectors allows the patients to administer the medications at home, reducing the need for frequent visits to healthcare facilities. This enables cost savings for both patients and healthcare systems by reducing transportation costs, clinic overhead and staff resources.

Restraints in Autoinjectors Domain

Despite the various advantages offered by autoinjectors, there are certain concerns which limit the use of autoinjectors. Some of the concerns are as follows:

  • The automatic autoinjectors precisely deliver the drug but are less reliable. This can be attributed to the fact that automatically programmed devices have the risk of technical errors. These errors may be associated with battery, pump components, needle insertion / retraction mechanism or dose programming.
  • Further, over the years, the emergence of some concerns related to dosing errors, issues related to drug stability and / or device malfunctions, has resulted in the recall of several autoinjectors. Such situations are unpredictable and have the potential to permanently damage the reputation of a specific brand / category of commercialized products.


Over the years, auto-injectors have demonstrated significant potential to be able to establish themselves as the next generation of patient-centric devices, capable of safe and reliable delivery of injectables. With simple push-button mechanism, patients can easily administer the prescribed drug, often without the need of healthcare professional assistance. With increasing awareness among patients, pharmaceutical companies are bringing various advancements into their autoinjector devices, such as integration of feedback features (audible and visual indicators), Bluetooth connectivity, extended battery life and variable injection speeds. These aspects are likely to contribute to positive patient experience, foster greater adherence to treatment regimens and enhance quality of life for the patients.