With the development of large protein-based drugs on the rise and the increase of available treatments for chronic conditions, researchers have been developing new technologies capable of delivering drugs in the home setting — including jet injectors, which inject a very thin, very fast stream of medication into the skin and tissue – without a needle.

Needle-free drug delivery devices have been around since the 1960s but their adoption has been hampered because most can only deliver a limited volume of medication1, 4 have limited ability to control injection depth2,4 and last but certainly not least, can be loud and painful1, 3.

The technical explanation behind the challenge with historic needle-free devices is that they used stored energy (e.g. a high-powered spring, compressed air or gas cartridges like CO2 or Nitrogen) to generate the force and pressure necessary for the injection.  When that spring releases or the CO2 cartridge explodes, there is a sudden burst of energy (and often an accompanying loud bang) that drives the injection. This energy level is the same fixed amount for every patient, despite differences in skin types and patient profiles, resulting in an injection depth that is difficult to regulate.  Portal refers to this as an ‘open-loop system’.

And just as this energy is released quickly, it dissipates quickly – meaning only a limited volume of medication can be delivered at a time.  For every doubling of dosage volume, a four-fold increase in power is required, resulting in more force (and theoretically more discomfort) on the patient.

To solve these problems, researchers at the Massachusetts Institute of Technology (MIT) and subsequently Portal Instruments, have developed a needle-free injector with a computer-controlled motor and with an internal feedback control system (similar to a car’s cruise control).  This ‘closed-loop’ control system senses pressure and adjusts the jet speed to appropriately delivery the drug.

This can result in several benefits, all leading to a better patient experience.

  1. Highly customizable:  The feedback controls allow for accurate and repeatable medication fill in the subcutaneous space.  This depth level can be adjusted, based upon the requirements of the drug.
  2. Quick:  The narrow stream of medication (thinner than a strand of hair) penetrates the skin in less than half a second.
  3. Adaptable to different viscosities:  The Portal injector can handle high viscosities – up to 60 cP.  This makes it well-suited for mAB (biologic drugs).
  4. Temperature independent:  Because the platform can adjust to handle high viscosities, medication can be administered after removal from the refrigerator.
  5. High volume:  Portal’s device can deliver high volumes – over 1 ml.
  6. Quiet:  The Portal solution is computer controlled, resulting in a quiet injection.
  7. Patient preferred: Studies have shown that patients perceive less pain and prefer the Portal needle-free injector versus needle and syringe injections5.
  8. Connected:  Unlike legacy devices, the Portal device and related phone app logs patient adherence, sends reminder notifications, tracks symptoms and allows for sharing with medical professionals.

Samir Mitragotri, a professor of chemical engineering at the University of California at Santa Barbara, was quoted in the MIT News as saying, “Commercially available jet injectors … provide limited control, which limits their applications to certain drugs or patient populations,” Mitragotri says. “[This] design provides excellent control over jet parameters, including speed and doses … this will enhance the applicability of needle-less drug devices.”2

While needle-free injectors have been on the marketplace for decades, the Portal platform is truly a next-generation device that is looking to improve the patient experience all around.

To learn more about how our device works and how it’s different from traditional needle-free devices, click here.


1 Ravi, Ansh, et al.  “Needle free injection technology:  A complete insight.” Int J Pharm Investig. 2015 Oct-Dec; 5(4): 192–199.
2 Chu, Jennifer. “Device may inject a variety of drugs without using needles.” MIT News Office, May 24 2012.
3 Bhagyashri Chavan et al. “Review on Needle Free Drug Delivery Systems.” International Journal of Pharma Research & Review. Sept 2013; 2(9):30-36.
4 Taberner, Andrew, et al. “Needle-free jet injection using real-time controlled linear Lorentz-force actuators. Medical Engineering & Physics 34 (2012) 1228– 1235.
5 Kojic, Nikola. “An Innovative Needle-free Injection System: Comparison to 1 ml Standard Subcutaneous Injection.” AAPS PharmSciTech. Vol. 18, No. 8, November 2017.

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Portal’s platform is in development and not available for sale or use.