Technology Overview

Needle-free injection - What is it?

Bioject's needle-free injection technology works by forcing liquid medication at high speed through a tiny orifice that is held against the skin. The diameter of the orifice is smaller than the diameter of a human hair. This creates an ultra-fine stream of high-pressure fluid that penetrates the skin without using a needle.

Bioject's technology is unique because it delivers injections to a number of injection depths and supports a wide range of injection volumes. For instance, the Biojector 2000 can deliver intramuscular or subcutaneous injections up to 1 mL in volume. In addition, Bioject is developing a syringe for the Biojector 2000 that delivers intradermal injections that is currently in clinical trials.

Click on the pictures below to see needle-free injection in action.

	Intramuscular injections are the deepest injection type, delivering the medication into the muscle tissue. Most vaccines are currently delivered to the intramuscular depth.
	Subcutaneous injections are delivered to the adipose (fat) layer just below the skin. Many therapeutic proteins are delivered to the subcutaneous depth, such as human growth hormone.
	Intradermal* injections are very shallow injections that deposit the medication between the layers of the skin. Many new DNA-based vaccines are delivered to the intradermal layer.
	* Investigational use only

Dispersion Patterns

Bioject's needle-free injection technology improves the dispersion of medication throughout the tissue as compared to needle-based injection.

As the plunger on a needle-syringe is depressed, a spherical pool of medication called a bolus forms at the tip of the needle.

Needle-free injection relies instead on a high-pressure stream of the medication itself to penetrate the skin. As the fluid stream forces its way through the tissue, it follows the path of least resistance, resulting in a widely dispersed, spider web-like distribution of the medication.

Click here to see how the dispersion of medication is improved by needle-free injection as compared to a needle.