One Step Closer To Needle-Free Injections

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One Step Closer To Needle-Free Injections

Article Date: 11 Mar 2007 - 5:00 PDT

A team of UCSB researchers, in collaboration with colleagues from UC Berkeley

and StrataGent Life Sciences, of Los Gatos, California, has designed a novel

pulsed microjet system engineered to deliver protein drugs into the skin without

the pain or bruising that deeper penetration injection systems cause. The

research was published in the Proceedings of the National Academy of Sciences.

The effort to create needle-free drug delivery systems is driven by a

combination of factors, including needle phobia, pain and discomfort,

infections, and accidental needle sticks to healthcare providers. Currently,

about 12 billion needle injections are performed every year for the delivery of

vaccines and protein therapeutics such as insulin, growth hormone and

erythropoietin, a red blood cell booster. Needle-free delivery of vaccines has

recently been identified as one of the significant emerging challenges in global

health.

The researchers felt that the pain and bruising caused by previously-developed

jet injectors was caused by the deep penetration of jets into the skin, creating

negative reactions of nerves and capillaries. The pulsed mircrojets engineered

by the researchers combine high velocity (more than 100 meters per second) with

very small jet diameters (between 50 and 100 micrometers), delivering only 2 to

15 nanoliters of liquid drug at a time. The research showed that the pulsed

microjet system could be used to effectively deliver drugs for local and

systemic applications without using needles.

" The microjet system delivers precise doses into superficial skin layers,

thereby mitigating pain, " says Samir Mitragotri, a professor of chemical

engineering at UCSB and a lead author of the paper. The system was designed as

an alternative to the macro-scale systems that had been causing pain and

bruising. " We realized that we had to find a way to stop the jets from going

deep into the skin, " says Mitragotri. " Speeding the delivery, combined with

using extremely small jet diameters and less liquid per pulsation, was shown to

be more effective. "