'Painless' vaccine needle invented in Japan

TOKYO — Kanji Takada, a professor of pharmacokinetics — or the study of the absorption, distribution and fate of substances delivered to the human body — has developed a round vaccine "chip" measuring 1.5 centimeters in diameter that contains as many as 300 micro needles. The device can deliver drugs to the body without breaking the dermis layer of skin.

By penetrating just 0.5 millimeters before the needles dissolve and administer the vaccine, the patient feels no discomfort and there is no bleeding, said Takada, of Kyoto Pharmaceutical University.

"The patch can be used to deliver any type of vaccine and people are not frightened of having the injection because they feel nothing at all," Takada told London’s Telegraph in a story posted March 4.

It has taken Takada six years to develop the new drug delivery system, with earlier efforts by other researchers to use micro needles made out of sugar failing because they degraded at temperatures above 100 degrees centigrade, he said.

Takada replaced sugar with a water-soluble polymer that dissolves when pressed into the epidermis, the very outer layer of skin, releasing the vaccine to be absorbed into the circulatory system.

Each of the dozens of needles is a 0.5 mm long and 0.3 mm wide at the base and tests show that the efficiency of the vaccine is not adversely affected by the method of delivery.

Takada's new injection system could be available for use in hospitals in Japan within two years.