The Gene Delivery Research Group based at the Welsh School of Pharmacy at Cardiff University and clinicians at Gwent Healthcare NHS Trust found healthy volunteers who were injected with micro-needles and the traditional hypodermic reported the hypodermic needle was up to five-times more painful than the micro alternative. The team are considering whether it is viable and feasible to replace the traditional hypodermic needle with micro-needles, which are being developed but have yet to enter the marketplace. "Micro-needles provide a method for delivering medicines into and through skin and our pilot study has shown that volunteers report significantly less pain with a micro-needle," PhD researcher Mohammed Inaam-ul Haq said. The drug-free micro-needles used in the study, manufactured by the Tyndall National Institute in Ireland, were solid needle projections from silicon wafer that were less than 1mm in length. The device worked by penetrating into only the very outer layer of skin, the stratum corneum, compared to the hypodermic needle which may penetrate into the skin some two to five millimetres. Because the micro-needle did not penetrate into the skin as deeply, it did not hit the pain receptors, Haq told in-PharmaTechnologist.com. Meanwhile, the risk of needle stick injuries using micro-needles was "nominal", he said. The lack of penetration depth meant blood vessels were not hit, reducing blood to blood contact. The debate on hypodermic needles has been going on for some time with many turning their attention to needle-free delivery systems as a means to solving the traditional problems such as needle injuries and needle phobias. Haq said while there were advantages to the needle-free delivery systems, the micro-needle system promised to be much cheaper to manufacture and was being looked at as a disposable/biodegradable device. The study also showed the micro-needle punctured the skin at a regular rate and the injection site healed quicker when using the micro-needle compared to the traditional counterpart. The team, which presented its results at the British Pharmaceutical Conference in Manchester, is now considering further studies on the administration of drugs using micro-needles. In April, Drug delivery technology firm Apogee signed an exclusive license to use a micro-needle technology from the Georgia Tech Research Corporation (GTRC) to enhance its intradermal drug delivery system. The technology consists of hollow micro-needles made by micro-electrical mechanical system technology (MEMS) designed to painlessly increase permeability of the skin and allow fluid delivery with less risk of clogging. The GTRC has made sharp-tipped, solid polymer micro-needles as a core structure, which are then coated with metal to add strength.