Needle-free injections are preferable to the use of standard needle and syringe procedure because Needle-free injections significantly reduce the pain inherent in injection procedure. For example, Needle-free injections are used in Digital ring block anesthesia, before performing surgery on ingrown toenails.
Needle-less injection devices are used to induce digital anesthesia before the surgery and a comparison of patients’ discomfort and preference to using a standard needle and syringe injection for the procedure shows that there is a significant reduction of the pain and discomfort associated with this procedure when needle-less injections are used. The first to create a “needle-free injector” was the American anesthetist Robert A. Hingson, 65 year ago. Since that time those devices underwent a changeful history.
In 1986 an outbreak of hepatitis B among patients receiving injections from a needle-free multiple-use-nozzle injector was documented and related to the use of the injector device. Due to such risk of transmission of infection with these reusable devices, their application has been restricted. In 1998 the WHO recommended that only conventional needles and syringes should be used for immunization until safe needle-free injectors are identified through independent safety testing. Ziegler A.
(2007). http://lib. bioinfo. pl/auth:Ziegler,A A needle-less hypodermic jet injection device includes an injection orifice, a drug injection cartridge, which provides a cylinder of liquid medication to be injected, hand-held injector, and an injection piston which is used for moving the cylinder forcefully, and thus causes an injection jet of medication to be expelled from the injection orifice. A Needle-less injection device also includes a gas pressure capsule that powers the jet injection.
Another function of this gas pressure capsule is to reset the injection device automatically, when an injection is being administered, so as to ensure that the device is ready for subsequent injections. A newest research field in the area of the needle-free injection systems has also been opened “with the development of powder injectors, in which the drug preparation is no longer a suspension or solution, but a powdered solid. ” Ziegler A.
(2007). This needle-less technology of using powder formulations has proven to have quite a number of advantages over the conventional syringe and needle injection technique. As a result of this new kind of needle-free injectors, there is optimism that the use of needle-less injections in large-scale WHO vaccination programs will be very reasonable, and within reach.
References
J Am Podiatr. (2003) Med Assoc 93(1): 23-26. Ziegler A. (2007) Needle-free injection–science fiction or comeback of an almost forgotten drug delivery system (http://www. ncbi. nlm. nih. gov/sites/entrez? Db=pubmed&Cmd=ShowDetailView&TermToSearch=17879809&ordinalpos=4&itool=EntrezSystem2. PEntrez. Pubmed. Pubmed_ResultsPanel. Pubmed_RVDocSum) http://www. google. com/patents? id=qr8WAAAAEBAJ&printsec=abstract&zoom=4&dq= needle-free+or+needle-less+injections http://www. nhicb. gov. tw/nhicbd00/Surg12. doc http://lib. bioinfo. pl/auth:Ziegler,A