INJECTION…. The first emotion which this word evokes is fear. The title needless injection suggest that the traditional definition of the injection has now received a modified perspective. After reading which I hope it will stimulate your serotonin and not amygdala. So as the name suggests, we are now actually introduced to injections without needles which are also known as jet injectors, jet gun injector, air gun, or pneumatic injector. They use a high-pressure narrow jet of the injection liquid instead of a hypodermic needle to penetrate the epidermis. They can also be used to drive medicaments into the muscle. The needle free injection technology is not only known to be beneficial for the pharmaceutical industry but also in developing world. It is found to be highly useful in mass immunization programmes, bypassing the chances of needle stick injuries and avoiding other complications including those arising due to multiple use of single needle.

Jet injectors are found to be quite safe and effective for use and are known to reduce the drawbacks and injuries caused

by use of needle. Their invention is as idiosyncratic/ aberrant as them. They were first published accidentally in the year 1937 by a diesel engine fuel injector. 1951 was a year of large scale immunization, The Commission on Immunization of the Armed Forces Epidemiological Board requested the Army Medical Service Graduate School to develop injection equipment specifically intended for rapid semiautomatic operation in large-scale immunization programs. This device was known as the multi-use nozzle jet injector (MUNJI). In 1961, the Department of the Army made multi-use nozzle jet injectors the standard for administering immunizations. In 2014, the U.S. Food and Drug Administration (FDA) approved the use of the PharmaJet Stratis 0.5ml, Needle-free Jet Injector for delivery of one particular flu vaccine and in 2017, David Fernandez Rivas developed a new type of laser-based jet injection.

Needle free injections use a jet of liquid instead of a syringe. To power this jet of liquid, compressed air or gas, either from a pressure hose from a large cylinder, or from a built-in gas cartridge, small cylinder, or spring is used. They can be single-dose or multi-dose jet injectors. So, for injectors to work, the power source has to be actuated by subsequently triggering a piston or plunger, which causes an instantaneous increase in pressure onto the liquid medicament. The pressure range is from 2,000 to 5,000 psi which is needed for the jet stream to penetrate skin. The liquid medicament is ejected through the nozzle at a velocity ranging from 100 to 200 meters per second. The jet stream penetrates the skin by eroding and fracturing of the skin and tissue. The liquid medicament after penetration disperses into surrounding tissue, cells and muscle. The absorption of the liquid medicament slows down the pressure of the jet stream and now the flow of jet stream changes from unidirectional to multidirectional. During this process a splash back phenomenon might be possible which was simply paraphrased by Voelker (1999) as, “Jet injection builds pressure in the skin that is greater than the pressure in the injector, causing a small backflow.” After the administration of an injection the skin tends to can redden, bruise, or develop a wheal. It eventually goes away as the fluid is absorbed into the deeper tissue layers. The skin site is cleaned with alcohol in usual manner.

The Injection is prepared by using pressure lever and is held, then the dose is adjusted with the dose of nozzle. The filled nozzle is put into injection device. The jet injector gun or pen tightly against skin and aiming it towards the site.

Thus, the use of jet injectors have proved to be easy and safe for mankind. One of the major drawback associated with two piece system of injection was associated with pain which can be now ruled out. This technology is capable of delivering a wide spectrum of medicinal formulations into the body with the same bioequivalence and with more antigen dispersibility. These devices are very easy to use and don't require any expert supervision or handling. They are easy to store and dispose. These devices are suitable for delivery of drugs to some of the most sensitive parts of the body like cornea. They are efficient to administer intra-muscular, subcutaneous and intra-dermal injections. They have also overcome the risk of carrying contamination to subsequent subjects by use of single syringe for multiple times to multiple patients which indirectly increases the risk of spread of diseases. However, they have not completely overcome the use of needles. The users have to face few difficulties such as, higher startup costs and maintenance, requirement of infrastructure for exhaustible gas systems. Even though the disadvantages outnumber the advantages, one cannot be oblivious to the array of advantages offered by this system.

The use of jet injectors have shown a considerable rise through the years. Study forecasts that overall worldwide sales of needle-free injection devices will reach $1.98 billion in 2020.The growth can be accredited to increasing life expectancy, biologics, and growing prevalence of chronic technological advancements. The global jet injector device market can be segmented based on product type, methods of injection, end-user, medication type and region. Key market players include Antares Pharma, Inc. (U.S.), Endo International plc (U.S.), Pharma Jet (U.S), Bioject Medical Technologies Inc. (U.S), Medical International Technology, Inc. (U.S), INJEX Pharma AG (Germany), National Medical Products Inc. (U.S.), Valeritas, Inc. (U.S.), European Pharma Group (Netherland), PenJet Corporation (U.S), Crossject SA (France). This shows the dominance of North America on the market. Though in India the sales are not much, jet injectors are mainly used by diabetic patients as it serves the purpose of ease of daily administration at home without the need if assistance. According to the research conducted, in India Johnson and Johnson is the emerging company in market of jet injectors. Thus, the increasing use of NFIT will increase patient co-operation and compliance and therefore the efficiency of medical care. So, I hope the rising market of needless injections, eradicates trypanophobia and proves to be a boon for humanity.

Sayali Ayare

T. Y. B. Pharm

Tags: MET Institute of Pharmacy