Injections of drugs or vaccines have become an indispensable part of living systems.
Introduction to injections begins from the vaccination regimen at the neonatal stage
and continues throughout the life span of an individual. Conventionally, injections
are administered using hypodermic needles and syringes. These usually inject the liquid
in the muscle, thus making intramuscular injections the most common form of administration.
Although hypodermic syringes have been a clinician's tool in global vaccination efforts,
they also have a set of undesirable characteristics. Pathogen transmission in case
of HIV and HBV is one of the deadliest disadvantages of the needle-based injection
system. Generation of plastic wastes in clinics, needlestick injury, and most importantly,
pain associated with needle-based injections are a few more reasons of concern. In
light of these issues, developing needle-free injection systems has excited researchers
across the globe since the 1950s. Significant advancement has been reported in this
field and various needle-free injection systems have been developed and are in clinical
practice. This article briefly describes the history of needle-free injection systems
and provides a detailed account of a few well-known methods of needle-less injections
available.
