Jet injection through microneedles for large volume subcutaneous delivery.

Subcutaneous (SC) drug delivery offers several advantages over intravenous (IV) delivery including: self-administration, improved patient experience, and reduced treatment costs. Unfortunately, each SC delivery is currently limited to ∼ 2.25 mL with IV administration required when the delivery volume exceeds this value.

Measurement of Blood Dilution during Lancet-Free Blood Sampling.

In this paper, we report on a fluorescent and colorimetric system for measuring the dilution of capillary blood released by a needle-free jet injector. Jet injection uses a high-speed liquid jet to penetrate tissue, and in the process can release capillary blood that can be collected for performing blood tests. In this way, blood sampling can be performed without the use of a lancet.

Rotatable Orifice for Needle-Free Jet Injection.

This research explores a new development in orifice technology for needle-free jet injection. The premise lies in the ability to control the angle at which the drug is delivered into the tissue to increase the lateral dispersion of the drug. Towards this aim, a spherical orifice that can rotate to adjust the injection angle is explored.

Large volume subcutaneous delivery using multi-orifice jet injection.

Needle-free jet injection is an alternative drug delivery technique that uses the liquid drug itself to penetrate through the skin. This technology is not only a promising alternative to hypodermic needles but also has the potential to replace intravenous delivery with rapid, needle-free subcutaneous delivery for large-volume treatments. In this work we propose a parallelised, 'multi-orifice' approach to overcome the volume constraints of subcutaneous tissue.

Preliminary pharmacokinetics and patient experience of jet-injected dexmedetomidine in healthy adults.

Jet injection is a drug delivery system without a needle. A compressed liquid drug formulation pierces the skin, depositing the drug into the subcutaneous or intramuscular tissues. We investigated the pharmacokinetics and patient experience of dexmedetomidine administered using jet injection in six healthy adult study participants.

Vacuum-Assisted Needle-Free Capillary Blood Sampling.

Background: Poor glycemic management persists among people practicing insulin therapy in relation to type 1 and 2 diabetes despite a clear relationship with negative health outcomes. Skin penetration by jet injection has recently been shown as a viable method for inducing blood release from fingertips. This study examines the use of vacuum to enhance the volume of blood released and quantifies any dilution of the collected blood.

Minimally invasive capillary blood sampling methods.

Introduction: Whole blood samples, including arterial, venous, and capillary blood, are regularly used for disease diagnosis and monitoring. The global Covid-19 pandemic has highlighted the need for a more resilient screening capacity. Minimally invasive sampling techniques, such as capillary blood sampling, are routinely used for point of care testing in the home healthcare setting and clinical settings such as the Intensive Care Unit with less pain and wounding than conventional venepuncture.

Case study of user experience-driven design in a new local anaesthetic dentistry jet injection device.

This case study explored how human-centred design methodologies can improve clinician experience and reduce patient treatment anxiety in the application of a new dental local anaesthetic jet-injection system. An initial embodiment of the prototype injector, dubbed the 'Kiwi' injector, was developed to better understand the user experience during dental-injection procedures. Further design development was undertaken in two distinct phases.

Jet injection needle-free dental anaesthesia: Initial findings.

Objectives: We evaluated patient preference and reported levels of anxiety and discomfort of participants treated with a new needle-free electric motor-driven device vs. conventional local anaesthetic for dental extractions in a proof-of-principle study. Healing and response of gingival tissues to injection were also evaluated at 1, 3- and 7-days post-procedure.

Jet-Induced Tissue Disruption for Blood Release.

Objective: Needle-free jet injection is a drug delivery technique that uses the momentum of the fluid drug to break through the skin. This technique has recently also been applied to blood release, aiming to collect samples from capillaries in the skin without needing a lancet prick. This work provides new information about the wound geometry and tissue disruption caused by shallow jet injection with circular-shaped and slot-shaped jets.

Jet-Induced Blood Release From Human Fingertips: A Single-Blind, Randomized, Crossover Trial.

Background: Lancet pricks are often poorly received by individuals with diabetes; jet injection may allow lancet-free blood sampling. We examine whether the technique of jet injection can release sufficient blood from the fingertip to enable measurement of blood glucose concentration. In addition, we assess the effect of jet shape and cross-sectional area on fluid release, blood dilution, and perceived pain.

Blood Collection from The Porcine Ear Using a Jet Injector.

We present a new lancet-free method of capillary blood collection for the measurement of blood glucose concentration using a needle-free jet injector. This technique is tested on living animals and directly compared to the current best practice, lancet prick. Shallow jet injection into porcine outer-ear was performed using a portable needle-free jet injector with a slot-shaped nozzle.

Laterally Dispersing Nozzles for Needle-assisted Jet Injection.

Most transdermal drug delivery systems are designed to inject drugs through the skin in a direction normal to the skin surface. However, in some applications, such as local anaesthesia, it is desirable to disperse the drug in a direction parallel to the surface of the skin. In this paper we present nozzles for needle-assisted jet injection that are designed to laterally disperse the fluid drug at a chosen depth in tissue.

Subcutaneous nicotine delivery via needle-free jet injection: A porcine model.

Subcutaneous delivery of nicotine was performed using a novel electrically-operated needle-free jet injector, and compared to hypodermic needle delivery in a porcine model. Nicotine was delivered as a single, one-milligram dose into the abdominal skin, formulated as a 50 microliter aqueous solution. Plasma levels of nicotine and cotinine, its main metabolite, were then monitored over 2 h, following which the injection site was excised for histological examination.

Viscous Heating Assists Jet Formation During Needle-Free Jet Injection of Viscous Drugs.

Objective: Jet injectors use a high-pressure liquid jet to pierce the skin and deliver drug into underlying tissues. This jet is formed through a short, narrow orifice; the geometry of the orifice and the properties of the fluid affect the nature of the flow. We aimed to discover information about the turbulent and viscous processes that contribute to pressure loss and flow patterns during jet injection.

Power-efficient controlled jet injection using a compound ampoule.

We present a new mechanism for achieving needle free jet injection that significantly reduces the power required to perform a given injection. Our 'compound ampoule' produces two phases of jet speed under a constant force input by changing the effective piston area part-way through the injection. In this paper we define the benefits associated with a compound ampoule, relative to those of the conventional single piston design, by developing expressions for the power and energy required to perform an injection.

The effect of jet speed on large volume jet injection.

Jet injection presents a promising alternative to needle and syringe injection for transdermal drug delivery. The controllability of recently-developed jet injection devices now allows jet speed to be modulated during delivery, and has enabled efficient and accurate delivery of volumes up to 0.3 mL.

High-speed X-ray analysis of liquid delivery during jet injection.

The effect of varying velocity during jet injection on the dispersion of fluid into tissue is investigated using a custom-built X-ray imaging system. Injections are performed into ex-vivo porcine abdominal tissue using a voice coil actuated injection device. Single velocity and two-phase velocity injections reveal the complex nature of the dispersion of the fluid jet in layered tissue and highlight the effects of changing the jet velocity following the initial penetration of the liquid into the tissue.

A device for controlled jet injection of large volumes of liquid.

We present a needle-free jet injection device controllably actuated by a voice coil and capable of injecting up to 1.3 mL. This device is used to perform jet injections of ~900 μL into porcine tissue.

A compound ampoule for large-volume controllable jet injection.

We present a new design for a needle-free injector ampoule, using two concentric pistons to pressurize the fluid during the injection. The smaller, inner piston is used to provide an initial high-velocity piercing jet; it then engages the outer piston to deliver the remaining drug via a low-velocity jet. The goal of this design is to enable needle-free delivery of relatively large volumes to controlled depths in tissue, a task impractical with conventional ampoules and actuators.