Insulin Jet Injectors.
Go directly to- Jet Injector Manufacturers. (Will load another page.)
What the jet injector consists of.
How they work.
Advantages.
Disadvantages.
Why are these not more popular?
Looking like a large pen, in fact very similar to the insulin pen, these are insulin delivery devices that have no needles - do I hear screams of "yippee"?
Should you get excited? The jury still seems to be out on that, you will have to decide for yourself from the following information.
Medi-Ject Corp (now Antares Pharma, Inc.) first developed these devices for individual insulin delivery around 1979. Strangely enough they do not seem to have taken off the way one would expect. In my search to find out why I have read comments about them causing pain & bruising, being heavy and awkward, needing to be sterilised, taking to much time to clean and to prepare for the injection and giving incomplete injections, and last, but I suspect not least, expense.
Do not let all these comments put you off just yet. There have been advances in these products since the early days that, as far as I can tell, address many of these issues.
For instance, a needle free insulin device called the Derma-Ject, made by Derata in 1979 was not a roaring success, possibly due to the fact that it weighed around one and a half pounds, cost a staggering $925 and had no pressure adjustment - it was described as having a kick like a mule or like the recoil of a really powerful firearm. Not the sort of thing you want to use once, never mind 4 times a day!
Fortunatly the modern jet injectors have come a long way from there!
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What the jet injector consists of.
They are made up of three main pieces, the actual pen shaped injector device which powers the system, the disposable nozzle that injects the insulin and the disposable vial adapter.
The injector device is made to last for a considerable period of time (Bioject Corp claims over 3,000 injections for the Vitajet 3) but the nozzle and the vial adapters are disposable. They are not 'one time use' objects however. The nozzles can be used a number of times (Antares Pharma Inc claims 21 uses for the Medi-jector Vision).
The Vial Adapter, which is a connector that enables one to withdraw insulin fron a vial without using a needle, is usually thrown away with the insulin vial when the vial is empty or expired.
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How they work.
By forcing the insulin through a specially designed nozzle a very fine, extremely high pressure jet is produced. This jet is able to penetrate the skin without the assistance of a needle - I suppose one could say it does have a 'sort of' needle, just one made of insulin instead of steel!
The opening at the end of the nozzle is really, really small, even compared to what we would consider the tiny opening in a fine insulin needle - around 0.006 inches as compared to 0.28 inches.
There are two different 'power sources' for achieving the pressure needed, either a compressed spring or a carbon dioxide or nitrogen cartridge. Springs have the advantage of being small, light, economical and durable, and do not need to be disposed of like a cartridge. If they have a disadvantage it is that you get a limited amount of force from a coiled spring but as we only want to get a reasonably small quantity of insulin into the subcutaneous layer, springs produce more than enough pressure for our needs.
To use the device the spring needs to be compressed (charged) before each delivery. This is usually done by turning part of the device in one direction to wind the spring up.
Once it is fully wound the amount of required insulin is chosen by turning the dosing dial. The device is placed in the vial adapter (which holds the insulin vial) and the insulin is drawn into the nozzle. The nozzle is placed firmly against the skin, at 90 degrees to the body, at the chosen injection site and the actuator button is pressed which releases the spring. The insulin is injected through the skin to the correct depth.
Before I deal with the advantages and disadvantages of these devices I want to separate one factor out - Pain!
It is unfortunate that some of the original advertising blurb concentrated on the fact that these were going to produce totally painless insulin delivery. When this did not always occur they then received very bad press which turned many potential users away from them.
As all diabetics know, pain is a personal thing. Some people have a much higher pain threshold than others. There are folk who find their finger pricks excruciatingly painful while others do not feel a thing. That appears to be what happened with the jet injectors. Apparently the force of the pressure causes a stinging sensation for some.
It being human nature, those who felt pain with them after being promised a pain free device, soon let everyone know (and who can blame them). Those who were quite happy with them carried on using them quietly in the background.
Fortunately it would appear some companies now state that they do not promise pain free injection, as shown in the statement I found on one home site - "However, Bioject does not claim that its systems are painless".
Better one points out the possibilities and leaves it up to the consumer to decide whether it is important too them or not than promise what may not be delivered.
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Advantages.
1. No needle required. This is definite benefit to folk with a real needle phobia or who are just plain scared of needles, as many children, not to mention adults, are. Naturally it also removes the problems of bent and broken needles.
2. Simple to use. Just wind, dial, fill, inject.
3. Flexible. They can be used with all brands of U-100 insulin in standard 10 ml vials.
You are able to mix insulins so eliminating the need for multiple injections that occur with an insulin pen.
This is done by attaching a separate Vial Adapter to each insulin bottle, drawing in the first dose from the one bottle then changing to the second bottle and continue to fill until you have the correct dosage.
4. No disposal problems because there are no 'sharps' involved.
5. No needle removes the danger of needle-stick injuries to a person giving insulin to someone who is unable to do it for themselves.
6. Versatility - Due to the ability in some brands to change nozzles a single device can be adjusted to suit different peoples needs in relation to skin thickness and body mass. Other manufacturers offer versatility by offering different pens for different situations.
7. This method of delivery produces a better spread of insulin into the subcutaneous tissue. With a needle the insulin forms a round pool at the tip of the needle and absorption only takes place from the edge of this pool. With a jet injector the pressure causes the insulin to penetrate the tissue and flow through it via the easiest routes (like most of us it takes the path of least resistance). This results in a net like distribution of insulin over a large area of tissue.
8. The insulin automatically goes to the correct depth, no more decisions needed on what length needle to use and no chance of intra-muscular injections.
9. Speed of injection. From the time you depress the actuator the time taken to complete the injection is around 300 milliseconds. With a syringe or pen you have to keep the needle in place for at least 6 seconds to prevent the risk of insulin leaking back through the injector site.
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Disadvantages.
1. Cost. This definitely tops the list. Compared to syringes the initial cost of these devices is high.
2. Bruising. Just as one can get bruising from a needle puncture so one can get the same from these devices. However you look at it you are forcing a foreign substance into your body - you cannot blame it for fighting back!
3. There is more to do in setting up the injector than there is in a syringe, so it takes more time.
4. They are not widely used so the disposable bits can be more difficult to find. If you travel you will have to take sufficient supplies with you because it is likely you will not be able to find pieces for your particular injector in foreign countries.
5. Sterilisation issues. This was a big problem with the older models and even some of the newer ones advocate cleaning every two weeks.
6. Not as convenient as an insulin pen. You still have to carry around the device, the insulin vial, which needs to be kept refrigerated, the vial adapter and possible the disposable nozzle.
7. Some people do not like the noise the injector makes when it delivers it's insulin.
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Why are these not more popular?
During research on these devices I found what appears to me to be viable comments on why they have not taken off. The quotes I read are found below, along with the URL of the relevant websites.
Quote 1 from Carousel Medical Systems, Inc.TM
"Steve Wills, an account manager for Antares Pharmaceuticals in Minneapolis, Minn., which makes another needleless device, the Medi-Jector VISION, believes needleless injectors aren't used by more patients because "their developers tend to be relatively small companies that don't have the resources" to do widespread promotion.
About 3,000 of his company's injectors are in use, he says. The device has been redesigned several times over more than a decade.
"It's not a new technology, and it's an excellent technology," Wills says, but patients and their doctors tend not to find out about it unless they search it out themselves.
Brian Anderson, director of operations and business development for Equidyne, agrees. The company has been marketing the Injex system for about two years to doctors and diabetes educators, but the response has not been as great as had been hoped, he says. Recently, the company began marketing directly to patients through pharmacy chains, including Rite-Aid and CVS, and ads in diabetes- oriented magazines.
"I think early on it [needleless technology] was oversold," Anderson says, noting that early devices were bulkier, had to be cleaned and didn't eliminate pain. "So there's a little bit of baggage there," he says.
Diabetes educators say another reason more people don't use needleless injectors may be cost. Not all insurers cover needleless systems in every case or all of the cost. Insurers do cover standard needles and syringes.
For example, the Medi-ject device costs about $300, plus about $25 a month for other disposable supplies if a person is taking three shots a day, according to Wills. The Injex costs $260 and $50 per 100 shots for disposable supplies. The AdvantaJet, which does not have disposable parts but must be cleaned, is about $500".
Quote 2 also from the same source above:-
"Eileen Cole, a diabetes educator at Easton Hospital, says she's taught two patients to use a needleless system, the Injex 30, a competitor of the AdvantaJet. Injex is made by Equidyne Systems of San Diego, Calif.
But when she recently took one to a diabetes support group of about a half-dozen patients, only two were willing even to test the device. The resistance is not uncommon, she notes.
"Many diabetics are elderly, and have had diabetes for many years. ... They get so they are used to needles. They want to stay with what has worked," she says".
Quote 3 from mendosa.com
"Getting insurance coverage is often difficult for people who use jet injectors. "Our big struggle right now is getting medical insurance to pay," Dr. Neufeld says.
Because federal and state insurance plans often have given her patients a hard time, she compared how well Health-Mor's GentleJet and syringes delivered low doses of insulin. "At doses of insulin commonly used in the youngest patients, we found that the GentleJet injector was uniformly more consistent in delivering a given dose of insulin than currently available low-dose syringes," she concluded in an article accepted for publication in Diabetes Educator.
Aside from insurance difficulties, "Jet injectors are not suitable for everybody," says Vitajet President Sergio Landau. He says that people who are very thin often can't use it. He also doesn't recommend them for people who would have difficulty winding the coil spring power pack or who are visually impaired.
"One way or another 20 to 25 percent of the people will come to the conclusion that for them it is no better than a standard syringe," Mr. Landau admits. "It might cause bruising. Some people cannot use the system because of the speed and pressure."
A Medi-Ject Web page mentions others who should not use a jet injector. People taking anti-coagulant medicine, those with haemophilia and those on dialysis are among those who should avoid using a jet injector as it could cause a bleeding problem".
So there you have it folks. Personally, I have not read anything that would stop me trying out one of these devices, if I had to give myself daily injections, except the possible cost. Living in the UK as I do, I would definitely try the one supplied free on the NHS. But then I am into experimentation, on the principal that if you do not try something you will never know what you may be missing out on. If it does not work for you then you do not have to keep on using it, but then again it may be the answer to your prayers!