Altrnative Insulin Delivery System

Alternative Insulin Delivery Systems
Ever since insulin was first identified as the key to restoring normal glucose levels in people with diabetes, doctors and patients have been hoping for an alternative to insulin injections. Don't get us wrong, injecting insulin works pretty well. Many people have been able to lead relatively normal lives because of it. We have pretty advanced syringe and needle technology and insulin pens and pumps have made getting insulin into the body even easier. Even so, the quest continues to find an alternative way of administering insulin.
Scientists have been working on a number of new advances in insulin administration.
Transdermal (through the skin)
Our skin is a remarkable organ. It's very good at letting almost nothing in, and letting just a few selected things out. Patches to help people quit smoking have made it seem almost easy to deliver a drug through the skin. In fact, nicotine is a small molecule that is readily absorbed into the skin. It only takes a tiny amount to have an effect on the body. Insulin on the other hand, is far too large to get through the skin without a lot of help. Trying to change that is tough.
Scientists have been working on patches using electrical currents, ultrasound waves, and chemicals to help transport insulin through the skin. Although some companies are hoping to develop products that could provide boluses of insulin through the skin for mealtime, any success for transdermal delivery is likely to come with basal delivery of relatively small amounts over time. Either way, we have a while to wait before insulin patches might be available in pharmacies.
Inhaled Insulin Is On The Way (PDF)The world's first inhalable insulin should be on pharmacy shelves sometime in the summer of 2006, offering people with diabetes a new way to take a treatment that for more than 80 years has been accessible only through needles.
Read this article which appears in the April 2006 issue of Diabetes Forecast magazine.
Inhaled Insulin
Inhaled insulin is probably what you've been hearing the most about lately. Several products are being created in laboratories and have shown success at controlling blood glucose levels. Some of these are in phase 3 clinical trials (the final phase of testing before you can submit a device for FDA approval), but only one has been approved for use. And that one is only approved for adults.
In clinical trials, the approved inhaled insulin, Exubera, managed blood glucose levels as well as injected fast-acting insulin. Inhaled insulin does not replace longer-acting insulins, so those would still need to be injected.
The new inhaled insulin does not come without limitations. First, you have to inhale a lot of insulin to get the amount your body needs. That's because only a small percentage of the inhaled insulin actually reaches the bloodstream and lowers blood glucose. So, a lot of it is "wasted." Because of that, the cost of inhaled insulin is fairly high -- you have to pay for all that waste.
There are also questions about the safety of delivering insulin to the lungs. After all, that's what you're doing when you inhale the insulin. You send it straight to the lungs. Many scientists think the lungs are a great place to deliver a drug because of the large surface area and ready absorption. The fact remains: that is not what lungs were designed to do. Although inhaling insulin has proven safe in short-term studies, the long-term safety remains a question. Exubera's manufacturer, Pfizer, will study the long-term effects of Exubera on the lungs, as well as its safety and effectiveness in patients with lung disease.
Buccal
Buccal (BUCK-el) insulin is similar to inhaled insulin in some ways. Buccal or delivery into the mouth, involves a device that delivers a spray of insulin like what you'd get out of a can of spray paint. Instead of going into the lungs, the insulin is absorbed in the lining at the back of the mouth and throat. The good part is that it avoids any problems from putting large amounts of insulin in the lungs. The problem is that even more of the insulin gets wasted.
Other than that, research shows that buccal insulin works about as well as inhaled insulin.
Oral
Okay, we've got shots, pumps, inhaled insulin, and insulin sprays. What's left? You probably already know that insulin taken as a pill is quickly broken down in the stomach, just like the food you eat. That makes it useless for lowering blood glucose levels.
So insulin can't be taken by itself in a pill form. Some scientists are trying to "package" insulin using special coatings, or by altering the insulin structure to get it through the stomach. Like inhaled insulin and insulin sprays, it's likely that a lot of the insulin will be wasted before it gets where it's going. It would probably also take a long time to start working after you swallowed the pill. Not much research has been done on insulin pills so far.
What does all this mean? The fact is that injected insulin (by syringe, pump, or pen) is a really effective way to lower blood glucose levels. Even if one of these insulin delivery methods does become available, its possible people with diabetes (particularly people with type 1) will still be better able to control blood glucose with injections or they may be able to use one of the other methods for their basal dose, but would still need injections for mealtimes and other bolus doses.