Under normal circumstances, insulin—a polypeptide hormone secreted by the pancreas is responsible for the metabolism of carbohydrates, carefully balances the amount of glucose in the blood, by promoting the uptake of sugar by the cells where it is then used as an important fuel by the body.

Diabetes is a common condition in which the amount of glucose (sugar) in the blood is rising because the body is unable to use it properly. This is because the body’s method of converting glucose into energy is not working as it should. Diabetes can lead to serious complications, such as heart disease, strokes, limb's amputations, eye and kidney damage, and premature death. Other ill effects also include thrombosis, painful skin ulcers and blindness. In developing countries, diabetes is the fourth-ranking cause of death.

There are two major types of diabetes. Type 1 diabetes, known as juvenile-onset diabetes, which develops when the body’s immune system destroys the cells that produce the hormone insulin that regulates blood glucose. In order to survive, people with Type 1 diabetes must have insulin injections.

Type 2 diabetes, which accounts about 90% of all diagnosed cases of diabetes, develops when the body produces less than requested insulin, or when the insulin  does not work properly. Type 2 diabetes can be treated by diet alone or by a combination of diet and medication (some of the medicine stimulates the production of insulin). As the dependency on insulin or alternative medicines rise, the pancreas gradually loses its ability to produce insulin. At this stage, daily injections of insulin may become necessary.

The introduction of oral insulin for Type 2 diabetics may in fact help to reduce the dependency on insulin shots and preclude the need for repeated injections at a later stage of Type 2 diabetes.

What other choices do diabetics have when they need insulin?

Several alternative methods to deliver insulin have emerged in recent years. Many of those choices are quite expensive and require frequent glucose monitoring.  

Insulin pen – a device that resembles a pen and has a cartridge of insulin attached. Patients turn a dial to set the dosage amount and press a plunger to deliver the medicine in their abdomen, upper arms, thighs or buttocks.

Insulin jet injector – a high-pressure mechanism that sends a fine spray of insulin through the skin. No needles are involved, but some patients find the high-pressure air painful, expensive and inaccurate.

Inhaler – recently approved by the FDA, the inhaler is a device that uses compressed air to create a cloud of insulin powder that is inhaled deep into the lungs where it is absorbed into the bloodstream. Unfortunately, inhalers do not cover all of the insulin doses many patients need. Inhalers are not suitable for smokers, patients with asthma or other chronic lung conditions.

Oral insulin spray - administered in the mouth and absorbed through the tongue, throat and mucosal lining of the mouth.

Of all of the methods available to diabetics to administer insulin, only the oral capsules mimic the physiological delivery of insulin.