Insulin is produced by beta cells of pancreas in our body. Production of insulin can be done in industry by using various techniques. It is gold standard for the treatment of diabetes. Patients of type 1 diabetes are dependent on Insulin for survival. While majority of patients of type 2 diabetes will require insulin for the control of blood glucose level some time in their life.
Insulin assists the uptake of glucose from the blood into the cells of tissues. This prevents abnormal high blood glucose level during periods of food intake and provides energy to cells.
Types of insulin:
Insulin can be classified into four different types depending upon the source of insulin. They are
- Bovine: Insulin obtained from beef pancreas.
- Porcine: Insulin obtained form pork pancreas
- Human Insulin: They are obtained by recombinant technology in which we use Yeast or E. Coli for the production of insulin.
Insulin analogues: They are obtained by altering the sequence of amino acids in human insulin.
Out of this human insulin and insulin analogues are the most widely used insulin.
Depending on the duration of action insulin is also classified as Short acting, Intermediate acting, and long acting insulin. Also preprations containing combination of various proportion of short acting and intermediate insulin is available.
Insulin strength is measured in international units (IU). The formulations of insulin are available in 40 IU/ml and 100 IU/ml strength.
Refer the table for the details of different type of insulin available. Following table gives examples of types of insulin available.
||Effective Duration (hours)
|NPH (Neutral protamine Hagedorn)
||6 to 8 hours
||up to 14 hours
|30/70 (i.e. 30% regular + 70%NPH)
|50/50 (i.e. 50% NPH, 50% regular)
|Lispro 75/25 (75% protamine lispro + 25% Lispro)
|Biphasic Aspart (BIAsp 30/70)
When does doctor advise insulin to a diabetic patient?
- Severe fasting hyperglycemia at diagnosis i.e. FPG between 250 to 300mg/dL
- Type 2 diabetic patients failing to achieve target glucose control with oral antidiabetic drugs i.e. FPG >130mg/dL
- Diabetic patients with complications like ketoacidosis.
- Diabetic patients having illness and undergoing surgery.
Your doctor will choose the best time for initiation of insulin for you.
Stability and storage of insulin:
- Insulin is stored in a refrigerator at approximately 35 to 46°F (Approx. 2 to 8°C). Unopened and stored in this manner, these products maintain potency until the expiry date on the package label. (Applicable for Vials, cartridges and pens loaded with cartridges).
- However, all of the available insulin products may be left unrefrigerated between 59°F and 86°F (15 to 30°C) for up to 28 days and still maintains potency.
- Try to keep insulin away from direct heat and out of direct sunlight, but if you are using ice, also avoid freezing the insulin.
- Avoid excess agitation (handle carefully).
- Prefilled syringes should be kept upright in position.
- Single pass of insulin through airport surveillance instrument DOES NOT affect stability. REPEATED PASS THROUGH AIRPORT SURVELIENCE INSTRUMENT OR EXCESS EXPOSURE TO RADIATION MAY ALTER INSULIN POTENCY.
Insulin which has been frozen must not be used after thawing.
Too high storage temperatures may lead to a gradual decrease in biological potency. Certain visible changes may also appear, depending on the rise in temperature and the period of storage. Clear, soluble insulin may precipitate and give the preparation a cloudy appearance. Cloudy insulin suspensions may become granular or clumped. The combination of high temperature and prolonged shaking or vibration will speed up the process just described.
A classic example is the insulin user who, on a warm and sunny day, places his insulin in the glove compartment of his car while driving a long distance. This must be avoided.
In conclusion, losses in potency are usually gradual and seldom drastic. However, certain conditions can make insulin useless within a relatively short time: Freezing, direct sunlight, and the combination of high temperature and vibrations.
Points to remember for the storage and stability of insulin:
- Store the insulin in a cold place, preferably a refrigerator between 2°C and 8°C. Avoid freezing.
- Do not expose insulin to heat and direct sunlight.
- When traveling by air, place the insulin in a handbag, not in the check-in luggage due to risk of temperatures below the freezing point.
INSULIN DELIVERY DEVICES
You will get two types of insulin syringes in the market viz. 40 IU syringe and 100 IU syringe.
In 40 IU syringe 1 ml is divided into 40 equal parts. Therefore minimum amount of insulin which you can inject with this syringe is one IU. You can use this syringe for injection of insulin preparation having 40 IU/ml strength only.
In 100 IU syringe 1 ml is divided into 100 equal parts. Therefore minimum amount of insulin which you can inject with this syringe is one IU. You can use this syringe for injection of insulin preparation having 100 IU/ml strength only.
Insulin Injection with a Syringe:
- Wash hands with soap and water. Remove protective tamperproof cup (must be removed the first time a vial is used). Clean the rubber stopper on the vial with an alcohol swap. When using an insulin suspension (cloudy insulin), roll the vial between the hands until all the liquid is uniformly white and cloudy.
- Remove any caps from the syringe and needle.
Drawing up the insulin dose from a vial with syringe:
Remember always to carefully read the instructions while preparing for the injection.
- To facilitate the withdrawal of insulin, air should be injected into the vial. Start by pulling out the plunger to the number of insulin units needed back.
- Put needle through the rubber stopper of insulin vial. Push plunger down, putting air into the vial. Leave needle in vial.
- Turn vial and syringe upside down and hold together in one hand at eye level. Pull plunger down to any unit marker slightly beyond the needed dose of insulin. This pulls insulin into the syringe.
- Check syringe for air bubbles. If any present, flick syringe firmly with finger. Now push plunger up to unit marker for the insulin dose. This pushes bubbles out and leaves the correct amount of insulin in the syringe.
- Take needle out of vial for injection.
- Make a skin fold and inject the insulin (subcutaneous injection).
Injection Technique with a Syringe:
- Clean injection area (avoid frequent alcoholic swabs) and make a skin fold. Holding syringe like a pencil, quickly push needle all the way into the skin fold perpendicular to skin surface.
- Push plunger all the way in to inject insulin beneath folded skin (subcutaneous tissue layer). Release skin and hold syringe in place for ten seconds to help ensure that the full dose is received.
- Remove syringe. If slight bleeding occurs, gently press finger over the area for a few seconds to stop the bleeding. Do not rub injection area (this may cause insulin to be absorbed too quickly).
- Syringe/needle disposal
- Place syringes, needles, lancets in a metal container with a screw-on tightly or tightly secured lid.
- Please consult your local laws and regulative for the disposal of syringe needle and lancet.
Use of Insulin Delivery Device Wosulin pen Royale
Insulin pumps are often worn in a small fancy-pack around your waist, although other options exist. They are programmable, and can be set to deliver a constant amount of insulin throughout the day (the basal rate) as well as larger amounts after meals and snacks (boluses). Insulin is delivered from the pump into a small catheter placed in your abdomen that is replaced every 3 days. The advantage of a pump is that it more closely mimics the way the body would naturally release insulin. And, of course, it's more convenient. You no longer have to inject yourself with insulin several times a day.
Principle of insulin pumps:
An insulin pump is made up of a pump reservoir (like a regular syringe, but bigger) filled with insulin, a small battery operated pump and a computer chip that allows the user to control exactly how much insulin the pump delivers. It is all contained in a plastic case about the size of a beeper.
The pump reservoir delivers insulin to the body by a thin plastic tube called an "infusion set." Infusion sets come in 24 inch and 42 inch lengths and have a needle or soft cannula at the end, through which the insulin passes. The needle or cannula is inserted under the skin, usually on the abdomen. The process of putting the infusion set in place is called "insertion," and is very much like giving a standard insulin injection. The infusion set is changed approximately every two to three days.
The pump is intended to be used continuously and delivers insulin 24 hours a day according to a programmed plan unique to each pump wearer. A small amount of insulin is given continually (the "basal rate"). This insulin keeps blood glucose in the desired range between meals and over night. When food is eaten, the user programs the pump to deliver a "bolus dose" of insulin matched to the amount of food that will be consumed.
The pump is not automatic! The user still has to decide how much insulin will be given. But pumps are the most accurate, precise, and flexible insulin delivery systems currently available. Using the results of blood glucose monitoring, the experienced pump user can use this tool to obtain excellent blood glucose control while living a normal lifestyle, free of the strict scheduling demands that are required by conventional insulin regimens.
Salient features of insulin pump:
- Insulin pumps usually allow better control of your blood glucose, as well as some freedom from the daily routine of injecting insulin.
- Waterproof/shockproof pouch is available, which allows you to take it into the shower or a swimming pool.
- Most people keep the pump in a specially designed case to minimize cosmetic damage caused by bumps, perspiration, dirt and grime. To clean the pump, it should be washed with a damp cloth and mild soap. No other regular maintenance of the pump is required.
- Pump has multiple built-in safety alarms to alert you if your pump stops delivering insulin, including alarms for low and depleted batteries, empty reservoir, and clogged infusion set. A series of safety checks are performed every minute, every motor stroke, and upon each programming change
Tips on how to use insulin pump:
- Sterile technique
- Wash your hands thoroughly with soap and water .
- Another source for bacteria is the breath exiting the mouth and nose. Do not blow on the infusion site or anything else to dry it. Keep your reservoir and infusion set at eye level to avoid breathing on them.
- The countertop on which the infusion set and equipment are placed before insertion can be another source for bacteria. Use a clean countertop and keep critical items like the infusion set safely in their sterile wrapping prior to insertion.
- Insulin, tapes, dressing: Usually lispro insulin is preferred for use although it is not officially approved . Any standard insulin can be used with consultation of your doctor. Tapes, skin preparations, and transparent dressings can greatly aid safe pump operation. For dressings, a bio-occlusive dressing is preferred. They allow sweating but keep bacteria from passing through to the skin
- Sites: For sites, most pumpers prefer the abdomen, but anywhere that has padding will do. Normal skin contains bacteria, so it's best to use a sterile prep on the new site prior to inserting the infusion set to reduce the chance for an infection. Bacteria move on the skin, so a wide swath is smart. This can greatly reduce the risk of an infection through the hole created by the infusion set.
- Preventing infections: Bio-occlusive dressings are preferred for the skin. They allow sweating but keep bacteria from passing through to the skin. This can greatly reduce the risk of an infection through the hole created by the infusion set.
- Use of infusion set: There are a wide variety of infusion sets available. Many have an adhesive surface that sticks to the skin.
- Insert the infusion set: Once the infusion set is inserted, hold the infusion line gently against the skin until a safety loop is in place.
- A safety loop is placed to the side away from the infusion set. Safety loops keep the infusion set from being pulled out when a pump is dropped or the line catches on something.
Approaches under development:
Implantable insulin pumps are surgically implanted, usually on the left side of the abdomen. The pump is disk shaped and weighs about 6 to 8 ounces. It delivers a basal dose of insulin continuously. Users deliver bolus insulin doses with a remote control unit that prompts the pump to give the specified amount of insulin.
An advantage of this method is that, like insulin produced naturally from the pancreas, the insulin from the pump goes directly to the liver to prevent excess sugar production there.