How is Insulin manufactured?

Insulin is the hormone which is produced by the pancreas in order to regulate the level of glucose in the blood. Insulin facilitates the entry of glucose into the cells. Without insulin, glucose builds up in the blood and this often shows as raised blood glucose levels.

How is insulin manufactured? Insulin is produced by the islets of Langerhans, specifically by beta pancreatic cells. Damage to these cells causes insulin to be produced in very low amounts or non at all. When insulin is absent or in low amounts, glucose is not taken by the body cells and as a result the body begins to use fat in order to generate energy. This is often the case in individuals with type 1 diabetes. In individuals with type 2 diabetes the number of beta pancreatic cells often diminishes over time.

Patients with type 1 diabetes often need to be treated with external insulin, since their own bodies cannot produce it.

If the body cannot produce enough insulin on its own, a manufactured form of insulin is the solution. The first successful purification of insulin was conducted way back in 1921, by Canadian scientists Frederick G. Banting and Charles H. Best.

They were able to create a purified form of insulin from a dog’s pancreas, and from then on the process of creating insulin continued to improve. In 1936, scientists found a way to create insulin which can be slowly released in the blood by the addition of a fish protein which is slowly broken down by the body. In 1950 a faster-acting form of insulin was developed and in the 70s researches tried to create a form of insulin which worked similar to natural insulin-one that was released all throughout the day in small amounts and in surges during meals.

Insulin for diabetics is usually extracted from cows and pigs and placed under a purification process. Cow and pig (often referred to as porcine and bovine insulin) insulin is only slightly different from human insulin, which makes them function almost as well in the human body. However, this does not mean that allergic reactions never occur. Some people still experience allergic reactions to purified insulin, which is the reason why diabetics about to undergo insulin therapy are first tested for any allergic reactions.

Genetic engineering became an important tool in manufacturing insulin in the 1980s. In 1982, the human insulin, named Humulin, was created by the Eli Lilly Corporation and was approved for use. With the use of genetic engineering, we no longer had to rely on animals to supply us with insulin since it can already be manufactured in unlimited supplies in the laboratory. As of 2001, almost 95% of insulin users are already using human insulin and insulin analogs, which is a modified form of insulin.

Human insulin is grown inside the lab, using bacteria like E. coli and some forms of yeast. Through the use of amino-acid sequencing and large amounts of the bacteria, DNA is inserted into the host cells (i.e. E.coli) and the bacteria are allowed to grow. The bacteria are able to create a synthetic form of the hormone, which is then purified in a centrifuge or through high-frequency liquid chromatography. However, clinical preparations differ from naturally-produced insulin, one of them being that synthetic insulin lacks C-peptides, a substance which has been found to reduce the risk of neuropathy among diabetic patients.