Insulin Production Methods: A Comprehensive Guide

History of Insulin Production

Question:

Prepare a Detailed Report on a Specific Product which is Currently being Marketed by Either a Major Pharmaceutical or Biopharmaceutical Company.

The pharmaceutical companies have embarked on the large-scale manufacture of synthetic insulin to meeting the increasing demand for health care. The types of insulin also are based on how soon it becomes functional (Klubo-Gwiezdzinska et al., 2015). There are short acting, intermediate acting, and long-acting insulin. In terms of history, before scientist discovered the production of insulin, patients with type 1 diabetes used to die. A Canadian scientist Friendrick Banting was able to purify insulin in 1921. Continued experiments later found a type of insulin which could be released at lower doses in blood. This was the addition of a fish protein, protamine which the human body breaks down at a slow rate. Although there have been several modifications in insulin, the method of production still remains the same. Initially, insulin was derived from the pancreas of calves and pigs followed by purification.

The insulin in these animals and human are quite similar and hence function well. However, some people would complain of allergies which led to the development if biotechnological industrial production of insulin in 1980. This was enabled by the determination of the chemical structure of insulin which then made it possible to determine the location of the gene which codes for insulin in the chromosome. Initial experiments involved the splicing of the insulin gene in mice into a bacterium which enabled insulin synthesis. In the year 1980s, the scientists were able to make use of genetic engineering methods to synthesize the human insulin protein. For example, in the year 1982, Eli Lily Corporation manufactured the first human insulin which was later widely accepted for use as a pharmaceutical product. This insulin did not have any animal contaminants, production was on large scale and there were no fears concerning the transmission of diseases between animals to humans were lowered. The majority of the pharmaceutical companies use the recombinant DNA technology to produce insulin (Wang et al., 2014).

Insulin is a very important hormone in the body, whose function is to regulate the amount of sugar in the blood. More specifically, insulin is involved in transporting sugar in blood into the cells for metabolism (Higgs and Fernandez, 2014). This hormone is needs produced by the beta cells of the pancreas. These cells sometimes release insulin in small amounts while in other cases, the release insulin surge. Once the food is digested din the gut, it is converted into molecules which can be easily get absorbed by the body cells. The carbohydrates are the ones which are converted into sugars for use by the cells to drive various body processes like glycolysis. When the blood glucose is high, following a meal, the pancreatic cells are triggered to produce proportionate levels of insulin. Upon binding of glucose transporters by the insulin on the cell membrane, the sugar in the blood begins to get into the cells via the plasma membrane. If there is no enough insulin production of the pancreatic cells are defective, blood glucose accumulates making the cells to starve (Lipska and Montori, 2015).

Types of Insulin

Continued starvation of cells activates other metabolic pathways leading to the formation of ketones by the liver, which in turn complicate the health of patients and can lead to coma. Lack of proper insulin production also results in the development of diabetes; which can be type 1 or type 2. The type 1 diabetic patients are placed on medication such that they receive insulin injection doses about three times per day. The diabetes type 2 patients produce a little amount of insulin from their pancreas but they may need to inject some more either once to twice per day.

Method 1

The raw materials used for the production of insulin are E. coli bacteria, although yeast is used to some extent. Of great concern to the manufacturers is the protein or gene which produces insulin. This is obtained by use of a machine which sequences amino acids in order to produce DNA fragments (Heinemann and Hompesch, 2014). The production also requires large tanks where bacteria are grown as well as nutrients and carbon sources which are food for the bacteria.  Production of insulin is a biochemical process which requires several steps by use of recombinant DNA technology upon isolation of the insulin gene.

The insulin gene codes for the insulin protein and as the cell carries its metabolism, the insulin gene is translated to make proteins. In this case, the manufacturers manipulate the biological processes of the bacteria (Kumar and Partha, 2017). The insulin gene is then transferred into the bacteria and metabolism continues. The insulin gene has two sub units the A and B chain in its structure. The A chain has 21 amino acids while the B chain has 30 amino acids. Before it becomes active, the proinsulin has co-joined A and B subunits but it lacks the signal sequence. In the pharmaceutical companies, the A and B subunits are grown separately so as to avoid the manufacturing of each of the enzymes. Two minigenes are thus used. A minigene which forms the chain A and the minigene B which gives chain B. bearing in mind that the manufacturers already know the DNA sequence of each of the two chains, the minigenes are made by use of amino acid sequencing equipment. The resulting chains are inserted into the plasmid (cloning vectors) which is then taken up by competent bacteria. For instance, the plasmid is inserted into the and cultured followed by transfection. DNA ligase is added so as to aid the sticking together of the recombinants into the bacteria.

The bacteria which make insulin are then subjected to fermentation at optimal temperatures, processes carried out in large tanks. The bacteria replicate and form millions of copies by mitotic processes with each copy having insulin genes (Mimi et al., 2015).  The cells are then broken open so that DNA can be removed. The methionine is then broken by treating the DNA with cyanogens bromide so that the insulin chains are separated. The insulin chains A and B are the joined together using disulfide bonds in the oxidation-reduction process.

Biotechnological Industrial Production of Insulin

Method 2

In this method, the manufacture of insulin begins with the precursor called proinsulin. All the processes are similar to method 1, apart from the use of a machine for amino acid sequences. The proinsulin is fermented in large tanks where the A and B insulin chains are spliced using an enzyme so that the insulin is then purified (Sandow et al., 2015). The ingredients are then added to insulin so as to hinder the entry of bacteria and maintain a neutral pH. This method is important in the manufacture of the long-acting insulin.

The manufacturers then purify the insulin chains by use of a method like chromatography, reverse HPLC and other size separation methods. The batches of insulin produced are then tested per batches so as to make sure that the E.coli proteins have been mixed with insulin (Moein et al., 2014). A marker protein used to detect the presence or absence of E. coli, where the bacteria is eventually removed, leaving behind the insulin only. When the insulin protein is being manufactured, quality control is of great importance. In case there are impurities in the insulin, other methods of purification such as gel filtration, X-ray crystallography, and amino acid sequencing can be used. The vials that are used to store insulin are also tested for the packaging to ensure that that sealing is proper (Thomas et al., 2014). According to the National Institute of Health, on safety measures should be followed when manufacturing insulin.

The commercial manufacture of insulin requires the use of large scale equipment with several challenges during scale up. The costs and dependency are done based on the parameters of the manufacturing process. It is important that unnecessary costs are minimized while the negative impact to the environment is lowered. A pharmaceutical manufacturing plant can involve an investment of $150 million. The unit production could be about $70/g during purification of insulin particles. If we make an assumption that each insulin costs about $100/g, this manufacturing plant can yield satisfactory returns of about 70 %. For instance, a 40 mg vial of insulin can cost about $25 in cost indicating that selling at $100/g is economically viable.

The pharmaceutical manufacturing company causes negative effects to the environment especially when it comes to disposal of wastes (Heldin et al., 2014). Therefore these wastes have been raising concerns over the effect of wastes from pharmaceuticals to the health of the communities around. As more and more people are diagnosed with diabetes while others are living with uncured diabetes, there need to be the development of sustainable plans to manage wastes (Ortigosa et al., 2015). The insulin infusion pumps and tubing free infusion sets have impacts to the environment. It is also important to consider waste water used in the manufacturing process especially the wastes from biological chemicals. This wastewater can be highly toxic and hence manufacturing companies should ensure that they carry put proper detoxification processes before releasing to the environment. They should also have proper plastic and paper disposal systems by adopting the use of packaging materials which are biodegradable especially after the diabetic patient has finally used the vials.

References

Heinemann, L. and Hompesch, M., 2014. Biosimilar Insulins Basic Considerations. Journal of diabetes science and technology, 8(1), pp.6-13.

Heldin, E., Grönlund, S., Shanagar, J., Hallgren, E., Eriksson, K., Xavier, M., Tunes, H. and Vilela, L., 2014. Development of an intermediate chromatography step in an insulin purification process. The use of a High Throughput Process Development approach based on selectivity parameters. Journal of Chromatography B, 973, pp.126-132.

Higgs, M. and Fernandez, R., 2014. PW367 The effect of insulin therapy algorithms on blood glucose levels in post-operative patients following cardiac surgery: A systematic review. Global Heart, 9(1), p.e334.

Klubo-Gwiezdzinska, J., Cochran, E., Semple, R.K., Brown, R.J. and Gorden, P., 2015. Continued Efficacy of Combination Therapy for Type B Insulin Resistance Due to Autoantibodies to the Insulin Receptor. In Clinical Issues in Type 1 and Type 2 Diabetes (pp. OR01-1). Endocrine Society.

Kumar, M.A.N.N.P. and Partha, M.B.U.R.K., 2017. Kinetic and Structural Differentiation of Trypsin from Different Origins. BioPharm International, 30(1).

Lipska, K.J. and Montori, V.M., 2015. ACP Journal Club. In type 1 diabetes, intensive insulin therapy for 6.5 y reduced mortality at 27 y compared with usual care. Annals of internal medicine, 162(10), p.JC12.

Mimi, N., Belkacemi, H., Sadoun, T., Sapin, A. and Maincent, P., 2015. How the composition and manufacturing parameters affect insulin release from polymeric nanoparticles. Journal of Drug Delivery Science and Technology, 30, pp.458-466.

Moein, M.M., Javanbakht, M. and Akbari-adergani, B., 2014. Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of human insulin in plasma and pharmaceutical formulations. Talanta, 121, pp.30-36.

Ortigosa, A.D., Coleman, M.P., George, S.T., Rauscher, M.A., Sleevi, M.C. and Kartoa, C.H.O.W., Merck Sharp & Dohme Corp., 2015. Purifying insulin using cation exchange and reverse phase chromatography in the presence of an organic modifier and elevated temperature. U.S. Patent Application 15/124,080.

Sandow, J., Landgraf, W., Becker, R. and Seipke, G., 2015. Equivalent recombinant human insulin preparations and their place in therapy. Eur Endocrinol, 11(1), pp.10-6.

Thomas, A., Schänzer, W. and Thevis, M., 2014. Determination of human insulin and its analogues in human blood using liquid chromatography coupled to ion mobility mass spectrometry (LC?IM?MS). Drug testing and analysis, 6(11-12), pp.1125-1132.

Wang, Z., York, N.W., Nichols, C.G. and Remedi, M.S., 2014. Pancreatic β cell dedifferentiation in diabetes and redifferentiation following insulin ther