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Monday, January 16, 2012

Insulin: Types, Insulin Infusion Pump Advantages, Therapy, Manufacturers & Insurance


Insulin is a 51 amino acid (aa) polypeptide hormone essential for normal glucose homeostasis and is therefore useful in treating diabetes. Insulin contains two polypeptide chains, A chain(21 aa) and B chain(30 aa), with three disulfide bonds. Two of these interlink the A- and B-chains, while the third one is an intra A-chain bond. initially, insulin was isolated from porcine (pig) pancreas, the advent of recombinant DNA technology helped to address the requirement for insulin more effectively. Researchers first gave an active extract of the pancreas containing insulin to a young diabetic patient in 1922, and the FDA first approved insulin in 1939. Insulin used for treatment are sourced from beef and pork pancreas as well as recombinant (human) technology. Recombinant insulin has almost completely replaced the use of insulin from other sources like pig, cattle etc. recombinant human insulin was the first licensed drug produced using recombinant DNA technology which was approved by FDA in 1982. It was developed by genentech and licensed by Eli Lilly The first recombinant human insulin was approved by the FDA in 1982.

List of some of the Current Manufacturers of Recombinant Human Insulin

Abbott Laboratories India Ltd

Eli Lilly and Company

Glenmark Pharmaceuticals

Novo Nordisk A/S

Sarabhai Ltd S (Baroda, India)

SciGen Ltd S (Australia)


Biocon - Insugen

Ranbaxy - Insucare

Novo Nordisk -

Pfizer - Exubera

Shreya Life Science Ltd.

Cadilla Pharmaceuticals - HUMSTARD

USV Ltd. - Human Mixact

Sanofi – Aventis – Lantus

Lupin Ltd – Lupsulin R – 40

Zenita Life Science

BIOMM Technology – Brazil.

Gan & Lee Pharmaceutical Ltd. - China

MJ Biopharma Pvt Ltd.

Torrent Pharmaceuticals for NOVO Insulin

Getz Pharma – UAE

Insulin is produced via recombinant DNA technology in bacteria, E.coli now its produced from yeast also. In bacteria A & B chains are expressed separately and joined together. In yeast full length chain can be expressed.

Types of Insulin

There are different types of insulin, based on the mode of action it is classified into these clasess

Rapid acting Insulin: rapid acting insulin is taken prior to meal, they act quickly to minimise the increased blood sugar level. Eg: Humalog from Eli Lilly, Novorapid from Novo Nordisk

Short acting Insulin: Short acting insulin will usually be taken before meals. Short acting insulins may also be called regular or neutral insulin. It is not as fast acting as rapid acting insulin.Eg: Humulin R

Intermediate acting Insulin: Intermediate acting insulin start to act within the first hour of injecting, followed by a period of peak activity lasting up to 7 hours. Intermediate acting insulins may also be referred to as 'isophane'or 'NPH' (Neutral Protamine Hagedorn) insulins.Eg: Hypurin Isophane

Long acting Insulin:Long acting insulin will shows its activity upto 24hrs.Eg: Lantus, Levemir

Insulin is given as injection subcutaneously using insulin pen or insulin infusion pumps.research is focusing on alternative methods or routes of insulin uptake by the body. Oral insulin, Exubera an inhalable form of recombinant human insulin, developed by pfizer, was not successful and has been discontinued because of the poor absorption rate and higher costs.

Insulin Pump / Insulin Infusion Pump - Advantages and Disadvantages

Insulin pump or insulin infusion pump is a medical device for the administration of insulin in subcutaneously for the treatment of diabetes mellitus. The components of the pump includes tubing, processors, controllers, infusion set including canula for subcutaneous insertion, reservoir, etc.

Insulin pump is used as an alternative to daily multiple insulin injections. it has various advantages over other injection methods.

The major advantage is it can be programmed to pump specific amount of insulin into the body at different time intervals, or insulin dosage can be scheduled.

Precise amount of insulin can be pumped into the body, which has shown better control of blood sugar.

The insulin usage through pump can be monitored and the level of insulin use can be analyzed.

Despite of the above advantages it has certain disadvantages also, it is expensive compared to other methods of injection, pump needs to be monitored for proper functioning, keeping the pump for years can cause problem in the skin since the canula is kept inside.

Insulin Pump Therapy

Treatment of diabetes / reducing blood sugar level by administrating insulin into the body of a diabetic patient using an insulin pump, a medical device which ensures the controlled insulin delivery.

Insulin Pump Manufactures

Major players in insulin pump manufacturing are Animas corporation, Disetronic Medicals, Insulet Corporation, Medtronic Diabetes, Nipro Diabetes, etc.

Insulin infusion pump insurance

Since insulin pumps are costly, insurance cover is available for the pumps. Insurance is covered under durable medical equipment.

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Wednesday, January 11, 2012

Protein Desalting and Concentration

Protein desalting is done to remove salts from a protein solution, the salts may come from the buffers or from the biological sample solutions. Protein desalting (removal of salts) is important while its coming to the analysis part. Salts can interfere with the analytical techniques. Separation techniques like electrophoresis, HPLC (high performance liquid chromatography), Mass Spectrometry etc requires protein solutions without salts so protein desalting becomes important steps before using these techniques. The presence of salts and other low molecular weight compounds can increase the ionic strength and there by decreasing the resolution of electrophoresis and also it gives false peak in the chromatograms.
The presence of proteins in blood, serum, urine and other biological samples are used for diagnostic purpose, in which elevated levels of particular protein or other compounds indicates specific disease state.concentrating protein is also very important, since most of the times proteins in the samples are in minute quantities this might go undetected during diagnosis and other analysis steps.

Methods for Protein Desalting

Desalting columns

Protein Desalting column

There are many methods for protein desalting and concentration, these includes dialysis, molecular sieve chromatography (Gel Filtration), HPLC, diafiltration, ultrafiltration, Ion Exchange, freeze drying, etc.
Gel Filtration is one of the best method for desalting protein solutions. Gel filtration matrix has beads having pores, based on the size, molecules get separated.Gel filtration Principle and method can be found from the previous posts.
Examples for gel filtration matrix includes, sephadex G-25, Biogel P-30, etc.
Diafiltration is another method used for protein desalting and protein concentration, here the solution is passed through a filter with specific pore size which retains salts and allow other components to pass through it. Complete desalting wont be achieved in single step. Membrane systems are available from Millipore, Pall etc. Even small amounts of protein solution can be desalted and buffer exchanged.
Ion Exchange is another method for desalting protein, here ion exchange resin is used as stationary phase, protein desalting can be achieved using this method.
For protein desalting and concentration certain columns are available like zeba column, centricons, which can be centrifuged and result in faster desalting and concentration.

Tuesday, January 3, 2012

Ouchterlony immunodiffusion / Ouchterlony double immunodiffusion (ODD)

Immunological techniques make use of the interaction of antigen and antibodies. Antigen is any foreign molecule which can elicit an immune reaction in the body. Antibody which is specific to antigen will be produced and it reacts to form antigen-antibody complex.
The Ouchterlony immunodiffusion can be used to quantify antibodies / antigen in the given sample.In Ouchterlony double immunodiffusion, double refers to the diffusion of both antigens and antibodies. In this diffusion methiod, test antigen and antibody diffuse toward each other in a semisolid medium to a point in the medium where optimum concentration of each is reached. A precipitation line or band is formed where the antigen-antibody complex is formed.

Ouchterlony Immuno Diffusion
 Ouchterlony Double Diffusion

The Ouchterlony test method involves making an agarose gel in a petriplate on to which wells are made using a cork borer. Antigen or antibody are added to the respective wells and incubated the plate for 24-48oC at room temperature.When homologous antigen and antibody diffuse toward each other from the individual wells, a precipitin line will form somewhere between the two wells.
Based on the precipitation line amount of test antigen/antibody can be found out.