|LETTER TO EDITOR
|Year : 2012 | Volume
| Issue : 2 | Page : 88-89
Storage of insulin in rural areas
Sanjay Kalra1, Bharti Kalra2
1 Department of Endocrinology, Bharti Hospital, Bharti Research Institute of Diabetes and Endocrinology, Karnal, Haryana, India
2 Department of Gynaecology, Bharti Hospital, Bharti Research Institute of Diabetes and Endocrinology, Karnal, Haryana, India
|Date of Web Publication||21-Sep-2013|
Bharti Hospital, Kunjpura Road, Karnal - 132001, Haryana
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kalra S, Kalra B. Storage of insulin in rural areas. J Acad Med Sci 2012;2:88-9
It is well-known that many drugs, biological products, and vaccines are temperature-sensitive. One life-saving drug, which needs to be stored under temperature-regulated condition, is insulin. 
Insulin is a life-saving product used for the management of all type 1, and many type 2 diabetes patients. It is a polypeptide, produced by recombinant DNA technology, using either E. coli or Saccharomyces sp.  Insulin analogs or modern insulins are also available, which are produced by changing the chemical structure of the insulin molecule.
Insulin can be classified as rapid or fasting acting, e.g., human insulin, aspart insulin, lispro insulin, and glulisine insulin; pre-mixed e.g., pre-mixed human insulin, aspart and lispro; intermediate- acting, e.g., NPH insulin, and long acting, e.g., detemir and glargine insulin.
For optimal effect, insulin need to be stored under refrigerated conditions, between 2 and 8°C, and be protected from light when vials or pens are unopened.  Pens or vials in use may be kept at room temperature, protected from sunlight, up to
Exposure to higher temperatures during storage and use may degrade insulin by hydrolysis, or transform it to higher molecular weight components.  A study performed in Puducherry, India, showed that storage of regular and biphasic insulin at 32°C and 37°C decreased the potency of insulin by 14 to 18%. 
This means that people with diabetes need to be educated about the temperature and duration of storage of insulin vials needed to maintain adequate glycemic control.
Improvisation in Storage
Lack of refrigerators is a hot, tropical climate can be a major challenge for people with diabetes on insulin therapy.  Even in places where refrigerators are available, electrical supply may be erratic. This makes it a challenge to store essential drug supplies correctly.
Some of the improvised methods for storage of insulin are listed below:
Insulin can be stored in a small bowl of water. Remember not to keep this container in direct sunlight. The water level should be below the neck of the vial, to prevent possible leakage into, and contamination of, insulin supply.
As the label tends to peel off when wet, one should use waterproof tape to stick a label with the name of the insulin, its expiry date, and its date of opening.
In a hospital ward where insulin vials of more than one patient are stored together, the name and bed number of the patient should be mentioned clearly.
If available, a small clay pot or earthenware pitcher is a perfect storage utensil for the drug, and reduces an exposure to external temperature variations. 
One should ensure that insulin vial cap is not submerged, and the labels with insulin name, date of opening, and date of expiry are preserved.
One can use thermo cool boxes, with ice packs inside them, as effective refrigeration devices for insulin. The temperature will remains within acceptable limits for many days and can be monitored using a room thermometer. Ice packs can be replaced by frozen ones on weekly basis.
Extra vaccination boxes, used for storing and transporting vaccines, can be utilized, if available, for keeping insulin. A good insulated vaccination box can keep insulin stable for many days.
Keeping a cool wet cloth around insulin helps to preserve insulin potency.
Using a Refrigerator
A refrigerator is the best place to store insulin in. Insulin should never be frozen as this will make it lose its potency. Unopened insulin is best kept at 2-8°C temperature. This temperature is maintained below the freezer or in the butter compartment of most fridges. Opened insulin may be kept at room temperature, or in the vegetable compartment of the fridge, where temperature is maintained at a stable 14°C. Avoid keeping insulin in the door of the fridge, as this area is most prone to temperature fluctuations.
Traveling with Insulin
Traveling with insulin can be a challenge in hot climates. Carry a small thermos flask, in which you can keep insulin, tightly packed in polythene so that water does not enter the vial. If this is not possible, wrap the insulin in cool, wet cloth, and keep it moist.
If possible, try disposable or reusable insulin pens, which are insulated and do not need refrigeration. Remember not to leave your insulin in a locked car or in the glove compartment in the heat. Temperature in closed vehicles may reach very high levels. When traveling by air, carry insulin supplies, along with a prescription, in cabin baggage or handbags. Luggage kept in the hold, i.e., check in luggage, may freeze, and any insulin kept here may lose its potency.
| Conclusion|| |
Doctors and patients living in underserved, resource-challenged areas should be aware of these methods of insulin storage and transport.
| References|| |
|1.||Chandler C, Gronkiewicz CM, Pringle T, Cunninglam F. Insulin temperature and stability under simulated transit conditions. Am J Health Syst Pharm 2008;65:953-63. |
|2.||Pingel M, Valund A. Stability of insulin preparation. Diabetes 1972;21:805-13. |
|3.||Storage of insulin. Available from: http://www.diabetesguidelines.com/health/dwk/pro/guidelines/ispad/09_04.asp. [Last accessed on 2011 Feb 13]. |
|4.||Gregory R, Edwards S, Yatemais NA. Demonstration of insulin transformation products in insulin vials by high-performance liquid chromatography. Diabetes Care 1991;14:42-8. |
|5.||Vimalavathini R, Gitanjali B. Effect of temperature on the potency and pharmacological action of insulin. Indian J Med Res 2009;130:166-9. |
|6.||Peupet FH, Mijingawa BB, Akogu I. Insulin storage by patient with diabetes mellitus in Jos, Nigeria. J Med Trop 2007;9:37-40. |
|7.||Arya SC. Insulin storage in clay pot. Ann Saudi Med 2000;20:491-2 |