CME INDIA Presentation by Dr. N.K. Singh, MD, FICP, Director, Diabetes and Heart Research Centre, Dhanbad, Jharkhand, India. Editor, www.cmeindia.in.

Role of Insulin injection is vital in the management of Diabetes. Frequently, physicians ignore to educate patients about the science and art of insulin storage, which is important for its proper action.

What are the issues?

  • Insulin due to its colloidal nature is highly prone to precipitation induced by changes in the environmental pH and temperatures.
  • Instability in the proteins is attributed to the differential level of changes in the protein structure.
  • This happens when exposed to variable physicochemical changes in the environment.
  • Insulin is very sensitive to sunlight and extreme temperatures resulting in its degradation.

How variation in various storage conditions and climatic changes causes change in therapeutic efficacy?

  • Storage condition affects the stability of insulin as observed in a study in which insulin stored at temperature between 32 and 37°C showed 14 to 18% decrease in its potency and could not cause a significant decrease in blood sugar level when compared with those receiving insulin stored at 5°C. (1)

In India heat can severely degrade the insulin

  • There is a small proportion of patients storing insulin in refrigerator.
  • Political challenges that unsettle people make most DM patients to live in very pathetic housing conditions – street families in particular.
  • This makes correct home storage practice of insulin to be practically impossible for the low-income earners and the poverty-stricken class that constitutes about 70% of the urban population.
  • 26% – 77% DM patients have refrigerators for storing insulin.

Two types of Degradation

Science and Art of Insulin Storage

In India, Be Aware

  • During summers, as the room temperature rises, the pot temperature also may rise above 25°C or even beyond 35°C.
  • Pot, wherein the inside temperature will be a few degrees lower than the room temperature, will provide a near ideal storage environment for insulin to maintain stability as far as possible.
  • Therefore, even the insulin stored in a mud pot is not protected from denaturation due to high temperatures during summer. This could be one of the reasons why some patients require comparatively higher doses of insulin and show clinical symptoms of drug resistance.

Ever considered effect of Cold?

Science and Art of Insulin Storage
  • The biggest challenge remains how to store insulin in the winter when outside temperature dips to −30°C mostly during midnight and inside temperature of the living room goes up to 40 to 70°F due to constant burning of “Bukhari” made up of iron.
  • Unique cloth people wear in the winter is an abdominal binder, which measures 2 to 3 ft in width and 5 to 15 ft in length.
  • It was thought to store insulin in multiple layers of abdominal binder, which prevents it from freezing in Winter.
  • They were advised to wrap the insulin vials and/or pens in “multiple layers” in the abdominal binder (where the temperature recorded was between 5°C and 10°C.
  • The success of this practice was evident from the normal HbA1C values and the smiles on their faces, when they visit state capital for routine medical consultation.

How to store Insulin in Refrigerator?

Science and Art of Insulin Storage

Care of Insulin Vial

Science and Art of Insulin Storage
  • Insulin should be stored at refrigeration temperature (2–8°C). Once in use, insulin may be stored at room temperature.
  • Insulin should never be frozen or exposed to extreme heat (> 30ºC) for prolonged periods as this will affect insulin potency and alter its action.

Factors affecting Insulin action: Decreased potency over time – Setting the Scene

  • Most insulins remain potent and effective for up to a month after the vial/cartridge/pen has been opened (if kept in room temperature in between use).
  • Potency begins to decrease after a period of one month.
  • Can be a problem for people who require very small insulin doses..
  • Advisable to start a new vial/cartridge/pen after every 30 days
  • During storage & use, insulin is degraded by hydrolytic reactions or transformed to higher molecular weight components.
  • A vial of insulin stored at room temperature can lose as much as 1.5% potency/month.
  • Unpredictable potency, can lead to unexpected & potentially dangerous blood glucose excursions.
  • Risk of Lipohypertrophy is ~ 3 times more if insulin is stored incorrectly.
  • Thus, Incorrect storage of Insulin can lead to degradation, loss of potency & increased risk of Lipohypertrophy. (6)
  • Recap:
    • Every insulin product has specific instructions on storage and usage.
    • Unopened insulin pens/cartridges/vials are usually stored in refrigerator.
    • Once opened, most pens are kept at room temperature for up to 2-4 weeks, depending upon the manufacturer’s instructions.
    • Important to avoid exposing the pens/cartridges/vials to extreme temperatures (hot or cold).
    • If there is a suspicion that the insulin has lost potency (example: if the pen was left in hot car), a new pen or insulin cartridge should be used.

Why is Cold Chain Management important? 

  • Cold chain management is important to ensure that the right quality is maintained throughout the supply chain.
  • Standardized guidelines recommend on the right storage and transportation, and adhering to these standards is very crucial for sensitive biological substances that can become less effective or lose their potency.
  • Cold chain medicines are those that requires special temperature-controlled cold storage to maintain their quality and efficacy.
  • A cold chain is an uninterrupted series of storage and distribution activities that maintains products at a required temperature range of 2°C and 8°C or between -10°C and 20°C as per their requirements.
  • The cold chain process is essential for all biologicals within a recommended temperature range, mostly between 2 and 8 degrees Celsius throughout the supply chain.
  • Temperatures outside the recommended range reduce the potency of biologicals, leading to lack of desired response.
  • A cold chain must be used while transporting insulin from the production facility to the distributor’s storage facility.
  • A temperature log should be used for the whole transport.
  • This option should be considered whenever feasible.
  • Suitable rigid containers should be used to maintain the temperature between 2- and 8-degree C.
  • Suitable cool boxes and gel packs.
  • Insulin should not be transported in containers having temperatures below 2 C, or be exposed to temperatures above 32 C.
  • Nowadays, boxes with sensors and a temperature logger are available that can accurately record the temperature within the box.
Science and Art of Insulin Storage

Storage Genius

Science and Art of Insulin Storage
Science and Art of Insulin Storage
  • Using thermo cool boxes, with ice packs inside them (replaced by frozen ones on weekly basis), as effective refrigeration devices for insulin that would keep the temperature within acceptable limits for many days.
  • Using a good insulated extra vaccination box that can keep insulin stable for many days.
  • Keeping a cool wet cloth around insulin to preserve insulin potency.
Science and Art of Insulin Storage
Science and Art of Insulin Storage

Storage of insulin in cold climate – current practice

Science and Art of Insulin Storage
Science and Art of Insulin Storage

  • It is a common practice with easy solution that avoiding storing insulin in the door of a refrigerator protects insulin from temperature fluctuations.
  • If there is no refrigerator, insulin vial can be stored in a cool wet cloth.

Final Points

Science and Art of Insulin Storage

(Based on talk delivered at Diabetes Research and Welfare Association Conference at Kurseong (WB) on 19th Feb 2022.)

References:

1. Effect of Climatic Changes and Storage Condition on Efficacy of Insulin Khurana, Gupta

Journal of Social Health and Diabetes Vol. 7 No. 1/2019

2. EADSG Guidelines: Insulin Storage and Optimisation of Injection Technique in Diabetes Management. Diabetes Ther (2019) 10:341–366

3. R. Vimalavathini et al. Effect of temperature on the potency & pharmacological action of Insulin. Indian J Med Res, August 2009

4. Albergo R et al. Insulin Storage and Injection Recommendation Diabetes Care, Volume 15, N0. 8, August 1992.

5. Ogle GD et al. nsulin storage in hot climates without refrigeration: temperature reduction efficacy of clay pots and other techniques. Diabet. Med. 33, 1544–1553 (2016).

6. Baruah MP et al. An Audit of Insulin Usage and Insulin Injection Practices in a Large Indian Cohort. Indian J Endocrinol Metab. 2017 May-Jun; 21(3): 443–452

7. Last Mile Delivery of Cold Chain Medicines – Challenges and Recommendations. Indian J. Pharm. Biol. Res.2018; 6 (1):34-41



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