From the Guidelines
Used glargine insulin can be stored at room temperature (59-86°F or 15-30°C) for up to 28 days after first use, as recommended by recent guidelines 1. When storing used glargine insulin at room temperature, it's essential to protect it from direct heat and light, and never freeze insulin. Unused insulin glargine should be stored in the refrigerator (36-46°F or 2-8°C) until its expiration date. The benefits of room temperature storage include less painful injections, as cold insulin can be more painful to inject. However, the 28-day limit exists because insulin gradually loses potency after opening due to degradation from exposure to air and repeated needle insertions, which can introduce contaminants. Always check the insulin for any changes in appearance (cloudiness, particles, or discoloration) before use, and discard it after 28 days even if there's solution remaining, as suggested by recent expert recommendations 1. Key considerations for insulin storage and handling include:
- Storing unopened insulin vials/pens in a refrigerator at 2 to 8 °C (36 to 46 °F)
- Storing opened insulin vials/pens at ambient temperatures (15 to 30 °C or 59 to 86 °F) away from direct sunlight exposure
- Avoiding removal of insulin from a prefilled disposable insulin pen using a syringe to fill another device unless absolutely necessary
- Checking the temperature of the refrigerator where insulin is stored to ensure it's within the recommended range.
From the FDA Drug Label
After Insulin Glargine vials have been opened (in-use) Store in-use (opened) Insulin Glargine vials in a refrigerator from 36°F to 46°F (2°C to 8°C) or at room temperature below 86°F (30°C) for up to 28 days.
Used glargine vials can be stored at room temperature below 86°F (30°C) for up to 28 days after opening. However, it is essential to follow the storage instructions carefully to maintain the efficacy and safety of the insulin. 2
From the Research
Storage of Used Glargine
- The storage of used glargine at room temperature is not directly addressed in the provided studies 3, 4, 5, 6, 7.
- However, study 3 mentions that insulin glargine has a 28-day limit on the use of a 10-mL (1000 units) multiple-dose vial once the bottle is punctured, but it does not specify the storage conditions for used glargine.
- Study 4 discusses the allowable room temperature excursions for refrigerated medications, but it does not provide specific information on the storage of used glargine at room temperature.
- Studies 5, 6, 7 focus on the pharmacology, efficacy, and safety of insulin glargine, but they do not address the storage of used glargine at room temperature.
Stability and Sterility of Used Glargine
- Study 3 notes that using insulin glargine beyond the 28-day window can result in questionable stability and sterility of the product.
- However, it does not provide information on the storage conditions that can affect the stability and sterility of used glargine.
- There is no direct evidence in the provided studies to support or refute the storage of used glargine at room temperature 3, 4, 5, 6, 7.