Do Medicines Become Unsafe After Expiry? Indian Researchers Examine Drug Stability and Degradation

The review was authored by Dr (Prof) Raju Vaishya and Lt. Gen. Dr Bipin Puri, both from Indraprastha Apollo Hospital, New Delhi, India, and colleagues.

For the review, the authors searched PubMed, Scopus and Google Scholar in September 2025 to identify evidence on drug degradation, environmental influences on medication stability and the potential consequences of using expired pharmaceuticals.

The findings highlighted the importance of expiry dates in ensuring that medicines retain their expected potency, purity and safety throughout the manufacturer-guaranteed shelf life.

The authors noted that “not all expired medications pose immediate risks,” although the possibility of continued effectiveness should not be interpreted as a general assurance that expired medicines are safe to use.

Dr Vaishya told Medical Dialogues, “Evidence supporting extended shelf life is product-, formulation-, batch-, and storage-condition specific.” He emphasised that findings from individual pharmaceutical products cannot be extrapolated to other medicines without appropriate stability data and regulatory evaluation.

The review identified several factors that can compromise drug stability over time.

• Chemical degradation: Hydrolysis, oxidation, racemisation, and photolysis can alter active pharmaceutical ingredients, potentially reducing effectiveness or generating harmful degradation products.
• Environmental exposure: High temperatures may accelerate chemical breakdown, while humidity can promote hydrolysis and microbial contamination. Light and oxygen can also contribute to drug deterioration.
• Packaging and storage: Inadequate packaging may expose medicines to moisture, oxygen and microorganisms, further affecting their stability.

Certain medicines warrant particular caution once expired. Lt. Gen. Dr Bipin Puri told Medical Dialogues, “Certain medications, including insulin, nitroglycerin, and liquid antibiotics, are contraindicated for use post-expiration from significant safety concerns.” The review also highlights the susceptibility of some antibiotics, including penicillins and cephalosporins, to degradation. Insulin products may additionally be affected by storage conditions and contamination risks, particularly after opening.

Beyond patient safety, the authors identified improper disposal of expired medicines as an environmental concern. Discarding pharmaceuticals in household waste or flushing them into drains can contribute to soil and water contamination, with potential implications for public health and antimicrobial resistance.

The review calls for greater public awareness, regular medication audits, improved pharmaceutical waste management and appropriate disposal practices. The authors also highlight the potential role of community medicine take-back programmes, pharmacists and advanced analytical techniques in improving medication management and reducing avoidable waste.

The authors conclude that medicines should generally be used within their approved shelf life and expired products disposed of appropriately. They stress that although some medicines may retain potency beyond their labelled expiry dates, such evidence requires product-specific verification. Further research into stability testing and storage monitoring could help clarify extended shelf life while balancing patient safety, environmental protection and pharmaceutical waste reduction.

Reference:

Vaishya R, Puri B, Sharma S, Vaish A and Migliorini F. Pharmaceutical expiry: Chemical degradation, environmental influences and the evidence behind drug shelf life. Apollo Med 2026; XX:XX–XX. https://doi.org/10.1177/09760016261489873