Drug stability is the ability of a drug to retain its original physical, chemical and microbiological properties as well as its quality, efficacy and safety under the prescribed storage conditions over a certain period of time. Drug stability is one of the most important aspects examined during the development and marketing authorization of drugs, as changes in stability (German translation: Stabilität) can have a direct impact on drug efficacy and safety.

Important aspects of drug stability:

• Physical stability refers to the preservation of the homogeneity, appearance, color, solubility, particle distribution and viscosity of the drug.
• Chemical stability means that the active pharmaceutical ingredient and the excipients do not change chemically, which could reduce the efficacy of the drug. Hydrolysis and oxidation reactions occur most frequently.
• Microbiological stability: Microbial growth reduces the quality of drugs, especially in sterile dosage forms.

Measures to ensure drug stability include the following:

• Stability testing (translation into German: Stabilitätsprüfung): Stability testing is done to determine the shelf life of a drug and its storage conditions. Stability tests include storage of the drug at different temperatures, different humidity levels and different levels of exposure to light.
• Packaging: Packaging plays an important role in protecting the drug from external influences that can have a negative impact on its stability.
• Storage conditions: Based on the test results, specific storage conditions (German: Lagerungsbedingungen) are defined to ensure the stability of the drug.
• Quality management system: This includes procedures for monitoring stability in all stages of the life cycle of a drug, from manufacture to distribution to the end consumer.

The stability of drugs is directly related to their therapeutic value and safety of use. Deterioration in stability can lead to reduced efficacy, development of toxic degradation products or loss of sterility, which in turn can have a detrimental effect on patients’ health. Strict stability control is therefore an integral part of the GMP guidelines and legal requirements in the pharmaceutical industry. These requirements ensure that the drugs on the market meet high quality and safety standards for the duration of their shelf life.

Do you require experienced pharmaceutical interpreters for a foreign-language GMP inspection by foreign pharmaceutical authorities? Please contact us for an individual offer — we will take care of your request.