Drug Stability & Instability Explained | Causes, Types & Solutions

Drug Stability & Instability Explained | Causes, Types & Solutions Here is a comprehensive breakdown of Drug Stability and Instability, covering why drugs degrade, how instability manifests, and the strategies used to ensure safety and effectiveness. ​1. What is Drug Stability? ​Drug stability refers to the extent to which a pharmaceutical product retains, within specified limits, the same properties and characteristics it possessed at the time of manufacture throughout its period of storage and use (shelf-life). ​A stable drug maintains its: ​Chemical integrity: Active Pharmaceutical Ingredient (API) concentration remains unchanged. ​Physical appearance: Color, texture, clarity, and consistency stay intact. ​Microbiological safety: Free from harmful microbial growth or loss of sterility. ​Therapeutic activity: Provides the intended biological effect. ​Toxicological safety: Does not form harmful degradation products (degradants). ​2. Types of Drug Instability ​Drug degradation generally falls under five main categories: