Sample interview questions: Explain your experience with performing stability indicating assays and impurity profiling in pharmaceutical analysis.
Sample answer:
-
Stability-indicating Assays:
-
Objective: Determine the stability of pharmaceutical formulations under various stress conditions (e.g., temperature, humidity, light, pH, oxidation).
- Methodologies:
- Accelerated Stability Testing: Use elevated temperature and humidity to accelerate degradation and predict long-term stability.
- Stress Testing: Subject samples to specific stress conditions to induce degradation and observe changes in the drug substance or product.
- Real-Time Stability Testing: Conduct stability studies under real-time conditions, such as room temperature and ambient humidity, to assess the stability of the product during its shelf life.
- Analysis:
- Chromatographic Techniques: Employ HPLC, GC, and LC-MS to separate and quantify the drug substance, degradation products, and impurities.
- Spectrophotometry: Utilize UV-Vis spectrophotometry to determine the purity and monitor the degradation of the drug substance.
- Thermal Analysis: Use TGA and DSC to study the physical and chemical changes in the drug substance and product during stability studies.
-
Reporting: Provide detailed reports summarizing the stability data, including the degradation profile, half-life, and recommended storage conditions.
-
Impurity Profiling:
-
Objective: Identify and quantify impurities in pharmaceutical substances and products.
- Methodologies:
- Chromatographic Techniques: Utilize HPLC, GC, and LC-MS to separate and quantify impurities.
- Mass Spectrometry: Employ MS techniques to identify and characterize impurities based on their molecular weight and fragmentation patterns.
- NMR Spe… Read full answer