Active Pharmaceutical Ingredients (APIs) are analyzed to ensure their identity, purity, potency, and stability. This is crucial for drug safety, efficacy, and regulatory compliance. Here’s a clear breakdown of how APIs are analyzed:
1. Identification of API
- Purpose: Confirm that the substance is the correct API.
- Techniques Used:
- Spectroscopy:
- IR (Infrared): Detects functional groups in the molecule.
- UV-Vis: Shows absorption characteristics of the molecule.
- NMR (Nuclear Magnetic Resonance): Reveals detailed molecular structure.
- Mass Spectrometry (MS): Determines molecular weight and fragmentation pattern.
- Chromatography: HPLC or TLC comparison with reference standards.
- Spectroscopy:
2. Purity Testing
- Purpose: Ensure API is free from contaminants, degradation products, or residual solvents.
- Techniques Used:
- HPLC (High-Performance Liquid Chromatography): Quantifies impurities.
- GC (Gas Chromatography): Detects volatile impurities.
- TLC (Thin Layer Chromatography): Quick screening for contaminants.
- Elemental Analysis: Checks for inorganic impurities.
3. Quantitative Analysis
- Purpose: Measure the exact amount of API in a formulation.
- Techniques Used:
- HPLC: Most common for tablets, capsules, or injections.
- UV-Vis Spectroscopy: Used when the API absorbs light in the UV or visible range.
- Titration: For APIs that can react chemically with known reagents.
4. Stability Studies
- Purpose: Determine how the API behaves under stress (temperature, light, humidity, oxidation).
- Techniques Used:
- HPLC or LC-MS: Detects degradation products over time.
- DSC (Differential Scanning Calorimetry): Studies thermal stability.
- Spectroscopic Methods: Monitor changes in molecular structure.
5. Dissolution and Solubility Testing
- Purpose: Ensure the API can dissolve properly, which is essential for bioavailability.
- Methods:
- Dissolution testers in simulated fluids.
- Solubility studies in water, buffers, or solvents.
In short: API analysis involves identification, purity assessment, quantitative measurement, stability testing, and solubility studies. Techniques like HPLC, GC, spectroscopy, and mass spectrometry are commonly used to ensure the API is safe, effective, and meets regulatory standards.