Tablet dissolution testing is one of the most important quality control tests in pharmaceutical manufacturing, providing critical information about drug release and bioavailability.
Fundamental Principles
What is Dissolution?
Dissolution is the process by which a solid substance enters into solution. For pharmaceutical tablets, it measures how quickly and completely the active ingredient is released into a liquid medium.
Why Test Dissolution?
- Predicts in vivo drug release
- Ensures batch-to-batch consistency
- Supports bioequivalence claims
- Monitors stability over shelf life
Testing Equipment
USP Apparatus Types
Different apparatus types suit different dosage forms:
- Apparatus 1 (Basket): Capsules, beads, floating forms
- Apparatus 2 (Paddle): Most tablets
- Apparatus 5 (Paddle Over Disk): Transdermal patches
- Apparatus 6 (Cylinder): Large transdermal systems
Key Components
- Dissolution vessels
- Temperature-controlled water bath
- Paddle or basket assemblies
- Sampling systems
- Analytical detection
Test Parameters
Temperature
Standard: 37°C ± 0.5°C (body temperature simulation)
Medium
Selected based on:
- Drug solubility
- Physiological relevance
- Regulatory requirements
Agitation
Typical speeds: 50-100 RPM depending on method
Sampling
Time points mapped to create dissolution profile
Regulatory Framework
Pharmacopeial requirements from USP, EP, JP, and IP guide method development and acceptance criteria establishment.
Data Interpretation
Dissolution Profiles
Graphical representation of percent dissolved vs. time reveals release characteristics.
Comparison Metrics
f1 (difference factor) and f2 (similarity factor) compare profiles mathematically.
Quality Control Application
Routine testing verifies every batch meets specifications before release to market.