Dissolution testing can be performed using manual or automated sampling approaches, each with distinct advantages.
Manual Offline Sampling
Process
- Operator manually withdraws samples at specified times
- Samples transferred to containers for analysis
- Analysis performed separately (UV, HPLC)
Advantages
- Lower equipment cost
- Flexibility in sample handling
- Simple to implement
Limitations
- Labor intensive
- Subject to timing variability
- Potential for sampling errors
Online Sampling Systems
Process
- Automated sample withdrawal at programmed times
- Direct transfer to analytical system
- Real-time result generation
Advantages
- Precise sampling times
- Reduced operator involvement
- Consistent sample volumes
- Faster turnaround
Limitations
- Higher initial investment
- More complex setup
- Requires compatible analytical equipment
Key Differences
Timing Accuracy
Online systems provide superior timing accuracy with samples withdrawn within seconds of programmed times.
Labor Requirements
Manual sampling requires constant operator attention while online systems run unattended.
Data Quality
Online sampling reduces variability introduced by human factors.
Throughput
Automated systems enable higher throughput by freeing operators for other tasks.
Choosing the Right Approach
Consider:
- Sample volume requirements
- Analytical method compatibility
- Budget constraints
- Throughput needs
- Regulatory requirements