How to Choose a Dissolution Apparatus: When to Use USP 1/2/5/7 and How to Transfer Methods
Share
Selecting the right dissolution apparatus directly affects repeatability and registration consistency. Use a “scenario–variables–validation” approach to match USP 1/2/5/7 to your dosage form and prepare robust evidence for method transfer.
Where selection goes wrong
- Using the “most common” apparatus instead of the best-matched one—ignoring floating/aggregation or adhesion behavior.
- Tweaking only speed and medium while overlooking filtration, sampling position, and temperature control—sources of systematic bias.
- Judging transfer by similar curves alone, without defining an SST (system suitability) window and operating limits.
- Inconsistent media prep (deaeration, preheat, hold time) causing early-time variability.
Variables to lock before you choose
- Dosage behavior: propensity to float/aggregate, risk of sticking, need for multi-stage media.
- Hydrodynamics & mechanics: basket vs. paddle shear; reciprocation stroke consistency (USP 7).
- Medium & sampling: deaeration method, sampling point, filtration path—especially for early time points.
- Thermal control & records: medium prep, sampling timestamps, SST criteria, and deviation limits.
HUANGHAI’s selection & transfer recommendations
- Anchor on your dosage and registration pathway: pick the apparatus first, then back-calculate medium, speed/stroke, and sampling logic.
- Standardize media preparation with vacuum deaeration, preheat, and hold time—write it into SOPs.
- Build an auditable method file and SST: define sampling location, filtration conditions, temperature control, and equivalence ranges.
Conclusion
There is no “universal” apparatus—only a better match. Define the variable window and SST first, then finalize apparatus and workflow to improve transferability across sites.