Basket vs. Paddle Method in Dissolution Testing: Selection Criteria for Different Dosage Forms
Dissolution testing is a vital quality control method in the pharmaceutical industry, used to evaluate drug release from oral solid dosage forms. The United States Pharmacopeia (USP) defines two primary apparatuses: the basket method (Apparatus 1) and the paddle method (Apparatus 2). Selecting the right method depends on the physical properties and release characteristics of the dosage form.
Basket vs. Paddle: Key Differences
🧺 Basket Method (Apparatus 1)
Rotating mesh basket holds the dosage form
Best for low-density or floating capsules/tablets
Common speed: 100 rpm
🥄 Paddle Method (Apparatus 2)
Flat paddle stirs above dosage resting at vessel bottom
Suitable for dense, fast-disintegrating, or immediate-release forms
Most widely used method globally
How to Choose: Selection Criteria
Criteria | Basket Method | Paddle Method |
---|---|---|
Density | Low-density, floating forms | Dense tablets that sink easily |
Shape | Irregular or multiparticulate forms | Compact, regular shapes |
Disintegration Speed | Slow-disintegrating dosage | Rapid disintegration |
Floating Tendency | Prevents floating via enclosure | May require sinkers |
Common Forms | Hard gelatin capsules, buoyant tablets | Tablets, ODTs, soft gelatin capsules |
Typical Applications
Basket Method:
Hard gelatin capsules
Enteric-coated or delayed-release tablets
Buoyant dosage forms
Paddle Method:
Immediate- and extended-release tablets
Orally disintegrating tablets (ODTs)
Soft gelatin capsules
Regulatory Expectations
Both methods are recognized by USP, EP, and JP, but regulatory agencies require method justification. The selected method must be proven suitable through data on reproducibility, discriminatory power, and product relevance.
Practical Tips
✅ Method Transfer: Switching between methods? Provide comparative validation data.
✅ Use of Sinkers: For floating forms in paddle testing, sinkers help maintain position.
✅ Ease of Use: Paddle is generally easier to operate, but not ideal for all dosage types.
Conclusion
Choosing the right dissolution apparatus—basket or paddle—ensures accurate drug release data that reflects in vivo performance. Selection should be based on dosage form behavior, backed by scientific rationale and regulatory compliance. A proper method improves test reliability, product quality, and regulatory success.