Sink Conditions: Volume of medium should be at least 3 times that needed to form a saturated solution (USP definition).
pH Range: Typical range is 1.1 to 6.8, but can be adjusted up to pH 8.0 for solubility.
Common Buffers:
- Hydrochloric acid: pH 1.0–3.0
- Glycine: pH 2.0–3.0
- Citrate: pH 2.5–3.5
- Acetate: pH 4.0–5.5
- Phosphate: pH 6.0–8.0
Surfactants:
- Use sodium dodecyl sulfate (SDS) as the first choice.
- Typical SDS concentration: 0.1% to 3% (adjust if needed for acceptable dissolution).
- If SDS doesn’t work, explore other FDA-approved surfactants.
Medium Deaeration: Ensure medium is deaerated to prevent bubbles, which can interfere with dissolution.
Medium Volume and Time Points
- Standard volumes: 500 mL and 900 mL are commonly used and accepted by regulatory agencies.
- Typical Sampling Times: 15, 30, 45, 60 minutes.
- Early Time Points (e.g., 5–10 minutes): If monitoring disintegration or rapid dissolution.
- Extended Time Points: If concerned about stability or slower dissolution.
- 15-min Sampling: Often useful for compounds that dissolve ≥85% in this time.
Sinkers
- Use of Sinkers: For capsules or sticky tablets to prevent adherence to the vessel and ensure consistent dissolution.
- Helps avoid variability caused by non-centered tablets or dosage forms.
Read also:
- Discriminating Dissolution Media
- Does an F2 Similarity Value of 50 Mean the Two Dissolution Profiles are Only 50% Similar?
Resource Person: Muhammad Taaha Khan