Understand the source comparison
Comparison: Fresh vs Degraded PE-22-28 Characteristics
Color (lyophilised) White to off-white Yellow, tan, or brown Visual inspection under bright light Any color shift indicates oxidation. Discard immediately Odor Odorless Acrid, ammonia-like, sour Smell test upon vial opening Odor indicates microbial contaminati
No winner is assigned.
This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- Color (lyophilised)
- White to off-white
- Yellow, tan, or brown
- Visual inspection under bright light
- Any color shift indicates oxidation. Discard immediately
- Odor
- Odorless
- Acrid, ammonia-like, sour
- Smell test upon vial opening
- Odor indicates microbial contamination or advanced hydrolysis
- Solubility
- Dissolves completely in <60 seconds
- Incomplete dissolution, sediment
- Reconstitution test in sterile water
- Aggregation from oxidative cross-linking. Not salvageable
- pH (reconstituted)
- 6.0–7.2
- <5.5 or >7.5
- pH meter measurement
- pH drift signals hydrolysis or bacterial metabolites
- Clarity (reconstituted)
- Crystal clear, no particles
- Cloudy, particulates, turbidity
- Visual inspection against light
- Cloudiness is microbial growth or protein aggregation
- HPLC purity
- >95% single peak
- Multiple peaks, <80% primary peak
- HPLC-MS analysis
- Gold standard. Confirms degradation products definitively