Preparation
Visual inspection
What visual inspection of a vial or a reconstituted solution can and cannot rule out.
- Last updated:
- 2026-07-22
Overview
Visual inspection is the process of looking at a vial and, after reconstitution, at the solution inside it, and comparing what you see to what the compound page and the manufacturer describe as normal appearance. It is quick, free, and the first line of quality screening.
For a lyophilized vial, the normal appearance is usually a white or off-white, well-formed cake or powder. For a reconstituted solution, it is usually clear and colourless, without visible particulate.
Why it matters
Visual inspection reliably catches gross problems: contamination, collapse, discolouration, precipitation. It does not detect microbiological contamination, endotoxin, potency loss, or identity errors — the risks that most often matter clinically.
Key concepts
Discard on visible abnormality
Turbidity, particulate, colour change, or precipitate in a solution that should be clear is a reason to discard. Cake collapse or discolouration in a vial that should be intact is also a reason to discard.
Absence of visible abnormality is weak evidence
A visually normal vial is consistent with a normal vial, but does not prove it. Contamination and potency loss can be invisible.
Compare to compound page
Compound pages document the expected appearance for each vial and solution. If yours differs, treat the discrepancy as a signal, not as a variation.
Common misconceptions
- "Clear equals sterile." It does not.
- "Colourless equals identity-correct." It does not.
- "Small particulate is normal." It generally is not; consult the compound page's expected appearance and treat unexpected particulate as a discard signal.
Practical interpretation
Visual inspection is a necessary quality check, not a sufficient one. Combine it with matching CoA batch numbers, cold-chain confirmation, and, where applicable, in-use records.
Limitations
The reader's ability to detect subtle appearance changes varies with lighting, background, and experience. When in doubt, discard.