fill_homogeneity

A high figure on one vial is a statement about one vial. The within-lot spread on the batch rollup is what tells you whether the bulk was well mixed, and it is the rarer and more useful number.

One retail vial is one draw from a fill. Two or three from the same lot would separate fill variation from lot quality, and that is the cheapest useful experiment in this whole field.

Three vials from one lot sent to three laboratories blind is the design that removes this ambiguity. It costs three tests and it settles the question permanently for that lot.

One vial is one fill event. Three from the same lot would separate fill variability from a systematic offset, and that distinction changes what you do about it.

A single vial is a single draw from a fill. Within-lot variation in this index has a median of 0.28 pp, so a second result would usually land close — but usually is not a finding.

Vial-to-vial variation is the parameter that most directly determines whether a certificate applies to the vial you hold. It is measured on a tiny fraction of lots.

Direct despatch means the submitter never held the vial. That is a cleaner custody chain and a weaker selection story, simultaneously.

Well-mixed bulk, well-controlled fill, documented custody and three agreeing results. That combination is the best a record on this site can look.

Every headline figure on the corresponding scorecard survives restriction to buyer-sourced records. That sensitivity analysis is published on the scorecard and it is the reason this record can be included at all.

Seconded.

Purity 99.18 %, water 5.60 %, mass balance closed. The measurements are what they are; the provenance qualifies how far they generalise, not whether they are correct.

Three vials from one lot to three laboratories is the design that answers everything at once. It costs three tests and it is the best value in this whole field.