Helios Blog

USP <85> sets the endotoxin limit per dose, not per vial: 5.0 EU/kg per hour for most routes. A bare “under 1 EU/mg” needs that arithmetic behind it.

The chromatogram is the record behind the purity number. Without it, no one can check the integration, the method or whether the trace belongs to the lot.

Mass spectrometry compares the observed mass with the mass calculated from the sequence. HPLC alone can’t, because a wrong peptide can be 99% pure.

Net peptide content is the share of the powder that is peptide after water, counterions and salts are subtracted. Published values run 45% to 88%.

A purity number alone can’t answer it. Ask what the other 2% is, whether each impurity at 0.10% or more is named, and whether any unknown exceeds 0.5%.

HPLC purity is the main peak’s share of all peaks the detector sees, usually by UV near 210 to 220 nm. It does not measure content, identity or sterility.

Stop and quarantine the lot, photograph and record the mismatch that day, get the right certificate and lab confirmation, and release only when all agree.

Ask who made it, for a batch-specific certificate, the lab and its scope, the per-lot tests, shipping records, stability data and the recall procedure.

Reach the lab through details you looked up, not those on the certificate, and have it confirm report number, lot, test date and results. File the reply.