Full stated quantity, and nothing rounded up — purity by HPLC and the Cu : peptide molar ratio by ICP-MS, measured and transcribed on a lot-numbered COA for every batch.
Full stated quantity; HPLC purity and Cu : peptide ratio by ICP-MS — measured, not rounded; per-lot COA.
Full quantity; purity + Cu : ratio, not rounded.
Why Cu²⁺ : Peptide Ratio Matters — A 90-Second Quality Check for Formulators. Read our briefing →
Why Cu²⁺ Ratio Matters — a field guide. Read →
On the Cu²⁺ ratio. Read →
Lot Data · Per Lot
Every Cupratec lot ships with a UV-Vis spectrum, a measured Cu²⁺ : peptide molar ratio, 6-month solution-stability data, and a color ΔE against the in-house master lot. The lot report is how the atelier proves coordination — not assumes it.
Lot-release bench · captured during a production day
Lot Data, on Every Lot
A GHK-Cu lot without a UV-Vis spectrum is just a blue powder. Every Cupratec lot ships with the characterisation data formulators actually need — and the analytical packet behind it on request.
~606 nm
λmax · Cu(II) d-d band
ΔE < 1.0
Color vs. master lot
6-month
Solution stability data
UV-Vis spectrum on every lot — λmax position and absorbance at brand-relevant wavelengths, the diagnostic for intact Cu(II) coordination.
Cu²⁺ : peptide molar ratio by ICP-MS or atomic absorption, target with documented tolerance — never assumed from synthesis stoichiometry.
Solution stability + color ΔE, tracked through 6 months at 25 / 40 / 60 °C against an in-house master-lot reference.
Cu²⁺ Characterisation · On Every Lot
The Cu²⁺ panel runs on every lot before release — it is the test set that defines whether a copper-peptide lot is what the spec says it is. The four lines below are documented on the lot release report and available as raw analytics under mutual NDA.
| Test | Method | Target |
|---|---|---|
| Cu²⁺ : peptide molar ratio | ICP-MS (Cu) + HPLC-UV (peptide) with internal standard | 1.00 ± 0.05 (theoretical 1:1) |
| Why we run itThe single most important Cu-peptide spec — bioactivity scales with the bound fraction, not the total peptide. Out-of-band lots are held. | ||
| UV-Vis · Cu(II) d-d band | 200–800 nm scan in chelator-free pure water | λmax ~605–606 nm (physiological pH; broad, condition-dependent) · broad single band |
| Why we run itDirect visual + spectral confirmation of intact 3N+O Cu(II) coordination. Shifted or split λmax flags a coordination problem. | ||
| Solution stability (6 months) | 25 / 40 / 60 °C across reference and finished-product matrices | Documented decay envelope; release-spec retention ≥ 90% at 6 mo / 25 °C |
| Why we run itLets formulators size shelf-life claims for the active independently of the carrier system; basis for finished-product stability scoping. | ||
| Color ΔE vs. master lot | CIELab against in-house Cupratec master reference | ΔE < 1.0 (visually indistinguishable) |
| Why we run itCatches subtle copper-loading or impurity-profile drift the molar-ratio measurement can absorb but the human eye in a finished product will not. | ||
Peptide-Level Analytics
Before the copper is coordinated, the peptide has to be a characterised peptide. These are the analytical lines Cupratec runs on the peptide itself — alongside the Cu²⁺ panel above, never as a substitute for it.
| Test | Method | Target |
|---|---|---|
| HPLC purity (peptide) | RP-HPLC at the peptide's UV-active wavelength | ≥ 99.0% |
| Why we run itStandard purity floor for cosmetic-grade actives. Released lots do not contain peptide-impurity peaks above the integration threshold. | ||
| Identity by mass spec | ESI-MS, observed vs. theoretical [M+H]⁺ | Confirmed (±0.5 Da) |
| Why we run itSequence confirmation; rules out the synthesis-side failure modes that can hide behind HPLC purity (e.g. truncations at the same retention time). | ||
| Water content (Karl Fischer) | Coulometric KF | ≤ 8.0% (lyophilised powder) |
| Why we run itLyophilisation control. Out-of-band water increases the dissociation kinetics of the Cu(II)-peptide complex during long-term storage. | ||
| Residual solvents | GC headspace | ICH Q3C limits |
| Why we run itSynthesis solvent residues; relevant for any peptide active going into a leave-on cosmetic. | ||
Mesotherapy-Grade Lots
Cupratec ships a mesotherapy-grade lot variant of select Cu-peptides for licensed mesotherapy and aesthetic-clinic buyers. These lots add bacterial-endotoxin and microbial- limits testing on top of the standard Cu²⁺ + peptide analytical packet — and ship only on clinic-licence verification.
Cosmetic-grade default lots do not carry these tests; see the B2B policy for how the qualification works.
| Test | Method | Target |
|---|---|---|
| Bacterial endotoxin | LAL (gel-clot / kinetic chromogenic) | < 0.25 EU/mg |
| Why we run itRequired for any lot intended for licensed clinical mesotherapy use. Cosmetic-only lots do not carry this test by default. | ||
| Microbial limits | USP <61>/<62> | Compliant |
| Why we run itSterile-route-adjacent applications. Same scoping as above — mesotherapy lots only, on clinic-licence verification. | ||
Lot Report Contents
Every commercial lot ships with the release report below. On request we attach the raw analytics — UV-Vis trace, HPLC chromatogram with peak integration, mass spectrum, stability series, and the master-lot ΔE photograph — as the QA work-packet your dossier needs.
A copper-peptide lot release file should include the Cu²⁺ : peptide molar ratio, UV-Vis spectrum, solution-stability series, color ΔE, HPLC purity, MS identity, and a signed lot release statement. Mesotherapy-grade lots add endotoxin and microbial-limit testing when the buyer is licensed for that pathway.
Measured value with documented tolerance, ICP-MS / AA traceable.
λmax, absorbance at brand-relevant wavelengths, full 200–800 nm trace on request.
Decay envelope across 25 / 40 / 60 °C, 6-month timepoints.
CIELab value against the in-house master lot; photograph available on request.
Peak-integration chromatogram and ESI-MS confirmation of the peptide molecule.
Single-page commercial release document signed by QA; the version your buyer-side dossier files.
From the Atelier
First response under 24 hours. We send a 25 mg sample of the active you specify, the lot's UV-Vis spectrum, the Cu²⁺ : peptide ratio measurement, and a feasibility note for the formulation application you have in mind.