AssayIndex

AX-2026-043109

Epitalon · 20 mg declared · Zhuhai Kerui Biotechnology Co., Ltd. · lot KP-2508-Y5884

FAILMETHOD LIMITED
Report ID
AX-2026-043109
Compound
Epitalon
Compound class
Short bioregulator peptides
Supplier
KP — Zhuhai Kerui Biotechnology Co., Ltd.
Batch / lot
KP-2508-Y5884
Declared label claim
20mg
Laboratory
Janoshik Analytical
Assay date
28 Jan 2026
Submitted
14 Feb 2026
Quarter
2026-Q1
Submitter
ion_pair_ip
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the short bioregulator peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 30 min gradient, 214 nm98.39% area≥ 99.0FAIL
Total impuritiesRP-HPLC, sum of reported peaks1.61% area≤ 1.0FAIL
Largest single impurityRP-HPLC — Ala-Glu-Asp tripeptide (−57 Da)0.83% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula390.1387DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)390.1382DaNOT TESTED
Mass accuracyobserved vs theoretical-1.4ppm± 20PASS
Total peptide contentby difference from the gravimetric mass balance82.24%w/wNOT TESTED
Target-compound contenttotal peptide content × purity80.92%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen24.67mg20 mg declaredNOT TESTED
Recovered target peptidegross fill × target content19.963mg20 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim99.8%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate8.24%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography8.94%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.58%NOT TESTED
Endotoxinkinetic chromogenic LAL0.27EU/mg≤ 5.0PASS
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundOff-white lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.122.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient4.73min4.62 ± 0.20 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.200.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²96,017≥ 20,000PASS
Resolution to nearest impurityvs β-Asp isomer1.60no index criterionREPORTED
Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

06783135662034927132 Epitalon4.73 min · 98.39 % 4.53 same trace · ×50 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 30 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 96,017, and skew follows the reported asymmetry factor of 1.20. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.83 % impurity against a 98.39 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Epitalon — main peak4.734,782,05998.39
2Ala-Glu-Asp tripeptide (−57 Da)4.5340,3410.83-57.021
3aspartimide (−18 Da)4.8515,5530.32-18.011
4diketopiperazine (−18 Da)4.8912,6370.26-18.011
5β-Asp isomer4.639,7210.200.000
Closure check — purity + Σ impurities 100.00CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 3

Mass spectrum and identity

Theoretical monoisotopic mass 390.1387 Da, computed from C14H22N4O9. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100350375400425450475 [M+1H]1+391.15 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 390.1382 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.
ChargeTheoretical m/zObserved m/zΔ m/zRel. abundance (%)
1+391.1460391.1455-0.0005100.0
Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

ComponentDetermination%w/w of cake
WaterKarl Fischer8.24
Counter-ion (acetate)ion chromatography8.94
Residual solvent + inorganic residueestimated0.58
Total peptide contentby difference82.24
Total100.00 CLOSES

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

FigureSupplier COAThis reportIndex note
Purity (% area)98.4398.39divergence -0.15 pp vs batch median
Total impurities (% area)1.571.61
Largest single impurity (% area)not stated0.83
Water (%)6.18.24
Counter-ion (%)not stated8.94
Peptide content (%w/w)89.182.24
Endotoxin (EU/mg)not stated0.27
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance
Buyer-sourced
Evidentiary weight
Strongest available evidence in this index.
Chain of custody
Retail purchase → submitter (ambient, 14 d) → laboratory (hand-carried, 12 d) → assay.
Assay date
28 Jan 2026
Submitted to the index
14 Feb 2026
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
METHOD LIMITED
Section 6

Annotations 2

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

peak_integrator
98.39 % on Epitalon is below the index specification for the class. The interesting part is the distribution: Ala-Glu-Asp tripeptide (−57 Da) at 0.83 % is doing most of the work, and that species is a synthesis artefact rather than a degradation product. This is a process observation about lot KP-2508-Y5884, not a storage one.
scale_up_delta
Purity commonly falls a few tenths between pilot and production scale, and a result below a laboratory-batch figure is the most ordinary thing in this dataset. Comparing a commercial lot against a research-batch certificate compares two different processes.
Section 7

Related records

Same batch — lot KP-2508-Y5884 n=6

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043105KP-2508-Y5884VendorInvestigate2026-Q198.077.50103.6Buyer-sourced0FAIL
AX-2026-043106KP-2508-Y5884PeptideMeter2026-Q198.228.7198.4Buyer-sourced0FAIL
AX-2026-043107KP-2508-Y5884Medutest2026-Q199.207.9396.6Supplier-supplied1MARGINAL
AX-2026-043108KP-2508-Y5884Kestrel2026-Q199.047.77104.2Supplier-supplied1MARGINAL
AX-2026-043110KP-2508-Y5884PeptideMeter2026-Q198.777.55Supplier-supplied1FAIL
Other recent Epitalon records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042008AMBAMB-2602-Y6433Janoshik2026-Q399.308.75105.1Buyer-sourced0PASS
AX-2026-042009AMBAMB-2602-Y6433VendorInvestigate2026-Q399.168.62102.3Buyer-sourced0FAIL
AX-2026-042010AMBAMB-2602-Y6433Janoshik2026-Q399.098.20103.4Laboratory-retained0FAIL
AX-2026-042007AMBAMB-2602-Y6433Janoshik2026-Q399.428.6293.8Buyer-sourced0FAIL
AX-2026-042468HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.81100.8Buyer-sourced0PASS
AX-2026-042463HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.6893.2Buyer-sourced0FAIL
AX-2026-042041HYBHYB-2603-U7133Janoshik2026-Q299.656.8295.3Buyer-sourced0FAIL
AX-2026-042470HomopeptideHOMO-2512-A5108Janoshik2026-Q299.637.99Buyer-sourced0FAIL
Other recent KP records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043095RetatrutideKP-2607-H5774Janoshik2026-Q395.815.48105.2Buyer-sourced0FAIL
AX-2026-043094RetatrutideKP-2607-H5774PeptideMeter2026-Q396.326.40Buyer-sourced0FAIL
AX-2026-043096RetatrutideKP-2607-H5774VendorInvestigate2026-Q396.486.05104.9Buyer-sourced0FAIL
AX-2026-043090RetatrutideKP-2607-H5774Janoshik2026-Q396.465.81Buyer-sourced0FAIL
AX-2026-043091RetatrutideKP-2607-H5774Janoshik2026-Q396.135.94Buyer-sourced0FAIL
AX-2026-043077TB-500KP-2605-C5214Janoshik2026-Q299.615.6490.2Buyer-sourced0PASS
AX-2026-043093RetatrutideKP-2607-H5774Janoshik2026-Q396.545.54Buyer-sourced0PASS
AX-2026-043092RetatrutideKP-2607-H5774Medutest2026-Q396.646.12Buyer-sourced1FAIL