AssayIndex

AX-2025-018843

PT-141 (Bremelanotide) · 10 mg declared · Flourishglobal Peptide Biotech (Chengdu) Co., Ltd. · lot FGP-2409-W9076

PASSIDENTITY CONSISTENT
Report ID
AX-2025-018843
Compound
PT-141 (Bremelanotide)
Compound class
Melanocortin-receptor peptides
Supplier
FGP — Flourishglobal Peptide Biotech (Chengdu) Co., Ltd.
Batch / lot
FGP-2409-W9076
Declared label claim
10mg
Laboratory
PeptideMeter
Assay date
21 Mar 2025
Submitted
10 Apr 2025
Quarter
2025-Q1
Submitter
mi.ibarra
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the melanocortin-receptor 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, 28 min gradient, 214 nm99.58% area≥ 98.5PASS
Total impuritiesRP-HPLC, sum of reported peaks0.42% area≤ 1.5PASS
Largest single impurityRP-HPLC — linear precursor (+18 Da)0.19% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula1024.5242DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)1024.5198DaNOT TESTED
Mass accuracyobserved vs theoretical-4.3ppm± 15PASS
Peptide contentnot ordered on this submissionnot determinedrequired to check label claimNOT TESTED
Water contentKarl Fischer, coulometric, duplicate5.25%≤ 8.0PASS
Counter-ion (acetate)anion-exchange ion chromatography6.18%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.16%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundWhite lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureFaint haze, clearing on standingclear, no visible particulatesFAIL
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.192.5 – 8.0PASS
Retention time (observed)RP-HPLC, 28 min gradient9.06min8.94 ± 0.25 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.460.960.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²47,090≥ 20,000PASS
Resolution to nearest impurityvs melanotan II (C-terminal amide, −1 Da)1.74no 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.

028175635845211269 PT-141 (Bremelanotide)9.06 min · 99.58 % 8.41 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 051015202530 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 28 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 47,090, and skew follows the reported asymmetry factor of 0.96. 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 0.19 % impurity against a 99.58 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1PT-141 (Bremelanotide) — main peak9.064,839,89799.58
2linear precursor (+18 Da)8.419,2350.19+18.011
3oxidised Trp (+16 Da)8.746,8040.14+15.995
4melanotan II (C-terminal amide, −1 Da)9.362,4300.05-0.984
5des-acetyl (−42 Da)8.631,9440.04-42.011
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 1024.5242 Da, computed from C50H68N14O10. All ppm figures on this site are against monoisotopic values — see why that matters.

025507510025040055070085010001150 [M+1H]1+1025.53[M+2H]2+513.27 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 1024.5198 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 (%)
3+342.5153342.5139-0.00148.2
2+513.2694513.2672-0.002251.6
1+1025.53151025.5271-0.0044100.0
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.

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)99.8199.58divergence +0.05 pp vs batch median
Total impurities (% area)0.190.42
Largest single impurity (% area)0.130.19
Water (%)4.05.25
Counter-ion (%)not stated6.18
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)not statednot determined
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, 28 d) → laboratory (courier, cold pack, 3 d) → assay.
Assay date
21 Mar 2025
Submitted to the index
10 Apr 2025
Laboratory
PeptideMeter, Tallinn, Estonia
Method basis
28 min gradient · high-resolution MS
Verification status
IDENTITY CONSISTENT
Section 6

Annotations 3

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.

plate_count
Plate count on this run supports the separation claimed. A high purity figure from an inefficient column is a merged peak reported as a clean one; that is not what happened here.
median_not_mean
One result at the top of the distribution should not move anybody's estimate much on its own. Purity distributions are compressed at the top and long-tailed at the bottom, so the informative observations are the low ones.
ppm_error
Instrument was evidently in calibration on the day. A run of results at this accuracy across a laboratory's sequence is the background against which an excursion becomes interpretable.
Section 7

Related records

Same batch — lot FGP-2409-W9076 n=4

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-018840FGP-2409-W9076Janoshik2025-Q199.835.63Laboratory-retained0PASS
AX-2025-018841FGP-2409-W9076Medutest2025-Q199.855.01105.3Buyer-sourced0PASS
AX-2025-018842FGP-2409-W9076PeptideMeter2025-Q199.694.56Buyer-sourced0PASS
Other recent PT-141 (Bremelanotide) records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041471QYBQYB-2607-L4875Janoshik2026-Q399.723.75101.7Buyer-sourced0PASS
AX-2026-041473QYBQYB-2607-L4875PeptideMeter2026-Q399.583.7494.4Buyer-sourced0PASS
AX-2026-041472QYBQYB-2607-L4875PeptideMeter2026-Q399.933.94Buyer-sourced0PASS
AX-2026-041474QYBQYB-2607-L4875VendorInvestigate2026-Q399.163.7895.6Buyer-sourced0PASS
AX-2026-041470QYBQYB-2607-L4875Janoshik2026-Q399.774.10Buyer-sourced0PASS
AX-2026-042139JEEPJEEP-2601-K8195VendorInvestigate2026-Q298.324.2999.4Buyer-sourced1FAIL
AX-2026-041964AMBAMB-2601-M5602Janoshik2026-Q299.933.20Buyer-sourced0PASS
AX-2026-041664FGPFGP-2602-Y8741Janoshik2026-Q299.904.48106.5Buyer-sourced0PASS
Other recent FGP records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041643SemaglutideFGP-2602-M8547Janoshik2026-Q399.312.79100.7Buyer-sourced0PASS
AX-2026-041638SemaglutideFGP-2602-M8547Janoshik2026-Q399.402.75105.8Buyer-sourced0PASS
AX-2026-041641SemaglutideFGP-2602-M8547PeptideMeter2026-Q398.982.38105.0Buyer-sourced0PASS
AX-2026-041610TirzepatideFGP-2603-L7753Janoshik2026-Q398.812.45101.0Buyer-sourced0PASS
AX-2026-041637SemaglutideFGP-2602-M8547PeptideMeter2026-Q399.402.83Laboratory-retained0PASS
AX-2026-041642SemaglutideFGP-2602-M8547PeptideMeter2026-Q398.782.24Buyer-sourced0PASS
AX-2026-041609TirzepatideFGP-2603-L7753Janoshik2026-Q398.522.0098.0Buyer-sourced0PASS
AX-2026-041636SemaglutideFGP-2602-M8547Nordanalyt2026-Q399.392.17Buyer-sourced0PASS