AssayIndex

AX-2025-021024

PT-141 (Bremelanotide) · 10 mg declared · WuXi TIDES (WuXi AppTec Testing Division) · lot WXT-2411-R3766

FAILVERIFIED
Report ID
AX-2025-021024
Compound
PT-141 (Bremelanotide)
Compound class
Melanocortin-receptor peptides
Supplier
WXT — WuXi TIDES (WuXi AppTec Testing Division)
Batch / lot
WXT-2411-R3766
Declared label claim
10mg
Laboratory
Janoshik Analytical
Assay date
04 Feb 2025
Submitted
18 Feb 2025
Quarter
2025-Q1
Submitter
e.salgado
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, 30 min gradient, 214 nm98.42% area≥ 98.5FAIL
Total impuritiesRP-HPLC, sum of reported peaks1.58% area≤ 1.5FAIL
Largest single impurityRP-HPLC — oxidised Trp (+16 Da)0.77% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula1024.5242DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)1024.5219DaNOT TESTED
Mass accuracyobserved vs theoretical-2.2ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance89.16%w/wNOT TESTED
Target-compound contenttotal peptide content × purity87.75%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen10.64mg10 mg declaredNOT TESTED
Recovered target peptidegross fill × target content9.337mg10 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim93.4%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate5.52%≤ 8.0PASS
Counter-ion (acetate)anion-exchange ion chromatography5.01%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.31%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitymembrane filtration, USP <71>, 14 dNo growth at 14 dno growthPASS
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 calibration5.002.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient9.47min9.52 ± 0.25 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.050.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²89,091≥ 20,000PASS
Resolution to nearest impurityvs melanotan II (C-terminal amide, −1 Da)2.46no 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.

0350370061051014013 PT-141 (Bremelanotide)9.47 min · 98.42 % 9.13 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 89,091, and skew follows the reported asymmetry factor of 1.05. 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 0.77 % impurity against a 98.42 % 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 peak9.474,783,51798.42
2oxidised Trp (+16 Da)9.1337,4240.77+15.995
3linear precursor (+18 Da)8.7721,3850.44+18.011
4des-acetyl (−42 Da)9.0111,1790.23-42.011
5melanotan II (C-terminal amide, −1 Da)9.796,8040.14-0.984
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 1024.5219 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+342.5153342.5146-0.00078.0
2+513.2694513.2682-0.001249.2
1+1025.53151025.5292-0.0023100.0
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 Fischer5.52
Counter-ion (acetate)ion chromatography5.01
Residual solvent + inorganic residueestimated0.31
Total peptide contentby difference89.16
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)98.0298.42divergence -0.47 pp vs batch median
Total impurities (% area)not stated1.58
Largest single impurity (% area)not stated0.77
Water (%)3.05.52
Counter-ion (%)not stated5.01
Peptide content (%w/w)92.289.16
Endotoxin (EU/mg)0.90not 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, 32 d) → laboratory (courier, cold pack, 3 d) → assay.
Assay date
04 Feb 2025
Submitted to the index
18 Feb 2025
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
VERIFIED
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.

sodium_adduct
Adduct bookkeeping on this one is tidy. The sodium series is present at the expected intensity ratio and has not been counted as an impurity, which happens more often than it should.
quad_unit
The index grades identity by instrument class, not by the ppm figure alone: "confirmed" where the determination was made at high resolution, "consistent with" where it was not. The status block above says which applies to this record, and it is worth reading before the number.
Section 7

Related records

Same batch — lot WXT-2411-R3766 n=8

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-021019WXT-2411-R3766Medutest2025-Q198.414.9494.1Buyer-sourced0FAIL
AX-2025-021020WXT-2411-R3766Janoshik2025-Q198.366.61101.2Buyer-sourced0FAIL
AX-2025-021021WXT-2411-R3766Nordanalyt2025-Q198.555.25Supplier-supplied0PASS
AX-2025-021022WXT-2411-R3766Janoshik2025-Q198.635.79Buyer-sourced0PASS
AX-2025-021023WXT-2411-R3766Nordanalyt2025-Q198.725.40103.2Buyer-sourced0PASS
AX-2025-021025WXT-2411-R3766Medutest2025-Q198.696.18Buyer-sourced0PASS
AX-2025-021026WXT-2411-R3766Janoshik2025-Q198.435.65Buyer-sourced0FAIL
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 WXT records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043376SemaglutideWXT-2604-C3248Janoshik2026-Q397.084.22Buyer-sourced1MARGINAL
AX-2026-043429L-Glutathione (reduced)WXT-2605-B3833Nordanalyt2026-Q398.486.5896.9Supplier-supplied1FAIL
AX-2026-043347LeuprolideWXT-2604-K2596PeptideMeter2026-Q399.165.9993.6Buyer-sourced0PASS
AX-2026-043353LeuprolideWXT-2604-K2596Janoshik2026-Q399.194.9095.3Laboratory-retained0PASS
AX-2026-043345LeuprolideWXT-2604-K2596Janoshik2026-Q398.935.28Buyer-sourced0PASS
AX-2026-043424L-Glutathione (reduced)WXT-2605-B3833PeptideMeter2026-Q398.376.86Buyer-sourced0FAIL
AX-2026-043374SemaglutideWXT-2604-C3248Janoshik2026-Q397.003.56Buyer-sourced1MARGINAL
AX-2026-043377SemaglutideWXT-2604-C3248PeptideMeter2026-Q397.204.08Buyer-sourced1MARGINAL