AssayIndex

AX-2025-020974

PT-141 (Bremelanotide) · 10 mg declared · WuXi TIDES (WuXi AppTec Testing Division) · lot WXT-2507-R4042

PASSVERIFIED
Report ID
AX-2025-020974
Compound
PT-141 (Bremelanotide)
Compound class
Melanocortin-receptor peptides
Supplier
WXT — WuXi TIDES (WuXi AppTec Testing Division)
Batch / lot
WXT-2507-R4042
Declared label claim
10mg
Laboratory
VendorInvestigate
Assay date
10 Aug 2025
Submitted
12 Aug 2025
Quarter
2025-Q3
Submitter
fr.villalobos
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, 32 min gradient, 214 nm99.38% area≥ 98.5PASS
Total impuritiesRP-HPLC, sum of reported peaks0.62% area≤ 1.5PASS
Largest single impurityRP-HPLC — oxidised Trp (+16 Da)0.30% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula1024.5242Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)1024.5234Da—NOT TESTED
Mass accuracyobserved vs theoretical-0.8ppm± 15PASS
Peptide contentnot ordered on this submissionnot determined—required to check label claimNOT TESTED
Water contentKarl Fischer, coulometric, duplicate4.71%≤ 8.0PASS
Counter-ion (acetate)anion-exchange ion chromatography5.08%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.95%—NOT TESTED
Endotoxinkinetic chromogenic LAL1.41EU/mg≤ 5.0PASS
Sterilitymembrane filtration, USP <71>, 14 dNo growth at 14 d—no growthPASS
Appearancevisual, diffuse light, black and white backgroundWhite powder, no defined cake (melt-back)—white to off-white intact cakeFAIL
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulates—clear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration4.49—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 32 min gradient10.06min10.10 ± 0.25 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.24—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²33,191—≥ 20,000PASS
Resolution to nearest impurityvs melanotan II (C-terminal amide, −1 Da)1.51—no 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.

01860372055807440 PT-141 (Bremelanotide)10.06 min · 99.38 % 9.70 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 32 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 33,191, and skew follows the reported asymmetry factor of 1.24. 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 0.30 % impurity against a 99.38 % 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 peak10.064,830,17699.38—
2oxidised Trp (+16 Da)9.7014,5810.30+15.995
3melanotan II (C-terminal amide, −1 Da)10.408,7490.18-0.984
4des-acetyl (−42 Da)9.573,4020.07-42.011
5linear precursor (+18 Da)9.313,4020.07+18.011
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 1024.5234 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+342.5153342.5151-0.00028.8
2+513.2694513.2690-0.000455.7
1+1025.53151025.5307-0.0008100.0
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)99.0599.38divergence +0.01 pp vs batch median
Total impurities (% area)0.950.62
Largest single impurity (% area)0.580.30
Water (%)3.94.71
Counter-ion (%)not stated5.08
Peptide content (%w/w)91.3not determined
Endotoxin (EU/mg)0.751.41
Method stated on certificateYES—column, 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
Domestic warehouse despatch → submitter (2–8 °C, 27 d) → laboratory (courier, cold pack, 3 d) → assay.
Assay date
10 Aug 2025
Submitted to the index
12 Aug 2025
Laboratory
VendorInvestigate, Riga, Latvia
Method basis
32 min gradient · high-resolution MS
Verification status
VERIFIED
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.

ms_confirm
A reference standard on the same sequence would upgrade this from a good mass to a traceable one. The distinction matters where a result is going to be cited rather than merely read.
sample_vs_retail
A retail vial at 99.38 % is worth more evidentially than a selected vial at a higher figure. That is the whole argument for recording provenance at all.
shipping_temp
The custody block above records the shipping conditions this vial actually experienced, which is the condition an ordinary buyer's vial experiences too. That representativeness is the point.
Section 7

Related records

Same batch — lot WXT-2507-R4042 n=12

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-020972WXT-2507-R4042PeptideMeter2025-Q399.045.29—Buyer-sourced1MARGINAL
AX-2025-020973WXT-2507-R4042Kestrel2025-Q399.754.62—Buyer-sourced0PASS
AX-2025-020975WXT-2507-R4042Janoshik2025-Q398.884.76—Buyer-sourced0PASS
AX-2025-020976WXT-2507-R4042Medutest2025-Q399.004.50101.5Buyer-sourced0PASS
AX-2025-020977WXT-2507-R4042PeptideMeter2025-Q398.984.6594.0Buyer-sourced0PASS
AX-2025-020978WXT-2507-R4042Medutest2025-Q398.654.38—Buyer-sourced0PASS
AX-2025-020979WXT-2507-R4042Janoshik2025-Q399.114.8593.2Buyer-sourced0PASS
AX-2025-020980WXT-2507-R4042PeptideMeter2025-Q399.264.6095.9Buyer-sourced0PASS
AX-2025-020981WXT-2507-R4042Nordanalyt2025-Q399.034.87105.2Buyer-sourced0PASS
AX-2025-020982WXT-2507-R4042Janoshik2025-Q399.324.5799.4Buyer-sourced1MARGINAL
AX-2025-020983WXT-2507-R4042Janoshik2025-Q398.975.11—Laboratory-retained0PASS

Cross-sections

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-Q399.933.94—Buyer-sourced0PASS
AX-2026-041474QYBQYB-2607-L4875VendorInvestigate2026-Q399.163.7895.6Buyer-sourced0PASS
AX-2026-041470QYBQYB-2607-L4875Janoshik2026-Q399.774.10—Buyer-sourced0PASS
AX-2026-042139JEEPJEEP-2601-K8195VendorInvestigate2026-Q298.324.2999.4Buyer-sourced1FAIL
AX-2026-041964AMBAMB-2601-M5602Janoshik2026-Q299.933.20—Buyer-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-Q397.084.22—Buyer-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-Q398.935.28—Buyer-sourced0PASS
AX-2026-043424L-Glutathione (reduced)WXT-2605-B3833PeptideMeter2026-Q398.376.86—Buyer-sourced0FAIL
AX-2026-043374SemaglutideWXT-2604-C3248Janoshik2026-Q397.003.56—Buyer-sourced1MARGINAL
AX-2026-043377SemaglutideWXT-2604-C3248PeptideMeter2026-Q397.204.08—Buyer-sourced1MARGINAL