AssayIndex

AX-2025-021219

MK-677 (Ibutamoren mesylate) · 500 mg declared · PolyPeptide Group (Hangzhou) Co., Ltd. · lot PPG-2508-N7944

FAILVERIFIED
Report ID
AX-2025-021219
Compound
MK-677 (Ibutamoren mesylate)
Compound class
Non-peptide adjuncts
Supplier
PPG — PolyPeptide Group (Hangzhou) Co., Ltd.
Batch / lot
PPG-2508-N7944
Declared label claim
500mg
Laboratory
Nordanalyt Laboratories
Assay date
18 Aug 2025
Submitted
23 Aug 2025
Quarter
2025-Q3
Submitter
so.beaulieu
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the non-peptide adjuncts class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 35 min gradient, 214 nm99.49% area≥ 98.5PASS
Total impuritiesRP-HPLC, sum of reported peaks0.51% area≤ 1.5PASS
Largest single impurityRP-HPLC — spiroindane regioisomer0.34% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula624.2181Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)624.2176Da—NOT TESTED
Mass accuracyobserved vs theoretical-0.8ppm± 10PASS
Total peptide contentby difference from the gravimetric mass balance80.46%w/w—NOT TESTED
Target-compound contenttotal peptide content × purity80.05%w/w—NOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen635.29mg500 mg declaredNOT TESTED
Recovered target peptidegross fill × target content508.550mg500 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim101.7%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate4.86%≤ 10.0PASS
Counter-ion (mesylate)anion-exchange ion chromatography14.43%≤ 12.0FAIL
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.25%—NOT TESTED
Endotoxinkinetic chromogenic LAL0.95EU/mg≤ 5.0PASS
Sterilitynot ordered on this submissionnot determined—no growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundOff-white lyophilised cake, intact—white to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulates—clear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration4.19—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 35 min gradient15.84min15.99 ± 0.30 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.19—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²53,084—≥ 20,000PASS
Resolution to nearest impurityvs spiroindane regioisomer1.82—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.

01530306045896119 MK-677 (Ibutamoren mesylate)15.84 min · 99.49 % 16.356.27 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 0510152025303540 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 35 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 53,084, and skew follows the reported asymmetry factor of 1.19. 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 0.34 % impurity against a 99.49 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1MK-677 (Ibutamoren mesylate) — main peak15.844,835,52299.49—
2spiroindane regioisomer16.3516,5250.340.000
3sulfonamide hydrolysis product (+18 Da)14.844,8600.10+18.011
4residual DMF (process solvent)6.271,9440.04-551.000
5O-desmethyl metabolite analogue (−14 Da)15.231,4580.03-14.016
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 624.2181 Da, computed from C27H36N4O5S · CH4O3S. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100250325400475550625700 [M+1H]1+625.22[M+2H]2+313.12 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 624.2176 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 (%)
2+313.1163313.1161-0.000251.6
1+625.2254625.2249-0.0005100.0
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 Fischer4.86
Counter-ion (mesylate)ion chromatography14.43
Residual solvent + inorganic residueestimated0.25
Total peptide contentby difference80.46
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)99.2799.49divergence -0.35 pp vs batch median
Total impurities (% area)not stated0.51
Largest single impurity (% area)not stated0.34
Water (%)1.84.86
Counter-ion (%)4.614.43
Peptide content (%w/w)93.080.46
Endotoxin (EU/mg)not stated0.95
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
Retail purchase → submitter (ambient, 18 d) → laboratory (hand-carried, 4 d) → assay.
Assay date
18 Aug 2025
Submitted to the index
23 Aug 2025
Laboratory
Nordanalyt Laboratories, Uppsala, Sweden
Method basis
35 min gradient · high-resolution MS
Verification status
VERIFIED
Section 6

Annotations 4

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.

valley_drop
Largest single impurity is spiroindane regioisomer at 0.34 % area, and it is the only named peak above 0.1 %. The integration is unambiguous and 99.49 % can be taken at face value.
mass_defect
Every named impurity on this record has a mass defect consistent with its structural assignment. That is the check that distinguishes an assignment from a guess.
buyer_sourced
Buyer-sourced through an ordinary retail order, so the supplier had no opportunity to select the vial. This is the provenance class the index weights and it is roughly 87 % of the dataset.
lot_traceability
Independently purchased, at the submitter's own cost, forwarded without the supplier's involvement. That is the definition and this record meets it.
Section 7

Related records

Same batch — lot PPG-2508-N7944 n=4

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-021218PPG-2508-N7944Janoshik2025-Q399.494.09—Buyer-sourced0FAIL
AX-2025-021220PPG-2508-N7944PeptideMeter2025-Q399.924.65—Buyer-sourced0FAIL
AX-2025-021221PPG-2508-N7944Janoshik2025-Q399.753.89104.6Buyer-sourced0FAIL

Cross-sections

Other recent MK-677 (Ibutamoren mesylate) records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041633FGPFGP-2604-K8509PeptideMeter2026-Q299.814.9196.2Buyer-sourced0FAIL
AX-2026-041733TFSTFS-{CAT}-1096PeptideMeter2026-Q299.073.9395.1Laboratory-retained0FAIL
AX-2026-043468BCHBCH-2511-G5204Medutest2026-Q298.854.3096.5Buyer-sourced1FAIL
AX-2026-042647SWBSWB-2605-B7365Nordanalyt2026-Q299.282.8693.1Buyer-sourced0FAIL
AX-2026-041634FGPFGP-2604-K8509PeptideMeter2026-Q299.865.17—Buyer-sourced0FAIL
AX-2026-043469BCHBCH-2511-G5204Medutest2026-Q298.514.86—Buyer-sourced1FAIL
AX-2026-042648SWBSWB-2605-B7365Janoshik2026-Q299.932.6096.9Supplier-supplied0FAIL
AX-2026-041732TFSTFS-{CAT}-1096Janoshik2026-Q299.483.16106.4Buyer-sourced0FAIL
Other recent PPG records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043598TesamorelinPPG-2608-A6835Kestrel2026-Q398.912.56100.3Buyer-sourced1FAIL
AX-2026-043597TesamorelinPPG-2608-A6835Janoshik2026-Q398.541.15—Buyer-sourced0PASS
AX-2026-043596TesamorelinPPG-2608-A6835PeptideMeter2026-Q398.741.83105.1Buyer-sourced1MARGINAL
AX-2026-043605RetatrutidePPG-2604-X7060Janoshik2026-Q298.174.2999.7Buyer-sourced0PASS
AX-2026-043601RetatrutidePPG-2604-X7060Janoshik2026-Q298.283.9695.3Buyer-sourced0PASS
AX-2026-043668AOD-9604PPG-2602-W8018PeptideMeter2026-Q299.473.06—Buyer-sourced0PASS
AX-2026-043670AOD-9604PPG-2602-W8018PeptideMeter2026-Q299.562.71104.5Buyer-sourced0PASS
AX-2026-043630CJC-1295 (no DAC)PPG-2512-D7211Janoshik2026-Q299.665.1192.5Buyer-sourced0PASS