AX-2025-018413 · Semaglutide · WWB lot WWB-2502-W1846

Section 1

Results

Measured against the index acceptance specification for the incretin analogues and co-agonists class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 15 min gradient, 214 nm	99.93	% area	≥ 97.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.07	% area	≤ 3.0	PASS
Largest single impurity	RP-HPLC — des-His1 truncate (−137 Da)	0.04	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	4111.0524	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	4111.1535	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+24.6	ppm	± 15	FAIL
Total peptide content	by difference from the gravimetric mass balance	82.60	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	82.54	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	3.84	mg	3 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	3.170	mg	3 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	105.7	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.78	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	11.06	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.56	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.22	EU/mg	≤ 5.0	PASS
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	Off-white lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	2.97	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 15 min gradient	9.85	min	9.95 ± 0.45 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.20	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	44,796	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-AEEA semaglutide (−145 Da)	2.15	—	no index criterion	REPORTED

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.

Figure 1. RP-HPLC trace, 15 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 44,796, 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 0.04 % impurity against a 99.93 % main peak is a line two pixels tall; the main peak runs off-scale there by design.

#	Peak	RT	Area (µV·s)	% area	Δ mass (Da)
1	Semaglutide — main peak	9.85	4,856,908	99.93	—
2	des-His1 truncate (−137 Da)	9.28	1,944	0.04	-137.059
3	des-AEEA semaglutide (−145 Da)	9.44	1,458	0.03	-145.074
Closure check — purity + Σ impurities				100.00	CLOSES

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 4111.0524 Da, computed from C187H291N45O59. All ppm figures on this site are against monoisotopic values — see why that matters.

Figure 2. ESI charge-state envelope, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 4111.1535 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.

Charge	Theoretical m/z	Observed m/z	Δ m/z	Rel. abundance (%)
6+	686.1827	686.1995	0.0168	8.4
5+	823.2178	823.2380	0.0202	53.9
4+	1028.7704	1028.7957	0.0253	100.0
3+	1371.3581	1371.3918	0.0337	56.4
2+	2056.5335	2056.5840	0.0505	8.8

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.

Component	Determination	%w/w of cake
Water	Karl Fischer	5.78
Counter-ion (TFA)	ion chromatography	11.06
Residual solvent + inorganic residue	estimated	0.56
Total peptide content	by difference	82.60
Total		100.00 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.

Figure	Supplier COA	This report	Index note
Purity (% area)	99.5	99.93	divergence +0.19 pp vs batch median
Total impurities (% area)	0.50	0.07
Largest single impurity (% area)	not stated	0.04
Water (%)	3.8	5.78
Counter-ion (%)	7.5	11.06
Peptide content (%w/w)	88.1	82.60
Endotoxin (EU/mg)	not stated	0.22
Method stated on certificate	YES	—	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, 2 d) → laboratory (hand-carried, 12 d) → assay.
Assay date: 04 Feb 2025
Submitted to the index: 10 Feb 2025
Laboratory: Kestrel Bioanalytical, Melbourne, Australia
Method basis: 15 min gradient · unit-resolution MS
Verification status: METHOD LIMITED

What this report does not establish

That the compound is not a near-isobaric alternative. Identity was confirmed at unit mass resolution, which cannot exclude species differing by 1 or 2 Da. The specific alternatives not excluded are named in the identity block above.
That mass-identical impurities are absent. The gradient used is shorter than the index reference method and does not resolve the diastereomers named in the compound fingerprint. The purity figure is an upper bound.
That the material is sterile. Sterility was not tested.
That any other vial in the same lot has the same composition. One vial was tested. Within-lot vial-to-vial variation in this index has a median of 0.28 pp and a 90th percentile of 0.74 pp.
That any other lot from the same supplier has the same composition. Batch-to-batch variation is larger than within-batch variation for every supplier here.
That the material is suitable for administration to a human or an animal. These are research compounds. No result on this site is a safety assessment and the index takes no position on use.
That the material was manufactured by the supplier that sold it. Contract synthesis is normal in this market and twenty-nine batches in the index fingerprint to a bulk from a different company than the one named on the label.

Section 6

Annotations 5

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.

lambda_21410 Feb 2025

At 214 nm the amide bond dominates the response, so a peptide impurity is seen roughly in proportion to its size. 99.93 % on this detection is the conservative reading; a 280 nm trace would flatter it.

racemisation_ala10 Feb 2025

Epimerisation during activation produces a diastereomer that is mass-identical and only chromatographically separable. At this gradient length the separation exists, and 99.93 % is net of it.

sig_figs10 Feb 2025

A figure reported to the nearest half point is reporting less precision than the method has, which is the opposite of the usual complaint. It is conservative rather than optimistic.

benford_check10 Feb 2025

Nothing on this record contradicts the declaration. Purity 99.93 %, largest single impurity des-His1 truncate (−137 Da) at 0.04 %, mass balance closed.

bootstrap_ci10 Feb 2025

That matches my own notes on this compound.

Section 7

Related records

Same batch — lot WWB-2502-W1846 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-018409	WWB-2502-W1846	Kestrel	2025-Q1	99.93	5.78	—	Laboratory-retained	1	MARGINAL
AX-2025-018410	WWB-2502-W1846	PeptideMeter	2025-Q1	99.23	5.88	92.7	Buyer-sourced	1	MARGINAL
AX-2025-018411	WWB-2502-W1846	VendorInvestigate	2025-Q1	99.15	5.59	—	Buyer-sourced	1	MARGINAL
AX-2025-018412	WWB-2502-W1846	Medutest	2025-Q1	99.05	5.91	101.7	Buyer-sourced	1	MARGINAL
AX-2025-018414	WWB-2502-W1846	Kestrel	2025-Q1	99.79	5.75	103.3	Buyer-sourced	1	MARGINAL
AX-2025-018415	WWB-2502-W1846	Medutest	2025-Q1	99.39	5.31	106.9	Buyer-sourced	1	MARGINAL
AX-2025-018416	WWB-2502-W1846	Janoshik	2025-Q1	98.82	6.62	100.3	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Semaglutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043376	WXT	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-042424	Homopeptide	HOMO-2604-X3806	PeptideMeter	2026-Q3	98.85	4.87	92.0	Buyer-sourced	0	PASS
AX-2026-041643	FGP	FGP-2602-M8547	Janoshik	2026-Q3	99.31	2.79	100.7	Buyer-sourced	0	PASS
AX-2026-041334	WWB	WWB-2606-N3192	Janoshik	2026-Q3	98.93	4.62	99.9	Buyer-sourced	0	PASS
AX-2026-042002	AMB	AMB-2607-N6274	VendorInvestigate	2026-Q3	98.23	6.37	97.1	Buyer-sourced	1	MARGINAL
AX-2026-041337	WWB	WWB-2606-N3192	Nordanalyt	2026-Q3	99.52	3.92	—	Buyer-sourced	0	PASS
AX-2026-042595	HJ	HJ-2608-C7002	Janoshik	2026-Q3	99.50	3.55	—	Buyer-sourced	1	MARGINAL
AX-2026-042217	TFC	TFC-2604-X9037	PeptideMeter	2026-Q3	98.95	4.61	96.9	Buyer-sourced	0	PASS

Other recent WWB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041275	Liraglutide	WWB-2607-X2189	Nordanalyt	2026-Q3	99.33	4.39	—	Buyer-sourced	1	MARGINAL
AX-2026-041334	Semaglutide	WWB-2606-N3192	Janoshik	2026-Q3	98.93	4.62	99.9	Buyer-sourced	0	PASS
AX-2026-041337	Semaglutide	WWB-2606-N3192	Nordanalyt	2026-Q3	99.52	3.92	—	Buyer-sourced	0	PASS
AX-2026-041335	Semaglutide	WWB-2606-N3192	Janoshik	2026-Q3	99.15	4.27	98.9	Buyer-sourced	0	PASS
AX-2026-041271	Liraglutide	WWB-2607-X2189	Medutest	2026-Q3	99.52	4.57	97.4	Buyer-sourced	1	MARGINAL
AX-2026-041328	Semaglutide	WWB-2606-N3192	Janoshik	2026-Q3	98.99	4.47	106.1	Buyer-sourced	0	PASS
AX-2026-041333	Semaglutide	WWB-2606-N3192	Janoshik	2026-Q3	99.18	4.51	90.4	Laboratory-retained	0	PASS
AX-2026-041273	Liraglutide	WWB-2607-X2189	Janoshik	2026-Q3	99.31	5.52	104.8	Buyer-sourced	1	MARGINAL