AX-2024-004719 · Oxytocin · Homopeptide lot HOMO-2405-U3389

Section 1

Results

Measured against the index acceptance specification for the hypothalamic and posterior-pituitary hormones 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, 25 min gradient, 214 nm	99.73	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.27	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — open-chain (reduced disulfide, +2 Da)	0.10	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	1006.4365	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	1006.4364	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-0.1	ppm	± 15	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	5.50	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	3.78	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.37	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
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	5.67	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	5.90	min	6.71 ± 0.25 (normalised)	FAIL
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.29	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	58,690	—	≥ 20,000	PASS
Resolution to nearest impurity	vs deamidated Gln4 (+1 Da)	1.84	—	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, 25 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 58,690, and skew follows the reported asymmetry factor of 1.29. 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 0.10 % impurity against a 99.73 % 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	Oxytocin — main peak	5.90	4,847,187	99.73	—
2	open-chain (reduced disulfide, +2 Da)	5.47	4,860	0.10	+2.016
3	oxytocin dimer (intermolecular disulfide)	7.72	4,374	0.09	+1004.421
4	Tyr sulfoxide artefact (+16 Da)	5.67	1,944	0.04	+15.995
5	deamidated Gln4 (+1 Da)	5.72	1,944	0.04	+0.984
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 1006.4365 Da, computed from C43H66N12O12S2. 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 1006.4364 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 (%)
3+	336.4861	336.4861	-0.0000	9.2
2+	504.2255	504.2255	-0.0000	57.0
1+	1007.4438	1007.4437	-0.0001	100.0

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.

Figure	Supplier COA	This report	Index note
Purity (% area)	99.73	99.73	divergence -0.20 pp vs batch median
Total impurities (% area)	0.27	0.27
Largest single impurity (% area)	not stated	0.10
Water (%)	5.5	5.50
Counter-ion (%)	not stated	3.78
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	4.09	not determined
Method stated on certificate	NO	—	no method section — the result cannot be reconciled against any other

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, 26 d) → laboratory (hand-carried, 5 d) → assay.
Assay date: 13 Sep 2024
Submitted to the index: 17 Sep 2024
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-resolution MS
Verification status: IDENTITY CONSISTENT

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.
How much of the named compound is in the vial. Peptide content was not determined, so recovered mass cannot be calculated and the label claim cannot be checked.
That the material is free of bacterial endotoxin. Endotoxin was not measured. No chromatographic result bears on it.
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 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.

aib_coupling17 Sep 2024

Hindered couplings are where a synthesis loses purity, and the deletion products they leave are the first thing to look for. On this record they are not there in quantity.

lambda_21417 Sep 2024

Detection wavelength does not affect a mass determination but it does affect the purity figure sitting next to it. Both are stated on this record, which is the point.

moq_reality17 Sep 2024

Retail purchases test the retail channel. Manufacturer-tier material bought at kilogram scale is a different product with different documentation, and this index sees very little of it.

ms_confirm17 Sep 2024

Retention alone never establishes identity. Retention plus mass does, and where the two disagree it is nearly always retention that is wrong for a documented reason.

Section 7

Related records

Same batch — lot HOMO-2405-U3389 n=14

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2024-004706	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	5.57	104.1	Buyer-sourced	0	PASS
AX-2024-004707	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	6.28	94.4	Buyer-sourced	0	PASS
AX-2024-004708	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	5.74	90.4	Buyer-sourced	1	FAIL
AX-2024-004709	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	5.12	—	Buyer-sourced	0	PASS
AX-2024-004710	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	6.56	101.4	Buyer-sourced	0	PASS
AX-2024-004711	HOMO-2405-U3389	Nordanalyt	2024-Q3	99.92	5.88	104.0	Buyer-sourced	0	PASS
AX-2024-004712	HOMO-2405-U3389	VendorInvestigate	2024-Q3	99.73	6.24	92.2	Buyer-sourced	0	PASS
AX-2024-004713	HOMO-2405-U3389	VendorInvestigate	2024-Q3	99.63	5.73	102.3	Laboratory-retained	0	PASS
AX-2024-004714	HOMO-2405-U3389	Nordanalyt	2024-Q3	99.93	6.78	105.5	Supplier-supplied	0	PASS
AX-2024-004715	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	6.44	—	Buyer-sourced	0	PASS
AX-2024-004716	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	5.57	—	Buyer-sourced	0	FAIL
AX-2024-004717	HOMO-2405-U3389	Medutest	2024-Q3	99.86	6.13	—	Buyer-sourced	0	PASS
AX-2024-004718	HOMO-2405-U3389	Janoshik	2024-Q3	99.93	6.05	—	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Oxytocin records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041398	QYB	QYB-2601-V4429	Medutest	2026-Q2	99.60	4.73	91.8	Buyer-sourced	0	PASS
AX-2026-041400	QYB	QYB-2601-V4429	Medutest	2026-Q2	99.51	4.55	—	Buyer-sourced	1	MARGINAL
AX-2026-041393	QYB	QYB-2601-V4429	PeptideMeter	2026-Q2	99.69	4.63	—	Buyer-sourced	0	PASS
AX-2026-041395	QYB	QYB-2601-V4429	Janoshik	2026-Q2	99.93	4.24	101.7	Buyer-sourced	0	PASS
AX-2026-041950	AMB	AMB-2602-G4870	Janoshik	2026-Q2	99.82	3.21	—	Buyer-sourced	0	PASS
AX-2026-041397	QYB	QYB-2601-V4429	Janoshik	2026-Q2	99.62	4.38	102.8	Buyer-sourced	0	PASS
AX-2026-041396	QYB	QYB-2601-V4429	PeptideMeter	2026-Q2	99.69	3.97	—	Buyer-sourced	0	PASS
AX-2026-041394	QYB	QYB-2601-V4429	Medutest	2026-Q2	99.66	5.17	—	Buyer-sourced	0	PASS

Other recent Homopeptide records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042437	Retatrutide	HOMO-2605-V4718	Nordanalyt	2026-Q3	98.68	3.67	102.8	Buyer-sourced	PASS
AX-2026-042424	Semaglutide	HOMO-2604-X3806	PeptideMeter	2026-Q3	98.85	4.87	92.0	Buyer-sourced	PASS
AX-2026-042503	IGF-1 LR3	HOMO-2607-P5131	Janoshik	2026-Q3	99.36	5.99	—	Buyer-sourced	PASS
AX-2026-042492	SS-31 (Elamipretide)	HOMO-2604-D5484	Medutest	2026-Q3	99.93	2.40	—	Buyer-sourced	PASS
AX-2026-042491	SS-31 (Elamipretide)	HOMO-2604-D5484	Kestrel	2026-Q3	99.93	3.24	—	Supplier-supplied	PASS
AX-2026-042473	LL-37	HOMO-2602-G5165	Janoshik	2026-Q3	99.01	5.00	—	Buyer-sourced	PASS
AX-2026-042441	Retatrutide	HOMO-2605-V4718	Medutest	2026-Q3	98.93	4.22	—	Buyer-sourced	PASS
AX-2026-042474	LL-37	HOMO-2602-G5165	Janoshik	2026-Q3	99.18	5.44	—	Buyer-sourced	PASS