AX-2025-020206 · Oxytocin · ERP lot ERP-2503-A9615

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	99.09	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.91	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — open-chain (reduced disulfide, +2 Da)	0.58	% 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)	1006.4450	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+8.4	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	90.68	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	89.85	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	10.90	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	9.794	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	97.9	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.03	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	3.59	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.70	%	—	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	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	4.74	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	6.83	min	6.71 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.04	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	63,280	—	≥ 20,000	PASS
Resolution to nearest impurity	vs deamidated Gln4 (+1 Da)	1.65	—	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 63,280, and skew follows the reported asymmetry factor of 1.04. 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 0.58 % impurity against a 99.09 % 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	6.83	4,816,081	99.09	—
2	open-chain (reduced disulfide, +2 Da)	6.40	28,190	0.58	+2.016
3	deamidated Gln4 (+1 Da)	6.65	9,235	0.19	+0.984
4	des-Gly9 (−57 Da)	6.58	2,916	0.06	-57.021
5	oxytocin dimer (intermolecular disulfide)	8.65	2,430	0.05	+1004.421
6	Tyr sulfoxide artefact (+16 Da)	6.60	1,458	0.03	+15.995
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 1006.4450 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	336.4889	0.0028	8.8
2+	504.2255	504.2298	0.0043	57.9
1+	1007.4438	1007.4523	0.0085	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.

Component	Determination	%w/w of cake
Water	Karl Fischer	5.03
Counter-ion (acetate)	ion chromatography	3.59
Residual solvent + inorganic residue	estimated	0.70
Total peptide content	by difference	90.68
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)	99.56	99.09	divergence +0.47 pp vs batch median
Total impurities (% area)	0.44	0.91
Largest single impurity (% area)	0.21	0.58
Water (%)	2.9	5.03
Counter-ion (%)	not stated	3.59
Peptide content (%w/w)	not stated	90.68
Endotoxin (EU/mg)	not stated	not determined
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 → third-party forwarder (7 d) → laboratory (courier, cold pack, 6 d) → assay.
Assay date: 12 May 2025
Submitted to the index: 16 May 2025
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.
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 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.

shipping_temp16 May 2025

A data logger in the box would upgrade this record further. Custody is documented; temperature history is inferred, and inference is weaker than measurement.

Contributor #M-368416 May 2025

Two decimal places on a closure is not precision theatre — it is a tolerance. The index asserts 0.02 pp and the checker fails the build if any record misses it.

Section 7

Related records

Same batch — lot ERP-2503-A9615 n=5

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020204	ERP-2503-A9615	Janoshik	2025-Q2	99.10	4.94	—	Buyer-sourced	1	MARGINAL
AX-2025-020205	ERP-2503-A9615	PeptideMeter	2025-Q2	98.98	4.91	—	Buyer-sourced	0	PASS
AX-2025-020207	ERP-2503-A9615	VendorInvestigate	2025-Q2	99.02	4.59	93.3	Buyer-sourced	0	PASS
AX-2025-020208	ERP-2503-A9615	VendorInvestigate	2025-Q2	99.11	5.36	102.6	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 ERP records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042706	Survodutide	ERP-2605-E9865	PeptideMeter	2026-Q3	98.38	5.33	103.5	Buyer-sourced	0	PASS
AX-2026-042704	Tesamorelin	ERP-2604-W9463	Janoshik	2026-Q3	99.02	4.08	—	Buyer-sourced	1	MARGINAL
AX-2026-042705	Survodutide	ERP-2605-E9865	Janoshik	2026-Q3	98.24	5.36	92.3	Buyer-sourced	0	PASS
AX-2026-042708	GHK-Cu	ERP-2601-F9816	Nordanalyt	2026-Q2	98.88	3.87	91.5	Buyer-sourced	1	MARGINAL
AX-2026-042694	Liraglutide	ERP-2601-P8985	Kestrel	2026-Q2	99.25	4.35	107.3	Buyer-sourced	1	MARGINAL
AX-2026-042707	GHK-Cu	ERP-2601-F9816	Janoshik	2026-Q2	98.53	4.70	96.3	Buyer-sourced	1	MARGINAL
AX-2026-042711	GHK-Cu	ERP-2601-F9816	Kestrel	2026-Q2	98.53	3.84	89.7	Laboratory-retained	2	MARGINAL
AX-2026-042722	Tirzepatide	ERP-2512-T9616	Medutest	2026-Q2	99.18	2.07	—	Buyer-sourced	1	MARGINAL