AX-2026-041969 · PT-141 (Bremelanotide) · AMB lot AMB-2601-M5602

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.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 25 min gradient, 214 nm	99.79	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.21	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — linear precursor (+18 Da)	0.10	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	1024.5242	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	1024.5166	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-7.4	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	91.33	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	91.14	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	9.85	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	8.977	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	89.8	%	90.0 – 110.0	FAIL
Water content	Karl Fischer, coulometric, duplicate	3.07	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	4.93	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.67	%	—	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	5.46	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	7.98	min	8.06 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.05	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	71,452	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	2.18	—	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 71,452, and skew follows the reported asymmetry factor of 1.05. 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 99.79 % 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	PT-141 (Bremelanotide) — main peak	7.98	4,850,103	99.79	—
2	linear precursor (+18 Da)	7.40	4,860	0.10	+18.011
3	oxidised Trp (+16 Da)	7.70	2,916	0.06	+15.995
4	melanotan II (C-terminal amide, −1 Da)	8.25	2,430	0.05	-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 1024.5242 Da, computed from C50H68N14O10. 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 1024.5166 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+	342.5153	342.5128	-0.0025	7.8
2+	513.2694	513.2656	-0.0038	55.9
1+	1025.5315	1025.5239	-0.0076	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	3.07
Counter-ion (acetate)	ion chromatography	4.93
Residual solvent + inorganic residue	estimated	0.67
Total peptide content	by difference	91.33
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)	99.90	99.79	divergence +0.07 pp vs batch median
Total impurities (% area)	0.10	0.21
Largest single impurity (% area)	0.07	0.10
Water (%)	3.1	3.07
Counter-ion (%)	2.9	4.93
Peptide content (%w/w)	93.4	91.33
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: Laboratory-retained
Evidentiary weight: Provenance documented, selection uncontrolled.
Chain of custody: Laboratory retained sample (−20 °C, 6 d since original receipt) → re-assay.
Assay date: 12 Jun 2026
Submitted to the index: 27 Jun 2026
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 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.

lambda_21427 Jun 2026

At 214 nm the amide bond dominates the response, so a peptide impurity is seen roughly in proportion to its size. 99.79 % on this detection is the conservative reading; a 280 nm trace would flatter it.

buyer_sourced27 Jun 2026

Provenance and purity together are what make a figure like this usable. An independently purchased vial at 99.79 % is worth several supplier-selected ones.

aaa_hydrolysis27 Jun 2026

Content determined against a certified reference standard is a stronger number than content by hydrolysis. The record states which was used and the difference is worth a percent or two.

gc_headspace27 Jun 2026

Residual solvent occupies mass in the cake that is neither peptide, water nor counter-ion. On a freshly dried lot it can be a percent, and it is measured on very few records.

Section 7

Related records

Same batch — lot AMB-2601-M5602 n=10

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-041960	AMB-2601-M5602	Janoshik	2026-Q2	99.45	3.63	100.1	Buyer-sourced	PASS
AX-2026-041961	AMB-2601-M5602	VendorInvestigate	2026-Q2	99.93	2.48	97.9	Buyer-sourced	PASS
AX-2026-041962	AMB-2601-M5602	VendorInvestigate	2026-Q2	99.93	3.36	—	Buyer-sourced	PASS
AX-2026-041963	AMB-2601-M5602	Janoshik	2026-Q2	99.73	3.65	101.5	Buyer-sourced	PASS
AX-2026-041964	AMB-2601-M5602	Janoshik	2026-Q2	99.93	3.20	—	Buyer-sourced	PASS
AX-2026-041965	AMB-2601-M5602	Janoshik	2026-Q2	99.91	3.44	106.0	Buyer-sourced	PASS
AX-2026-041966	AMB-2601-M5602	PeptideMeter	2026-Q2	99.77	3.19	—	Buyer-sourced	PASS
AX-2026-041967	AMB-2601-M5602	Janoshik	2026-Q2	99.87	3.49	98.3	Buyer-sourced	PASS
AX-2026-041968	AMB-2601-M5602	Janoshik	2026-Q2	99.67	3.68	—	Buyer-sourced	PASS

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=152
All AMB records n=203
All Medutest records n=934
All 2026-Q2 records n=1126
PT-141 (Bremelanotide) by supplier
PT-141 (Bremelanotide) impurity profile

Other recent PT-141 (Bremelanotide) records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041471	QYB	QYB-2607-L4875	Janoshik	2026-Q3	99.72	3.75	101.7	Buyer-sourced	0	PASS
AX-2026-041473	QYB	QYB-2607-L4875	PeptideMeter	2026-Q3	99.58	3.74	94.4	Buyer-sourced	0	PASS
AX-2026-041472	QYB	QYB-2607-L4875	PeptideMeter	2026-Q3	99.93	3.94	—	Buyer-sourced	0	PASS
AX-2026-041474	QYB	QYB-2607-L4875	VendorInvestigate	2026-Q3	99.16	3.78	95.6	Buyer-sourced	0	PASS
AX-2026-041470	QYB	QYB-2607-L4875	Janoshik	2026-Q3	99.77	4.10	—	Buyer-sourced	0	PASS
AX-2026-042139	JEEP	JEEP-2601-K8195	VendorInvestigate	2026-Q2	98.32	4.29	99.4	Buyer-sourced	1	FAIL
AX-2026-041964	AMB	AMB-2601-M5602	Janoshik	2026-Q2	99.93	3.20	—	Buyer-sourced	0	PASS
AX-2026-041664	FGP	FGP-2602-Y8741	Janoshik	2026-Q2	99.90	4.48	106.5	Buyer-sourced	0	PASS

Other recent AMB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042002	Semaglutide	AMB-2607-N6274	VendorInvestigate	2026-Q3	98.23	6.37	97.1	Buyer-sourced	1	MARGINAL
AX-2026-042012	GHRP-6	AMB-2603-S5667	Janoshik	2026-Q3	99.37	5.90	88.8	Laboratory-retained	1	MARGINAL
AX-2026-041974	Tirzepatide	AMB-2603-C5112	Nordanalyt	2026-Q3	98.20	3.41	—	Buyer-sourced	0	PASS
AX-2026-041975	Tirzepatide	AMB-2603-C5112	Medutest	2026-Q3	97.88	3.45	106.9	Laboratory-retained	0	PASS
AX-2026-042005	Semaglutide	AMB-2607-N6274	PeptideMeter	2026-Q3	98.09	6.48	98.6	Buyer-sourced	1	MARGINAL
AX-2026-042008	Epitalon	AMB-2602-Y6433	Janoshik	2026-Q3	99.30	8.75	105.1	Buyer-sourced	0	PASS
AX-2026-042021	TB-500	AMB-2602-P5987	VendorInvestigate	2026-Q3	99.86	4.79	101.4	Buyer-sourced	0	PASS
AX-2026-042015	GHRP-6	AMB-2603-S5667	Janoshik	2026-Q3	99.54	6.44	97.1	Buyer-sourced	0	PASS