AX-2025-020386

PT-141 (Bremelanotide) · 10 mg declared · Xi'an Mokemei Biotechnology Co., Ltd. · lot MKM-2509-B4043

MARGINALVERIFIED

Report ID: AX-2025-020386
Compound: PT-141 (Bremelanotide)
Compound class: Melanocortin-receptor peptides
Supplier: MKM — Xi'an Mokemei Biotechnology Co., Ltd.
Batch / lot: MKM-2509-B4043
Declared label claim: 10mg
Laboratory: Janoshik Analytical
Assay date: 05 Oct 2025
Submitted: 21 Oct 2025
Quarter: 2025-Q4
Submitter: a.duarte
Sample provenance: Buyer-sourced

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, 30 min gradient, 214 nm	99.21	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.79	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-acetyl (−42 Da)	0.50	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	1024.5242	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	1024.5229	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-1.3	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	87.79	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	87.10	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	11.39	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	9.921	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	99.2	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.61	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	5.64	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.96	%	—	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 powder, no defined cake (melt-back)	—	white to off-white intact cake	FAIL
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	5.06	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	8.62	min	9.52 ± 0.25 (normalised)	FAIL
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.02	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	52,005	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	2.06	—	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, 30 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 52,005, and skew follows the reported asymmetry factor of 1.02. 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 0.50 % impurity against a 99.21 % 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	8.62	4,821,914	99.21	—
2	des-acetyl (−42 Da)	8.16	24,302	0.50	-42.011
3	oxidised Trp (+16 Da)	8.28	7,776	0.16	+15.995
4	melanotan II (C-terminal amide, −1 Da)	8.94	3,402	0.07	-0.984
5	linear precursor (+18 Da)	7.92	2,916	0.06	+18.011
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, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 1024.5229 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	342.5149	-0.0004	7.7
2+	513.2694	513.2687	-0.0007	52.1
1+	1025.5315	1025.5302	-0.0013	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	5.61
Counter-ion (acetate)	ion chromatography	5.64
Residual solvent + inorganic residue	estimated	0.96
Total peptide content	by difference	87.79
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)	99.33	99.21	divergence -0.06 pp vs batch median
Total impurities (% area)	0.67	0.79
Largest single impurity (% area)	0.41	0.50
Water (%)	3.9	5.61
Counter-ion (%)	not stated	5.64
Peptide content (%w/w)	not stated	87.79
Endotoxin (EU/mg)	0.45	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 → submitter (ambient, 32 d) → laboratory (courier, cold pack, 5 d) → assay.
Assay date: 05 Oct 2025
Submitted to the index: 21 Oct 2025
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

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.

buyer_sourced21 Oct 2025

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.

price_per_mg21 Oct 2025

A retail purchase carries a price, which makes cost per milligram of recovered peptide computable. That is the comparison a buyer actually needs and it exists only for this provenance class.

Section 7

Related records

Same batch — lot MKM-2509-B4043 n=14

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020378	MKM-2509-B4043	PeptideMeter	2025-Q4	99.43	6.01	—	Buyer-sourced	0	PASS
AX-2025-020379	MKM-2509-B4043	Janoshik	2025-Q4	99.77	6.11	100.0	Supplier-supplied	0	PASS
AX-2025-020380	MKM-2509-B4043	PeptideMeter	2025-Q4	99.06	6.28	—	Buyer-sourced	0	PASS
AX-2025-020381	MKM-2509-B4043	Janoshik	2025-Q4	99.83	5.81	—	Buyer-sourced	0	PASS
AX-2026-042992	MKM-2509-B4043	PeptideMeter	2025-Q4	99.44	6.08	—	Buyer-sourced	0	PASS
AX-2025-020382	MKM-2509-B4043	Medutest	2025-Q4	99.93	6.47	95.8	Supplier-supplied	0	PASS
AX-2025-020383	MKM-2509-B4043	PeptideMeter	2025-Q4	99.73	5.69	90.6	Buyer-sourced	0	PASS
AX-2025-020384	MKM-2509-B4043	Nordanalyt	2025-Q4	99.37	6.07	88.6	Laboratory-retained	1	MARGINAL
AX-2026-042993	MKM-2509-B4043	Janoshik	2025-Q4	99.41	5.25	—	Laboratory-retained	0	PASS
AX-2025-020385	MKM-2509-B4043	PeptideMeter	2025-Q4	99.06	5.52	105.6	Buyer-sourced	0	PASS
AX-2026-042994	MKM-2509-B4043	Medutest	2025-Q4	99.37	5.38	105.6	Buyer-sourced	0	PASS
AX-2025-020387	MKM-2509-B4043	Janoshik	2025-Q4	99.32	5.68	99.6	Buyer-sourced	0	PASS
AX-2026-042995	MKM-2509-B4043	VendorInvestigate	2025-Q4	99.00	6.35	96.7	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=152
All MKM records n=229
All Janoshik records n=2989
All 2025-Q4 records n=762
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 MKM records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042942	CJC-1295 (no DAC)	MKM-2603-V3346	Janoshik	2026-Q3	99.52	3.43	—	Supplier-supplied	PASS
AX-2026-043019	Adipotide	MKM-2606-K5012	Janoshik	2026-Q3	97.61	5.77	105.1	Buyer-sourced	PASS
AX-2026-042939	CJC-1295 (no DAC)	MKM-2603-V3346	PeptideMeter	2026-Q3	99.44	3.39	—	Buyer-sourced	PASS
AX-2026-043020	Adipotide	MKM-2606-K5012	Medutest	2026-Q3	97.73	5.74	—	Buyer-sourced	PASS
AX-2026-043022	Adipotide	MKM-2606-K5012	Kestrel	2026-Q3	97.69	6.33	106.9	Buyer-sourced	PASS
AX-2026-043023	Adipotide	MKM-2606-K5012	Medutest	2026-Q3	97.48	5.56	103.7	Supplier-supplied	PASS
AX-2026-042945	CJC-1295 (no DAC)	MKM-2603-V3346	PeptideMeter	2026-Q3	99.39	3.54	—	Laboratory-retained	PASS
AX-2026-042938	CJC-1295 (no DAC)	MKM-2603-V3346	Nordanalyt	2026-Q3	99.47	3.67	95.0	Buyer-sourced	PASS