AX-2025-020829

PT-141 (Bremelanotide) · 10 mg declared · Chinese Peptide Company Co., Ltd. · lot CPC-2502-X2309

FAILPURITY ONLY

Report ID: AX-2025-020829
Compound: PT-141 (Bremelanotide)
Compound class: Melanocortin-receptor peptides
Supplier: CPC — Chinese Peptide Company Co., Ltd.
Batch / lot: CPC-2502-X2309
Declared label claim: 10mg
Laboratory: Medutest
Assay date: 13 Jul 2025
Submitted: 27 Jul 2025
Quarter: 2025-Q3
Submitter: b.bhattacharya
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, 25 min gradient, 214 nm	97.78	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	2.22	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — melanotan II (C-terminal amide, −1 Da)	1.31	% area	≤ 1.00	FAIL
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Total peptide content	by difference from the gravimetric mass balance	90.63	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	88.62	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	10.28	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	9.110	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	91.1	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.93	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	3.92	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.52	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.50	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	Faint haze, clearing on standing	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.38	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	8.13	min	8.06 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.12	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	69,457	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	2.11	—	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 69,457, and skew follows the reported asymmetry factor of 1.12. 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 1.31 % impurity against a 97.78 % 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	8.13	4,752,411	97.78	—
2	melanotan II (C-terminal amide, −1 Da)	8.40	63,670	1.31	-0.984
3	oxidised Trp (+16 Da)	7.85	18,469	0.38	+15.995
4	linear precursor (+18 Da)	7.55	14,095	0.29	+18.011
5	des-acetyl (−42 Da)	7.75	11,665	0.24	-42.011
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 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	4.93
Counter-ion (acetate)	ion chromatography	3.92
Residual solvent + inorganic residue	estimated	0.52
Total peptide content	by difference	90.63
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)	97.99	97.78	divergence +0.22 pp vs batch median
Total impurities (% area)	2.01	2.22
Largest single impurity (% area)	not stated	1.31
Water (%)	not stated	4.93
Counter-ion (%)	not stated	3.92
Peptide content (%w/w)	not stated	90.63
Endotoxin (EU/mg)	not stated	0.50
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 (2–8 °C, 13 d) → laboratory (courier, ambient, 9 d) → assay.
Assay date: 13 Jul 2025
Submitted to the index: 27 Jul 2025
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-resolution MS
Verification status: PURITY ONLY

What this report does not establish

That the compound is the compound named. No identity confirmation was ordered on this submission. A purity figure describes chromatographic homogeneity of whatever eluted; it does not name 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.

hilic_hana27 Jul 2025

Short and polar sequences are poorly served by reverse phase, and a low area-percent figure on one can be a method artefact rather than a material property. HILIC or ion pairing would settle it.

chain_custody27 Jul 2025

A retail vial at 97.78 % is worth more evidentially than a selected vial at a higher figure. That is the whole argument for recording provenance at all.

Section 7

Related records

Same batch — lot CPC-2502-X2309 n=4

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2025-020828	CPC-2502-X2309	PeptideMeter	2025-Q3	97.76	5.13	90.8	Supplier-supplied	FAIL
AX-2025-020830	CPC-2502-X2309	Janoshik	2025-Q3	97.73	4.93	—	Buyer-sourced	FAIL
AX-2025-020831	CPC-2502-X2309	Janoshik	2025-Q3	98.03	4.98	97.3	Buyer-sourced	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=152
All CPC records n=227
All Medutest records n=934
All 2025-Q3 records n=816
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 CPC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043319	BPC-157	CPC-2602-W1610	Medutest	2026-Q3	98.82	2.88	103.5	Buyer-sourced	2	MARGINAL
AX-2026-043295	Liraglutide	CPC-2602-G9942	Janoshik	2026-Q3	97.34	5.17	106.3	Buyer-sourced	0	FAIL
AX-2026-043288	Tirzepatide	CPC-2607-L1516	Janoshik	2026-Q3	96.89	5.11	101.1	Laboratory-retained	0	FAIL
AX-2026-043327	N-Acetyl Semax Amide	CPC-2602-D1905	Nordanalyt	2026-Q3	99.05	5.67	90.6	Buyer-sourced	1	FAIL
AX-2026-043328	N-Acetyl Semax Amide	CPC-2602-D1905	Janoshik	2026-Q3	99.49	6.83	100.9	Supplier-supplied	0	PASS
AX-2026-043257	L-Carnosine	CPC-2603-G9615	VendorInvestigate	2026-Q3	98.20	10.41	102.2	Buyer-sourced	0	FAIL
AX-2026-043297	Liraglutide	CPC-2602-G9942	Janoshik	2026-Q3	97.01	4.95	103.5	Buyer-sourced	0	FAIL
AX-2026-043331	N-Acetyl Semax Amide	CPC-2602-D1905	Janoshik	2026-Q3	99.46	6.22	—	Supplier-supplied	0	PASS