AX-2024-005115

PT-141 (Bremelanotide) · 10 mg declared · GL Biochem (Shanghai) Ltd. · lot GLBI-2402-T8219

MARGINALIDENTITY CONSISTENT

Report ID: AX-2024-005115
Compound: PT-141 (Bremelanotide)
Compound class: Melanocortin-receptor peptides
Supplier: GL Biochem — GL Biochem (Shanghai) Ltd.
Batch / lot: GLBI-2402-T8219
Declared label claim: 10mg
Laboratory: VendorInvestigate
Assay date: 21 Aug 2024
Submitted: 26 Aug 2024
Quarter: 2024-Q3
Submitter: gsh_gssg
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, 32 min gradient, 214 nm	98.59	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.41	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — linear precursor (+18 Da)	0.72	% 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)	1024.5278	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+3.5	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	4.66	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	4.67	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.59	%	—	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	5.40	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 32 min gradient	10.25	min	10.10 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.28	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	77,270	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	2.26	—	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, 32 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 77,270, and skew follows the reported asymmetry factor of 1.28. 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 0.72 % impurity against a 98.59 % 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	10.25	4,791,780	98.59	—
2	linear precursor (+18 Da)	9.50	34,994	0.72	+18.011
3	melanotan II (C-terminal amide, −1 Da)	10.59	23,329	0.48	-0.984
4	oxidised Trp (+16 Da)	9.89	6,804	0.14	+15.995
5	des-acetyl (−42 Da)	9.76	3,402	0.07	-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 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 1024.5278 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	342.5165	0.0012	8.2
2+	513.2694	513.2712	0.0018	49.9
1+	1025.5315	1025.5351	0.0036	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)	98.52	98.59	divergence -0.17 pp vs batch median
Total impurities (% area)	1.48	1.41
Largest single impurity (% area)	not stated	0.72
Water (%)	4.7	4.66
Counter-ion (%)	8.2	4.67
Peptide content (%w/w)	86.5	not determined
Endotoxin (EU/mg)	3.99	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 (−20 °C, 32 d) → laboratory (courier, dry ice, 5 d) → assay.
Assay date: 21 Aug 2024
Submitted to the index: 26 Aug 2024
Laboratory: VendorInvestigate, Riga, Latvia
Method basis: 32 min gradient · high-resolution MS
Verification status: IDENTITY CONSISTENT

What this report does not establish

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 3

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.

ms_confirm26 Aug 2024

A reference standard on the same sequence would upgrade this from a good mass to a traceable one. The distinction matters where a result is going to be cited rather than merely read.

diode_array26 Aug 2024

Spectral homogeneity across the main peak would complete this record. Mass confirms what eluted; the spectrum confirms that only one thing did.

isotope_cluster26 Aug 2024

Identity confirmed, purity 98.59 %, mass balance closed. This record is complete against the index definition of complete and there is nothing outstanding on it.

Section 7

Related records

Same batch — lot GLBI-2402-T8219 n=2

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2024-005114	GLBI-2402-T8219	VendorInvestigate	2024-Q3	98.78	5.06	91.6	Laboratory-retained	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=152
All GL Biochem records n=83
All VendorInvestigate records n=593
All 2024-Q3 records n=464
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 GL Biochem records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043179	Kisspeptin-10	GLBI-2608-N7715	Medutest	2026-Q3	98.97	4.37	—	Buyer-sourced	1	MARGINAL
AX-2026-043178	Kisspeptin-10	GLBI-2608-N7715	Janoshik	2026-Q3	98.50	4.55	—	Buyer-sourced	1	MARGINAL
AX-2026-043166	L-Glutathione (reduced)	GLBI-2606-S7352	Janoshik	2026-Q3	99.01	8.84	105.4	Laboratory-retained	1	MARGINAL
AX-2026-043184	Kisspeptin-10	GLBI-2608-N7715	Janoshik	2026-Q3	98.99	3.63	100.6	Supplier-supplied	1	MARGINAL
AX-2026-043185	Kisspeptin-10	GLBI-2608-N7715	Medutest	2026-Q3	98.71	3.71	107.0	Buyer-sourced	1	MARGINAL
AX-2026-043165	L-Glutathione (reduced)	GLBI-2606-S7352	Medutest	2026-Q3	99.47	8.60	—	Supplier-supplied	1	MARGINAL
AX-2026-043182	Kisspeptin-10	GLBI-2608-N7715	Janoshik	2026-Q3	98.93	3.86	95.7	Buyer-sourced	1	MARGINAL
AX-2026-043183	Kisspeptin-10	GLBI-2608-N7715	PeptideMeter	2026-Q3	98.54	4.17	102.2	Buyer-sourced	1	MARGINAL