AX-2024-005066 · TB-500 · MKM lot MKM-2402-N3279

Section 1

Results

Measured against the index acceptance specification for the tissue-repair and immunomodulatory 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, 28 min gradient, 214 nm	99.72	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.28	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-acetyl TB-500 (−42 Da)	0.14	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	887.4964	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	887.4941	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-2.6	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	4.85	%	≤ 10.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	3.98	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.28	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	11.08	EU/mg	≤ 5.0	FAIL
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 with a single visible fibre	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	4.53	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	7.43	min	7.38 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.21	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	80,096	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Thr]-diastereomer	0.95	—	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, 28 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 80,096, and skew follows the reported asymmetry factor of 1.21. 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 0.14 % impurity against a 99.72 % 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	TB-500 — main peak	7.43	4,846,701	99.72	—
2	des-acetyl TB-500 (−42 Da)	6.94	6,804	0.14	-42.011
3	C-terminal amide (−1 Da)	7.60	4,374	0.09	-0.984
4	[D-Thr]-diastereomer	7.33	1,944	0.04	0.000
5	des-Gln truncate (−128 Da)	7.21	486	0.01	-128.059
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 887.4964 Da, computed from C39H69N9O14. 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 887.4941 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 (%)
2+	444.7555	444.7543	-0.0012	57.5
1+	888.5037	888.5014	-0.0023	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)	99.90	99.72	divergence +0.24 pp vs batch median
Total impurities (% area)	0.10	0.28
Largest single impurity (% area)	not stated	0.14
Water (%)	not stated	4.85
Counter-ion (%)	not stated	3.98
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	not stated	11.08
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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 8 d) → assay. Submitter did not handle the vial.
Assay date: 19 May 2024
Submitted to the index: 05 Jun 2024
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: VERIFIED

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 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.

endotoxin_limit05 Jun 2024

Endotoxin burden at this level usually tracks water quality at the fill step rather than anything about the synthesis. A high-purity lot with high endotoxin is an entirely coherent result and this is one.

coa_reader05 Jun 2024

Endotoxin determined but the LAL method is not stated. Kinetic chromogenic and gel-clot give different results and different sensitivity. The value cannot be interpreted without knowing which.

tb500_vs_tb405 Jun 2024

11.08 EU/mg but the material was passed through a sterile sterile filter. Some filters leach endotoxins; the measurement does not distinguish material from filter contribution.

oxytocin_pheur05 Jun 2024

High endotoxin 11.08 EU/mg on high-purity material vs purity suggests water quality at the fill step. If the lot was lyophilised from non-purified water, this is the expected finding.

Section 7

Related records

Same batch — lot MKM-2402-N3279 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2024-005067	MKM-2402-N3279	VendorInvestigate	2024-Q2	99.37	4.68	—	Buyer-sourced	1	MARGINAL
AX-2024-005068	MKM-2402-N3279	Medutest	2024-Q2	99.72	3.94	—	Supplier-supplied	1	MARGINAL
AX-2024-005069	MKM-2402-N3279	Janoshik	2024-Q2	99.92	4.52	—	Supplier-supplied	1	MARGINAL
AX-2024-005070	MKM-2402-N3279	Janoshik	2024-Q2	99.59	4.49	101.9	Supplier-supplied	1	MARGINAL
AX-2024-005071	MKM-2402-N3279	Janoshik	2024-Q2	99.93	3.91	—	Supplier-supplied	2	FAIL
AX-2024-005072	MKM-2402-N3279	VendorInvestigate	2024-Q2	99.43	4.59	—	Laboratory-retained	1	MARGINAL
AX-2024-005073	MKM-2402-N3279	Nordanalyt	2024-Q2	99.39	4.09	90.3	Supplier-supplied	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent TB-500 records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041847	JEEP	JEEP-2602-V3434	Nordanalyt	2026-Q3	99.72	3.85	—	Supplier-supplied	1	MARGINAL
AX-2026-042574	ERP	ERP-2605-S8022	VendorInvestigate	2026-Q3	99.54	2.91	96.4	Buyer-sourced	1	MARGINAL
AX-2026-042577	ERP	ERP-2605-S8022	Janoshik	2026-Q3	99.51	3.45	—	Supplier-supplied	1	MARGINAL
AX-2026-041845	JEEP	JEEP-2602-V3434	Janoshik	2026-Q3	99.72	4.04	102.2	Supplier-supplied	1	MARGINAL
AX-2026-041921	JEEP	JEEP-2605-M4874	Janoshik	2026-Q3	99.90	1.76	—	Supplier-supplied	2	MARGINAL
AX-2026-041922	JEEP	JEEP-2605-M4874	Janoshik	2026-Q3	99.41	2.60	95.7	Laboratory-retained	2	MARGINAL
AX-2026-041928	JEEP	JEEP-2605-M4874	Janoshik	2026-Q3	99.88	1.84	92.8	Laboratory-retained	2	MARGINAL
AX-2026-041849	JEEP	JEEP-2602-V3434	VendorInvestigate	2026-Q3	99.73	3.60	88.6	Buyer-sourced	2	MARGINAL

Other recent MKM records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042943	Adipotide	MKM-2606-K4013	Janoshik	2026-Q3	97.92	6.31	—	Supplier-supplied	1	MARGINAL
AX-2026-042891	CJC-1295 (no DAC)	MKM-2603-V2347	Janoshik	2026-Q3	99.28	3.63	—	Supplier-supplied	1	MARGINAL
AX-2026-042942	Adipotide	MKM-2606-K4013	VendorInvestigate	2026-Q3	97.04	5.56	94.6	Buyer-sourced	1	FAIL
AX-2026-042914	Gonadorelin	MKM-2604-A2596	Janoshik	2026-Q2	99.93	5.19	—	Supplier-supplied	0	PASS
AX-2026-042884	BPC-157	MKM-2605-X2575	Nordanalyt	2026-Q2	98.12	2.89	—	Laboratory-retained	1	MARGINAL
AX-2026-042946	Tirzepatide	MKM-2601-L3752	Medutest	2026-Q2	97.71	8.10	—	Supplier-supplied	1	FAIL
AX-2026-042911	Gonadorelin	MKM-2604-A2596	Medutest	2026-Q2	99.08	5.55	—	Buyer-sourced	1	MARGINAL
AX-2026-042932	L-Glutathione (reduced)	MKM-2511-F2902	Janoshik	2026-Q2	98.57	8.41	92.9	Supplier-supplied	1	MARGINAL