AX-2026-043314

TB-500 · 2 mg declared · Chinese Peptide Company Co., Ltd. · lot CPC-2605-B1397

FAILPURITY ONLY

Report ID: AX-2026-043314
Compound: TB-500
Compound class: Tissue-repair and immunomodulatory peptides
Supplier: CPC — Chinese Peptide Company Co., Ltd.
Batch / lot: CPC-2605-B1397
Declared label claim: 2mg
Laboratory: Janoshik Analytical
Assay date: 01 Jun 2026
Submitted: 25 Jun 2026
Quarter: 2026-Q2
Submitter: n.bruun
Sample provenance: Buyer-sourced

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, 30 min gradient, 214 nm	98.49	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.51	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — des-Gln truncate (−128 Da)	0.67	% area	≤ 1.00	PASS
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	5.56	%	≤ 10.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	6.81	%	≤ 12.0	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 cake, partial shrinkage from vial wall	—	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	6.01	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	7.95	min	7.86 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.06	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	83,490	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Thr]-diastereomer	0.98	—	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 83,490, and skew follows the reported asymmetry factor of 1.06. 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 0.67 % impurity against a 98.49 % 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	7.95	4,786,919	98.49	—
2	des-Gln truncate (−128 Da)	7.71	32,564	0.67	-128.059
3	des-acetyl TB-500 (−42 Da)	7.43	19,927	0.41	-42.011
4	[D-Thr]-diastereomer	7.84	12,151	0.25	0.000
5	C-terminal amide (−1 Da)	8.13	8,749	0.18	-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 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)	98.55	98.49	divergence +0.06 pp vs batch median
Total impurities (% area)	1.45	1.51
Largest single impurity (% area)	0.97	0.67
Water (%)	not stated	5.56
Counter-ion (%)	9.3	6.81
Peptide content (%w/w)	86.6	not determined
Endotoxin (EU/mg)	0.20	not determined
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: Domestic warehouse despatch → submitter (2–8 °C, 30 d) → laboratory (courier, cold pack, 3 d) → assay.
Assay date: 01 Jun 2026
Submitted to the index: 25 Jun 2026
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-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.
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 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.

des_gly25 Jun 2026

des-Gln truncate (−128 Da) at 0.67 % points at an incomplete coupling rather than at decomposition. Deletion sequences do not form in a vial; they form on a resin, and they are fixed by a double coupling rather than by a colder courier.

low_n25 Jun 2026

n=1 on this lot. A single result below specification is a finding about a vial. Two agreeing results would make it a finding about a lot, and the batch page will say which of those exists.

Section 7

Related records

Same batch — lot CPC-2605-B1397 n=9

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043307	CPC-2605-B1397	Medutest	2026-Q2	98.65	5.96	—	Buyer-sourced	0	PASS
AX-2026-043308	CPC-2605-B1397	Kestrel	2026-Q2	98.79	5.54	—	Buyer-sourced	0	PASS
AX-2026-043309	CPC-2605-B1397	PeptideMeter	2026-Q2	99.03	5.60	—	Buyer-sourced	0	PASS
AX-2026-043310	CPC-2605-B1397	Medutest	2026-Q2	98.15	5.62	—	Buyer-sourced	0	FAIL
AX-2026-043311	CPC-2605-B1397	Janoshik	2026-Q2	98.23	5.52	91.6	Buyer-sourced	0	FAIL
AX-2026-043312	CPC-2605-B1397	Medutest	2026-Q2	98.34	5.83	89.9	Buyer-sourced	2	FAIL
AX-2026-043313	CPC-2605-B1397	Medutest	2026-Q2	98.46	5.14	101.8	Buyer-sourced	0	FAIL
AX-2026-043315	CPC-2605-B1397	Kestrel	2026-Q2	99.59	5.70	102.4	Buyer-sourced	0	PASS

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-2026-041776	ASY	ASY-{CAT}-2167	Janoshik	2026-Q3	99.92	4.61	98.2	Buyer-sourced	0	PASS
AX-2026-041777	ASY	ASY-{CAT}-2167	PeptideMeter	2026-Q3	99.78	4.09	92.8	Buyer-sourced	0	PASS
AX-2026-041782	ASY	ASY-{CAT}-2167	Nordanalyt	2026-Q3	99.93	3.94	—	Buyer-sourced	0	PASS
AX-2026-041774	ASY	ASY-{CAT}-2167	PeptideMeter	2026-Q3	99.93	4.41	96.2	Buyer-sourced	0	PASS
AX-2026-042127	JEEP	JEEP-2602-V8614	Medutest	2026-Q3	99.68	3.55	—	Buyer-sourced	1	FAIL
AX-2026-042021	AMB	AMB-2602-P5987	VendorInvestigate	2026-Q3	99.86	4.79	101.4	Buyer-sourced	0	PASS
AX-2026-041780	ASY	ASY-{CAT}-2167	Janoshik	2026-Q3	99.93	3.48	102.5	Buyer-sourced	1	FAIL
AX-2026-041779	ASY	ASY-{CAT}-2167	Janoshik	2026-Q3	99.84	3.85	—	Buyer-sourced	1	FAIL

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