AssayIndex
Acceptance specification

Tissue-repair and immunomodulatory peptides

Short to medium linear peptides marketed for tissue repair, mucosal integrity and immune modulation. 10 compounds in this class, 1,229 records.

10 compounds1,229 recordspurity spec 98.0 %observed median 99.26 %
Section 1

The specification

ParameterLimitWhere the limit came from
Purity by RP-HPLC≥ 98.0 % areaSet at the 6.4 th percentile of observed results for this class — low enough that ordinary material passes, high enough that a genuinely poor lot does not. Reviewed each quarter and last moved in 2025-Q1.
Water by Karl Fischer≤ 10.0 %Lyophilised peptides routinely carry 2–6 % residual water. The limit sits above the normal range and below the point at which water displaces enough cake mass to move the recovered-mass figure by more than the label tolerance.
Counter-ion≤ 12.0 %Derived from the stoichiometric maximum for a fully-protonated peptide of this class's typical basic-residue count, plus a margin. Above it, the salt is either non-stoichiometric or the cake contains free acid.
Bacterial endotoxin≤ 5.0 EU/mgAn index convention chosen so that the figure is comparable across records. It is not a pharmacopoeial limit: a real limit is dose-dependent and is computed per use from the K/M ratio. The endotoxin calculator does that calculation.
Mass accuracy± 15 ppmAchievable accuracy depends on mass. This class's limit reflects both the instrument capability and the mass differences that must be resolved within it — see mass-accuracy calibration.
Section 2

Compounds in this class

Per-compound thresholds override the class default where the chemistry requires it. Where a compound row differs from the class row above, the compound row wins.

CompoundMonoisotopic DaPurity specWaterCounter-ionppmRecordsObserved median
BPC-1571418.709398.010.012.01559199.15
TB-500887.496498.510.012.01535699.47
Thymosin α13106.549397.510.012.0152499.11
KPV342.226799.010.012.0159499.21
GHK-Cu401.102497.010.012.0154198.54
ARA-2901189.609698.010.012.0156599.45
Larazotide acetate749.407298.510.012.0150n<3
LL-374490.426596.510.012.0153698.61
VIP3324.814697.510.012.015498.22
Thymulin873.371698.010.012.0151899.06
Section 3

What actually fails, and how often

A specification nobody fails is not a specification. These are the failure rates the thresholds above produce on the records the index holds.

ParameterLimitRecords outsideRate
Purity≥ 98.0 % area1219.85%
Water≤ 10.0 %00.00%
Counter-ion≤ 12.0 %594.80%
Endotoxin≤ 5.0 EU/mg90.73%
Mass accuracy± 15 ppm433.50%
08416825292.093.094.095.096.097.098.099.0100.092.00–92.25 %: n=092.25–92.50 %: n=092.50–92.75 %: n=092.75–93.00 %: n=093.00–93.25 %: n=093.25–93.50 %: n=093.50–93.75 %: n=093.75–94.00 %: n=094.00–94.25 %: n=094.25–94.50 %: n=094.50–94.75 %: n=094.75–95.00 %: n=095.00–95.25 %: n=095.25–95.50 %: n=095.50–95.75 %: n=095.75–96.00 %: n=096.00–96.25 %: n=096.25–96.50 %: n=096.50–96.75 %: n=196.75–97.00 %: n=297.00–97.25 %: n=197.25–97.50 %: n=1297.50–97.75 %: n=1897.75–98.00 %: n=4598.00–98.25 %: n=6198.25–98.50 %: n=10098.50–98.75 %: n=10298.75–99.00 %: n=14099.00–99.25 %: n=12499.25–99.50 %: n=16399.50–99.75 %: n=16299.75–100.00 %: n=298median 99.26 Purity (% area) Reports
Figure. Class-wide purity distribution with the acceptance specification drawn as a solid vertical and the observed median dashed. The area to the left of the solid line is the failure rate. A specification sitting deep in the left tail is doing its job; one sitting in the body of the distribution is measuring the population rather than screening it.