Compound Stability (t½ @ 25 °C)
VC-MET-218 — the half-life of the finished compound at 25 °C — the shelf-stability figure that sets storage class.
Definition
Compound Stability is the measured half-life (t½, days) of the finished compound held at 25 °C, derived from accelerated-aging assay and confirmed by real-time lots. It determines storage class and expiry dating.
Why it matters
Stability sets how a lot is stored and how long it remains usable. A short half-life forces cold storage and tighter rotation; a critical value indicates a formulation or purity problem that shortens usable inventory.
Formula
t½ = ln(2) / k_deg
k_deg = first-order degradation constant from
accelerated aging (Arrhenius-extrapolated to 25 °C)
Confirmed against real-time retained lots; reported per
lot with the 90 % confidence interval.
Inputs
| Input | Detail | Source |
|---|---|---|
| Accelerated aging | Arrhenius k_deg fit | Lab |
| Retained lots | Real-time confirmation | Lab |
| Purity | Initial extraction purity | Lab |
Units & Scale
Days (t½) at 25 °C, integer, per lot. Decreasing-is-worse: lower thresholds apply; sets storage class.
Sampling & Source
- Assayed per lot by accelerated aging.
- Confirmed against real-time retained samples.
- Result assigns storage class and expiry date.
Thresholds
OK
WARN
CRIT
Recent Trend
Zone roll-up, last 14 sampling periods (current 214):
Interpretation Guidance
| Band | Reading | Likely Driver | Action |
|---|---|---|---|
| > 240 | Very stable | Clean, well-formulated | Ambient; standard dating. |
| 180–240 | Stable | Normal | Ambient storage. |
| 120–179 | Reduced | Purity or formulation | Cold storage; tighten rotation. |
| < 120 | WARN / CRIT | Degradation risk | Formulation review; re-date. |
Related Metrics
Extraction Purity
Primary stability driver.
VC-MET-200Alkaloid Concentration
Potency at release.
VC-MET-310Substrate Stock Coverage
Inventory rotation.
VC-MET-216Phytotoxicity Index
Activity at release.
Related SOPs
- Storage classification & rotation — SOP Library.