# Evidence: Kohlrausch-Williams-Watts equation

Parent: — · class: kinetics · names merged here: Kohlrausch-Williams-Watts equation

2 papers measured or used it, 0 only mentioned it (of 207 kept papers). Papers in year order; each section heading ends with the paper's category / subcategory. Generated by tools/build_evidence.py from registry/concepts.csv and the cards; do not edit.

## 2006 Konno — Influence of Different Polymers on the Crystallization Tendency of Molecularly Dispersed Amorphous Felodipine · Solid state stability / Physical stability

[2006-konno-felodipine-polymer-crystallization-nucleation-solid-dispersions](../../../cards/2006-konno-felodipine-polymer-crystallization-nucleation-solid-dispersions/paper.html) · Solid state stability / Physical stability · used · as: Kohlrausch-Williams-Watts equation

| id | kind | content | locator |
|---|---|---|---|
| E7 | equation | Kohlrausch-Williams-Watts equation: 1 − φ(t) = exp[(−t/τ)^β] (as printed) | p.2695 |
| R9 | record, derived (E7) | KWW average relaxation time τ and stretch exponent β — 9:1 dispersions at 2 °C (P6); nonlinear regression, R² > 0.9 — PVP τ 208 h, β 0.42; HPMCAS τ 687 h, β 0.45; HPMC τ 319 h, β 0.47; no τ for felodipine alone reported | p.2698 |

## 2006 Marsac — A Comparison of the Physical Stability of Amorphous Felodipine and Nifedipine Systems · Solid state stability / Physical stability

[2006-marsac-physical-stability-amorphous-felodipine-nifedipine](../../../cards/2006-marsac-physical-stability-amorphous-felodipine-nifedipine/paper.html) · Solid state stability / Physical stability · used · as: Kohlrausch-Williams-Watts equation

| id | kind | content | locator |
|---|---|---|---|
| E7 | equation | Kohlrausch-Williams-Watts (stretched exponential) relaxation: ΔH_t,T / ΔH_max,T = 1 − exp(−t/τ)^β (exponent β printed outside the parenthesis) | p.2308 |
| R7 | record, derived (E7) | KWW β and τ of dispersions — 10 wt% PVP dispersions, 23.5 °C, dry — nifedipine with 10% PVP: β 0.57 (±0.03), τ 42.1 (±0.6) h; felodipine with 10% PVP: β 0.45 (±0.04), τ 16.7 (±0.5) h | p.2310-2311 |