STABILITY OF FERULIC ACID 485 Table I Stability Results of Creams 1–3 and Serums 4–8 under All Conditions (a): Stability of Cream 1-3 @ RT/dark[8] Cream AspectColorOdor pH[2] F.A%[3] (RT/dark) 1 [1] blank No change — — pH 4.5 No change — 0.942[4] 5.5 No change — 0.949[4] 6.5 No change — 0.916[4] 2 [1] blank No change — — pH 4.5 No change — 0.991[4] 5.5 No change — 0.971[4] 6.5 Impossible to formulate — — 3 blank No change — — pH 5.1[6] Slight O change +0.10 0.963[4] 5.5 Slight O change -0.05 0.981[4] 6.5 Diphase, C & O change +0.23 0.972[4] See p. 488 for footnotes relating to all parts of Table I. (b): Stability of Creams 1-3 @ RT/light[8] Cream AspectColorOdor 1 [1] blank No change pH 4.5 Slightly yellowish 5.5 Slightly yellowish 6.5 Slightly yellowish 2 [1] blank No change pH 4.5 No change 5.5 Slight C & O change 6.5 Impossible to formulate 3 blank No change pH 5.1[6] Slight C & O change 5.5 Slight C & O change 6.5 Slight C & O change (c): Stability of Creams 1-3 @ 4°C/dark[8] Cream AspectColorOdor F.A%[3] (4°C/dark) 1 [1] blank No change — pH 4.5 No change 0.990[4] 5.5 No change 0.990[4] 6.5 No change 0.991[4] 2 [1] blank No change — pH 4.5 No change 0.991[4] 5.5 No change 0.990[4] 6.5 Impossible to formulate — 3 blank No change — pH 5.1[6] No change 0.991[4] 5.5 No change 0.990[4] 6.5 No change 0.991[4]

JOURNAL OF COSMETIC SCIENCE 486 (d): Stability of Creams 1-3 @ 37°C/dark[8] Cream AspectColorOdor 1 [1] blank Thicker, but acceptable pH 4.5 Thicker, C & O change 5.5 Severe C change 6.5 Severe C & O change 2 [1] blank No change pH 4.5 Slight C & O change 5.5 Severe C change 6.5 Impossible to formulate 3 blank Thicker, but acceptable pH 5.1[6] C & O change 5.5 C & O change 6.5 Diphase, C & O change (e): Stability of Creams 1-3 @ 45°C/dark[8] Cream AspectColorOdor pH[2] F.A%[3] (45°C/dark) 1 [1] blank Thicker, but acceptable — — pH 4.5 Thicker, C & O change — 0.534[4] 5.5 Thicker, Severe C change — 0.353[4] 6.5 Thicker, Severe C change — 0.215[4] 2 [1] blank No change — — pH 4.5 C & O change — 0.583[4] 5.5 Diphase, severe C change — 0.365[4] 6.5 Impossible to formulate — — 3 blank Thicker, but acceptable 0 — pH 5.1[6] Severe C & O change -0.1 0.670[4] 5.5 Severe C & O change +1.0 0.581[4] 6.5 Diphase, severe C & O change +1.2 0.404[4] (a-1): Stability of Serums 4-8 @ RT/dark[8] Serum AspectColorOdor pH[2] F.A%[3] (RT/dark) 4 blank No change -0.1 — pH 5.0 No change -0.0 0.979[5] 6.0 No change +0.3 0.951[5] 5 blank No change +0.1 — pH 5.0 Impossible to formulate — N/A 6.2[7] No change +0.2 0.969[4] 6 blank No change +0.0 — pH 5.0 Impossible to formulate — N/A 6.0 No change +0.0 0.981[4] 7 [1] blank No change — — pH 5.0 Crystal↓ — 0.962[5] 6.0 No change — 0.945[5] 8 blank No change -0.1 — pH 5.0 Crystal↓ — N/A 6.0 No change +0.1 0.972[5]