Table 5.
Skin irritancy and skin corrosion study results using pig ear skin.
| Samples | ΔTEWL a,b (g/m2/h) |
F a,c | |
|---|---|---|---|
| Water | 0.9 ± 0.3 | − | |
| 20% w/v of SDS solution | 24.6 ± 2.2 d | − | |
| 0.9% w/v of NaCl solution | − | 0.00 ± 0.00 | |
| 37% v/v of HNO3 solution | − | −0.50 ± 0.03 | |
| 1% w/w of MSKE solution | 1.5 ± 0.9 e | 4.82 ± 0.42 | |
| 1% w/w MSKE-loaded w/o microemulsions | |||
| 1. Absolute EtOH | 3.2 ± 1.0 f | 4.12 ± 0.47 g | |
| 2. 96.3% EtOH | 4.0 ± 2.0 f | 7.47 ± 0.27 g | |
| 3. 1-PA | 3.1 ± 1.9 f | 11.32 ± 0.83 g | |
| 4. 2-PA | 4.1 ± 2.4 f | 6.59 ± 0.21 g | |
| 5. 1,2-PA * | 4.8 ± 0.8 f | 7.00 ± 1.07 g | |
| 6. 1,2-PA ** | 4.7 ± 1.8 f | 6.99 ± 1.05 g | |
| 1% w/w MSKE-loaded o/w microemulsions | |||
| 1. Absolute EtOH | 5.1 ± 0.8 f | 8.05 ± 0.47 g | |
| 2. 96.3% EtOH | 5.6 ± 2.0 f | 7.85 ± 0.35 g | |
| 3. 1-PA | 5.4 ± 1.5 f | 6.56 ± 0.25 g | |
| 4. 2-PA | 5.9 ± 1.6 f | 9.56 ± 0.96 g | |
a The values are expressed as the mean ± SEM (n = 3); b ΔTEWL = the mean absolute increase of transepidermal water loss; c F = corrosive factor; d Significant difference between ΔTEWL of SDS solution and water (p < 0.05); e No significant difference between ΔTEWL of MSKE solution and water (p > 0.05); f No significant difference between ΔTEWL of all MSKE-loaded microemulsions and water (p > 0.05); g No significant difference of corrosive factor among MSKE-loaded microemulsion formulations (p > 0.05); * = MSKE-loaded w/o microemulsion containing IPM (44.55%) and aqueous phase of 1,2-PA (14.85%); ** = MSKE-loaded w/o microemulsion containing IPM (29.70%) and aqueous phase of 1,2-PA (29.70%).