Table 1.
Composition of the four developed hydroquinone (HQ) formulations expressed in weight percentage. Key: DMI: Isosorbide dimethyl ether, PG: Propylene glycol, Vit. C: Vitamin C, Vit. E: Vitamin E. Further details in Tables S1 and S2.
| Formulation | HQ (%) | PG (%) | Vit. C (%) | Vit E (%) | DMI (%) | Beeler’s Base (%) | Olive Oil Base * (%) | Nourivan® (%) | pH |
|---|---|---|---|---|---|---|---|---|---|
| F1 | 5 | 5 | 1.25 | 1.25 | - | 87.5 | - | - | 3.6 |
| F2 | 5 | - | - | - | 15 | 80 | - | - | 3.7 |
| F3 | 5 | - | - | - | 15 | - | 80 | - | 3.6 |
| F4 | 5 | - | - | - | 15 | - | - | 80 | 3.2 |
* The base contains 2.5% oleic acid and 1.8% α-tocopherol acetate.