Table 2.
Results of stability testing for formulation A containing minoxidil, diclofenac, and tea tree oil at baseline and after 24 months of storage
| Test | Initial product | After 24 months of storage |
|---|---|---|
| Appearance | Clear and transparent | Clear and transparent |
| Color | Conforms | |
| Odor | Characteristically aromatic | Conforms |
| Specific gravity | 1.21 ± 0.015 g/mL | 1.25 ± 0.01 g/mL |
| pH | 5.7 ± 0.01 | 5.9 ± 0.025 |
| Water dilution test | Clear/transparent o/w | Clear/transparent o/w |
| Staining tests | Confirm o/w emulsion | Confirm o/w emulsion with no phase inversion |
| Optical transparency | Transparent/translucent/clear | Transparent/translucent/clear |
| Mean viscosity (PaS) | 0.79 ± 0.012 | 0.81 ± 0.071 |
| Centrifugation at 3000 rpm | No phase separation, turbidity, cracking, or creaming (stable) | No phase separation, turbidity, cracking, or creaming (stable) |
| Centrifugation at 5000 rpm | No phase separation, turbidity, cracking, or creaming (stable) | No phase separation, turbidity, cracking, or creaming (stable) |