Table 1.
Formulation and rheological characterization of lidocaine ointments.
| Excipient | L1 | L2 | L3 | L4 | L5 | L6 |
|---|---|---|---|---|---|---|
| Petrolatum | 95.00 | 91.00 | 86.00 | 91.95 | 86.45 | 81.45 |
| MCT oil | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Glycerol monostearate | - | 5.00 | 10.00 | - | 5.00 | 10.00 |
| Vitamin E-acetate | - | - | - | 3.00 | 3.00 | 3.00 |
| Lidocaine base | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 | 3.00 |
| Allantoin | - | - | - | 1.00 | 1.00 | 1.00 |
| Prednisolone acetate | - | - | - | 0.05 | 0.05 | 0.05 |
| dl-Methylephedrine HCl | - | - | - | - | 0.5 | 0.5 |
| pH | 8.4 | 8.4 | 8.5 | 8.5 | 8.5 | 8.5 |
| Viscosity (×103 cP) | - | - | - | 23.5 ± 0.5 | 41.9 ± 0.8 | 95.2 ± 0.9 |
| Minimum extrusion force (N) | - | - | - | 19.5 ± 0.2 | 25.2 ± 0.8 | 54.9 ± 0.9 |
Abbreviations: MCT, Medium-chain triglyceride, HCl, hydrochloride.