Table I.
Screened Penetration Enhancers for Transungual Formulation
| No. | Penetration enhancers (PEs) | Abbreviation | Concentration of PEs (% w/w) | Mechanism of action (18,19) |
|---|---|---|---|---|
| 1 | Diethylene glycol monoethyl ether or (transcutol) | TCL | 100 | Increase drug solubility and formation of drug depot in skin |
| 2 | N-methyl pyrrolidone | NMP | 100 | Altering membrane solvent nature, increase drug partition into skin |
| 3 | Poly(oxyethylene)(4) lauryl ether or BRIJ 30 | B30 | 2.5 | Potential to solubilize lipids in stratum corneum of skin, increase solubility of drug, emulsify sebum |
| 4 | Polyoxyethylene (20) oleyl ether or BRIJ 98 | B98 | 2.5 | |
| 5 | Sorbitan laurate or SPAN 20 | S20 | 2.5 | |
| 6 | Propylene glycol | PG | 100 | In the skin shows “solvent drag,” solubilizes α keratin in SC |
| 7 | Polyethylene glycol 400 | PEG | 100 | |
| 8 | Isopropyl myristate | IPM | 100 | Penetrates into lipid bilayers and increases lipid fluidity |
| 9 | Oleic acid | OA | 100 | Modify intercellular lipid domains and fluidizes the membrane |
| 10 | Thiourea | TU | 5 | Reduces disulphide linkages in keratin of nail |
| 11 | Thioglycolic acid | TA | 5 | |
| 12 | Urea-hydrogen peroxide | UH | 8.75 | Oxidizes disulphide linkages in nail |