Novel dithranol phospholipid microemulsion for topical application: development, characterization and percutaneous absorption studies

Abstract

The objective of this study was to develop and characterize a novel dithranol-containing phospholipid microemulsion systems for enhanced skin permeation and retention. Based on the solubility of dithranol, the selected oils were isopropyl myristate (IPM) and tocopherol acetate (TA), and the surfactants were Tween 80 (T80) and Tween 20 (T20). The ratios of cosurfactants comprising of phospholipids and ethanol (1 : 10) and surfactant to co-surfactant (1 : 1 and 2.75 : 1) were fixed for the phase diagram construction. Selected microemulsions were evaluated for globule size, zeta potential, viscosity, refractive index, per cent transmittance, stability (freeze thaw and centrifugation), ex vivo skin permeation and retention. The microemulsion systems composed of IPM and T80 with mean particle diameter of 72.8 nm showed maximum skin permeation (82.23%), skin permeation flux (0.281 mg/cm²/h) along with skin retention (8.31%) vis-à-vis systems containing TA and T20. The results suggest that the developed novel lecithinized microemulsion systems have a promising potential for the improved topical delivery of dithranol.

• Dermal delivery
• colloidal delivery
• phase diagrams
• topical
• anthralin
• surfactant

Acknowledgements

The authors thank the University Grants Commission (UGC), New Delhi, India for their financial assistance. The authors also thank Phospholipid GmbH, Nattermannallee, Germany, for generously providing the gift sample of lecithin.

Declaration of interest

The authors report no conflicts of interest.