title: Topical delivery of clobetasol propionate loaded microemulsion based gel for effective treatment of vitiligo: ex vivo permeation and skin irritation studies.
abstract: The aim of the present investigation was to evaluate microemulsion as a vehicle for dermal drug delivery and to develop microemulsion based gel (MBC) of clobetasol propionate (CP) for the effective treatment of vitiligo. D-Optimal mixture experimental design was adopted to optimize the amount of oil (X(1)), S(mix) (mixture of surfactant and cosurfactant) (X(2)) and water (X(3)) in the microemulsion. The formulations were assessed for globule size (nm) (Y(1)) and solubility of CP in microemulsion (mg/ml) (Y(2)). The microemulsion containing 3% oil, 45% S(mix) and 50% water was selected as the optimized batch (ME). The globule size and solubility of CP in ME were 18.26 nm and 36.42 mg/ml respectively. Transmission electron microscopy showed that ME globules were spherical in shape. Carbopol 934P was used to convert microemulsion containing drug into gel form without affecting its structure. Ex-vivo permeation studies showed that cumulative amount of CP permeated (Q(n)) from ME, MBC and market formulation (MFCP) at 8h after application were 53.6±2.18, 28.43±0.67 and 37.73±0.77 μg cm(-2) respectively. MBC showed greater retention of CP in to skin layers than ME and MFCP. Skin irritation studies showed MBC to be significantly less irritating than MFCP. Photomicrographs and scanning electron micrographs of skin sections treated with MBC showed significant changes in the skin structure, which was attributed to the interaction of microemulsion components with skin resulting in permeation enhancement and retention of CP into skin layers. It was concluded that CP loaded gel could be a promising formulation for effective treatment of vitiligo.
authors.affiliation: Department of Pharmaceutics, K. B. Institute of Pharmaceutical Education and Research, Kadi Sarva Vishwavidyalaya, Sector 23, Gandhinagar 382023, India. forhetal@gmail.com
authors.forename: Hetal K
authors.initials: HK
authors.lastname: Patel
authors.forename: Bhavesh S
authors.initials: BS
authors.lastname: Barot
authors.forename: Punit B
authors.initials: PB
authors.lastname: Parejiya
authors.forename: Pragna K
authors.initials: PK
authors.lastname: Shelat
authors.forename: Arunkumar
authors.initials: A
authors.lastname: Shukla
mesh_terms: D000818:Animals; D002990:Clobetasol / Q000008:administration & dosage* / Q000627:therapeutic use*; D005782:Gels / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D011817:Rabbits; D012867:Skin / Q000187:drug effects; D012869:Skin Absorption; D013501:Surface-Active Agents / Q000737:chemistry; D014820:Vitiligo / Q000188:drug therapy*
chemical_list: D005782:Gels; D013501:Surface-Active Agents; D002990:Clobetasol