title: Novel Drug Delivery System for Dermal Uptake of Etofenamate: Semisolid SLN Dispersion.
abstract: BACKGROUND
  Semisolid SLNs are novel strategy for dermal drug administration instead of incorporating the SLN dispersions into conventional semisolids. Etofenamate loaded semisolid SLNs were successfully prepared and in vitro characterization of formulations were performed in our previous study. The present study is an attempt to evaluate the dermal behavior of the semisolid SLNs selected on the basis of previous research and investigate the properties in terms of the convenience for topical applications.
  
  
  OBJECTIVE
  The objective of this study is to evaluate the skin penetration characteristics of semisolid SLN formulations. The occlusive and mechanical properties of semisolid SLNs were also evaluated because of their impression on the dermal behavior of the formulations.
  
  
  METHODS
  The occlusive properties were investigated by in vitro occlusion test. Texture analysis was performed to define the hardness, compressibility, adhesiveness, cohesiveness and elasticity of the formulations. Rat skin was chosen to evaluate the ex vivo penetration of etofenamate loaded semisolid SLNs and commercial gel product. Coumarin-6 was used to visualize the dermal distribution of the semisolid SLN formulations. For monitorizing the penetration of coumarin-6 into the skin samples Confocal Laser Scanning Microscopy was employed.
  
  
  RESULTS
  The occlusive and mechanical properties of C1 coded semisolid SLN formulation were found more favorable in comparison with P1. The cumulative etofenamate amount in skin samples was found to be 39.88 ± 1.50 μg/cm2 for C1 and 30.56 ± 2.10 μg/cm2 for P1 coded formulations. According to CLSM images, greater fluorescence intensities and deeper skin penetrations were obtained with both of the semisolid SLNs in comparison to plain Carbopol gel.
  
  
  CONCLUSIONS
  It can be concluded that the semisolid SLNs are promising alternative dermal drug delivery systems to the conventional dosage forms.
authors: Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100 Tandogan, Ankara. Turkey.
authors: Ulya
authors: U
authors: Badilli
authors: Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100 Tandogan, Ankara. Turkey.
authors: C Tuba
authors: CT
authors: Sengel-Turk
authors: Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100 Tandogan, Ankara. Turkey.
authors: Gulin
authors: G
authors: Amasya
authors: Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 06100 Tandogan, Ankara. Turkey.
authors: Nilufer
authors: N
authors: Tarimci
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D003374:Coumarins; D016503:Drug Delivery Systems; D005439:Flufenamic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D066298:In Vitro Techniques; D008297:Male; D053758:Nanoparticles; D051381:Rats; D017207:Rats, Sprague-Dawley; D012869:Skin Absorption; D013844:Thiazoles
chemical_list: D003374:Coumarins; D013844:Thiazoles; C517282:coumarin 6; D005439:Flufenamic Acid; C015207:etofenamate
keywords: Dermal uptake; etofenamate; occlusive effect; semisolid SLN dispersion; skin penetration; texture profile analysis