Microemulsion formulations for the transdermal delivery of testosterone

R M Hathout, Timothy J Woodman, S Mansour, N D Mortada, A S Geneidi, Richard H Guy

Research output: Contribution to journalArticlepeer-review

152 Citations (SciVal)
396 Downloads (Pure)


The objective was to develop a microemulsion formulation for the transdermal delivery of testosterone. Microemulsion formulations were prepared using oleic acid as the oil phase, Tween20 as a surfactant, Transcutol (R) as cosurfactant, and water. The microemulsions were characterized visually, with the polarizing microscope, and by dynamic light scattering. In addition, the pH, conductivity (sigma) and viscosity (eta) of the formulations were measured. Moreover, differential scanning calorimetry and diffusion-ordered nuclear magnetic resonance spectroscopy were used to study the formulations investigated. Conductivity measurements revealed, as a function of the weight fraction of the aqueous phase, the point at which the microemulsion made the transition from water-in-oil to bicontinuous. Alterations in the microstructure of the microemulsions, following incorporation of testosterone, have been evaluated using the same physical parameters (pH, sigma and eta) and via Fourier-transform infrared spectroscopy (FT-IR), H-1 NMR and C-13 NMR. These methods were also used to determine the location of the drug in the colloidal formulation. Finally, testosterone delivery from selected formulations was assessed across porcine skin in vitro in Franz diffusion cells. The physical parameter determinations, combined with the spectroscopic studies, demonstrated that the drug was principally located in the oily domains of the microemulsions. Testosterone was delivered successfully across the skin from the microemulsions examined, with the highest flux achieved (4.6 +/- 0.6 mu g cm(-2) h(-1)) from a formulation containing 3% (w/v) of the active drug and the composition (w/w) of 16% oleic acid, 32% Tween20, 32% Transcutol (R) and 20% water. The microemulsions considered offer potentially useful vehicles for the transdermal delivery of testosterone.
Original languageEnglish
Pages (from-to)188-196
Number of pages9
JournalEuropean Journal of Pharmaceutical Sciences
Issue number3
Publication statusPublished - 14 Jun 2010


  • transdermal drug delivery
  • H-1 NMR
  • testosterone
  • microemulsions
  • skin permeation


Dive into the research topics of 'Microemulsion formulations for the transdermal delivery of testosterone'. Together they form a unique fingerprint.

Cite this