Enhancing effect of temperature on the transmucosal penetration kinetics of 17 beta-estradiol.

van der Bijl P. ; van Eyk A.D. ; van der Bijl P. ; Kriel J. (2003)


Human vaginal mucosa may be used as a model of buccal mucosa for in vitro permeability studies using various chemical compounds. Rectilinear temperature dependence of water flux across vaginal mucosa between 25 degrees C and 41 degrees C has been shown. The objective of this study was to examine the behaviour of the above barrier on fluxes of 17 beta-estradiol at various temperatures. Frozen vaginal mucosa specimens from a single patient were used (snap-frozen in liquid nitrogen and stored at -85 degrees C). The permeability to tritiated 17 beta-estradiol was determined using a continous flow-through perfusion system at temperatures of 20 degrees C, 25 degrees C, 30 degrees C, 37 degrees C and 41 degrees C. Histological examinations were performed before and after permeability experiments. Estimated steady state flux values were used at 20 degrees C, 25 degrees C and 30 degrees C. Estimated and true mean 17 beta-estradiol steady state flux rates (20-24 h) were found to be 415 +/- 27 standard error of the Mean (SEM), 848 +/- 60 SEM, 1355 +/- 77 SEM, 1436 +/- 37 SEM and 1482 +/- 35 SEM cpm.cm-2.min-1, at temperatures of 20 degrees C, 25 degrees C, 30 degrees C, 37 degrees C and 41 degrees C, respectively. A non-linear regression analysis and plot (R2 = 0.9941) displayed a curvilinear flux-temperature relationship. The results from this study showed that, notwithstanding cellular damage, the principal physical permeability barrier governing permeation kinetics was non-linearly temperature-dependent between the temperatures studied, providing further support for the concept that this barrier is lipoidal in nature.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/9057
This item appears in the following collections: