Advanced trans-epithelial drug delivery devices.

The presented paper describes the drug delivery devices which can be considered as advanced or potentially "intelligent". Due to the current development state and the legal problems of implantable drug releasing electronic devices the review is limited to the systems which delivers drugs through the skin or mucosa. The article shows the principle of operation and some construction details of such devices. It also discusses the possible methods of sampling body fluids across the drug delivery barriers to introduce a feedback loop which is necessary to react on the metabolic process in the human body and their malfunctioning. In the near future presented devices will evolve towards the highly sophisticated systems which will monitor our metabolism and deliver necessary drugs and hormones in the precisely calculated doses to regulate our body functions without absorbing our attention.

Electroosmotic flow as a result of buccal iontophoresis--buccal mucosa properties.

The objective of this study was to investigate and to better understand the properties of buccal mucosa as a semipermeable membrane and a portal for drug administration by iontophoretic and electroosmotic means. In vitro experiments showed that buccal mucosa at the pH of about 7.4 behaved as a cation-exchange membrane and non-linear resistor. It had lower resistance and was more permeable for water than a skin. The electroosmotic volume flow through mucosa depended on current density, mucosa resistance and electrolyte concentration. Sodium dodecyl sulfate (in concentration range 0.001-0.005 mol L(-1)) and urea (in concentration range 0.42-1.67 mol L(-1)) did not promote a water transfer through buccal mucosa, however, both substances enhanced flow through the skin.