Controlled transport of timolol maleate through artificial membranes under passive and iontophoretic conditions

Delivery of timolol through artificial membranes and pig stratum corneum

“…In previous work, 4 we found that the passive and iontophoretic permeability of TM through the dialysis support membrane alone was practically the same (56.5 AE 8.0 Â 10 À6 cm/s and 58.5 AE 6.3 Â 10 À6 cm/s, respectively). The fact that the overall TM permeability through the supported pig SC was much lower than through the support membrane alone indicated that the SC strongly inhibited the transport of TM.…”

“…4. The SC was very fragile, and was supported by a dialysis membrane (MWCO: 5kDa, Diachema, Germany).…”

“…In a previous study, 4 we investigated the permeability of timolol (TM, pK a ¼ 9.21); a nonselective beta-adrenergic blocking agent; through artificial membranes. We found that the incorporation of a porous membrane within a transdermal TM patch seems feasible.…”

pH- and electro-responsive characteristics of silk fibroin–hyaluronic acid polyelectrolyte complex membranes

“…Total mass balance calculations showed that the decline on the peaks caused by two reasons: mainly with respect to decrease in the drug concentration in the donor compartment and possibly due to fouling caused by adsorption of the drug on the membrane surface. In literature, it was reported that high adsorption of the drug to the membrane, besides the loss of valuable drug molecule, probably caused fouling of the material, which influences the membrane's permeability (Stamatialis et al, 2002). Since the membrane was shown to be negatively charged in all pH levels, and the drug molecule was positively charged, ionic interactions may have accelerated the possible adsorption mechanism.…”

“…Iontophoretic drug delivery implies the use of small amounts of physiologically acceptable electric current across a membrane to drive charged molecules into the body. Drug is driven into the skin by electrostatic repulsion by using an electrode of the same polarity as the charge of the drug (Stamatialis et al, 2002;Eljarrat-Binstock and Domb, 2006). Electric field applied results in an electric current, which is transformed into an ionic current at the electrode/liquid or electrode/skin interface.…”