Ion-exchange and iontophoresis-controlled delivery of apomorphine

Controlled transdermal delivery of leuprorelin by pulsed iontophoresis and ion-exchange fiber

“…The differences in the release of leuprorelin acetate from the fibers are in agreement with small molecular weight hydrophobic (e.g. tacrine, propranolol, apomorphine) but not hydrophilic (nadolol) cationic compounds that possess stronger specific interaction with sulfonic acid fiber than with carboxylic acid fiber [26,36]. As a result, lipophilic drugs are attached more strongly to Smopex Ò -101 fibers and are released more easily from Smopex Ò -102 fibers.…”

“…At the same time the presence of higher amounts of small and more mobile co-ions means higher competition for the peptide in the iontophoretic transport. We have demonstrated previously that the latter factor affects the iontophoretic transport more than the amount of drug released in the donor compartment; so in order to obtain the highest transdermal flux, the concentration of the competing co-ions in the donor solution should be kept at minimum [26]. Another and more feasible way to aim for higher permeation rates would be to increase the loading of the peptide in the fibers.…”

“…Therefore, our study was aimed: (1) to test whether transdermal delivery of cationic peptide leuprorelin could be improved by pulsed current iontophoresis in comparison with the most common current profile À constant current, (2) to investigate and quantify the possible changes in iontophoretic transport mechanisms involved under these two current profiles, and (3) to study the potential of cation-exchange fibers as drug reservoirs for the transdermal delivery of this peptidic drug. [26]. All other chemicals were at least of analytical grade.…”

Physical energy for drug delivery; poration, concentration and activation

“…Iontophoresis which also uses an electric field is an emerging modality of drug delivery through the skin by using a potential producing only a gentle electrical current [118, 119]. Unlike formation of pores in EP, in iontophoresis the ionized form of the drug penetrates through sweat ducts, sebaceous glands, hair follicles and imperfection sites in the skin layer.…”

Loading and Release of Amine Drugs by Ion-Exchange Fibers: Role of Amine Type

“…Compared with the liquid eye drops, the ophthalmic formulation with ion exchangers can reduce the loss of active ingredient and increase bioavailability of the drug, the 0.25% BETOPTIC S ophthalmic suspension product has been approved by United States Food and Drug Administration and is marketed in the United States since February 1990 . Ion exchangers incorporate into iontophoresis can also achieve the controlled drug release …”