The Effects of Formulation Variables on Iontophoretic Transdermal Delivery of Leuprolide to Humans

Transdermal Delivery of Cytochrome C—A 12.4 kDa Protein—Across Intact Skin by Constant–Current Iontophoresis

“…The addition of buffer or an increase in the ionic strength of the formulation by the addition of background electrolyte increases competition between charge carriers and generally decreases iontophoretic drug flux (29)(30)(31). The effect of Na + on the iontophoretic transport of Cyt c (0.7 mM) was confirmed by formulating the protein in PBS (pH 8.2).…”

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

“…Iontophoretic transdermal delivery can offer the possibility for noninvasive and continuous steady-state delivery of the peptide into the systemic circulation. Although, successful iontophoretic delivery of leuprorelin across the skin in vivo has been demonstrated earlier [9,25], problems related to the poor transport efficiency and biological variation of the peptide transport still remain to be solved. 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.…”

“…However, certain cationic hydrophobic peptides (e.g. LHRH and somatostatin analogues) have shown unexpected behavior [7][8][9][10][11]. Peptides containing adjacent cationic and lipophilic residues are able to associate to the negatively charged groups of the skin [12].…”

Electrically induced transport of macromolecules through oral buccal mucosa

“…Protein iontophoresis has been used to deliver insulin in diabetes [4], calcitonoin in osteoporosis [5] and human parathyroid hormone in Paget's disesase [6]. In the case of peptide delivery there have been reports of using ionotophoresis with analogs of vasopressin [7], somatorelin [8], somatostatin [9] and luteinising releasing hormone [10]. In contrast, the literature on the use of iontophoresis across oral mucosa is sparse [11,12], but the technique has been used in the treatment of herpes labialis, aphthous ulceration, dentin hypersensitive and for topical anesthesia [13][14][15].…”