Tolerance of Ocular Iontophoresis in Healthy Volunteers

Abstract

To evaluate ocular tolerance, healthy volunteers were iontophoresed transclerally using novel OcuPhor trade mark hydrogel drug delivery applicators filled with balanced salt solution. In this three-period crossover study in 24 male and female subjects, 16 subjects received 0 mA and two of the following DC currents: 0.1, 0.5., 1.0, 2.0, 3.0, or 4.0 mA for 20 min; 6 subjects received 3 mA for 20 min and 1.5 mA for 40 min (both equivalent to 60 mAmin total charge). Safety and tolerance were determined by subjective VAS and objective ophthalmic assessments. Subjects were evaluated before and up to 22 hr after dosing. The applicators were well-tolerated and no clinically significant changes in symptomology or in ophthalmic assessments were seen following exposure to 0-3.0 mA for 20 min or 1.5 mA for 40 min. At 4.0 mA 2 of 4 subjects reported a burning sensation under the applicator during dosing which resolved by 22 hr post-dose; superficial changes in fluorescein staining were observed at 1 hr, but not at 22 hr. The OcuPhor trade mark system has promise for noninvasive drug delivery to the eye.

Examination of penetration routes and distribution of ionic permeants during and after transscleral iontophoresis with magnetic resonance imaging

“…The iontophoresis condition of 20 min and 2 mA was selected in the present study because it was within the tolerable limit according to a previous human study (Parkinson et al, 2003). The higher current (4 mA) and longer duration (60 min) conditions were primarily selected for comparison.…”

“…In recent studies, ocular iontophoresis has been examined for the treatments of eye diseases (Behar-Cohen et al, 1997;Yoo et al, 2002;Eljarrat-Binstock et al, 2005), and it has been suggested that this technique may allow drug delivery to the back of the eye (Lam et al, 1989;Behar-Cohen et al, 2002;Voigt et al, 2002a). Low electric current (density) ocular iontophoresis has also been shown to be relatively safe in animal models and human (Hughes and Maurice, 1984;Behar-Cohen et al, 2002;Voigt et al, 2002a;Parkinson et al, 2003).…”

Corticosteroids and Anti-Complement Therapy in Retinal Diseases

“…Transscleral OcuPhor™ hydrogel has been tested for saline iontophoresis in healthy volunteers. Different intensities have been investigated for 20 and 40 min, and it was reported that the system was well tolerated (Parkinson et al 2003). DSP-Visulex ® is another transscleral iontophoresis system, which consists of a scleral-lens-shaped applicator and currently is in clinical trial phase I/II (Aciont).…”

Advances in iontophoresis for drug delivery

“…It has been suggested that this technique is relatively easy, convenient for use, safe, and provides fast and higher drug concentration in the specific ocular site, thereby providing solution to the low bioavailability of drugs. It is also well tolerated at low electric current density [8][9][10] . However, it causes minimum discomfort to patients and is not entirely harmless for ocular tissues [11][12] .…”