Plasma Levobunolol Levels following Topical Administration with Reference to Systemic Side Effects

Abstract

We determined the plasma level of levobunolol in normal volunteers after a single topical instillation of 0.5 or 1% levobunolol in both eyes, and after twice-daily instillations for 1 week. Levobunolol levels were detected within 1 h following acute instillation. During the study, mean plasma levels ranged from 0.1 to 0.3 ng/ml for the 0.5% group and 0.3 to 0.6 ng/ml for the 1% group. The highest individual plasma level was 1.2 ng/ml, which occurred in 1 patient receiving 1% levobunolol. After 1 week of twice-daily instillation mean plasma levels were similar to those observed after acute instillation. Minimal cardiovascular changes were observed in the 0.5% group while decreases in heart rate and systolic blood pressure were observed in the 1% treatment group.

Intraocular administration of tetramethylpyrazine hydrochloride to rats: a direct delivery pathway for brain targeting?

“…Based on the special structural characteristics of the eye and the fact that drugs can enter the rest of the body through a variety of routes after io administration (Hornof et al., 2005), we believe that drugs can be absorbed directly into the systemic circulation through io administration and therefore treat systemic diseases. Previous studies (Baba et al., 1983; Kumar et al., 1985; Novack et al., 1987; Lahdes et al., 1988, 1990; Kaila et al., 1989; Lahdes et al., 1994; Lanzl et al., 2016) have shown that the blood concentration of many eye drops, such as betamethasone and atropine, are high after io administration, which indicates that the drug can enter the systemic circulation through the eyes. Chiou (Chiou, 1994) explored the possibility of the systemic administration of insulin via io administration.…”