Effects of a Long-Acting Ophthalmic Formulation of Carteolol Containing Alginic Acid on the Corneal Epithelial Barrier Function and Water Retentive Effect

Abstract

Effects of a long-acting ophthalmic formulation of carteolol containing alginic acid on the corneal epithelial barrier function and its water retentive effect were investigated. Using 10 healthy adult subjects, 2% Mikelan Ophthalmic Solution(®) (MK) was instilled in the eye once daily for 7 days (MK group) and then after a washout period of at least 28 days, 2% Mikelan LA Ophthalmic Solution(®) (MKLA) was instilled in the eye once daily for 7 days (LA group). As an index of the corneal epithelial barrier function, the fluorescein uptake was measured using Kowa FL-500. A Schirmer test was conducted to evaluate the tear dynamics. In another 10 subjects, 0.5% Timoptol(®) (TM) was instilled in the eye unilaterally twice daily for 7 days (TM group), and the tests were conducted in the same manner. Concerning the fluorescein uptake before and after initiation of instillation, the levels before and at 7 days after initiation of instillation were 20.7 and 26.5 ng/mL, respectively, in the LA group and 20.6 and 26.4 ng/mL, respectively, in the MK group, showing no significant difference between levels before and after initiation of instillation in either group. In the TM group, the levels were 21.4 and 65.5 ng/mL, respectively, showing a significant increase after initiation of instillation. In the Schirmer test, the values before and after initiation of instillation were 16.8 and 20.7 mm, respectively, in the LA group and 13.7 and 12.7 mm, respectively, in the MK group, showing a trend toward increase in the LA group. The findings suggest that the long-acting ophthalmic formulation of carteolol containing alginic acid does not affect the corneal epithelial barrier function and that it may possess a water retentive action.