Ocular distribution of carteolol after single and repeated ocular instillation in pigmented rabbits

To investigate the distribution and elimination of carteolol in pigmented rabbits, 14C-carteolol eye drops were instilled singly and repeatedly. After single ocular instillation, the radioactivity in the iris and ciliary body reached maximum levels at 24 h. The elimination rate of pigmented tissues decreased at a half-life of approximately 15 days. The concentration of radioactivity in pigmented tissues increased markedly by repeating the ocular instillation and reached a maximum after the 80th repeated instillation. The concentration of radioactivity at 1 h after 80th instillation was 63.7 times that in the iris, 61.1 times that in the ciliary body and 17.2 times that in the retina & choroid after single instillation. No accumulation of radioactivity was found in other ocular tissues.