The concentration of phenothiazines in the eye of experimental animals.

Derivatives of IS!-substituted phenothiazine are concentrated in the tissues of the uveal tract of pigmented animals. The concentration levels for phenothiazine in the uveal tissue may reach 50 times the mean distribution value even 48 hours after a single dose of 5 mg. per kilogram. All other tissues have lower concentration levels than the mean distribution value. Only samples involved in excretion of the compounds (urine, kidney, liver) approach the mean distribution value. Albino rabbits do not shoio the uveal concentration phenomenon. Species and compound differences in the concentration phenomenon are noted. Chlorpromazine reaches higher levels of concentration in the rabbit uvea than does prochlorperazine. The reverse is true in hamsters. In rabbits the ciliary body has a higher concentration rate for prochlorperazine than the iris. For chlorpromazine the iris is higher than it is for the ciliary body. Phenothiazine itself is not concentrated in the uveal tract of pigmented rabbits or hamsters. The time course for disappearance of chlorpromazine from the rabbit uvea is biphasic. The first phase has a half-time of 2.8 to 4.0 days. After the first 10 to 12 days a very slow phase becomes dominant so that even 30 days after a single dose all parts of the uvea are still above the mean distribution value.