The comparative ophthalmic toxicology of 1-chloroacetophenone (CN) and dibenz(b.f)-1:4-oxazepine(CR)

Abstract

Rabbit eyes were contaminated with 1-chloroacetophenone (CN) and dibenz(b.f)-1:4-oxazepine (CR) in solution (1 to 10% in polyethylene glycol 300), as a solid (0.1 to 5 mg), and as aerosols (15 min exposure to 360 to 719 mg/m3). In solution, CN caused marked and persistent inflammatory effects, the severity and duration being related to the concentration used. Corneal damage was marked and persistent with 5 and 10% solutions; the lowest concentration causing just detectable keratitis in a small proportion of animals was 2%. Solid CN was even more damaging to the eye than similar amounts in solution. In marked contrast, CR in solution caused mild to moderate inflammatory effects, usually of only a few days duration, even at the higher concentrations. With 1 and 2%, these effects were just detectable to mild, lasting for 24 hrs or less. 10% CR caused just detectable keratitis of usually only a few days duration; the lowest concentration causing just detectable keratitis in a small proportion of treated animals was 5%. Solid CR merely caused minor irritation of the conjunctivae and eyelids for about 1 hr. Aerosols of CN and CR did not damage the eye, but irritation of the lids and conjunctivae was more marked and persistent with CN. Solutions of CN and CR caused concentration-related increases in corneal thickness and intraocular tension, being more marked and sustained with CN.