Cephalothin sodium (Keflin) was detected in low concentration in primary aqueous humor of rabbits 45 minutes following a single intramuscular injection of 150 mg/kg body weight. The ratio of aqueous humor level to blood level ranged between 1.1% and 9.7%. The aqueous humor level did not exceed 1.8γ/ml.
Uwaydah MM, Faris BM. Penetration of Cephalothin in the Aqueous Humor of the Rabbit. Arch Ophthalmol. 1970;83(3):349-351. doi:10.1001/archopht.1970.00990030349012