Pharmacokinetics of chloramphenicol in cows

The phe.rmacokinetics ofchlorampheniool waS estimated in ten Friesian COWS follo~ing a single intruscular inj-ectiQn of 10 mg/kg body weight. Samples of blood, silk, urine, saliva end ruminal fluid were collected just before, and 0.5, 1, 2, 4, 6, 8 and 12 hours after injection. A se-cond experiment on five cows of the ten,was carried :)’It using an intravenous injection ofchloramphenicol at the S8J!).e dose level (10 mg/kg body w9ight) and only blood sal71ples were co- llecte at the corresponding times as after intrusculardosing for dose of 10 mgFg body weight, the concentration of the d~ug in serum reached its rnaxiril.’$l levellstatistically at 3.3 hours)after ijection then decreased gradually, but still presentwithin the therapeutic level till the 8 !g hours p08J lnJecl.,10n. S~ilarly the highest concentration was acheived in milk, urine and saliva at 2 hours after injection, whereas in ruminal fluid at the 6 t~ hour. An in-:;raveno:at the sa’TIe dosage le\]’21concerrbrations with a therapeutic level maintained till 8 hourspost-injection. e t% value after intravenous injection was;.02 hours and the volume of distribution (Vd) was 0.53-0.58liter/kg body weight.