THIAMPHENICOL
Overview
Chemical Names
D-d-THREO-2-DICHLOROACETAMIDO-1-(4-METHYLSULFONYLPHENYL)-1,3-PROPANEDIOL;
D(+)-THREO-1-(4'-METHYLSULPHONYLPHENYL)-2-DICHLOROACETAMIDE PROPANE-1,3-DIOL;
D-THREO-2,2-DICHLORO-N-beta-HYDROXY-a-(HYDROXYMETHYL)-p-(METHYLSULPHONYL)-
PHENYL ACETAMIDE
Synonyms
DEXTROSULPHENIDOL; THIOPHENICOL
CAS number
15318-45-3
Functional Class
Veterinary Drug
ANTIMICROBIAL_AGENT
ANTIMICROBIAL_AGENT
Evaluations
Evaluation year: 2002
ADI:0-0.005 mg/kg bw (1999)
ADI:
0-0.005 mg/kg bw (1999)
Comments:
The 52nd Committee meeting established an ADI of 0-5 µg/kg bw on the basis of the microbiological end-point using the following formula: ADI (µg/kg bw) = (0.5 µg/g (MIC50) × 220 g (mass colonic content))/(0.4 (fractional bioavailability) x 1 (safety factor) x 60 kg (human bodyweight)) = 4.6 µg/kg bw. The MIC50 value used to calculate the ADI is the MIC50 value for Fusobacterium spp. as the most sensitive, relevant bacterial species. This ADI is one-tenth the toxicological ADI of 0-50 µg/kg bw that would be derived on the basis of the NOEL of 5 mg/kg bw per day in the two-year study of carcinogenicity in rats and a safety factor of 100.
MRL Comment:
The temporary MRLs in muscle, liver, kidney and fat of pigs, and in muscle of fish, were not extended because the information requested at the fifty-second meeting was not provided.
MRL Code:
TMRL
Meeting:
58
Report:
Tox Monograph:
Residues:
Toxicological study
Pivotal Study:
In vitro microbiological study (Sutter & Finegold, 1976)
Animal Specie:
Human gut flora
Effect:
Growth inhibition
Point of departure:
0.5 µg/g (MIC50)
Previous Years:
1999, TRS 893-JECFA 52/28, FNP 41/12-JECFA 52/119, FAS 43-JECFA 52/7. 0-0.005 mg/kg bw. MLRs (TEMPORARY UNTIL 2002, EXPRESSED AS THE SUM OF THIAMPHENICOL AND ITS CONJUGATES, MEASURED AS THIAMPHENICOL): MUSCLE, LIVER, KIDNEY AND FAT (PIGS): 0.05 mg/kg; MUS
1999, TRS 893-JECFA 52/28, FNP 41/12-JECFA 52/119, FAS 43-JECFA 52/7. 0-0.005 mg/kg bw. MLRs (TEMPORARY UNTIL 2002, EXPRESSED AS THE SUM OF THIAMPHENICOL AND ITS CONJUGATES, MEASURED AS THIAMPHENICOL): MUSCLE, LIVER, KIDNEY AND FAT (PIGS): 0.05 mg/kg; MUS