Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication

Data source

Reference
Reference Type:
publication
Title:
Metabolism and Biliary Exeretion of Arylaminosulphonic Acids in the Rat
Author:
McMahon K.A. & O´reilly W.J.
Year:
1969
Bibliographic source:
Fd Cosmet. Toxicol. Vol. 7, pp. 497-500

Materials and methods

Objective of study:
excretion
metabolism
Principles of method if other than guideline:
In vivo study in rats to gather information about the metabolism and the bilary excretion of Arylaminosupphonic acids including 4-aminotoluene-3-suphonic acid.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 4-aminotoluene-3-suphonic acid
The compounds were obtained commercially or provided by the respective Department, and were purified by recrystallization.

Test animals

Species:
rat
Strain:
not specified
Sex:
not specified
Details on test animals and environmental conditions:
The animals (250-350 g body weight) were starved overnight.

Administration / exposure

Route of administration:
other: oral: gavage or intravenous
Vehicle:
other: alkaline aqueous solution
Details on exposure:
- Amount of solution: 10 mg
Duration and frequency of treatment / exposure:
once
Doses / concentrations
Remarks:
Doses / Concentrations:
10 mg, presumably per animal (ca. 30-40 mg/kg bw)
No. of animals per sex per dose:
3 (urinary excretion)/ 5 (biliary excretion)
Control animals:
no
Details on dosing and sampling:
Urine was collected over a 24-hr period following oral or intravenous administration and was assayed first for free acid and then, after acid hydrolysis, for metabolite, by a method based on the procedure of Bratton & Marshall (1939), 0.1 N-HCl being substituted for trichloracetic acid. Biliary excretion of the compounds was studied by injecting the acid into the femoral arterial vein of rats anaesthetized with urethane (1.25 g/kg) and collecting bile samples over a 6-hr period via a biliary cannula. The cannulation of the bile duct and the preparation of bile samples for assay have been described previously (Priestly & O'Reilly, 1966).

Results and discussion

Main ADME resultsopen allclose all
Type:
excretion
Results:
Oral administration: Percentage of dose recovered as free acid in the urine after 24 h: 21.0 +-2.2%
Type:
excretion
Results:
Oral administration: Percentage of dose recovered as conjugate in the urine after 24 h: 0%
Type:
excretion
Results:
Intravenous administration: Percentage of dose recovered as free acid in the urine after 24 h: 59.0 +-6.8%
Type:
excretion
Results:
Intravenous administration: Percentage of dose recovered as conjugate in the urine after 24 h: 0%
Type:
excretion
Results:
Intravenous administration: Percentage of dose recovered as free acid in the bile after 6 h: 0.79%
Type:
excretion
Results:
Intravenous administration: Percentage of dose recovered as conjugate in the bile after 6 h: 0%

Any other information on results incl. tables

Of the fifteen compounds examined, only six showed evidence of metabolism involving conjugation of the a amino group (4-aminotoluene-3-suphonic acid did not). It. must be stressed that in no case was all of the compound accounted for so there may have been other metabolites from which the amino group had been removed and which were therefore undetectable by the Bratton-Marshall assay. In general, oral administration gave rise to lower total recoveries of the compounds but a greater degree of metabolism than intravenous dosage.

As conjugation of these compounds was not extensive, only slight biliary exeretion of the acids was expected based on their molecular weights range in the rat (below 300). The measured results indicate an increase in biliary excretion of the larger acids and their metabolites, but in no case was this excretion extensive.

Applicant's summary and conclusion