Reaction mass of tetrasodium 3-[[4-[[4-[(6-amino-1-hydroxy-3-sulphonato-2-naphthyl)azo]-6-sulphonato-1-naphthyl]azo]-1-naphthyl]azo]naphthalene-1,5-disulphonate and tetrasodium 3-[[4-[[4-[(6-amino-1-hydroxy-3-sulphonato-2-naphthyl)azo]-7-sulphonato-1-naphthyl]azo]-1-naphthyl]azo]naphthalene-1,5-disulphonate

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

other: read across from analogue substance

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1970

Materials and methods

Principles of method if other than guideline:

Metabolism experiments. Male white rats (300-400 g) were kept individually in all-glass metabolism cages and excreta were collected free from cross-contamination. Food and water were provided ad lib. Urine was collected under toluene at 24-hr intervals for 72 hr. Faeces were collected at 48 and 72 hr. Oral doses of Black PN (20-100 rag/rat) were given in aqueous solution by stomach tube. Intraperitoneal (10-I00 rag/rat) and intravenous (0.5-4 mg/rat) doses were injected in a maximum volume of 2 ml water.
When bile was collected, the animals were kept for 2 ha" after oral administration of Black PN (25 mg/rat) and then anaesthetized by parenteral, injection of 25 ~ aqueous urethane (5 ml/kg body weight). The bile duct was cannulated and bile was collected for 6 hr. The animals were killed with chloroform and the tissues were examined for metabolites. Intravenous dosage of Black PN was carried out after cannulation of the bile duct. The bile was collected for 8 hr. Three male human volunteers were given Black PN (240 mg) in a gelatine capsule. Urine was collected at 24 and 48 hr.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo))naphthalene-4,6-disulphonate

EC Number:

219-746-5

EC Name:

Tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo))naphthalene-4,6-disulphonate

Cas Number:

2519-30-4

Molecular formula:

C28H21N5O14S4.4Na

IUPAC Name:

Food Black 1

Radiolabelling:

no

Test animals

Species:

other: rats amd human

Strain:

not specified

Sex:

male

Details on test animals or test system and environmental conditions:

Male white rats (300-400 g) were kept individually in all-glass metabolism cages and excreta were collected free from cross-contamination. Food and water were provided ad lib. Urine was collected under toluene at 24-hr intervals for 72 hr.
Faeces were collected at 48 and 72 hr.

Administration / exposure

Route of administration:

other: gavage, intraperitoneal and intravenous

Vehicle:

water

Duration and frequency of treatment / exposure:

single administration

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

20 other: mg/rat

Remarks:

gavage, rat 300-400g bw

Doses / concentrations 2

Dose / conc.:

100 other: mg/rat

Remarks:

gavage, rat 300-400 g bw

Doses / concentrations 3

Dose / conc.:

10 other: mg/rat

Remarks:

intraperitoneal, rat 300-400g bw

Doses / concentrations 4

Dose / conc.:

100 other: mg/rat

Remarks:

intraperitoneal, rat 300-400g bw

Doses / concentrations 5

Dose / conc.:

0.5 other: mg/rat

Remarks:

intravenous, rat 300-400g bw

Doses / concentrations 6

Dose / conc.:

4 other: mg/rat

Remarks:

intravenous, rat 300-400g bw

No. of animals per sex per dose / concentration:

not specified

Control animals:

no

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on excretion:

The nature of the metabolites of Black PN excreted in urine and faeces was dependent upon the route of administration (Table 4). After oral dosage in rats neither unchanged Black PN nor any coloured metabolites were found in the urine and only SA and ANSA were detected. The 48-hr faeces which were very dark in colour contained traces of Black PN, ANSA and large amounts of SA, DSA and AHNDA. In separate experiments, rats given an oral dose of Black PN excreted only traces of SNSA and ANSA in bile during a 6-hr collection. A considerable amount of Black PN and traces of SNSA were found in the stomach wall and contents together with traces of a red pigment chromatographically distinguishable from SNSA. SA and DSA were found in the intestinal contents. No unchanged Black PN was found below the small intestine. In none of these experiments was any SASA found.
After oral dosage of 240 mg Black PN to man, SA was the only metabolite detected in the urine. Intraperitoneal injection of Black PN into rats at a dose of 10 or 20 mg/rat did not cause any visible change. After doses of 100 mg/rat, however, the rats were visibly blue for about 4 hr, In all cases dark-coloured faeces were excreted for 48 hr and a dark brown urine was voided. The metabolites identified are recorded in Table 4. In contrast to oral dosage no Black PN was found in the faeces but compared with oral dosage the urine following intraperitoneal dosage contained four additional metabolites (Black PN, SNSA, DSA and AHNDA). Intravenous injection of Black PN at doses of 0.5--4.0 mg Black PN/rat led to the excretion of bile coloured dark blue. After a few minutes the bile became red. Chromatography showed the presence of traces of unchanged Black PN and large amounts of SNSA. Traces of ANSA were also detected. No coloured metabolites were found in the liver, heart, stomach, intestines or bladder of the rats from these experiments. The bladder contents, however, were coloured orange, presumably because of the presence of SNSA

Metabolite characterisation studies

Metabolites identified:

yes

Details on metabolites:

After administration of oral doses to rats, aromatic amines derived from the azo reduction of Black PN were excreted in the urine and faeces.Sulphanilic acid (SA) and 4-acetamido-l-naphthylamine-6 or 7-sulphonic acid (ANSA) were detected in the urine and both these metabolites together with unchanged Black PN (in traces), 1,4-diaminonaphthalene-6-sulphonic acid (DSA) and 8-acetamido-l-hydroxy-2-naphthylamine-3,5-disulphonic acid (AHNDA) were detected in the faeces.

Following intraperituneal dosage to rats, unchanged Black PN (traces), 1-(4'-sulphophenylazo)-4-naphthylamine-6-sulphonic acid (SNSA), SA, DSA, ANSA and AHNDA were excreted in the urine and all but Black PN and SNSA in the faeces. The excretion of Black PN and SNSA in the bile followed oral or intravenous administration of the colouring, and ANSA was excreted in addition following administration by the latter route.

Applicant's summary and conclusion

Conclusions:

The analogue substance was tested for metabolism (in particular excretion) by exposing some male rats to gavage, intraperitoneal and intravenous doses. Differences in metabolism between the oral and intraperitoneal routes coupled with the finding of Black PN, SNSA and SA in the intestinal tract of rats dosed orally with Black PN indicate that the gut flora cleave both azo links in Black PN whereas rat-liver azoreductase preferentially attacks the azo group linking the two naphthalene rings. Quantitative estimations were limited to SA, ANSA, SNSA and Black PN. The amount of SA excreted in urine and faeces was such as to indicate that the reduction of the azo link between the benzene and naphthalene rings was virtually completed, the remaining intact azo grouping being accounted for by SNSA.