Registration Dossier

Administrative data

Endpoint:
phototoxicity
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 which meets basic scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Photocarcinogenesis: Lack of Enhancement by Fluorescent Whitening Agents.
Author:
Forbes P.D. and Urbach F.
Year:
1975
Bibliographic source:
Environ Qual Saf Suppl. 1975; 4:212-22

Materials and methods

Principles of method if other than guideline:
24 mice were bathed in the test solution daily for 2 minutes 30 to 60 minutes prior to be exposed to "sunlight simulation" UV-lamp, in order to evaluate the potential for photocarcinogenicity of the test substance. The treatment was repeated 5 days per week for 40 week.
GLP compliance:
no
Remarks:
Pre GLP.
Type of method:
in vivo
Endpoint addressed:
carcinogenicity

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: Disodium 4-,4'-bis{(4-anilino-6-morpholino-l,3,5-triazin-2yl)amino} stilbene-2,2'-disulfonate .

Test animals

Species:
mouse
Strain:
SKH/HR1
Details on test animals and environmental conditions:
- Test animals: hairless mice.
- Source: initially purchased from two commercial sources, propagated in the test laboratory animal colony over several generations, and their offspring were used in the experiments. Animals from the Jackson Laboratory (Bar Harbor, Maine) were designated HRS/J, from an inbred strain of albino mice. Homozygous hairless (hr/hr) mice were used. The second source of breeder stock was Sandra Biological (New York City]. These outbred mice were homozygous at the hr locus, with all offspring phenotypically hairless. Hetcrogenicity was maintained at the c (albinism) locus, resulting in the segregation of albino and pigmented animals. Albino offspring (cc hrhr) are designated Skh: hairless-l whereas the pigmented (CC hrhr) animals are designated Skh:hairless·2. Only thc albino hairless (Skh:hairless-I) were used in the work reported here.
- Age at study initiation: 6-8 weeks.
- Diet: free access to mouse chow.
- Water: free access to tap water.

ADAPTATION
Mice were treated daily with solution for 2 weeks prior to the first light treatment.

Administration / exposure

Route of administration:
dermal
Vehicle:
other: methanol
Details on exposure:
TEST SOLUTION
- Vehicle: 1 g of XTA 15 brighterner free detergent per liter of distilled water.
- Test solution: 0.1 g/I of test substance in the detergent solution.
Solutions were made fresh daily.

APPLICATION
The animals were bathed in the test solutions.

UV IRRADIATION
Light source was a 6 kw long arc xenon burner(Osmar XBF 6000) with a filter to eliminate UV shorter than 290 nm and to attenuate the IR.
The output curve is a good match for midlatitude level solar spectrum.
The long axis of the lamp was hung vertically and animal housing units were arranged around the lamp.
The UV flux at the side (exposed surface) of the cage was monitored with zirconium WL 767 phototube. The average flux was 0.042 w/m2 erythema energy during a daily 2 hour exposure period for a maximum surface dose of 300 j/m2 per day.

EXPOSURE
The solution was at treatment room temperature (27 °C), contained in a glass tray. Cage units with 6 mice in individual cubicles were set into the glass trays; the fluid level brought to within one cm of the top of the unit.
Duration of treatment / exposure:
All animals were bathed daily for 2 minutes in test solution 30 to 60 minutes prior to light treatment.

Frequency of treatment:
5 days per week for 40 week.
Doses / concentrations
Remarks:
Doses / Concentrations:
0.1 g/l
Basis:
nominal conc.
No. of animals per sex per dose:
24 animals dosed with the test substance, 24 with positive control and 24 animals unirradiated, as negative control.
Control animals:
yes, concurrent vehicle
Details on study design:
EXPOSURE NOTES
The actual skin dose was influenced by the position of mice during exposure. The cages on each rack were rotated daily to minimize cage position related differences. Mice were moved to clean cages ence weekly.

DETERMINATION on TS AMOUNT
Indirect determination was made of the amount of test substance on the skin, but the bathed mice were compared under blacklight with mice that have received various concentrations of test item dissolved in methanol once to controlled areas of skin.

Examinations

Positive control:
Solution containing vehicle and 0.1 g 8-MOP (8-Methoxypsoralen) per liter.

Results and discussion

Details on results:
The fluorescence of the skin of test item-treated mice increased during the first 2 weeks.
The substance residue on bathed mice was estimated to be approximately 1 µg/cm2 skin.
All irradiated mice had transitory erythema during the 2nd to 3rd week of UV treatment. By 10 weeks, the mice exposed to 8 -MOP
were distinguishable from all others. They showed areas of more severe erythema, hyperplasia, and dry desquamation.
Except for skin fluorescence, the groups of unirradiated mice were indistinguishable. The test item treated group had lower tumour yield and prevalence than the control. Most of the tumours developed on the animal sides, with very few on the midline of the back or on the head, ears, snout, or abdomen.

The 8-MOP treated mice had higher tumour yield and prevalent than the irradiated, detergent only treated controls.

Any other information on results incl. tables

Substance µg compound per cm2 skin Accumulated light dose (j/m2) Weeks of UV light exposure to elicil tumors in 50 % of survivors Surviving fraction
vehicle 28.5 x 10^3 19 22/24
8-MOP less than 1 22.5 x 10^3 15 19/24
Test substance approx. 1 30.0 x 10^3 20 23/24

Applicant's summary and conclusion

Conclusions:
No tendency to photocarcinogenesis.
Executive summary:

Method

24 mice were bathed in the test solution daily for 2 minutes 30 to 60 minutes prior to be exposed to "sunlight simulation" UV-lamp, in order to evaluate the potential for photocarcinogenicity of the test substance. The treatment was repeated 5 days per week for 40 week. Other two groups of 24 animals were exposed to vehicle and 8 -MOP (8-Methoxypsoralen) as control and positive control, respectively.

Results

All irradiated mice had transitory erythema during the 2nd to 3rd week of UV trentment.

The test item treated group had lower tumor yield and prevalence than the control. Most of the tumors developed on the animal sides, with very few on the midline of the back or on the head, ears, snout, or abdomen.

In conclusion the experiment showed no tendency to photocarcinogenesis.