N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 25 - November 08, 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): BMH
- Physical state: White crystal
- Storage condition of test material: In the refrigerator in the dark
- Stability under storage conditions: Stable
- Stability in corn oil: At least 24 h
- Solubility in corn oil: Not indicated

Test animals

Species:

rat

Strain:

other: Crl:(WI) BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: Females: 211-263 g, males: 371-402 g.
- Housing: Individually housed in labelled Macrolon cages containing purified sawdust as bedding material (SAWI, Jelu Werk, Rosenberg, Germany). Type III cages were used and since these cages were suitable for individual housing, this protocol deviation was considered not to have affected the study integrity.
- Diet (e.g. ad libitum): Free access to pelleted rodent diet (from Altromin (code VRF 1), Lage, Germany)
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: The acclimatization period was at least 5 days before the start of treatment under laboratory conditions.
- Health inspection: A health inspection was performed prior to treatment, to ensure that the animals were in a good state of health. Special attention was paid to the skin to be treated, which was intact and free from any abnormality.

Results of analysis for diet (nutrients and contaminants), sawdust and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

occlusive

Vehicle:

corn oil

Details on dermal exposure:

One day before exposure (Day -1) an area of approximately 5x7 cm on the back of the animal was clipped.

The formulation was applied in an area of approx. 10% of the total body surface, i.e. approx. 25 cm² for males and 18 cm² for females. The test substance was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D)*, successively covered with aluminium foil and Coban flexible bandage*. A piece of Micropore tape* was additionally used for fixation of the bandages in females only.

Frequency: Single dosage, on Day 1.

Washing: Following application, dressings were removed and the skin cleaned of residual test substance using tap water.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

VEHICLE
- Justification for choice of vehicle: The vehicle was selected based on a pretest performed at NOTOX and at request of the sponsor.

Dose volume: 10 ml/kg body weight

DOSAGE PREPARATION: The formulation (w/w) was prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level. Adjustment was made for specific gravity of vehicle.

Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: Twice daily
Body weights: Days 1 (pre-administration), 8 and 15
Clinical signs: At periodic intervals on the day of dosing (day 1) and once daily thereafter, until day 15. The time of onset, degree and duration were recorded and the symptoms graded according to fixed scales.
- Necropsy of survivors performed: At the end of the observation period, all animals were sacrificed by asphyxiation using an oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.
- Other examinations performed: none.

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No mortality occurred.

Clinical signs:

other: Chromodacryorrhoea of the snout was noted in three males and two females. The animals had recovered from the symptom by days 2 or 3.

Gross pathology:

No abnormalities were found.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an acute dermal toxicity study performed according to OECD 402 and GLP, the LD50 value of BMH in Wistar rats was established to exceed 2000 mg/kg body weight.