t-Butyl (2S,2aS,5aR)-1-azabicyclo[3.3.0] oct-2-carboxylate monooxalate salt

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-10-23 to 2007-04-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed according to OECD Guideline 402 (Acute Dermal Toxicity) and EU Method B.3. (Acute toxicity (dermal)) without deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Remarks:

The testing facility indicated that the protocol was followed without deviation.

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Remarks:

The testing facility indicated that the protocol was followed without deviation.

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from the Department of Health of the Government of the United Kingdom

Test type:

standard acute method

Limit test:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): VRT-126028
- Molecular formula (if other than submission substance): Not applicable
- Molecular weight (if other than submission substance): Not applicable
- Smiles notation (if other than submission substance): Not applicable
- InChl (if other than submission substance): Not applicable
- Structural formula attached as image file (if other than submission substance): Not applicable
- Substance type: No data
- Physical state: White powder
- Analytical purity: 99.3% area by GC
- Impurities (identity and concentrations): No data
- Composition of test material, percentage of components: No data
- Isomers composition: No data
- Purity test date: No data
- Lot/batch No.: 25414
- Expiration date of the lot/batch: 2006-09-15
- Stability under test conditions: No data
- Storage condition of test material: Room temperature
- Other: No data

Test animals

Species:

rat

Strain:

other: Crl: CD BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd., Margate, Kent, England
- Age at study initiation: Eight to twelve weeks of age
- Weight at study initiation: 202-297 g
- Fasting period before study: No data
- Housing: They were housed individually from Day -1. The cages were made of a stainless steel body with stainless steel mesh lid and floor, and were suspended above absorbent paper which was changed at appropriate intervals. Cages, cage-trays, food hoppers and water bottles were changed at appropriate intervals. Animals were housed inside a barriered rodent facility. The facility was designed and operated to minimize the entry of external biological and chemical agents and to minimize the transference of such agents between rooms.
- Diet: The animals were allowed free access to a standard rodent diet (Rat and Mouse No. 1 Maintenance Diet). This diet contained no added antibiotic or other chemotherapeutic or prophylactic agent.
- Water: Potable water taken from the public supply was freely available via polycarbonate bottles fitted with sipper tubes.
- Acclimation period: The animals were allowed to acclimatize to the conditions described below for six days before treatment.

ENVIRONMENTAL CONDITIONS
- Temperature (deg C): 19-23 deg C Temperature was monitored daily.
- Humidity (%): 40-70% Humidity was monitored daily.
- Air changes (per hr): Periodic checks were made on the number of air changes in the animal rooms.
- Photoperiod (hrs dark / hrs light): 12 hr continuous light/ 12 hr continuous dark per 24 hours

IN-LIFE DATES: From: 2006-10-23 To: 2006-11-14

Administration / exposure

Type of coverage:

not specified

Vehicle:

other: aqueous methylcellulose

Details on dermal exposure:

TEST SITE
- Area of exposure: One day prior to treatment, hair was removed from the dorso-lumbar region of each rat with electric clippers taking care to avoid damaging the skin.
- % coverage: 10% of the total body surface area
- Type of wrap if used: The test substance was applied by spreading it evenly over the prepared skin. The treatment area (approximately 50 mm x 50 mm) was covered with porous gauze held in place with a non-irritating dressing, and further covered by a waterproof dressing encircled firmly around the trunk of the animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was carefully removed and the treated area of skin was washed with warm water (30-40 degrees C), to remove any residual test substance. The treated area was blotted dry with absorbent paper.
- Time after start of exposure: At the end of the 24-hour exposure period.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 3.0 mL/kg bodyweight
- Concentration (if solution): 666.6 mg/mL
- Constant volume or concentration used: No
- For solids, paste formed: No data

VEHICLE
- Amount(s) applied (volume or weight with unit): No data
- Concentration (if solution): No data
- Lot/batch no. (if required): No data
- Purity: No data

Duration of exposure:

24 hours

Doses:

Single topical application of 2000 mg/kg bodyweight

No. of animals per sex per dose:

Ten rats (five male and five female)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Cages of rats were checked at least twice daily for any mortalities. Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days, animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15- morning only). The nature and severity, where appropriate, of the clinical signs and the time were recorded at each observation.
- Necropsy of survivors performed: Yes
- Other examinations performed:
Body weight: The weight of each rat was recorded on Days 1 (prior to dosing), 8 and 15. Individual weekly bodyweight changes and group mean bodyweights were calculated.
Dermal reactions: Local dermal irritation at the treatment site was assessed daily using the following numerical scoring system: See "Any other information on materials and methods" section below.
Macropathology: All animals were subjected to a macroscopic examination which consisted of opening the cranial, thoracic and abdominal cavities. The macroscopic appearance of all examined organs was recorded.

Statistics:

No data

Results and discussion

Preliminary study:

Not applicable

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

There were no deaths and no systemic response to treatment in any animal.

Clinical signs:

No data

Body weight:

A low body weight gain was recorded on Day 8 for three females, and one female on Day 15. All other animals were considered to have achieved satisfactory bodyweight gains throughout the study.

Gross pathology:

The macroscopic examination at study termination on Day 15 revealed congestion (darkened tissue/organ) of the liver in one male. White patches on the lungs were seen in one female and black patches on the lungs of another female. No other abnormalities were noted in the remaining animals.

Other findings:

- Organ weights: No data
- Histopathology: No data
- Potential target organs: No data
- Other observations: Yes
- Dermal reactions: After bandage removal, very slight irritation (Grade 1 erythema) was observed in three males and three females, also well defined irritation (Grade 2 erythema) was seen in one female from Day 5. These reactions had all resolved by Day 11. In addition, small areas of scabbing were seen in three males and three females from Day 2. These reactions had all resolved by Day 15.

Any other information on results incl. tables

Not applicable

Applicant's summary and conclusion

Conclusions:

The objective of this study was to assess the toxic potential of the test substance, a pharmaceutical intermediate, following a single dermal dose in the rat. The acute median lethal dermal dose (LD50) to rats of the test substance was demonstrated to be greater than 2000 mg/kg bodyweight.

Executive summary:

Not applicable