Amines, C12-14 (even numbered)-alkyldimethyl, N-oxides

Repeated dose toxicity: dermal

Administrative data

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

N/A to: 1978-12-26

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study was conducted in methods comparable to OECD guideline 411 " Subchronic Dermal Toxicity: 90-day Study". 25 animals per sex per dose, only two dose levels evaluated. Not GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

See rationale for reliability above.

Principles of method if other than guideline:

N/A

GLP compliance:

no

Remarks:

However, quality reviews of the study were performed and documented.

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Amines, C12-14 (even numbered)-alkyldimethyl, N-oxides

EC Number:

931-292-6

Cas Number:

308062-28-4

Molecular formula:

CnH(2n+3)NO, where n=14/16

IUPAC Name:

Amines, C12-14 (even numbered)-alkyldimethyl, N-oxides

Details on test material:

- Name of test material (as cited in study report): P7236A (or LH17,467) and P7236B (or LH17,468)
- Molecular formula (if other than submission substance): N/A
- Molecular weight (if other than submission substance): 235.7
- Smiles notation (if other than submission substance): N/A
- InChl (if other than submission substance): N/A
- Structural formula attached as image file (if other than submission substance): N/A
- Substance type: Active
- Physical state: clear liquid

Test animals

Species:

mouse

Strain:

other: ICR- Swiss CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: N/A
- Weight at study initiation: female mice: 21 to 31 grams, male mice: 28-31 grams
- Fasting period before study: N/A
- Housing: individually housed in steel hanging wire cages
- Diet: Wayne rodent diet, ad libitum
- Water: ad libitum
- Acclimation period: N/A


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72 - 79
- Humidity (%): 36-61%
- Air changes (per hr): 9.1 and 9 changes/hr
- Photoperiod (hrs dark / hrs light): N/A


IN-LIFE DATES: From: 1977-08-31 To: 1977-11-30

Administration / exposure

Type of coverage:

not specified

Vehicle:

not specified

Details on exposure:

TEST SITE
- Area of exposure: Dorsal area (2 X 3cm)
- % coverage: N/A
- Type of wrap if used:N/A
- Time intervals for shavings or clipplings: Clipped prior to initial treatment and weekly

REMOVAL OF TEST SUBSTANCE
- Washing (if done): N/A
- Time after start of exposure: N/A


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml
- Concentration (if solution): N/A
- Constant volume or concentration used: N/A
- For solids, paste formed: N/A


VEHICLE
- Justification for use and choice of vehicle (if other than water): water
- Amount(s) applied (volume or weight with unit): 0.1 ml
- Concentration (if solution): 0.27% and 1.33%
- Lot/batch no. (if required): N/A
- Purity: N/A


USE OF RESTRAINERS FOR PREVENTING INGESTION: N/A

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

N/A

Duration of treatment / exposure:

91 days

Frequency of treatment:

5 treatments per week

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0.27 mg DDAO/application
Basis:
other: total amount applied per application

Doses / concentrations 2

Remarks:

Doses / Concentrations:
1.33 mg DDAO/application
Basis:
other: total amount applied per application

No. of animals per sex per dose:

25/sex/dose

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: N/A
- Rationale for animal assignment: random
- Rationale for selecting satellite groups: N/A
- Post-exposure recovery period in satellite groups: N/A
- Section schedule rationale (if not random): N/A

Positive control:

N/A

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations checked: general health, mortality, and gross skin irritation effects

DETAILED CLINICAL OBSERVATIONS: No data
- Time schedule: N/A

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): N/A
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

FOOD EFFICIENCY: No
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: N/A

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
- Time schedule for examinations: N/A

OPHTHALMOSCOPIC EXAMINATION: No
- Time schedule for examinations: N/A
- Dose groups that were examined: N/A

HAEMATOLOGY: No
- Time schedule for collection of blood: N/A
- Anaesthetic used for blood collection: N/A
- Animals fasted: N/A
- How many animals: N/A
- Parameters checked: N/A

CLINICAL CHEMISTRY: No
- Time schedule for collection of blood: N/A
- Animals fasted: N/A
- How many animals: N/A
- Parameters checked: N/A

URINALYSIS: No
- Time schedule for collection of urine: N/A
- Metabolism cages used for collection of urine: No data
- Animals fasted: N/A
- Parameters checked: N/A

NEUROBEHAVIOURAL EXAMINATION: No
- Time schedule for examinations: N/A
- Dose groups that were examined: N/A
- Battery of functions tested: sensory activity / grip strength / motor activity / other: N/A

OTHER: After termination of the study, 5 females from each group were submitted to the study sponsor for in vitro skin penetration studies. Animals from the 1.33 mg/application group were submitted on day 90, and animals from the 0.27 mg/application group were submitted on day 92.

Sacrifice and pathology:

GROSS PATHOLOGY: After 28 days (20 dermal applications) 10 male and 10 females from each group were sacrificed and necropsied. Gross necropsies were performed.
The remaining animals continued on the treatment until the termination of the study. At study termination 5 animals from each dose group were submitted to the sponsor for skin penetration studies the remaining animals were sacrificed and necropsied. Organs collected and examined: brain, pituitary, thyroid, thymus, large intestine, small intestine, heart, trachea, axillary lymph nodes, stomach, esophagus, uterus, skin from treated area and dorsal untreated area, mesenteric lymph nodes, lungs, liver, spleen, kidneys, adrenals, urinary bladder, ovary, testis, eyes, aorta, pancreas, and carcass.

HISTOPATHOLOGY: Yes - but only skin was examined histologically.

Other examinations:

N/A

Statistics:

N/A

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
All animals in both dose groups survived until the designated termination at 28 and 91 days.

BODY WEIGHT AND WEIGHT GAIN
The weekly average body weights of the male and female mice in both dose groups were normal and comparable to the vehicle control group at 28 and 91 days.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): N/A

FOOD EFFICIENCY: N/A

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): N/A

OPHTHALMOSCOPIC EXAMINATION: N/A

HAEMATOLOGY: N/A

CLINICAL CHEMISTRY: N/A

URINALYSIS: N/A

NEUROBEHAVIOUR: N/A

ORGAN WEIGHTS: No data

GROSS PATHOLOGY and HISTOPATHOLOGY NON-NEOPLASTIC:
28 day interim sacrifice:
- 0.27% DDAO dose group:
- At necropsy, one male exhibited small red areas on lobes of the lungs and one female exhibited thickened uterus walls and stomach walls, other than the two animals no other gross pathological signs were observed. No effects were considered to be substance related.
- Minimal dermal irritation was present in six male and four female mice consisting of minimal or slight acanthosis.

- 1.33% DDAO dose group:
- Asmall gray area in the left lobe of one female, which was not considered to be substance related was noted.
- A more pronounced dermal irritation was present with more pronounced acanthosis and the presence of hyperkeratosis than the lower dose group sacrificed at 28 days.

91 day terminal sacrifice:
- 0.27% DDAO dose group:
- At necropsy, four males exhibited individual gross pathologies including: thickening of stomach wall; skin vascular; red areas in all lobes of lungs; and spleen slightly smaller than normal. Three females exhibited the following individual gross pathologies: brachial lymph nodes enlarged numerous small white foci on all lobes of liver, pale liver, and small gray cystic area on cortex of left kidney; left lobe of lung ill-regular in shape and had spongy areas, ovaries enlarged and firm; red cysts around right ovary, spleen slightly enlarged. These effects were considered to be substance related.
- Minimal dermal irritation was present in 11 male and the 10 female mice consisting of minimal or slightly acanthosis.

- 1.33% DDAO dose group:
- At necropsy, several males exhibited thickened dorsal skin. Another male exhibited discoloration of the liver, cystic liver mass and enlarged kidneys. One female exhibited an enlarged cervix and thickened walls in addition to an ovarian cyst. The systemic effects were not considered to be substance related. Only the skin effects at the site of treatment were considered to be test substance related.
- A more pronounced dermal irritation was present with minimal acanthosis in one mouse, slightly acanthosis in 11 mice and moderate acanthosis in 13 mice.

HISTOPATHOLOGY: NEOPLASTIC (if applicable): N/A

HISTORICAL CONTROL DATA (if applicable): N/A

OTHER FINDINGS: N/A

Effect levels

Dose descriptor:

LOEL

Remarks:

localized dermal effects

Effect level:

0.27 other: % DDAO

Sex:

male/female

Basis for effect level:

other: Slight to more pronounced dermal irritation was observed microscopically at both dose levels

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

N/A

Applicant's summary and conclusion

Conclusions:

Repeated dermal applications of the test substance at a dose of 0.27 mg DDAO/application for 28 and 91 days (5 times per week) resulted minimal to mild acanthosis with the effects being more pronounced with the repeated applications of 1.33 mg DDAO/application, resulting in both acanthosis and hyperkeratosis. No systemic effects were identified; however no histopathology was conducted (except on skin).

Executive summary:

The objective of the study was to obtain scientific data to determine the histopathological effects of the skin at treatment sites after repeated dermal exposure to the test substance over 91 days with a 28 day interim sacrifice.

Fifty ICR-Swiss CD-1 mice (25M, 25F) per group were assigned to each of the following treatment groups. The dose volume for each group was 0.1ml with the control group being sterile water. Treatment groups were 0.27% DDAO (0.27 mg per application) and 1.33% DDAO (1.33 mg per application). An area of 2 X 3 cm of the dorsal area of all animals was clipped and treated with 0.1ml of appropriate treatment 5 days per week.

All animals were observed daily for signs of general health, mortality and gross skin irritation effects. Gross signs of toxicity and body weights were recorded on a weekly basis throughout the study.

After 28 days (21 dermal applications) 10 males and 10 females from each group were sacrificed and necropsied. The remaining animals continued on the treatment regimen until the termination of the study. At study termination (90-92 days from initiation of the study), 5 females from each group were sent to the sponsor for in-vitro skin penetration studies. The remainder of the animals were sacrificed and necropsied.

At the 28 and 91 day necropsies, the following tissues were preserved in formalin: brain, pituitary, thyroid, thymus, small and large intestine, heart, trachea, axillary and mesenteric lymph nodes, stomach, esophagus, uterus, skin from treated and dorsal non-treated areas, lungs, liver, spleen, kidneys, adrenals, urinary bladder, ovary, testis, eyes, aorta, pancreas, and carcass. The skin tissues from treated animals and dermal non-treated areas were processed and examined histopathologically.

No mortalities were attributed to treatment and there were no significant differences in body weights in any animals throughout the study. Gross necropsies at interim or terminal sacrifice did not reveal any substance related lesions with the exception of skin effects at the site of treatment for the 0.27% group after 28 days applications of the test substance. Repeated applications of 1.33% over the 28 days resulted in slight to moderate erythema and scaling in most animals. The histological examinations of the 0.27% dose group after 28 days exhibited dermal irritation consisting of minimal to slight acanthosis. The dermal irritation effects were more pronounced in animals dosed with 1.33% consisting of acathosis and hyperkeratosis.   

The gross observations of skin effects of animals treated with 1.33% and sacrificed after 91 days were more severe than the irritation effects observed at 28 days. The gross observations of the skin effects of animals treated with 0.27% were erythema and scaling in most animals compared to no significant irritative effects at 28 days. When histological examinations were conducted, minimal dermal irritation was present in 11 male and the 10 female mice treated with 0.27% and consisted of minimal or slight acanthosis. In mice treated with 1.33%, a more pronounced dermal irritation was present with minimal acathosis in one mouse, slight acanthosis in 11 mice and moderate acanthosis in 13 mice.

Gonadal tissues were examined for gross pathology and no treatment-related effects were detected.

Repeated dermal applications of 0.1ml of 0.27% DDAO (0.27 mg/application) for five days/week for 28 and 91 days resulted minimal to mild acanthosis. Local effects were more pronounced with the repeated dermal applications of 0.1ml of 1.33% DDAO (1.33 mg/application) for five days/week, resulting in both acanthosis and hyperkeratosis. No systemic effects, based on mortality, clinical signs and gross necropsy observations were identified at either dose level; however, no histopathology was performed except on skin.