Dodecyl methacrylate

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

Combined repeated dose and reproduction / developmental screening study in rats

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12-Oct-2004 to 06-Dec-2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 422, Screening test, GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

adopted 22 March 1996

Principles of method if other than guideline:

OECD combined study TG422:
Combined repeated dose toxicity study by the oral route (gavage) with the reproduction/development toxicity screening test. Three groups of 10 
male and 10 female Sprague-Dawley rats received the test item, Lauryl MA, by daily oral (gavage) administration for 15 days before mating, through 
mating, gestation and the beginning of the lactation period (until day 5 post-partum, p.p.). The dose-levels were 100, 300 and 1000 mg/kg/day. The
control group (10 males and 10 females) received the vehicle only (corn/oil). The dosing volume was 5 mL/kg. Clinical signs and mortality were 
checked daily. Body weight and food consumption were recorded at designated intervals throughout the study. Detailed clinical observations, 
reactivity to different stimuli (Functional Observation Battery; (FOB)) and motor activity were also recorded. Blood was taken from five males and five
females for hematological and blood biochemical investigations at terminal sacrifice (i.e. in week 6 for males and week 7 for females). At the same 
time, urine was collected from five males for analysis. Males were sacrificed approximately two weeks (week 6) after the end of the mating period, 
females on day 6 p.p. The animals were subjected to a  macroscopic examination of the principal thoracic and abdominal organs. Designated organs were weighed and examined microscopically. In addition,  the numbers of corpora lutea and implantation sites were recorded for each female. The 
pups were observed daily for clinical signs, sexed and  weighed on days 1 and 5 p.p.  After sacrifice on day 6 p.p., the pups were examined for gross  abnormalities.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dodecyl methacrylate

EC Number:

205-570-6

EC Name:

Dodecyl methacrylate

Cas Number:

142-90-5

Molecular formula:

C16H30O2

IUPAC Name:

dodecyl 2-methylprop-2-enoate

Test material form:

liquid

Specific details on test material used for the study:

- Name of test material (as cited in study report): Lauryl methacrylate (CAS: 142-90-5)
- Supplier: Evonik RohMax Additives Inc., Horsham, PA 19044, USA

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Number: 88 rats (44 males and 44 females)
- Source: Sprague-Dawley, Crl CD® (SD) IGS BR, Caesarian Obtained, Barrier Sustained-Virus Antibody Free, (COBS-VAF®); Charles River Laboratories France, L’Arbresle, France.
- Age at study initiation: males were 8 weeks old and females were 10 weeks old
- Weight at study initiation: males: mean body weight of 317 g (range: 296 g to 345 g); females mean body weight of 223 g (range: 199 g to 261 g)
- Fasting period before study:
- Housing: The animals were individually housed (except during mating) in suspended wire-mesh cages (43.0 x 21.5 x 18.0 cm). A metallic tray
containing autoclaved sawdust (SISCA, Alfortville, France) was placed under these cages. During mating, gestation and lactation, the
animals were housed in polycarbonate cages (43.0 x 21.5 x 20.0 cm) containing autoclaved sawdust (SICSA, Alfortville, France), with wood shaving as nesting material.
- Diet: ad libitum (SNIFF R/M-H pelleted maintenance diet, batch No. 2764132 (SNIFF Spezialdiäten GmbH, Soest, Germany) distributed weekly)
- Water: ad libitum (tap water (filtered with a 0.22 μm filter)
- Acclimation period: 7 days before the beginning of the treatment period
- Allocation to group: during the acclimation period, the required number  of animals were selected according to body weight and/or clinical 
condition and allocated by sex to the groups, using a stratification procedure based on body weight (these data are not 
presented in the report). Body weights of the animals assigned to the study at the start of the  treatment period were within 
20% of the mean weight for each sex. Identification: each animal was individually identified by an ear tattoo detailing a unique 
CIT identity number.
- Contaminant analyses: The batches of diet and sawdust were analyzed by the suppliers for composition and contaminant levels. Bacterial and 
chemical analyses of water are performed regularly by external laboratories. These analyses include the detection of possible  contaminants 
(sawdust: pesticides and heavy metals; diet and water:  pesticides, heavy metals and nitrosamines). No contaminants were present in the diet, drinking water or sawdust at  levels which could be expected to interfere with or prejudice the outcome  of the study. A copy of the appropriate analyses was maintained with the study records.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20 %
- Air changes (per hr): about 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12h/12h

The corresponding instrumentation and equipment are checked and calibrated at regular intervals. The temperature and relative humidity  are 
recorded continuously and the records are checked daily and filed. The animal room was disinfected before the arrival of the animals and  cleaned 
regularly thereafter.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: The test item dosage formulations were prepared by suspending Lauryl Methacrylate (Lauryl MA; 
CAS: 142-90-5) in corn oil to achieve the concentrations of 20, 60 and 200 mg/mL and were stored at 
+4°C, protected  from light, for up to 9 days prior to use.
- Administration: The dosage formulations were administered by gavage using a plastic syringe fitted with a metal gavage tube (length of gavage 
tube: 7.6 cm),  once a day, at approximately the same time. The quantity of dosage formulation administered to each animal was 
adjusted according to the  most recently recorded body weight with the exception that body weights on day 14 post-coitum were 
used to calculate individual dosages for the  pregnant females from day 14 post-coitum through parturition (day 1 post-partum) to  avoid overdosing the dams because weight gain from GD 14 to 20 (GD: gestation day) is fetal weight. A constant dosage-volume of 5 mL/kg/day was used. Control animals (group 1) received the vehicle alone. The dosage formulations were stirred continuously throughout the dosing procedure.

VEHICLE
- Justification for use and choice of vehicle (if other than water): corn oil
- Lot/batch no. (if required): 122K0131 and 103K0107, supplied by Sigma (Saint-Quentin-Fallavier, France)
- Purity: no data, commercial product

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

- Homogeneity: Two dosage formulations were prepared at 5 and 300 mg/mL of test item in corn oil to cover all the concentrations intended for use 
in this study. From both dosage formulations, duplicate samples were taken at three different levels of the container (top, middle and bottom) and 
analyzed  for concentration of the test item to evaluate the homogeneity.
- Stability: The two dosage formulations prepared for homogeneity analysis were sampled after 0 (just after preparation, homogeneity), 4 and 9 days  storage at +4°C (protected from light). The aliquots sampled on day 4  were stored frozen at -20°C pending analysis on the last sampling  occasion 
(day 9) when all samples were assayed. The mean concentration  measured on day 0 (homogeneity) was taken as the initial value for the stability test. - Concentration: The concentration of the test item in samples taken from each dosage formulation (including the control) prepared for use in weeks 1, 2, 4 and  8 was determined. 

Duration of treatment / exposure:

Each animal was given the appropriate dosage formulation once a day, at  approximately the same time each day, 7 days a week, according to the  
following schedule:
in the males: 15 days before mating, during the mating and post-mating periods until sacrifice (approximately 6 weeks in total),
in the females: 15 days before mating, during the mating period, during pregnancy and lactation, until day 5 post-partum inclusive (or until sacrifice, for un-mated females). Day 1 corresponds to the first day of the treatment period.

Frequency of treatment:

once a day, 7 days/week

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300 and 1000 mg/kg/d
Basis:
nominal in diet

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Dose selection rationale: The dose-levels were selected in agreement with the Sponsor, following  the results of a previously conducted study 
CIT/Study No. 28196 TSR in which rats administered Lauryl MA at 0, 100, 300 or 1000 mg/kg/day for 10  consecutive 
days by gavage did not show any toxic effect. The highest dose-level, 1000 mg/kg/day, is the highest dose required by 
the guidelines.

Positive control:

No positive control.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes

MORBIDITY AND MORTALITY:
- Time schedule: Each animal was checked at least twice a day for mortality and signs of morbidity (except during the acclimation period when they
were checked at least once a day).

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Each animal was observed at least once a day at approximately the same time (i.e. after dosing the animals in the morning), for the
recording of clinical signs. Animals were also observed in the afternoon as part of the mortality check and any clinical signs were recorded.

All animals of each group were observed in the cage, in the hand and in the standard arena, by observers unaware of the animal's treatment, before
the first day of treatment and then once a week thereafter.
The animals were randomized in order to ensure "blind" evaluation, except for examination performed before the first day of treatment.
The following parameters were assessed:
- "touch escape" or ease of removal from the cage,
- in the hand: fur appearance, chromodacryorrhea, chromorhinorrhea, salivation, lachrymation, piloerection, eye, exophthalmia, mucous membrane, reactivity to handling, pupil size (presence of myosis or mydriasis),
- in the standard arena (two-minute recording): grooming, palpebral closure, defecation and urination counts, tremors, twitches, convulsions, gait,
arousal (hypo- and hyper-activity), posture, stereotypy behaviour and breathing, ataxia, hypotonia.

Reactivity to manipulation or to different stimuli (FOB):
In five males and five females per group, the examinations listed below were conducted shortly before terminal sacrifice, and before blood sampling
for clinical pathology. The observer performing the evaluation was not aware of the treatment group of the animal. The animals were randomly
selected in order to ensure "blind" evaluation.
The following measurements, reflexes and responses were recorded:
. touch response,
. forelimb grip strength qualitative approach,
. pupil reflex,
. visual stimulus,
. auditory startle reflex,
. tail pinch response,
. landing foot splay,
. righting reflex,
. at the end of observation: rectal temperature.

Motor activity
Motor activity was measured in five males and five females using automated infra-red sensor equipment, recording individual animal activity over a
one-hour period. The females were evaluated on or near day 17 post-coitum to avoid removal of the dam from her pups after parturition and the
males were evaluated at approximately the same time as the females and near the time of sacrifice.


BODY WEIGHT: Yes
- Time schedule for examinations: The body weight of each male was recorded on the first day of treatment (day 1), then once a week until sacrifice.
The body weight of each female was recorded on the first day of treatment (day 1), then once a week until mated (or until sacrifice) and on days 0, 7,
14 and 20 post-coitum and days 1 and 5 post-partum.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption/Compound intake: Yes
The quantity of food consumed by each animal was recorded once a week, over a 7-day period, from the first day of treatment through gestation
(days 0-7, 7-10, 10-14, 14-17 and 17-20 post-coitum intervals) and lactation (days 1-5 post-partum interval). During the mating period, the food
consumption was not recorded for males or females. Food intake per animal and per day was calculated by noting the difference between the food
given and that remaining in the food-hopper at the end of the specified interval.


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No


HAEMATOLOGY: Yes
- Time schedule for collection of blood:
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes
- How many animals: 10; five males and five females (adults) from each group at terminal sacrifice
- Parameters checked: Lithium heparin tubes: Sodium (Na+), Potassium (K+), Chloride (Cl-), Calcium (Ca++), Inorganic phosphorus (I.PHOS),
Glucose (GLUC), Urea (UREA), Creatinine (CREAT), Total bilirubin (TOT.BIL), Total proteins (PROT), Albumin (ALB), Albumin/globulin ratio (A/G),
Total cholesterol (CHOL), Triglycerides (TRIG), Alkaline phosphatase (ALP), Aspartate aminotransferase (ASAT), Alanine aminotransferase (ALAT),
Tubes without anticoagulant: Biles acids (BIL.AC)


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
- Animals fasted: Yes
- How many animals: 10; five males and five females (adults) from each group at terminal sacrifice
- Parameters checked: EDTA tubes: Erythrocytes (RBC), Hemoglobin (HB), Mean cell volume (MCV), Packed cell volume (PCV), Mean cell hemoglobin
concentration (MCHC), Mean cell hemoglobin (MCH) Thrombocytes (PLAT), Leucocytes (WBC), Differential white cell count with cell morphology
. neutrophils (N)
. eosinophils (E)
. basophils (B)
. lymphocytes (L)
. monocytes (M)
Sodium citrate tubes: Prothrombin time (PT), Activated partial thromboplastin time (APTT), Fibrinogen (FIB)


URINALYSIS: Yes
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- How many animals: 5; first surviving five males (adults) from each group at terminal sacrifice
- Parameters checked: Quantitative parameters: Volume (VOLUME), pH (pH), Specific gravity (SP.GRAV)
Semi-quantitative parameters: Proteins (PROT), Glucose (GLUC), Ketones (CETO), Bilirubin (BILI), Nitrites (NITR), Blood (BLOOD), Urobilinogen (UROB)
Cytology of sediment Microscopic:
. Leucocytes (WBC)
. Erythrocytes (RBC)
. Cylinders (CYLIN)
. Magnesium ammonium phosphate crystals (AMM.PH)
. Calcium phosphate crystals (CAL.PH)
. Calcium oxalate crystals (CAL.OX.)
. Cells (CELLS)
Qualitative parameters: Appearance (APP), Color (COLOR)


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Statistics:

Motor activity
The statistical comparison of results of motor activity (horizontal and rearing movements recorded from 5 males and 5 females per group) was
performed, according to the following
steps:
. step 1: normality and homogeneity of variances (Kolmogorov-Smirnov and Bartlett test respectively),
. step 2: parametric (ANOVA plus Dunnett test if necessary) or non-parametric (Kruskal-Wallis plus Dunn test if necessary) tests were conducted
based on the results obtained at step 1.
These statistics were performed using the software SAS Enterprise Guide V2 (2.0.0.417, SAS Institute Inc), with a level of significance of 0.05 for all
tests.
The other data are compared by one-way analysis of variances (ANOVA) and Dunnett test (quantitative values) or by Fisher exact probability test
(proportions).

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
There were no premature deaths during the study.
Hypersalivation: recorded in a dose-related incidence in males and females: 300 or 1000 mg/kg/day during premating (for males) and furthermore 
during gestation and lactation (for females).

BODY WEIGHT AND WEIGHT GAIN
Females given 1000 mg/kg/day gained 18% less weight than the controls between day 0 and day 7 post-coitum. This weight difference was 
statistically insignificant (limited to the first week of gestation). No other treatment-related effects on body weight were noted.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Males
The food consumption of treated males was similar to that of the controls during the study.
Females
There was no effect of treatment on group mean food consumption during the premating or lactation periods.
Between day 7 and day 10 post-coitum, all groups given Lauryl MA consumed less food than the controls, with no dose-relationship trend, achieving statistical significance at 100 and 1000 mg/kg/day (-17%, p<0.05 and -25%, p<0.001, respectively). Due to the lack of dose response and lack of
consistency with other time periods in the study, these differences in food consumption were not considered of toxicological importance.

HAEMATOLOGY
There was no treatment-related effect on any of the hematological parameters examined.
When compared with the mean control values, a lower value in total white cell count was recorded for females in the 1000 mg/kg/day group (4.95 vs 7.34 g/L: -33%, not statistically significant). This change was not considered related to treatment with the test item because of the great variability and the great inter-individual variations of this parameter and the lack of effects on other related parameters (differential cell counts).

Blood biochemistry
There was an increase in blood glucose concentration in male rats given 1000 mg/kg/day (7.63 mmol/L, p<0.01) when compared with the controls
(5.78 mmol/L); a relationship to the treatment with the test item cannot be excluded. However, this variation was not considered to be of toxicological importance since the number of animals/group was limited to five, all values were within historical data range (mean: 6.69 mmol/L,
[5.22-9.04 mmol/L]) and there were no histopathological findings in the liver.
All other differences were considered not to be relevant since either no clear dose-relationship was evident (increased triglyceride and cholesterol
plasma concentration in test item-treated females), or differences were slight (decrease in plasmatic protein concentration and increase in liver
enzyme activities in females).

URINALYSIS (males)
There was no effect of treatment on pH, specific gravity or volume of urine produced by the males in any group.

ORGAN WEIGHTS
There were no treatment-related effects on absolute or relative organ weights in any dose groups.

GROSS PATHOLOGY
At clinical pathology investigations, there was an increase in blood glucose concentration in male rats at 1000 mg/kg/day when compared with the 
controls. This difference was not considered to be adverse since all values were within historical background data and no histopathological findings 
were observed in the liver, although statistically different from controls.

HISTOPATHOLOGY:
There were no treatment-related findings at histopathological examination.

OTHER FINDINGS
There was no effect of treatment on mating at any dose-level. The male and female fertility indices were unaffected by treatment; all mated females,
except one given 1000 mg/kg/day, were pregnant with live fetuses. The duration of gestation was similar between the control and test
item-treated groups. There was no effect of treatment on the mean number of liveborn pups or on pup death after birth. There were no external pup abnormalities in the control or test item-treated groups.

There was no effect of treatment on mean pup body weight or body weight gain for males or females. The sex ratios on days 1 and 5 post-partum
were similar in the control and test item-treated groups. No relevant findings were observed in the pups sacrificed on day 6 post-partum.

Effect levels

1

Dose descriptor:

NOAEL

Remarks:

(parental toxicity)

Effect level:

1 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

clinical signs

food consumption and compound intake

gross pathology

mortality

organ weights and organ / body weight ratios

2

Dose descriptor:

NOEL

Remarks:

(toxic effect, reproductive performance and on developmental toxicity)

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: There was no effect of treatment on the mean number of liveborn pups or on pup death after birth. There were no external pup abnormalities in the control or test item-treated groups.

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions, the daily administration of the test item, Lauryl Methacrylate (Lauryl MA; CAS RN 142-90-5), to Sprague-Dawley
rats at 100, 300 or 1000 mg/kg/day did not elicit any signs of toxicity.
Based on the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) for parental toxicity was considered to be
1000 mg/kg/day and the No Observed Effect Level (NOEL) for toxic effect on reproductive performance and on developmental toxicity was greater
than or equal to 1000 mg/kg/day.

Executive summary:

The test item, Lauryl Methacrylate (Lauryl MA; CAS RN 142-90-5), was administered to male and female Sprague-Dawley rats by the oral route (gavage) at the dose-levels of 100, 300 or 1000 mg/kg/day. At 1000 mg/kg/day, hypersalivation was recorded in males and females, lower body weight gain was recorded in females during the GD 0-7 interval and increased plasma glucose concentrations were recorded in males. At 300 mg/kg/day, a few animals had hypersalivation. At 100 mg/kg/day, no treatment-related effects were detected. Hypersalivation was not considered to be a sign of toxicity to Lauryl MA. There were no substance-induced effects on the male and female reproductive performance, nor on the progeny of the parental rats at any dose-level. There were no treatment-related findings at histopathological examination. Based on the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) for parental toxicity was considered to be 1000 mg/kg/day and the No Observed Effect Level (NOEL) for toxic effect on reproductive performance and on developmental toxicity was greater than or equal to 1000 mg/kg/day.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.