Methacrylic acid, monoester with propane-1,2-diol

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

2006

Report date:

2007

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

1996

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:

Early version of guidance for OECD 422

Deviations:

yes

Remarks:

not containing functional observation battery test 

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methacrylic acid, monoester with propane-1,2-diol

EC Number:

248-666-3

EC Name:

Methacrylic acid, monoester with propane-1,2-diol

Cas Number:

27813-02-1

Molecular formula:

C7H12O3

IUPAC Name:

1-hydroxypropan-2-yl 2-methylprop-2-enoate; 2-hydroxypropyl 2-methylprop-2-enoate

Test material form:

liquid

Details on test material:

The chemical 2-propenoic acid, 2-methyl-, monoester with 1,2-propanediol (CAS No. 27813-02-1) consists of two isomers. This occurs due to the method of industrial production, which is usually either the reaction between methacrylic acid and propylene oxide, or methacrylic acid esterification of 1,2-propanediol. The predominant isomer is the secondary alcohol 2-propenoic acid, 2-methyl, 2-hydroxypropyl ester, which is assigned the CAS No. 923-26-2, and the isomer 2-propenoic acid, 2-methyl, 2-hydroxy- 1-methylethyl ester, the other chemical in this group, for which CAS 4664-49-7 is assigned. The purification of the two isomers requires extensive effort and it is supposed no such effort has been taken during data collection otherwise noted. Therefore toxicity information for both CAS No. 923-26-2 and CAS No. 27813-02-1 is considered to be applicable to both chemicals..

Specific details on test material used for the study:

Supplier: Mitsubishi Rayon Co., LTD. (Tokyo, Japan),
Lot No. 0348402.
Purity: 98 %
Impurity: <=2 % of dipropylene glycol monomethacrylate
Storage: in an airtight container with preventing light before use (at room temperature).
The substance was warranted to be stable for the test period by the supplier

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan
- Age at study initiation: 8 weeks
- Weight at study initiation: male 315 ~ 359 g; females 210 ~ 243 g,
- Fasting period before study: yes
- Housing: During the quarantine: suspended using a stainless steel cage type 1 with 5 per cage; Breeding: divided into separate rearing cages. Moved to a separate plastic cage, having had a natural birth .
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: five-day quarantine period and then set up a six-day acclimation period

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 deg C
- Humidity (%): 40-70%
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12 hour light / 12 hour dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Concentration of samples was prepared by dissolving the required water for injection. The concentrations of preparation is protected from light at room temperature for 7 days to ensure that there were no stability issues. Preparation of 0.6% solution concentration is below the threshold level of determination, because we could not confirm the stability during the preparation for the 6% solution diluted with water for injection prepared in concentration.

VEHICLE
- Justification for use and choice of vehicle (if other than water): water
- Concentration in vehicle: 0.6, 0.8, 2.6 and 20%
- Amount of vehicle (if gavage): 5 ml/kg

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

standard laboratory methodf, details not specified

Duration of treatment / exposure:

Males :49 days
Females: from 14 days before mating to day 3 of lactation

Frequency of treatment:

Once daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

control

Doses / concentrations 2

Dose / conc.:

30 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

100 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

300 mg/kg bw/day (nominal)

Doses / concentrations 5

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

12

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: 2-week preliminary study
- Rationale for animal assignment (if not random): random by weight
- Terminal kill: Males, day 50; Females, day 4 of lactation

Positive control:

not applicable

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice a day
- Cage side observations: general condition

DETAILED CLINICAL OBSERVATIONS: Yes / No / No data
- Time schedule:

BODY WEIGHT: Yes
- Time schedule for examinations: twice a week

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): 2 times per week
- 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:
- 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: No

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

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood:day after treatment
- Anaesthetic used for blood collection: Yes (identity) : sodium pentobarbital
- Animals fasted: No data
- Parameters checked:
red blood cells
hemoglobin
hematocrit
platelet count
white blood cell count
prothrombin time
mean orpuscular volume
mean corpuscular hemoglobin
mean corpuscular hemoglobin concentration
reticulocyte count
white blood cell fraction
activated partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day after treatment
- Animals fasted: No data
- Parameters checked:
GOT
GPT
ALP
γ-GTP
total protein
total bilirubin
urea nitrogen (BUN)
creatinine
glucose
total cholesterol
triglycerides
Ca
inorganic phosphorus
Na
K
Cl
protein fraction albumin
total protein content
A/G ratio

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

OTHER: sexual cycle until confirmation; status of delivery

Sacrifice and pathology:

GROSS PATHOLOGY: Yes; Males: Thymus, liver, kidney, testis and epididymis weight was measured after removal, adrenal gland, brain, heart and spleen and 10% neutral buffered formalin solution (However, testicular and epididymal fluid Buan) was fixed; Females: counting the number of corpora lutea and the number of implantation scars. Liver, kidney, ovary and thymus weight was measured after removal, adrenal gland, brain, heart and spleen with a fixed 10% neutral buffered formalin solution.
HISTOPATHOLOGY: Yes; Control group and 1000 mg / kg group of heart, liver, spleen, thymus, kidney, testis, epididymis, ovary, adrenal and brain for the Preparation HE staining of tissue was examined histologically.

Statistics:

Statistical Analysis: The means and standard deviation were calculated
body weight, food consumption, hematological examination results, blood
chemical examination results, organ weight, and relative organ weight.
The using tests (P < 0.05) were Bartlett's tests, Dunnett's test, Scheffé's
test, Kruskal-Wallis test, and ANOVA (analysis of variance).

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

No abnormal clinical changes were observed

Mortality:

mortality observed, treatment-related

Description (incidence):

-Males: In the 1000 mg/kg/day-treated group two animals died. (Each one animal died at the 11th and 20th day of administration.)
Observations: salivation (from the 3rd day of administration to the end of test period), decrease in locomotor activity (from the 11th day of administration to the end of test period), ptosis (from the 16th
day of administration to the end of test period)
In the 0, 30, 100, 300 mg/kg/day-treated groups no animals died.
-Females: In the 1000 mg/kg/day-treated group oOne animal died the 15th day of administration.
Observation: Salivation (from the 4th day of administration to the end of test period) decrease in locomotor activity (from the 11th day of administration to the end of test period) ptosis (from the 11th
day of administration to the end of test period)
In the 0, 30, 100, 300 mg/kg/day-treated group no animals died.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

-Males: The body weight gain in each treated group was similar to that in control group during the test period.
-Females: The body weight gain in each treated group was similar to that in control group during the test period.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

-Males: The food consumption in each treated group was similar to that in control group during the test period.
-Females: at 100, 1000 mg/kg/day-treated group the food consumption showed lower than that in control group at the 6th and 10th day of administration (pre-mating period), however, there was no diffe
rence during the pregnancy and the lactation period.
The author judged that these changes were non-toxicological.
In the 30, 300 mg/kg/day-treated group the food consumption in each treated group was similar to that in control group during the test period.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

-Males:
In the 1000 mg/kg/day-treated group the decrease in hematocrit and the tendencies for decrease in erythrocyte (RBC) and hemoglobin were observed.
In the 30, 100, 300 mg/kg/day-treated group no effects were observed on hematological parameters.
Details see: Any other information on results incl. table (table 1)
-Females: Not tested

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

Blood chemical examination:
-Males: No effects were observed on blood chemical parameters.
-Female: Not tested

Endocrine findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not specified

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

-Males:
In 1000 mg/kg/day-treated group the significant increase in the relative liver weights were observed.
In 30, 100, 300 mg/kg/day-treated group there were no significant differences in organ weights between the control and each treatment group.
-Females
There were no significant differences in organ weights between the control and each treatment group.
Details see: Any other information on results incl. table (table 2)

Gross pathological findings:

no effects observed

Description (incidence and severity):

Male [Survival animals]
In control, 1000 mg/kg/day-treated group No abnormalities caused by the treatment were found.
In 30 mg/kg/day-treated group unilateral pyelectasia (one animal) yellowish-white tuber in the tail of the bilateral parorchis (one animal)
In 100 mg/kg/day-treated group yellowish-white tuber in the tail of the unilateral parorchis (one animal)
In 300 mg/kg/day-treated group unilateral pyelectasia and yellowish-white tuber in the tail of the unilat
eral parorchis (one animal) atrophy of unilateral parorchis and testes
The author judged that these changes were non-toxicological.
[Dead animals]
In 100 mg/kg/day-treated group change to dark-red in lung, liver, kidney and red in jejunum and ileum (one animal) change to red in lung (one animal)
-Female [Survival animals]
No abnormalities caused by the treatment were found in any groups.
[Dead animals]
In 100 mg/kg/day-treated group change to dark-red in lung and red in jejunum and ileum (one animal)

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

-Male
[Survival animals]
In the1000 mg/kg/day-treated group several abnormalities caused by the treatment were observed in liver, testis, and epididymis (see table below)
[Dead animals]
In the 1000 mg/kg/day-treated group congestion in liver, lung, kidney, autolysis in lung, kidney, jejunum and ileum (one animal) Congestion, autolysis and oedema in lung (another animal)
Details see: Any other information on results incl. table (table 3 )
-Females
[Survival animals]
In the 1000 mg/kg/day-treated group a few abnormalities caused by the treatment were observed in th ymus and kidney (see table below)
[Dead animal]
In the 1000 mg/kg/day-treated group Edema in liver, autolysis in jejunum and ileum (one animal)
Details see: Any other information on results incl. table (table 4 )

Histopathological findings: neoplastic:

not examined

Details on results:

For the males, salivation, decrease in locomotor activity and ptosis were found in the 1000 mg/kg group, and 2 animals of the group died. Decrease in hematocrit, tendencies for decrease in RBC and hemoglobin, and increase in the relative liver weights were also found in the 1000 mg/kg group. 
For the females, salivation, decrease in locomotor activity and ptosis were found in the 1000 mg/kg group, and 1 animal died.

Effect levels

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical biochemistry

clinical signs

haematology

mortality

organ weights and organ / body weight ratios

Target system / organ toxicity

Critical effects observed:

no

Any other information on results incl. tables

Table 1 Hematological examination P0 (first partental generation)

Dose (mg/kg)	0	30	100	300	1000
Males
No. of animals	12	12	12	12	10
RBC (10E4/mm3)	871.3+/-41.5	884.9+/-18.5	849.9+/-38.4	841.8+/-40.5	834.6+/-36.6
Hemoglobin (g/dL)	15.63+/-0.63	15.64+/-0.56	15.27+/-0.63	15.07+/-0.51	14.85+/-0.57
Hematocrit (%)	46.13+/-1.61	46.11+/-1.18	44.93+/-1.37	44.63+/-1.37	43.72+/-1.66**

Values are expressed as Mean +/- S.D.
Significant difference from control group (*:p<0.05, **:p<0.01)

 

Table 2 Absolute and relative organ weights of rats treated orally with methacrylic acid, monoester with propane-1,2-diol /P0 (first parental generation)

Dose (mg/kg)	0	30	100	300	1000
Males
No. of animals	12	12	12	12	10
Body weight (g)	472.1	480.8	476.1	474.4	456.9
Absolut organ weight
Thymus (mg)	321.79	349.81	336.23	363.99	347.51
Liver (g)	11.675	12.306	11.871	12.154	12.34
Kidneys (g)	3.028	2.996	3.003	2.978	3.177
Testes (g)	3.279	3.335	3.385	3.320	3.271
Epididymides (g)	1.295	1.297	1.363	1.258	1.274
Relative organ weight
Thymus (mg%)	67.93	73.07	70.63	76.84	76.17
Liver (g%)	2.473	2.556	2.488	2.558	2.689*
Kidneys (g%)	0.642	0.624	0.633	0.628	0.697
Testes (g%)	0.697	0.696	0.713	0.701	0.718
Epididymides (g)	0.277	0.272	0.288	0.265	0.280
Female
No. of females	12	12	8	11	11
Body weight (g)	328.0	328.5	322.9	318.0	327.5
Absolute organ weight
Thymus (mg)	286.03	280.54	274.96	238.55	256.11
Liver (g)	13.739	14.225	14.390	13.312	14.164
Kidneys (g)	2.068	2.053	2.128	1.900	2.085
Ovaries (mg)	111.64	108.48	108.60	103.16	107.12
Relative organ weight
Thymus (mg %)	87.28	84.63	84.98	74.32	78.04
Liver (g %)	4.183	4.331	4.461	4.185	4.316
Kidneys (g %)	0.633	0.627	0.660	0.597	0.637
Ovaries (mg)	34.11	33.03	33.70	32.63	32.85

 

Values are expressed as mean. Significant difference from control group (*p<0.05)

 

Table 3 Histopathological examination of rats treated orally with methacrylic acid, monoester with propane-1,2-diol (MALE) /P0 (first parental generation)

Dose (mg/kg)	0		30		100		300		1000
Males
No. of animals	12		12		12		12		10
Finding grade	-	+/-	+	2+	3+	-	-	+/-	2+	3+
Liver /Vacoular degeneration of periportal hepatocytes	5	7	0	0	0	2	8	0	0	0
Testis / Atrophy of seminiferous tubules	11	1	0	0	0	10	0	0	0	0
Epididymis / Spermatogenic granuloma	12	0	0	0	0	9	0	1	0	0

 

Grade of histopathological finding; -:No abnormal detected, +/-:Slight, +:Mild, 2+:Moderate, 3+:Marked. No remarkable changes were recognized in heart, thymus, spleen, kidney, adrenal and brain.

 

Table 4 Histopathological examination of rats treated orally with methacrylic acid, monoester with propane-1,2-diol (FEMALE) ) / P0 (first parental generation)

Dose (mg/kg)	0		30		100		300		1000
Males
No. of animals	12		12		12		12		10
Finding grade	-	+/-	+	2+	3+	-	+/-	+	2+	3+
Thymus  Atrophy	12	0	0	0	0	10	0	0	1	0
Kidney  Calcium deposition in urinary tubules	11	1	0	0	0	11	0	0	0	0

 

Grade of histopathological finding; -:No abnormal detected, +/-:Slight, +:Mild, 2+:Moderate, 3+:Marked. No remarkable changes were recognized in heart, liver, ovary, adrenal and brain.

Applicant's summary and conclusion

Conclusions:

In an OECD 422 study in rats, the oral repeated dose NOAEL (males/females) was determined to be 300 mg/kg based on body weights.

Executive summary:

According to the OECD test guidelines for combined repeated dose toxicity study with the reproductive/developmental toxicity screening test [OECD TG 422], SD (Crj: CD) rats (12 animals/dose/sex) were administrated with this substance by gavage at doses of 0 (vehicle; water for injection), 30, 100, 300, and 1,000 mg/kg bw/day (12 animal/dose/sex). Males were dosed for a total of 49 days beginning 14 days before mating, and females were dosed for total of 41 to 48 days starting from 14 days before mating to day 4 of lactation throughout the mating and pregnancy period.

At 1000 mg/kg bw/day for males, two of the 12 animals died. Salivation, decreases in locomotor activity, ptosis were observed. The decrease in hematocrit and the tendencies for decrease in erythrocyte (RBC) and hemoglobin were found in haematological examination. The statistically significant increase in the relative liver weights was observed in organ weight. At that for females, one of the 12 animals died. Salivation, decreases in locomotor activity, ptosis were observed. Other significant toxicological changes were not observed. 

At 0, 30, 100 and 300 mg/kg bw/day for both sexes, no animals died and no abnormal clinical changes were observed. Moreover, significant toxicological changes were not observed in body and organ weight, food consumption, haematological examination, blood chemical examination, necropsy, and histopathological examination. Therefore, no adverse effect was observed in both sexes. 

The NOAELs for the repeated dose toxicity are considered to be 300 mg/kg bw/day for both sexes.