2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with phosphorus oxide

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 December 2012 - 28 January 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Organisation of Economic Co-operation and Development (OECD) Guidelines for Testing of Chemicals, Guideline 422, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, March 1996

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines, OPPTS 870.3650, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, July 2000.

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: OECD Guidelines for Testing of Chemicals, Guideline 421, Reproduction/Developmental Toxicity Screening Test, July 1995.

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: The United States EPA Health Effects Test Guidelines, OPPTS 870.3550, Reproduction/Developmental Toxicity Screening Test, July 2000.

Deviations:

no

Principles of method if other than guideline:

In addition, the procedures described in the report essentially conform to the following guidelines:
- Commission regulation (EC) No 440/2008 Part B: Methods for the Determination of Toxicity and other Health Effects; B.7: "Repeated Dose (28 days) Toxicity (oral)". Official Journal of the European Union No. L142, May 2008.
- OECD Guidelines for Testing of Chemicals, Guideline 407, Repeated Dose 28-day Oral Toxicity Study in Rodents, October 2008.
- The United States EPA Health Effects Test Guidelines, OPPTS 870.3050, Repeated dose 28-day oral toxicity study in rodents, July 2000.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Bis(methacryloyloxyethyl) hydrogen phosphate

EC Number:

251-040-2

EC Name:

Bis(methacryloyloxyethyl) hydrogen phosphate

Cas Number:

32435-46-4

Molecular formula:

C12H19O8P

IUPAC Name:

2-[hydroxy-[2-(2-methylprop-2-enoyloxy)ethoxy]phosphoryl]oxyethyl 2-methylprop-2-enoate

Constituent 2

Reference substance name:

2-(phosphonooxy)ethyl methacrylate

EC Number:

246-342-6

EC Name:

2-(phosphonooxy)ethyl methacrylate

Cas Number:

24599-21-1

Molecular formula:

C6H11O6P

IUPAC Name:

2-phosphonooxyethyl 2-methylprop-2-enoate

Test material form:

liquid: viscous

Details on test material:

- Name of test material (as cited in study report): POEMA
- Description: clear colourless to slightly yellow viscous liquid (visual observation at test facility)
- Storage condition of test material: at room temperature

Specific details on test material used for the study:

- Density: 1.286 g/mL
- pH: 0.5 at concentration of 1%

Test animals

Species:

rat

Strain:

other: Wistar (Han)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
Nulliparous and nonpregnant females and untreated animals were used at initiation of the study.
- Age at study initiation: Approximately 11 weeks.
- Weight at study initiation: mean weight at start of treatment was 327 gr (males) or 209 gr (females).
- Fasting period before study: no
- Housing:
Pre-mating: Animals were housed in groups of 5 animals/sex/cage in Macrolon cages.
Mating: Females were caged together with males on a one-to-one-basis in Macrolon cages.
Post-mating: Males were housed in their home cage with a maximum of 5 animals/cage. Females were individually housed in Macrolon cages. Pups were kept with the dam until termination
General: Sterilised sawdust as bedding material and paper as cage enrichment were supplied.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle. Any variations to these conditions were maintained in the raw data and had no effect on the outcome of the study.

IN-LIFE DATES
From: 06 December 2012 - 28 January 2013

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on exposure:

- Method of formulation: Formulations (w/w) were prepared daily within 6 hours prior to dosing and were homogenized to a visually acceptable level. Adjustment was made for the density of the test substance (1.286) and specific gravity of the vehicle (1.036). No correction was made for the purity/composition of the test substance.
- Storage conditions of formulations: At ambient temperature .
- Justification for use and choice of vehicle: Based on trial formulations performed at WIL Research Europe.
- Dose volume: 5 mL/kg body weight. Actual dose volumes were calculated according to the latest body weight.
- Preventative measures: The pH of the dose preparations was relatively low. The possibility of local esophageal effects was assessed in the dose range finding study without any additional protective measures introduced, using the standard procedure of wiping the outside surface of the cannula between dosing each animal. Additional preventative measures were implemented to avoid possible local esophageal and/or gastrointestinal effects for the main study:
* Wiping of the flexible catheter prior to dosing of each animal.
* Additional rinsing of the flexible catheter with approximately 0.5-0.6 mL water (Elix, Millipore S.A.S., Molsheim, France) after dosing each animal with the test formulations

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were conducted on a single occasion (18 February 2013), according to a validated method (Project 500763). Samples of formulations were analyzed for homogeneity (highest and lowest concentration) and accuracy of preparation (all concentrations). Stability in vehicle over 6 hours at room temperature was also determined (highest and lowest concentration). The accuracy of preparation was considered acceptable if the mean measured concentrations were 90-110% of the target concentration. Homogeneity was demonstrated if the coefficient of variation was ≤ 10%. Formulations were considered stable if the relative difference before and after storage was maximally 10%.

Details on mating procedure:

- M/F ratio per cage:1/1 (one female was cohabitated with one male of the same treatment group, avoiding sibling mating.
- Age at mating of the animals in the study: Approximately 13 weeks
- Length of cohabitation: A maximum of 14 days was allowed for mating.
- Proof of pregnancy: Detection of mating was confirmed by evidence of sperm in the vaginal lavage and/or or by the appearance of an intravaginal copulatory plug. This day was designated Day 0 post-coitum. Once mating had occurred, the males and females were separated.
- Detection of mating was not confirmed for one animal of Group 3 which did deliver live offspring. The mating date of this animal was estimated at 21 days prior to the actual delivery date. This day was designated Day 0 post-coitum.
- After successful mating each pregnant female was caged individually in Macrolon cages (MIII type, height 18 cm).

Duration of treatment / exposure:

Males were exposed for 29 days, i.e. 2 weeks prior to mating, during mating, and up to the day prior to scheduled necropsy. Females were exposed for 41-53 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation (up to the day prior to scheduled necropsy). One female of Group 1 was not dosed during littering.
Pups were not dosed directly but could have potentially be exposed to the test substance in utero, via maternal milk or from exposure to maternal urine/faeces.

Frequency of treatment:

Once daily for 7 d/w.

Duration of test:

Males: 29 days
Females: 41-53 days

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were based on results of a 10-day dose range finding study (Project 500767: Groups of 3 female Wistar Han rats were treated at 500 and 1000 mg/kg body weight. No toxicologically relevant changes were noted in any of the parameters examined (mortality, clinical appearance, body weights, food intake, macroscopy and liver and kidney weights).
- Selection of animals for selected measurements: 5 animals/sex/group were randomly selected at allocation for functional observations, clinical pathology, macroscopic examination (full list), organ weights (full list) and histopathology. Only females with live offspring were selected.
- Parturition: The females were allowed to litter normally. Day 1 of lactation was defined as the day when a litter was found completed (i.e. membranes, placentas cleaned up, nest built up and/or feeding of pups started). Females that were littering were left undisturbed.
- Identification of pups: On Day 1 of lactation, all pups were individually identified by means of subcutaneous injection of Indian ink.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS
- Time schedule: At least twice daily.

DETAILED CLINICAL OBSERVATIONS
- Time schedule: Daily from treatment onwards up to the day prior to necropsy, detailed clinical observations were conducted for all animals, at least immediately (0-15 min) after dosing. Once prior to the start of treatment and at weekly intervals during the treatment period this was also performed outside the home cage in a standard arena. The time of onset, grade and duration of any observed sign was recorded. Signs were graded for severity.

BODY WEIGHT
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum, and during lactation on Days 1 and 4.

FOOD CONSUMPTION
- Weekly, for males and females. Food consumption was not recorded during the mating period. Food consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and on Days 1 and 4 of lactation.

FOOD EFFICIENCY: yes

WATER CONSUMPTION
No. Subjective appraisal was maintained during the study, but no quantitative investigation introduced as no effect was suspected.

OPHTHALMOSCOPIC EXAMINATION
No

HAEMATOLOGY
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination.
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (with a maximum of 24 hours). Water was provided.
- How many animals: 5 animals/sex/group
- Parameters checked were: According to test guidelines

CLINICAL CHEMISTRY
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination.
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (with a maximum of 24 hours). Water was provided.
- How many animals: 5 animals/sex/group
- Parameters checked were: According to test guidelines

URINALYSIS
No

NEUROBEHAVIOURAL EXAMINATION
- Time schedule for examinations: The selected males were tested during Week 4 of treatment and the selected females were tested during lactation (all before blood sampling).
- Dose groups that were examined: all
- Battery of functions tested: According to test guidelines

GENERAL REPRODUCTION DATA
- Male number paired with, mating date, confirmation of pregnancy, and delivery day was recorded.
- Pregnant females were examined to detect signs of difficult or prolonged parturition, and cage debris of these females was examined to detect signs of abortion or premature birth.
- Any deficiencies in maternal care (such as inadequate construction or cleaning of the nest, pups left scattered and cold, physical abuse of pups or apparently inadequate lactation or feeding) were examined.

GROSS PATHOLOGY
- All animals were fasted overnight (with a maximum of 24 hours) prior to planned necropsy, but water was provided. Animals surviving to scheduled necropsy were deeply anaesthetised and subsequently exsanguinated.
- Selected 5 animals/sex/group: According to test guidelines
- The number of former implantation sites and corpora lutea were recorded for all paired females.

ORGAN WEIGHTS
- Selected 5 animals/sex/group: According to test guidelines
- All remaining males: Epididymides and Testes

HISTOPATHOLOGY
- According to test guidelines

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No
- Number of late resorptions: No

Fetal examinations:

The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross abnomalies, weight gain, physical or behavioural abnormalities.
- Mortality: The numbers of live and dead pups on Day 1 of lactation and daily thereafter were determined. If possible, defects or cause of death were evaluated.
- Clinical signs: At least once daily, detailed clinical observations were made in all animals.
- Body weights: Live pups were weighed on Days 1 and 4 of lactation.
- Sex: Sex was determined for all pups on Days 1 and 4 of lactation (by assessment of the ano-genital distance).

GROSS EXAMINATION OF DEAD PUPS:
Yes, if possible, defects or cause of death were evaluated.

Statistics:

The following statistical methods were used to analyze the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test was applied to frequency data.
- The Kruskal-Wallis nonparametric ANOVA test was applied to motor activity data to determine intergroup differences.

All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance. Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables. Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off before printing. Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.

Indices:

Reproductive indices; For each group, the following calculations were performed:
- Mating index: Number of females mated/Number of females paired x 100
- Fertility index: Number of pregnant females/Number of females paired x 100
- Conception index: Number of pregnant females/Number of females mated x 100
- Gestation index: Number of females bearing live pups/Number of pregnant females x 100
- Duration of gestation: Number of days between confirmation of mating and the beginning of parturition

Offspring indices:
- Percentage live males at First Litter Check: Number of live male pups at First Litter Check/Number of live pups at First Litter Check x 100
- Percentage live females at First Litter Check: Number of live female pups at First Litter Check/Number of live pups at First Litter Check x 100
- Percentage of postnatal loss Days 0-4 of lactation: Number of dead pups on Day 4 of lactation/Number of live pups at First Litter Check x 100
- Viability index: Number of live pups on Day 4 of lactation / Number of pups born alive x 100

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
MORTALITY
No mortality occurred during the study period.

CLINICAL SIGNS
No clinical signs of toxicity were noted during the observation period. Labored respiration, rales and piloerection were noted on limited occasions for a few animals at 300 and 1000 mg/kg. Since these signs were transient in nature and occurred for only a few individuals, they were not considered to be indicative of treatment related toxicity. Salivation was seen for all animals (both sexes) at 1000 mg/kg and was also seen for individuals animals at 300 and 100 mg/kg as well. Salivation was considered to be a physiological response rather than a sign of systemic toxicity considering the nature and minor severity of the effect and its time of occurrence (i.e. after dosing). This sign may be related to the taste of the test substance. Incidental findings that were noted included alopecia, scabs on the chest and chromodacryorrhoea. These findings occurred within the range of background findings to be expected for rats of this age and strain which are housed and treated under the conditions in this study. At the incidence observed, these were not considered toxicologically relevant.

FUNCTIONAL OBSERVATIONS
Hearing ability, pupillary reflex, static righting reflex and grip strength were normal in all selected animals. The variation in motor activity did not indicate a relation with treatment. All groups showed a similar habituation profile with very high activity in the first interval that decreased over the duration of the test period.

BODY WEIGHTS
Body weight gains were significantly lower for males at 1000 mg/kg from Day 8 of the premating period through the rest of the treatment duration. This was not considered to be adverse since the difference from controls was only slight, absolute body weights were not affected, and no other parameters were affected.

FOOD CONSUMPTION
Food consumption before or after allowance for body weight was similar between treated and control animals.

HAEMATOLOGY
There were no differences noted in haematological parameters between control and treated rats that were considered to be related to treatment with POEMA.

CLINICAL BIOCHEMISTRY
There were no toxicologically relevant effects on clinical biochemistry parameters with treatment up to 1000 mg/kg. At 1000 mg/kg total protein was significantly lower for males and alanine aminotransferase (ALAT) was significantly lower for females. Potassium was significantly increased for females at 300 and 1000 mg/kg. All of these values remained within the range of available historical control data, occurred in the absence of effects on any related parameters, and were thus not considered to be toxicologically relevant. The statistically significant increase in total bilirubin seen for females at 100 mg/kg was not considered to be toxicologically relevant as it occurred in the absence of a dose-dependent distribution.

MACROSCOPIC EXAMINATION
Macroscopic observations at necropsy did not reveal any treatment related alterations. Incidental findings noted for control and treated animals included pelvic dilation of the kidneys, reddish, dark red or pale discoloration of the mandibular lymph nodes or adrenal glands, tan focus on or reduced size of the preputial or clitoral glands, reddish foci on the stomach glandular mucosa, enlarged spleen, thickened wall of the duodenum, thickened limiting ridge of the stomach, jejunum or ileum distended with gas and alopecia. These findings remained within the range of findings that are encountered for rats of this age and strain and occurred without a treatment-related distribution. As such, these findings were not considered to be toxicologically relevant.

ORGAN WEIGHTS
No toxicologically relevant changes were noted in organ weights and organ to body weight ratios. Relative kidney weights were significantly higher for males at 1000 mg/kg than controls. This was not considered to be toxicologically relevant as the differences from controls was slight (13%) and no treatment related effects were seen in the microscopic examination. Seminal vesicle (absolute and relative) weights were significantly higher for males at 100 mg/kg than controls. In the absence of a treatment related distribution, no toxicological relevance was attributed to this.

MICROSCOPIC EXAMINATION
There were no treatment-related microscopic findings. The recorded microscopic findings were within the normal range of background pathology encountered in Wistar (Han) rats of this age. There were no pairs of rats who failed to sire or deliver healthy pups. The spermatogenic staging profiles were normal for all examined males.

REPRODUCTIVE DATA
No toxicologically relevant effects on reproductive parameters were noted. The mating, fertility and conception indices, precoital time, and number of corpora lutea and implantation sites were unaffected by treatment. The mating, fertility and conception indices were 100% for all groups. For one female at 300 mg/kg the number of pups was slightly higher than the number of implantations and corpora lutea. This was considered to be caused by normal resorption of these areas as these enumerations were performed on Day 5 of lactation.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects. Remark: Only early postnatal pup development parameters were examined including body weight, post-natal loss, sex ratio, clinical signs, body weight and external macroscopy.

Details on embryotoxic / teratogenic effects:
DEVELOPMENTAL DATA
No toxicologically relevant effects on gestation index and duration, parturition, maternal care and early postnatal pup development (mortality, clinical signs, body weight and macroscopy) were observed.

Gestation
The gestation index and duration of gestation were unaffected by treatment with 1000 mg/kg. The gestation index was 100% for all groups.
Parturition/maternal care
No signs of difficult or prolonged parturition were noted among the pregnant females.
Examination of cage debris of pregnant females revealed no signs of abortion or premature birth and no deficiencies in maternal care were observed.

Early postnatal pup development
Number of dead and living pups at first litter check, postnatal loss, viability index and sex ratio were unaffected by treatment, and clinical signs, body weight and external macroscopy did not reveal treatment-related findings.

Mortality
Two pups of the control group, one, four and four pups in the 100, 300 and 1000 mg/kg groups were found dead or went missing during the first days of lactation. Missing pups were most likely cannibalised. No toxicological relevance was attributed to these dead/missing pups since the mortality incidence did not show a dose-related trend and remained within the range considered normal for pups of this age.

Clinical signs
Incidental clinical symptoms of pups included a blue spot on the snout and a wound or scabs on the abdomen. The nature and incidence of these clinical signs remained within the range considered normal for pups of this age, and were not toxicologically relevant.

Body weights
Body weights of pups were unaffected by treatment up to 1000 mg/kg.

Macroscopy
Incidental macroscopic findings of pups that were found dead included autolysis and no milk in the stomach. The only macroscopic finding noted for surviving pups was scabbing on the abdomen. The nature and incidence of these findings remained within the range considered normal for pups of this age, and were not considered toxicologically relevant.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

FORMULATION ANALYSIS

Measurements were performed on the two major compounds Bis(methacryloyloxyethyl)hydrogen phosphate and 2-(phosphonooxy)ethyl methylacrylate analysed at mass/charge ratio (m/z) 209.1 atomic mass unit (amu) and m/z 321.1 amu.

Results based on m/z 209.1

Accuracy of preparation

In the Group 1 formulation, no response was observed at the retention time of this compound. The concentrations analysed in the formulations of Group 4 were in agreement with target concentrations (i.e. mean accuracy 103%). For the Group 2 and Group 3 formulations, the mean accuracy was 154% and 138% of target, respectively.The relatively high accuracy may be due to formation of this compound by hydrolysis of other compounds present in the test substance.

Homogeneity

The formulations of Group 2 and Group 4 were homogeneous (i.e. coefficient of variation≤ 10%).

Stability

Analysis of Group 2 and Group 4 formulations after storage yielded a relative difference of≤10%. Based on this, the formulations were found to be stable during storage at room temperature protected from light for at least 6 hours.

Results based on m/z 321.1

Accuracy of preparation

In the Group 1 formulation, a small response was observed at the retention time of this compound. Maximum contribution to the response of the Group 2 samples was 0.1% based on peak area. The concentrations analysed in the formulations of Group 3 were in agreement with target concentrations (i.e. mean accuracy 93%). For the Group 2 and Group 4 formulations, the mean accuracy was 84% and 79% of target, respectively. All values were comparable with the recoveries of the procedural recovery samples. Based on this, it was concluded that the formulations were prepared properly.

Homogeneity

The formulations of Group 2 and Group 4 were homogeneous (i.e. coefficient of variation≤ 10%).

Stability

Analysis of Group 2 and Group 4 formulations after storage yielded a relative difference of≤10%. Based on this, the formulations were found to be stable during storage at room temperature protected from light for at least 6 hours.

Conclusion

Because analysis at m/z 209.1 amu may be influenced by hydrolysis of other compounds present in the test substance, conclusion was based on analysis at m/z 321.1 amu. Based on analysis at this mass, formulations were prepared accurately and they were homogenous and stable during storage at room temperature protected from light for at least 6 hours.

Applicant's summary and conclusion

Conclusions:

In an oral OECD 422 screening study, the parental, developmental and reproductive NOAEL was derived to be >= 1000 mg/kg bw/day. Treatment with POEMA by oral gavage in male and female Wistar Han rats at dose levels of 100, 300 and 1000 mg/kg revealed no parental, reproductive or developmental toxicity up to 1000 mg/kg.

Executive summary:

For POEMA a combined repeated dose oral toxicity study in rat with the reproductive/developmental screening test according to OECD TG 422 was performed with dose groups 0, 100, 300 and 1000 mg/kg bw/day. Males were exposed for 29 days, i.e 2 weeks prior to mating, during mating, and up to termination. Females were exposed for 41 -53 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation. The following repeated dose toxicity parameters were recorded: mortality, clinical signs, body weight and food consumption, functional observations and locomotor activity, clinical pathology, macroscopy at termination, organ weights and histopathology on a selection of tissues. The parameters assessed for fertility and developmental toxicity included mating, fertility and conception indices, precoital time, number of corpora lutea and implantation sites, gestation index and duration, parturition, maternal care, sex ratio and early postnatal pup development (mortality, clinical signs, body weights and macroscopy).

Chemical analysis was performed measuring two main components of POEMA, Bis(methacryloyloxyethyl)hydrogen phosphate and 2-(phosphonooxy)ethyl methylacrylate analysed at m/z 209.1 amu and m/z 321.1 amu, respectively. The accuracies of m/z 209.1 amu were relatively high. However, since the hydrolysis of other components in POEMA were also likely detectable in the analysis of m/z 209.1 amu, the influence of other reaction components may have contributed to these higher values. However, accuracy was confirmed with analysis of m/z 321.1, the other main component, and thus the results were accepted. Homogeneity and stability over 6 hours were confirmed for both components. Accuracy of preparation based on m/z209.1 resulted in relatively high accuracy for groups 2 and 3 formulations, likely to be due to formation of this compound by hydrolysis of other compounds present in the test substance. Accuracy of preparation based on m/z321.1 resulted in relatively low mean accuracy for groups 2 and 4 formulations. All values were comparable with recoveries of the procedural recovery samples which were accepted because improvement of the analytical method was not considered possible. Overall it was concluded that the formulations were prepared properly and the low accuracies wee considered attributable to limitations with the analytical method.

No parental toxicity was observed up to and including 1000 mg/kg bw/day, the highest dose level tested. Based on these results, a parental NOAEL of at least 1000 mg/kg bw/day was derived.

No developmental toxicity was observed up to and including 1000 mg/kg bw/day, the highest dose tested. Based on these results a NOAEL for developmental toxicity of at least 1000 mg/kg bw/day was derived.