1-(3-sulphonatopropyl)pyridinium

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-03-05 to 2013-10-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-(3-sulphonatopropyl)pyridinium

EC Number:

239-491-3

EC Name:

1-(3-sulphonatopropyl)pyridinium

Cas Number:

15471-17-7

Molecular formula:

C8H11NO3S

IUPAC Name:

1-(2-hydroxy-3-sulphonatopropyl)pyridinium

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): 1-(3-sulphonatopropyl)pyridinium
- Substance type: organic
- Physical state: white powder
- Analytical purity: > 99 %
- Purity test date: 2013-02-06
- Storage condition of test material: Room temperature in the dark
- Other: The integrity of supplied data relating to the identity, purity and stability of the test item is the responsibility of the Sponsor.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: Han™:RccHan™:WIST.
- Source: Harlan Laboratories U.K. Ltd., Blackthorn, Bicester, Oxon, UK.
- Age at study initiation: 12 weeks.
- Weight at study initiation: 295 to 356 g (males), 188 to 217 g (females).
- Fasting period before study: no.
- Housing: Initially, all animals were housed in groups of four in solid floor polypropylene cages with stainless steel mesh lids and softwood flake bedding (Datesand Ltd., Cheshire, UK). During the pairing phase, animals were transferred to polypropylene grid floor cages suspended over trays lined with absorbent paper on a one male: one female basis within each dose group. Following evidence of successful mating, the males were returned to their original cages. Mated females were housed individually during gestation and lactation in solid floor polypropylene cages with stainless steel mesh lids and softwood flakes.
The animals were housed in a single air-conditioned room within the testing facility.
- Diet (e.g. ad libitum): ad libitum (Rodent 2018C Teklad Global Certified Diet, Harlan Laboratories U.K. Ltd., Oxon, UK).
- Water (e.g. ad libitum): ad libitum.
- Acclimation period: 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2
- Humidity (%): 55 ± 15
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2013-04-10 To: 2013-06-05

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

distilled

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
For the purpose of this study the test item was prepared at the appropriate concentrations as a suspension in Distilled water. The stability and homogeneity of the test item formulations were determined by Harlan Laboratories Ltd., Shardlow, UK, Analytical Services. Results show the formulations to be stable for at least twenty two days. Formulations were therefore prepared fortnightly and stored at approximately 4 °C in the dark.

VEHICLE
- Concentration in vehicle: 0, 20, 60 and 200 mg/mL for dose levels of 0, 100, 300 and 1000 mg/kg bw, respectively.
- Amount of vehicle (if gavage): 5 mL/kg bw. The volume of test and control item administered to each animal was based on the most recent scheduled body weight and was adjusted at weekly intervals.
- Lot/batch no. (if required):
- Purity: distilled water

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: 14 days
- Proof of pregnancy: [vaginal plug/ vaginal smear] referred to as [day 0] of pregnancy
Animals were paired on a 1 male: 1 female basis within each dose group, for a period of up to fourteen days. Cage tray-liners were checked each morning for the presence of ejected copulation plugs and each female was examined for the presence of a copulation plug in the vagina. A vaginal smear was prepared for each female and the stage of oestrus or the presence of sperm was recorded. The presence of sperm within the vaginal smear and/or vaginal plug in situ was taken as positive evidence of mating (Day 0 of gestation) and the males were subsequently returned to their original holding cages (unless required for additional pairing). Mated females were housed individually during the period of gestation and lactation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of the test item formulation were taken and analysed for concentration of 1-(3- sulphonatopropyl)pyridinium at Harlan Laboratories Ltd., Shardlow, UK, Analytical Services. The methods used for analysis of formulations was HPLC/UV. The results indicate that the prepared formulations were within ± 6% of the nominal concentration.

Duration of treatment / exposure:

up to 8 weeks ((including a two week pre-pairing phase, pairing, gestation and early lactation for females).

Frequency of treatment:

once daily

Details on study schedule:

Chronological Sequence of Study
i. Groups of twelve male and twelve female animals were treated daily at the appropriate
dose level throughout the study (except for females during parturition where applicable).
The first day of dosing was designated as Day 1 of the study.
ii. Prior to the start of treatment and once weekly thereafter, all animals were observed for
signs of functional/behavioural toxicity.
iii. On Day 15, animals were paired on a 1 male: 1 female basis within each dose group for a
maximum of fourteen days.
iv. Following evidence of mating (designated as Day 0 post coitum) the males were returned
to their original cages and females were transferred to individual cages.
v. On completion of the pairing phase (during Week 6), five selected males per dose group
were evaluated for functional/sensory responses to various stimuli.
vi. Pregnant females were allowed to give birth and maintain their offspring until Day 5 post
partum. Litter size, offspring weight and sex, surface righting and clinical signs were
also recorded during this period.
vii. At Day 4 post partum, five selected females per dose group were evaluated for
functional/sensory responses to various stimuli.
viii. Blood samples were taken from five males from each dose group for haematological and
blood chemical assessments on Day 42. The male dose groups were killed and examined
macroscopically on Day 43.
ix. Blood samples were taken from five randomly selected females from each dose group for
haematological and blood chemical assessment on Day 4 post partum. At Day 5 post
partum, all females and surviving offspring were killed and examined macroscopically.
Any female which did not show positive evidence of mating or produce a pregnancy was
also killed and examined macroscopically.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300 and 1000 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

12

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The dose levels were chosen based on the results of previous toxicity work (Harlan Laboratories Ltd., Project Number 41300261).
- Rationale for animal assignment: The animals were randomly allocated to treatment groups using a stratified body weight randomisation procedure and the group mean body weights were then determined to ensure similarity between the treatment groups. The cage distribution within the holding rack was also randomised.

Positive control:

None.

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: All animals were examined for overt signs of toxicity, ill-health and behavioural change immediately before dosing, soon after dosing, and one hour and five hours after dosing during the working week. Animals were observed immediately before dosing, soon after dosing and
one hour after dosing at weekends and public holidays (except for females during parturition where applicable). All observations were recorded.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Prior to the start of treatment and at weekly intervals thereafter, all animals were observed for signs of functional/behavioural toxicity. Detailed individual clinical observations were performed for each animal using a purpose built arena. The following parameters were observed: Gait, Hyper/Hypothermia, Tremors, Skin colour, Twitches, Respiration, Convulsions, Palpebral closure, Bizarre/Abnormal/Stereotypic behaviour, Urination, Salivation Defecation, Pilo-erection, Transfer arousal, Exophthalmia, Tail elevation, Lachrymation.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were recorded on Day 1 (prior to dosing) and then weekly for males until termination and weekly for females until mating was evident. Body weights were then recorded for females on Days 0, 7, 14 and 20 post coitum, and on Days 1 and 4 post partum. Body weights were also recorded at terminal kill.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
During the pre-pairing period, weekly food consumption was recorded for each cage of adults. This was continued for males after the mating phase. For females showing evidence of mating, food consumption was recorded for the periods covering post coitum Days 0-7, 7-14 and 14-20.
For females with live litters, food consumption was recorded on Days 1 and 4 post partum.

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: Yes
Food efficiency (the ratio of body weight change/dietary intake) was calculated retrospectively for males throughout the study period (with the exception of the mating phase) and for females during the pre-pairing phase. Due to offspring growth and milk production, food efficiency could not be accurately calculated for females during gestation and lactation.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
Water intake was observed daily by visual inspection of water bottles for any overt changes.

OTHER:
HAEMATOLOGY
CLINICAL CHEMISTRY
NEUROBEHAVIOURAL EXAMINATION: functional perfomance tests (motor activity, forelimb/hindlimb grip strength, sensor reactivity, see section 7.5.1.)
- Pregnancy and Parturition
Each pregnant female was observed at approximately 08:30, 12:30 and 16:30 hours and around the period of expected parturition. Observations were carried out at approximately 0830 and 1230 hours at weekends and public holidays. The following was recorded for each female:
i. Date of pairing
ii. Date of mating
iii. Date and time of observed start of parturition
iv. Date and time of observed completion of parturition

Oestrous cyclicity (parental animals):

A vaginal smear was prepared for each female and the stage of oestrus or the presence of sperm was recorded.

Sperm parameters (parental animals):

Parameters examined in [P] male parental generations:
[testis weight, epididymis weight, other:]
Detailed qualitative examination of the testes was undertaken, taking into account the tubular stages of the spermatogenic cycle. The examination was conducted in order to identify treatment-related effects such as missing germ cell layers or types, retained spermatids, multinucleated or apoptotic germ cells and sloughing of spermatogenic cells into the lumen. Any cell-or stage-specificity of testicular findings was noted.

Litter observations:

PARAMETERS EXAMINED
On completion of parturition (Day 0 post partum), the number of live and dead offspring was recorded. Offspring were individually identified within each litter by tattoo on Day 1 post partum.
For each litter the following was recorded:
i. Number of offspring born
ii. Number of offspring alive recorded daily and reported on Days 1 and 4 post partum
iii. Sex of offspring on Days 1 and 4 post partum
iv. Clinical condition of offspring from birth to Day 5 post partum
v. Individual offspring weights on Days 1 and 4 post partum (litter weights were calculated
retrospectively from this data)

GROSS EXAMINATION OF DEAD PUPS:
[yes, for external and internal abnormalities; possible cause of death was/was not determined for pups born or found dead.]

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: Adult males were killed by intravenous overdose of sodium pentobarbitone followed by exsanguination on Day 43.
- Maternal animals: Adult females were killed by intravenous overdose of sodium pentobarbitone followed by exsanguination on Day 5 post partum. Any females which failed to achieve pregnancy or produce a litter were killed on or after Day 25 post coitum. Any female which failed to mate was terminated on Day 57.

GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.]
For all females, the uterus was examined for signs of implantation and the number of uterine implantations in each horn was recorded. This procedure was enhanced; as necessary, by staining the uteri with a 0.5% ammonium polysulphide solution (Salewski 1964). The corpora lutea were also counted.
All adult animals and offspring, including those dying during the study, were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded.

HISTOPATHOLOGY / ORGAN WEIGHTS
Samples of the tissues mentioned in table 1 were removed from five selected males and five selected females from each dose group and preserved in buffered 10% formalin.
The following tissues were preserved from all remaining animals: Coagulating gland, Epididymides, Gross lesions, Mammary gland, Ovaries, Pituitary, Prostate, Seminal vesicles, Testes, Uterus/Cervix, Vagina.
The following organs were dissected free from fat and weighed before fixation from five selected males and five selected females from each dose group: Adrenals, Brain, Epididymides, Heart, Kidneys, Liver, Ovaries, Pituitary (post fixation), Prostate, Seminal vesicles, Spleen, Testes, Thymus, Thyroid (weighed post-fixation with Parathyroid), Uterus (weighed with Cervix). The following tissues were weighed from all remaining animals: Epididymides, Ovaries, Pituitary (post fixation), Prostate, Seminal vesicles, Testes, Uterus (weighed with Cervix).

Postmortem examinations (offspring):

SACRIFICE
Surviving offspring were terminated via intracardiac overdose of sodium pentobarbitone.
All adult animals and offspring, including those dying during the study, were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded.

GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.] All adult animals and offspring, including those dying during the study, were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded.

Statistics:

See "Any other information on materials and methods incl.tables".

Reproductive indices:

Mating Performance and Fertility:
The following parameters were calculated from the individual data during the mating period of
the parental generation:
i. Pre-coital Interval
Calculated as the time elapsing between initial pairing and the observation of positive
evidence of mating.
ii. Fertility Indices
For each group the following were calculated:
Mating Index (%) = (Number of animals mated/Number of animals paired) x 100
Pregnancy Index (%) = (Number of pregnant females/Number of animalsmated) x 100
Gestation and Parturition Data
The following parameters were calculated from individual data during the gestation and
parturition period of the parental generation:
i. Gestation Length
Calculated as the number of days of gestation including the day for observation of mating
and the start of parturition.
ii. Parturition Index
The following was calculated for each group:
Parturition Index (%) = (Number of females delivering live offspring/Number of pregnant females) x 100

Offspring viability indices:

The standard unit of assessment was considered to be the litter, therefore values were first calculated for each litter and the group mean was calculated using their individual litter values. Group mean values included all litters reared to termination (Day 5 of age).
i. Implantation Losses (%)
Group mean percentile pre-implantation and post-implantation loss were calculated for each female/litter as follows:
% pre–implantation loss = (Number of corpora lutea - Number of implantation sites / Number of corpora lutea) x 100
% post–implantation loss = (Number of implantation sites - Total number of offspring born /Number of implantation sites) x 100
ii. Live Birth and Viability Indices
The following indices were calculated for each litter as follows:
Live Birth Index (%) = (Number of offspring alive on Day 1/ Number of offspring born) x 100
Viability Index (%) = (Number of offspring alive on Day 4 / Number of offspring alive on Day 1) x 100
iii. Sex Ratio (% males)
Sex ratio was calculated for each litter value on Days 1 and 4 post partum, using the following formula:
(Number of male offspring /Total number of offspring) x 100

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

not specified

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
There were no treatment-related deaths.
One female treated with 100 mg/kg bw/day died during the bleeding procedure on Day 4 post partum. This death was considered procedure related and therefore is of no toxicological significance.
There were no toxicologically significant clinical signs detected in treated animals. One male treated with 300 mg/kg bw/day had generalised scab formation between Days 19 and 23. Observations of this nature are commonly observed in group housed animals and is considered not to be of toxicological significance.

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
There were no toxicologically significant effects detected in body weight development.
Males treated with 1000 and 300 mg/kg bw/day showed a statistically significant increase in body weight gain during Weeks 2 and 4 (p<0.05). Males treated with 100 mg/kg bw/day also showed a statistically significant increase in body weight gain during Week 4 (p<0.05). An increase in body weight gain is considered not to represent an adverse effect of treatment therefore the intergroup differences are of no toxicological importance.

No adverse effect on food consumption or food efficiency was detected in treated animals when compared to control animals.

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)
One control female failed to show any positive signs of mating and was non pregnant. One female treated with 300 mg/kg bw/day and one female treated with 100 mg/kg bw/day did not achieve pregnancy following evidence of mating. No histopathological correlates were evident in the female reproductive organs however, the male partners both showed tubular atrophy in the testes and intracellular debris and reduced sperm in the epididymides which was considered to be the cause of the non pregnancies. In the absence of any similar infertility effects detected at 1000 mg/kg bw/day the intergroup differences were considered not to be related to test item toxicity.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
There were no treatment-related effects on mating performance.
No treatment-related effects on fertility were detected for treated animals, when compared to controls.

There were no differences in gestation lengths. The distribution for treated females was comparable to controls. The gestation lengths were between 22 and 23½ days.

ORGAN WEIGHTS (PARENTAL ANIMALS)
No toxicologically significant effects were detected in the organ weights measured.
Males treated with 1000 and 300 mg/kg bw/day showed a statistically significant reduction in thyroid weight both absolute and relative to terminal body weight. The majority of individual values were within normal range for rats of the strain and age used and in the absence of any histology correlates the intergroup differences were considered not to be of toxicological importance.

GROSS PATHOLOGY (PARENTAL ANIMALS)
No toxicologically significant macroscopic abnormalities were detected.
One male treated with 100 mg/kg bw/day had small testes and one male treated with 300 mg/kg bw/day also had small and flaccid testes and small epididymides. Microscopic examinations revealed tubular atrophy in the testes and intratubular cellular debris and reduced sperm in the
epididymides. In the absence of a similar effect at 1000 mg/kg bw/day the intergroup differences were considered not to be of toxicological importance. One female treated with 1000 mg/kg bw/day had dark kidneys at necropsy. In the absence of any histology correlates the intergroup difference was considered not to be of toxicological importance. One control male had a small and flaccid left testis and a small left epididymis. A further control male had reddened lungs. In the absence of treatment these were considered to be incidental findings.

HISTOPATHOLOGY (PARENTAL ANIMALS)
There were no treatment related microscopic abnormalities detected.
The findings recorded were within the range of normal background lesions which may be recorded in rats of the strain and age used.

OTHER FINDINGS (PARENTAL ANIMALS)
Behavioural assessment, functional performance tests, sensory reactivity, haematology and clinical chemistry parameters were comparable to those of controls (see section 7.5.1.)

Effect levels (P0)

1

Dose descriptor:

NOAEL

Remarks:

systemic toxicity

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No toxicologically significant findings were observed in the treated animals.

2

Dose descriptor:

NOAEL

Remarks:

reproductive effects

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No effects on reproductive performance were observed.

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Details on results (F1)

In total eleven females from the control, 100, and 300 mg/kg bw/day dose groups and all females from the 1000 mg/kg bw/day dose group gave birth to a live litter and successfully reared young to Day 5 of age. The following assessment of litter response is based on all litters reared to termination on Day 5 of lactation/age.

VIABILITY (OFFSPRING)
No significant differences were detected for corpora lutea, implantation counts, implantation losses, litter size or litter viability for treated animals when compared to controls. Statistical analysis of the data did not reveal any significant intergroup differences.

CLINICAL SIGNS (OFFSPRING)
No obvious clinical signs of toxicity were detected for offspring from treated females when compared to controls. The incidental clinical signs detected throughout the control and treated groups, consisting of small size, cold, pale, missing tail and no apparent anus, no milk in stomach, found dead or missing, were considered to be low incidence findings observed in offspring in studies of this type and were considered unrelated to test item toxicity.
Litters from females treated with 100 mg/kg bw/day showed a statistically significant reduction in surface righting reflex (p<0.05). The level of statistical significance was minimal and in the absence of a similar effect in the high dose group the intergroup difference was considered to be incidental and of no toxicological importance.

BODY WEIGHT (OFFSPRING)
There were no toxicologically significant effects detected.
Statistical analysis of the litter or offspring weights data did not reveal any significant intergroup differences

SEXUAL MATURATION (OFFSPRING)
There were no intergroup differences in sex ratio (percentage male offspring) for litters from treated groups compared to controls. Statistical analysis of the data did not reveal any significant intergroup differences.

GROSS PATHOLOGY (OFFSPRING)

No treatment-related macroscopic abnormalities were detected for interim death or terminal kill offspring. The incidental findings observed were those occasionally observed in reproductive studies of this type and were considered to be unrelated to toxicity of the test item.

Effect levels (F1)

Remarks on result:

not determinable due to absence of adverse toxic effects

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The oral administration of 1-(3-sulphonatopropyl)pyridinium to rats by gavage, at dose levels of 100, 300 and 1000 mg/kg bw/day, did not result in any toxicologically significant effects. The "No Observed Adverse Effect Level" (NOAEL) for systemic toxicity was therefore considered to be 1000 mg/kg bw/day.
The "No Observed Effect Level" (NOEL) for reproductive toxicity was considered to be 1000 mg/kg bw/day.

Executive summary:

Introduction

The study was designed to investigate the systemic toxicity and potential adverse effects of the test item on reproduction (including offspring development) and is designed to be compatible with the requirements of the OECD Guidelines for Testing of Chemicals No. 422 “Combined Repeated Dose Toxicity Study with the Reproduction/ Developmental Toxicity Screening Test” (adopted 22 March 1996).

This study was also designed to be compatible with Commission Regulation (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

Methods

The test item was administered by gavage to three groups, each of twelve male and twelve female Wistar Han™:RccHan™:WIST strain rats, for up to eight weeks (including a two week pre-pairing phase, pairing, gestation and early lactation for females), at dose levels of 100, 300 and 1000 mg/kg bw/day. A control group of twelve males and twelve females was dosed with vehicle alone (Distilled water).

Clinical signs, behavioural assessments, body weight change and food and water consumption were monitored during the study.

Pairing of animals within each dose group was undertaken on a one male: one female basis within each treatment group on Day 15 of the study, with females subsequently being allowed to litter and rear their offspring to Day 5 of lactation.

During the lactation phase, daily clinical observations were performed on all surviving offspring, together with litter size and offspring weights and assessment of surface righting reflex.

Extensive functional observations were performed on five selected males from each dose group after the completion of the pairing phase, and for five selected parental females from each dose group on Day 4 post partum. Haematology and blood chemistry were evaluated prior to termination on five selected males and females from each dose group.

Adult males were terminated on Day 43, followed by the termination of all females and offspring on Day 5 post partum. Any female which did not produce a pregnancy was terminated on or after Day 25 post coitum. Any female which did not show positive evidence of mating and did not produce a pregnancy was terminated on Day 57. All animals were subjected to a gross necropsy examination and histopathological evaluation of selected tissues was performed.

Results

Adult Responses:

Mortality

There were no treatment-related deaths.

Clinical Observations

No toxicologically significant clinical observations were detected.

Behavioural Assessment

There were no treatment-related changes in the behavioural parameters measured.

Functional Performance Tests

There were no treatment-related changes in functional performance.

Sensory Reactivity Assessments

There were no treatment-related changes in sensory reactivity.

Body Weight

There were no toxicologically significant effects in body weight development.

Food Consumption

No adverse effect on food consumption or food efficiency was detected in treated animals.

Water Consumption

No adverse effect on water consumption was detected.

Reproductive Performance

Mating:

There were no treatment-related effects on mating for treated animals.

Fertility:

There were no treatment-related effects in conception rates for treated animals.

Gestation Lengths:

There were no differences in gestation lengths. The distribution for treated females was comparable to controls.

Litter Responses:

Offspring Litter Size, Sex Ratio and Viability:

Of the litters born, litter size at birth and subsequently on Day 1 and 4 post partum was comparable to controls. Sex ratio and surface righting were also comparable to controls.

Offspring Growth and Development

Offspring bodyweight gain and litter weights at birth and subsequently on Day 1 and 4 post partum were comparable to controls. No clinically observable signs of toxicity were detected for offspring from all treatment groups.

Laboratory Investigations

Haematology:

There were no toxicologically significant effects detected in the haematological parameters examined.

Blood Chemistry:

There were no toxicologically significant effects detected in the blood chemical parameters examined.

Pathology

Necropsy

No toxicologically significant macroscopic abnormalities were detected.

Organ Weights

There were no toxicologically significant effects detected in the organ weights measured.

Histopathology

There were no treatment related microscopic abnormalities detected.

Conclusion

The oral administration of 1-(3-sulphonatopropyl)pyridinium to rats by gavage, at dose levels of 100, 300 and 1000 mg/kg bw/day, did not result in any toxicologically significant effects. The “No Observed Adverse Effect Level” (NOAEL) for systemic toxicity was therefore considered to be 1000 mg/kg bw/day. The “No Observed Effect Level” (NOEL) for reproductive toxicity was considered to be 1000 mg/kg bw/day.