Registration Dossier

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
yes
Remarks:
dose preparation instruction issued as amendment; delay in identifcation of reserve females; delay in observations during dose range finding study. None had impact on integity of study.
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Identification: Furoxy Hydroxy (OK)
Appearance: Cream powder
Batch: G316533
Purity/Composition: See Certificate of Analysis (see Appendix 3)
Test item storage: In refrigerator (2-8°C)
Stable under storage conditions
until:
25 March 2018 (retest date)

Test animals

Species:
rat
Strain:
Wistar
Remarks:
Crl: WI(Han)
Details on species / strain selection:
The Wistar Han rat was chosen as the animal model for this study as it is an accepted rodent
species for toxicity testing by regulatory agencies. Charles River Den Bosch has general and
reproduction/developmental historical data in this species from the same strain and source.
This animal model has been proven to be susceptible to the effects of reproductive toxicants.
The total number of animals used in this study was considered to be the minimum required to
properly characterize the effects of the test item. This study has been designed such that it
does not require an unnecessary number of animals to accomplish its objectives.
At this time, studies in laboratory animals provide the best available basis for extrapolation to
humans and are required to support regulatory submissions. Acceptable models which do not
use live animals currently do not exist.
This type of study plan was reviewed and agreed by the Laboratory Animal Welfare Officer
and the Ethical Committee of Charles River Den Bosch as required by the Dutch Act on
Animal Experimentation (February 1997).
Sex:
male/female
Details on test animals and environmental conditions:
Test System: Animal Receipt
On 01 Nov 2017, female Crl: WI(Han) rats were received and on 15 Nov 2017, male
Crl:WI(Han) rats were received from Charles River Deutschland, Sulzfeld, Germany. At
initiation of dosing, males were 10-12 weeks old and weighed between 260 and 303 g and
females were 12-14 weeks old and weighed between 205 and 245 g.
A health inspection was performed before the initiation of dosing.

Animal Identification
Prior to start of the pretest period (females) or treatment period (males), each animal was
identified using earmark and tattoo. Prior to the pretest period, reserve females were
numbered R1 through R8 at random by indelible marker (see deviation in Appendix 9).
Pups were identified on postnatal day (PND) 1. They were randomized per litter and
individually identified by means of subcutaneous injection of Indian ink. When general hair
growth blurred the identification, the pups were identified by tattoo on the feet.

Environmental Acclimation
The animals were allowed to acclimate to the Test Facility toxicology accommodation for 7
days prior to start of the pretest period (females) or 6 days before the commencement of
dosing (males).

Selection, Assignment, Replacement, and Disposition of Animals
A total of 40 females was selected at randomization before initiation of the pretest phase. As
none of the selected females was classified as not having regular estrous cycles during the
pretest phase, no replacement was performed before initiation of dosing. A total of 40
females with regular estrous cycles continued in the study. The supernumerary females were
removed from the study, and their estrous cycle results were kept in the raw data but not
reported.
Animals were assigned to groups by a computer-generated random algorithm according to
body weights, with all animals within ± 20% of the sex mean. Males and females were
randomized separately.

Husbandry
Housing
On arrival and following the pretest (females only) and pre-mating period, animals were
group housed (up to 5 animals of the same sex and same dosing group together) in
polycarbonate cages (Macrolon, MIV type, height 18 cm).
During the mating phase, males and females were cohabitated on a 1:1 basis in Macrolon
plastic cages (MIII type, height 18 cm).
During the post-mating phase, males were housed in their home cage (Macrolon plastic cages,
MIV type, height 18 cm) with a maximum of 5 males/cage. Females were individually
housed in Macrolon plastic cages (MIII type, height 18 cm).
During the lactation phase, females were housed in Macrolon plastic cages (MIII type, height
18 cm). Pups were housed with the dam, except during locomotor activity monitoring of the
dams, when the pups were kept warm in their home cage using bottles filled with warm water.
In order to avoid hypothermia of pups, pups were not left without their dam or a bottle filled
with warm water for longer than 30-40 minutes.
During locomotor activity monitoring, animals were housed individually in a Hi-temp
polycarbonate cage (Ancare corp., USA; dimensions: 48.3 x 26.7 x 20.3 cm) without cage enrichment,
bedding material,food andwater.

The cages contained appropriate bedding (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne
GmbH + CO. KG, Rosenberg, Germany) and were equipped with water bottles. The rooms
in which the animals were kept were documented in the study records.
Animals were separated during designated procedures/activities.
Each cage was clearly labeled with a color-coded cage card indicating Test Facility Study
No., group, animal number(s), and sex.

Environmental Conditions
Target temperatures of 18 to 24°C with a relative target humidity of 40 to 70% were
maintained. The actual daily mean temperature during the study period was 19 to 22°C with
an actual daily mean relative humidity of 41 to 54%. A 12-hour light/12-hour dark cycle was
maintained, except when interrupted for designated procedures. Ten or greater air changes
per hour with 100% fresh air (no air recirculation) were maintained in the animal rooms.

Food
Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) was
provided ad libitum throughout the study, except during designated procedures. During
motor activity measurements, animals had no access to food for a maximum of 2 hours.
The feed was analyzed by the supplier for nutritional components and environmental
contaminants. Results of the analysis were provided by the supplier and are on file at the Test
Facility.
It is considered that there were no known contaminants in the feed that would interfere with
the objectives of the study.

Water
Municipal tap water was freely available to each animal via water bottles. During motor
activity measurements, animals had no access to water for a maximum of 2 hours.
Periodic analysis of the water is performed, and results of these analyses are on file at the Test
Facility.
It is considered that there were no known contaminants in the water that would interfere with
the objectives of the study.

Animal Enrichment
For psychological/environmental enrichment and nesting material, animals were provided
with paper (Enviro-dri, Wm. Lilico & Son (Wonham Mill Ltd), Surrey, United Kingdom).

Veterinary Care
Veterinary care was available throughout the course of the study; however, no examinations
or treatments were required.

Administration / exposure

Route of administration:
oral: gavage
Details on route of administration:
The oral route of administration was selected because this is a possible route of human
exposure during manufacture, handling or use of the test item.
Vehicle:
CMC (carboxymethyl cellulose)
Remarks:
1% w/v
Details on oral exposure:
The dose levels were selected based on the results of a 14-day dose range finder with oral
administration of Furoxy Hydroxy (OK) in rats. and in an attempt to produce graded responses to the test item.

Rationale for Vehicle
Trial preparations were performed at the Test Facility to select the suitable vehicle and to
establish a suitable formulation procedure. Trial preparation formulations were not used for
dosing and were discarded after the assessment is complete. These trial preparations have a
non-GLP status and were carried out in the quality assured environment of the Test Facility.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analytical Method
Analyses were performed by using a validated analytical procedure (Test Facility Study No.
520299, ABL No. 17287).

. Concentration Analysis
Duplicate sets of samples (approximately 500 mg) were sent to the analytical laboratory.
Concentration results were considered acceptable if mean sample concentration results were
within or equal to ± 15% for suspensions of target concentration.

Homogeneity Analysis
Duplicate sets of samples (approximately 500 mg) were sent to the analytical laboratory.
Homogeneity results were considered acceptable if the coefficient of variation (CV) of
concentrations was <= 10%.

Stability Analysis
Stability analyses performed previously in conjunction with the method development and
validation study (Test Facility Study No. 520299, ABL No. 17287) demonstrated that the test
item is stable in the vehicle when prepared and stored under the same conditions at
concentrations bracketing those used in the present study. Stability data have been retained in
the study records for Test Facility Study No. 520299, ABL No. 17287.
Duration of treatment / exposure:
The test item and vehicle were administered to the appropriate animals by once daily oral
gavage 7 days a week for a minimum of 28 days. Males were treated for 29 days, up to and
including the day before scheduled necropsy. This included a minimum of 14 days prior to
mating and during the mating period. Females that delivered were treated for 50-56 days, i.e.14 days prior to mating (with the objective to cover at least two complete estrous cycles), the
variable time to conception, the duration of pregnancy and 13-15 days after delivery, up to
and including the day before scheduled necropsy. Females which failed to deliver were
treated for 41, 44 or 54 days. The first day of dosing was designated as Day 1.
Female nos. 42, 49 (Group 1), 57, 60 (Group 2), 64 (Group 3) and 71 (Group 4), were not
dosed on one occasion as these females were littering at the moment of dosing. The omission
of one day of dosing over a period of several weeks was not considered to affect the
toxicological evaluation.
Animals were dosed approximately at the same time each day with a maximum of 6 hours
difference between the earliest and latest dose. The dose volume for each animal was based
on the most recent body weight measurement. The doses were given using a plastic feeding
tube. The dosing formulations were stirred continuously during dose administration.
A dose control system (DCS) was used as additional check to verify the dosing procedure
according to Standard Operating Procedures.
Pups were not treated directly but were potentially exposed to the test item in utero, via
maternal milk, or from exposure to maternal urine/feces.
Frequency of treatment:
Daily
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Remarks:
vehicle
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
10 animals per sex per dose
Control animals:
yes, concurrent vehicle
Details on study design:
A total of 40 females was selected at randomization before initiation of the pretest phase. As
none of the selected females was classified as not having regular estrous cycles during the
pretest phase, no replacement was performed before initiation of dosing. A total of 40
females with regular estrous cycles continued in the study. The supernumerary females were
removed from the study, and their estrous cycle results were kept in the raw data but not
reported.
Animals were assigned to groups by a computer-generated random algorithm according to
body weights, with all animals within ± 20% of the sex mean. Males and females were
randomized separately.

5 animals/sex/group were selected for functional tests, clinical pathology,
collection of full list of tissues and organs at macroscopic examination, organ weights (full
list) and histopathology (full list)
Positive control:
None

Examinations

Observations and examinations performed and frequency:
In-life Procedures, Observations, and Measurements – F0-Generation

Mortality/Moribundity Checks – F0-Generation
Throughout the study, animals were observed for general health/mortality and moribundity
twice daily, in the morning and at the end of the working day. Animals were not removed
from cage during observation, unless necessary for identification or confirmation of possible
findings.

Clinical Observations – F0-Generation
Clinical observations were performed once daily, beginning during the first administration of
the test item and lasting throughout the dosing periods up to the day prior to necropsy.
During the dosing period, these observations were performed at no specific time point, but
within a similar time period after dosing for the respective animals (no peak effect of
occurrence of clinical signs was observed in the dose range finder (Test Facility Study No.
520295, see Appendix 6)).
The time of onset, grade and duration of any observed sign was recorded. Signs were graded
for severity and the maximum grade was predefined at 3 or 4. Grades were coded as slight
(grade 1), moderate (grade 2), severe (grade 3) and very severe (grade 4). For certain signs,
only its presence (grade 1) or absence (grade 0) was scored. In the data tables, the scored
grades were reported, as well as the percentage of animals affected in summary tables.

Arena Observations – F0-Generation
Clinical observations were conducted in a standard arena beginning before the first
administration of the test item and then once weekly throughout treatment. These
observations were conducted after dosing.

Body Weights – F0-Generation
Animals were weighed individually on the first day of treatment (prior to dosing) and weekly
thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17, and 20 post-coitum and
during lactation on PND 1, 4, 7, and 13.
A terminal weight was recorded on the day of scheduled necropsy.

Food Consumption – F0-Generation
Food consumption was quantitatively measured weekly, except for males and females which
were housed together for mating and for females without evidence of mating. Food
consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17, and 20 post-coitum
and during lactation on PND 1, 4, 7, and 13.

Water Consumption – F0-Generation
Subjective appraisal was maintained during the study, but no quantitative investigation was
introduced for the test item groups as no effect was suspected.
From Day 10 of treatment (i.e. 01 December 2017) onwards, water consumption was
measured daily in control animals only. This data was used for collection of historical control
data only and will be kept in the raw data, but not evaluated or reported in this study. No
water consumption was measured for males and females which were housed together for the
mating period.

Functional Tests – F0-Generation
Functional tests were performed on the selected 5 males during Week 4 of treatment and the
selected 5 females during the last week of lactation (i.e. PND 6-13). These tests were
performed after completion of clinical observations (including arena observation, if
applicable).
The following tests were performed (abbreviations mentioned in the respective tables are
indicated between brackets):
-Hearing ability (HEARING) (Score 0 = normal/present, score 1 = abnormal/absent).
-Pupillary reflex (PUPIL L/R) (Score 0 = normal/present, score 1 = abnormal/absent).
-Static righting reflex (STATIC R) (Score 0 = normal/present, score 1 =
abnormal/absent).
- Fore- and hind-limb grip strength, recorded as the mean of three measurements per
animal (Series M4-10, Mark-10 Corporation, J.J. Bos, Gouda, The Netherlands).
-Locomotor activity (recording period: 1-hour under normal laboratory light
conditions, using a computerized monitoring system, Kinder Scientific LLC, Poway,
USA). Total movements and ambulations were reported. Ambulations represent
movements characterized by a relocation of the entire body position like walking,
whereas total movements represent all movements made by the animals, including
ambulations but also smaller or more fine movements like grooming, weaving or
movements of the head.

Laboratory Evaluations
Clinical Pathology
. Sample Collection
Blood of F0-animals was collected on the day of scheduled necropsy. Samples were
collected, between 7.00 and 10.30 a.m., from the retro-orbital sinus under anesthesia using
isoflurane in the animal facility. Due to clotting of non-serum samples, additional blood
samples were obtained in the necropsy room. After collection all samples were transferred to
the appropriate laboratory for analysis.
F0-males were fasted overnight with a maximum of 24 hours before blood sampling, but
water was available. F0-females were not fasted overnight.

4.11.1.2. Hematology
Blood samples were analyzed for the parameters specified as follows:

White blood cells (WBC); Red Blood Cell Distribution Width (RDW);
Neutrophil (absolute); Haemoglobin ;
Lymphocyte (absolute); Haematocrit;
Monocyte (absolute); Mean corpuscular volume (MCV);
Eosinophil (absolute); Mean corpuscular haemoglobin (MCH);
Basophil (absolute); Mean corpuscular haemoglobin concentration (MCHC);
Red blood cells; Platelet;
Reticulocyte (absolute);
A blood smear was prepared from each hematology sample. Blood smears were labeled,
stained, and stored. These smears were not examined.

Coagulation
Blood samples were processed for plasma, and plasma was analyzed for the parameters listed
as folows
Prothrombin Time (PT); Activated Partial Thromboplastin Time (APTT)

Clinical Chemistry
Blood samples were processed for plasma or serum (bile acids), which was analyzed for the
parameters specified below:

Alanine aminotransferase (ALAT); Creatinine;
Aspartate aminotransferase (ASAT); Glucose;
Alkaline Phosphatase (ALP); Cholesterol;
\Gamma glutamyl transpeptidase (GGT); Sodium;
Total protein; Potassium;
Albumin; Chloride;
Total Bilirubin; Calcium;
Bile Acids; Inorganic Phosphate (Inorg. Phos);
Urea

Thyroid hormone
Blood samples were processed for serum, and serum was analyzed for total Thyroxine (T4).
Measurement of total T4 was conducted for F0-males.
For the F0 -generation, assessment of T4 (females) and Thyroid Stimulating Hormone (TSH;
both sexes) was considered not relevant because there were no treatment-related changes in
T4 in F0 -males or in thyroid weight or morphology in either sex .
Serum samples retained for possible future analysis were maintained by the Test Facility in
the freezer (≤-75°C). Under these storage conditions, samples are stable for 6 months. Any
remaining sample will be discarded .

Sacrifice and pathology:
Unscheduled Deaths
No animals died during the course of the study.

Scheduled Euthanasia
Animals surviving until scheduled euthanasia were weighed, and deeply anaesthetized using
isoflurane and subsequently exsanguinated and subjected to a full post mortem examination.
Scheduled necropsies were conducted on the following days:
-Males: Following completion of the mating period.
-Females which delivered: PND 14-16.
-Females which failed to deliver : With evidence of mating: Post-coitum Days 26 or 27
(nos. 47, 51, 53, 61, 69, 72 and 77).
Without evidence of mating: 26 days after the last day
of the mating period (no. 44).
All males were fasted overnight with a maximum of 24 hours before necropsy. Water was
available. F0
- females were not fasted overnight.

Necropsy – F0-Generation
All animals were subjected to a full post mortem examination, with special attention being
paid to the reproductive organs.
Necropsy procedures were performed by qualified personnel with appropriate training and
experience in animal anatomy and gross pathology. A veterinary pathologist, or other
suitably qualified person, was available.
The numbers of former implantation sites were recorded for all paired females.
In case no macroscopically visible implantation sites were present, nongravid uteri were
stained using the Salewski technique in order to detect any former implantation sites and the
number of corpora lutea was recorded in addition.

Organ Weights – F0-Generation
The organs identified in the table below were weighed at necropsy for all scheduled
euthanasia animals. Paired organs were weighed together. In the event of gross
abnormalities, in addition to the combined weight, the weight of the aberrant organ was taken
and recorded in the raw data. Organ to body weight ratios (using the terminal body weight)
were calculated.
Brain
Cervix (weighed together with uterus)
Epididymis (paired organ weight)
Gland, adrenal (paired organ weight)
Gland, coagulation (paired organ weight, together with seminal vesicles)
Gland, parathyroid (weighed with thyroid)
Gland, prostate
Gland, seminal vesicle (paired organ weight)
Gland, thyroid
Heart
Kidney (paired organ weight)
Liver
Ovaries (paired organ weight)
Spleen
Testes(paired organ weight)
Thymus
Uterus

Tissue Collection and Preservation – F0-Generation
Representative samples of the tissues identified below were collected from all
animals and preserved in 10% neutral buffered formalin (neutral phosphate buffered 4%
formaldehyde solution, Klinipath, Duiven, The Netherlands), unless otherwise indicated.
Animal identification
Artery, aorta
Body cavity, nasopharynx
Bone marrow
Bone, femur
Bone, sternum
Brain (seven levels)
Cervix
Epididymis
Esophagus
Eye
Gland, adrenal
Gland, coagulation
Gland, harderian
Gland, lacrimal
Gland, mammary
Gland, parathyroid
Gland, pituitary
Gland, prostate
Gland, salivary
Gland, seminal vesicle
Gland, thyroid
Gross lesions/masses
Gut-associated lymphoid tissue
Heart
Kidney
Large intestine, cecum
Large intestine, colon
Large intestine, rectum
Larynx
Liver
Lung
Lymph node (mandibular and mesenteric site)
Muscle, skeletal
Nerve, optic
Nerve, sciatic
Ovaries
Pancreas
Skin
Small intestine, duodenum
Small intestine, ileum
Small intestine, jejunum
Spinal cord
Spleen
Stomach
Testes
Thymus
Tongue
Trachea
Urinary bladder
Uterus
Vagina

Histology – F0-Generation
The following tissues were embedded in paraffin, sectioned, mounted on glass slides, and
stained with hematoxylin and eosin:
Selected animals: Tissues identified above (except animal identification, aorta,
nasopharynx, esophagus, harderian gland, lacrimal gland, salivary gland, larynx, optic nerve, pancreas, skin
and tongue).
Males that failed to sire (except for
males which were selected) and
females that failed to deliver pups: Cervix, epididymis, coagulation gland, prostate gland, seminal vesicles, ovaries, testes, uterus and vagina.

Histopathology – F0-Generation
All tissues as defined under Histology – F0
-Generation were examined by a board-certified toxicological pathologist with training and experience in laboratory animal
pathology.
For the testes of all selected males of Groups 1 and 4, and all males that failed to sire, a
detailed qualitative examination was made, taking into account the tubular stages of the
spermatogenic cycle.
A peer review on the histopathology data was performed by a second pathologist.

Statistics:
6. STATISTICAL ANALYSIS
All statistical tests were conducted at the 5% significance level. All pairwise comparisons
were conducted using two sided tests and were reported at the 1% and or 5% levels.
Numerical data collected on scheduled occasions for the listed variables were analyzed as
indicated according to sex and occasion. Descriptive statistics number, mean and standard
deviation (or %CV or SE when deemed appropriate) were reported whenever possible.
Inferential statistics were performed according to the matrix below when possible, but
excluded semi-quantitative data, and any group with less than 3 observations.
The following pairwise comparisons were made:
Group 2 vs. Group 1
Group 3 vs. Group 1
Group 4 vs. Group 1

Parametric
Datasets with at least 3 groups (the designated control group and 2 other groups) were
compared using Dunnett-test (many-to-one-t-test).

Non-Parametric
Datasets with at least 3 groups was compared using a Steel-test (many-to-one rank test).
The motor activity data set was compared using an overall Kruskal-Wallis.

Incidence
An overall Fisher’s exact test was used to compare all groups at the 5% significance level.
The above pairwise comparisons were conducted using Fisher’s exact test whenever the
overall test is significant.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Fluid feces at a slight severity was noted in all cages (both sexes) at 300 and 1000 mg/kg on treatment Days 7-15.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
A finding of note at 300 mg/kg was the reduced body weight gain or slight weight loss which
occurred in half of the males and most females in the first week of the treatment period. As a
result, mean body weights at 300 mg/kg were about 5% lower compared to controls from
treatment Day 8 onwards (statistically significant in females on two occasions). After the
first treatment week, 300 mg/kg animals grew normally. As weight gain at 1000 mg/kg was
normal, the transiently reduced weight gain at 300 mg/kg was considered not to be related to
treatment.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
Slightly higher food consumption values were noted in females at 1000 mg/kg from lactation
Day 4 towards the end of the treatment period, correlating with slightly higher body weight
gain. Relative food consumption differed up to 9% when compared to controls. As values
remained within the normal range, this finding was regarded as non-adverse.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Isolated, statistically significant differences noted in males treated at 100 or 300 mg/kg (for
neutrophils, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH))
were considered to be unrelated to treatment due to the lack of a dose-related response.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Coagulation parameters were considered not to be affected by treatment.
A statistically significantly lower mean concentration of bile acids was noted in males at
1000 mg/kg (relative difference from control: 69%). All 1000 mg/kg males had bile acid
concentrations around the 5th percentile of the historical control range.
A statistically significantly higher mean activity of aspartate aminotransferase (ASAT) was
noted in females at 1000 mg/kg (relative difference from control: 30%). Mean ASAT activity
in 1000 mg/kg females remained within the historical control range.
The other statistically significant differences noted in clinical biochemistry parameters were
considered to be unrelated to treatment due to the lack of a dose-related response (ASAT and
glucose in males, urea and chloride in females) and/or slightly high concurrent control values
(ASAT in males)
Urinalysis findings:
not examined
Behaviour (functional findings):
effects observed, non-treatment-related
Description (incidence and severity):
Functional observation parameters were considered not to be affected by treatment.
Hearing ability, pupillary reflex and static righting reflex were normal in all examined
animals. Grip strength was not affected by treatment.
Motor activity data showed a similar habituation profile with a decreasing trend in activity
over the duration of the test period for all groups. A finding of note was the lower mean
value for total ambulations in females at 1000 mg/kg (relative difference from controls: 35%),
which remained in the historical control range.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
There were no toxicologically relevant changes in organ weights.
Heart to body weight ratio of males at 1000 mg/kg was statistically significantly lower than
that of controls (relative difference: 13%). Absolute heart weight was also lower (11%) but
not statistically significantly. As no dose-related response or correlated microscopic
abnormalities were observed, and as values remained within the range of historical control
data (at the lower end), these changes were not considered to be treatment related.
Other statistically significant differences noted (higher relative adrenal weight in males, lower
uterus weight in females at 300 mg/kg) were considered not to be related to treatment due to
the lack of a dose-related response.
Gross pathological findings:
no effects observed
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
not examined

Effect levels

Key result
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: lack of adverse effects
Remarks on result:
not determinable due to absence of adverse toxic effects

Target system / organ toxicity

Critical effects observed:
no

Applicant's summary and conclusion

Conclusions:
In conclusion, based on the results of this combined 28-day repeated dose toxicity study with
the reproduction/developmental toxicity screening test, the following No Observed Adverse
Effect Levels (NOAELs) of Furoxy Hydroxy (OK) were established: Parental NOAEL: at least 1000 mg/kg.