Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
repeated dose toxicity: oral, other
Remarks:
28 day oral toxicity study in rate
Type of information:
experimental study
Adequacy of study:
other information
Study period:
3 May 2006 to 5th September 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report date:
2006

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
Version / remarks:
1995
Qualifier:
according to guideline
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Version / remarks:
Annex V to Council Directive 67/548/EEC
Principles of method if other than guideline:
No deviations made from guideline
GLP compliance:
yes
Limit test:
no

Test material

Constituent 1
Test material form:
solid: particulate/powder
Details on test material:
Light pink tinted powder
Specific details on test material used for the study:
Light pink tinted powder, Batch 4, CTL reference number Y12511/002
Purity 99.8* (w/w)
Stored ambient temperature in the dark
Expirty date 5th April 2008

Test animals

Species:
rat
Strain:
other: HsdRccHan: WIST
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Limited, Shaw's Farm, Blackthorn, Bicester, Oxon, UK
- Age at study initiation: 5 to 6 weeks old
- Weight at study initiation: Males 120 to 145g, females 100 to 125g
- Fasting period before study: none
- Housing: 5 rats per cage, in multiple rat racks. Rats were transferred to clan cages and racks as ncessary during the study
- Diet (e.g. ad libitum): RM1 supplied by Special Diet Services Limited, Witham, Essex UK. Each batch routinely analysed for composiion and pres ence of contaminants.
- Water (e.g. ad libitum): mains water
- Acclimation period: min 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): min 15
- Photoperiod (hrs dark / hrs light): 12 hours continuous artificial light followed by 12 hours continuous dark

Administration / exposure

Route of administration:
oral: unspecified
Details on route of administration:
The rats were dose orally by gavage at 1.0ml/100g according to their daily individual body weights. The rates were dosed sequantially in group order at approximately the same time each day.
Vehicle:
corn oil
Details on oral exposure:
Method of administration:
gavage
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Representative samples of dosing preparations were analysed prior to the start of dosing to verify the achieved concentration of UL125 in corn oil. Samples were taken for the determination of homogeneity in corn oil.

The chemical stability of UL125 in corn oil, stored at room temperature, was determined on samples from the preliminary study (CTL study number: KR1668) at concentrations of 1.5 mg/ml and 40mg /ml which spanned the range of concentrations used in this study.
Duration of treatment / exposure:
Test duration: 28 days
Frequency of treatment:
Dosing regime: 7 days/week
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
15 mg/kg bw/day (actual dose received)
Dose / conc.:
150 mg/kg bw/day (actual dose received)
Dose / conc.:
400 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
Male: 5 animals at 0 mg/kg bw/day
Male: 5 animals at 15 mg/kg bw/day
Male: 5 animals at 150 mg/kg bw/day
Male: 5 animals at 400 mg/kg bw/day
Female: 5 animals at 0 mg/kg bw/day
Female: 5 animals at 15 mg/kg bw/day
Female: 5 animals at 150 mg/kg bw/day
Female: 5 animals at 400 mg/kg bw/day
Details on study design:
- Dose selection rationale:
- Rationale for animal assignment (if not random): 2 single sex replicates (randomised blocks) each containing one cage of animals (5 rats)
- Rationale for selecting satellite groups: n/a
- Post-exposure recovery period in satellite groups: n/a
- Section schedule rationale (if not random): n/a
Positive control:
No positive control used

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: As soon as possible after dosing, then towards the end of each working day.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily at the same time as weight measurements

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes - Food consumption was recorded continuously throughout the study for each cage of rats and calculated, at weekly intervals, as a mean value (g food/rat/day) for each cage.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

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: Not specified

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): N/A
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: daily
- Dose groups that were examined: All

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Post Mortem
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: All
- Parameters examined:
red blood cell count
total white cell count
platelet count
mean cell haemoglobin concentration
differential white cell count
haemoglobin
haematocrit
mean cell volume
mean cell haemoglobin
blood cell morphology

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Post Mortem
- Animals fasted: No
- How many animals: All
- Parameters examined:
Urea
creatinine
Glucose
Albumin
total protein
Sodium alkaline
potassium
Chloride
cholesterol
Albumin/globulin ratio
calcium
phosphorus (as phosphate)
total bilirubin
triglycerides
creatine kinase activity
phosphatase activity
aspartate aminotransferase activity
alanine aminotransferase activity
gamma-glutamyl transferase activity

URINALYSIS: Yes
- Time schedule for collection of urine: One week prior to termination - Samples were collected over a period of 16-18 hours during which the rats were housed individually in metabolism cages and denied access to food, but water was available
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined:
Colour
Volume
Specific gravity
Glucose
Bilirubin
appearance
pH
protein
ketones
blood

In addition, each urine sample was centrifuged and the sediment stained and examined microscopically to identify the components.

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: during week 4
- Dose groups that were examined: All
- Battery of functions tested:
sensory activity
grip strength
motor activity

IMMUNOLOGY: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Oral administration of 400 mg/kg/day was not well tolerated in males and females resulting in significant clinical signs of toxicity including breathing irregularities, subdued appearance, and posture and gait abnormalities. One female was humanely killed on day 2 and the top dose level was reduced to 300 mg/kg/day in both males and females from day 4 or 3 respectively. At 300 mg/kg/day, clinical signs were again evident in females and 2 further animals were humanely killed on day 3. The remaining females in this group were also terminated on day 3 because insufficient animals remained for a meaningful evaluation of any effects. With the exception of salivation, which was observed in males and females at all dose levels there were very few clinical abnormalities recorded after day 4 of the study.
Mortality:
no mortality observed
Description (incidence):
Clinical signs of toxicity including breathing irregularities, subdued appearance, and posture and gait abnormalities led to top dose being reduced to 300 mg/kg and on female rat was killed on day 2 humanely.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
At 300/400 mg/kg/day, bodyweights were slightly lower inmales.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
At 300/400 mg/kg/day, bodyweights were slightly lower inmales. There were no adverse effects on food consumption at any dose level.
Food efficiency:
no effects observed
Description (incidence and severity):
there were no teatment-related effects on weekly food consumption for males. Group mean food consumption was slightly higher from week 2 for females dosed at 150 mg/kg/day compared to controls.
Water consumption and compound intake (if drinking water study):
no effects observed
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Group mean neutrophil count was statistically significantly lower for males at 300/400 and at 150 mg/kg/day compared to controls. The toxicological significance of this isolated difference in white blood cell counts is unclear.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
There were treatment-related differences in a small number of blood clinical chemistry parameters in males and females at 150 and in males at 300/400 mg/kg/day. These differences included higher plasma urea in males at 300/400 mg/kg/day, higher cholesterol in males at 300/400 and in females at 150 mg/kg/day, lower bilirubin in males at 150 and 300/400 mg/kg/day and higher gamma-glutamyl transferease and alanine aminotransferase activities in males only at 300/400 mg/kg/day. The higher plasma cholesterol and higher plasma enzyme activities may indicate an effect on liver function.
Urinalysis findings:
effects observed, non-treatment-related
Description (incidence and severity):
Differences in urine clinical chemistry parameters were limited to higher urine volume in males at 300 mg/kg/day. In the absence of any effects on other urine clinical chemistry parameters or associated pathology findings this difference from concurrent controls is considered not to be of toxicological significance.
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
With the exception of salivation in males at all dose levels, there were no treatment-related functional observation baterry clincal observations.

For males, group mean landing foot splay was higher than controls at 300/400 mg/kg/day and motor activity was lower than controls at both 150 and 300/400 mg/kg/day. In the absence of any treatment-related effects on other functional observation battery parameters or any associated pathology changes the toxicological significance of these differences from control values is unclear.

There were no treatment related effects on grip strength.

there were no treatment related effects on time to tail flick measurements.
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Treatment-related effects on organ weights were limited to higher liver weights in males at all dose levels and in females at 150 mg/kg/day and lower spleen weight in females only at 150 mg/kg/day. In males at 300/400 mg/kg/day the higher liver weights were associated with pathology findings in the liver. In the absence of any related pathology findings, the higher liver weights at lower dose levels are considered to be of limited toxicological significance. In the absence of any associated pathology findings in the spleen the slightly lower spleen weights in females are considered not to be of toxicological significance.
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Administration of 300/400 mg/kg/day UL125 resulted in liver lesions characterised by centrilobular (males) and diffuse (females) hypertrophy. Findings in the non-glandular stomach of female rats dosed at 300 mg/kg/day and terminated early were suggestive of an irritant effect of the test material.
Neuropathological findings:
effects observed, treatment-related
Description (incidence and severity):
Treatment related effects on motor-activity were observed in males at 150 and 300/400 mg/kg/day. There were no treatment related effects on motor activity in females.

In makes dosed at 150 and 300/400 mg/kg/day motor activity was generally lower than controls after the first 10 minutes (table 12, Figure 3). The differences attained stastical significance at both sode levels up to and including the 26-30 minute measurement period and overlal.
Description (incidence and severity):
Treatment related microscopic pathology fidings were observed at the top dose level with findings limited to changes in the liver (males and females) and the stomach (females only).

Slight centrilobular hepatocyte hypertrophy was observed in all males and slight diffuse hepatocyte hypertrophy was observed in all female rates recieving 300/400 mg/kg/day. At this dose level, females showed slight-moderate epithelial erosion and keratin erosion of the non-glandular stomach. This was accompanied by inflammation and varying degrees of oedema.
Details on results:
Clinical observations:
Oral administration of 400 mg/kg/day was not well tolerated
in males and females resulting in significant clinical signs
of toxicity including breathing irregularities, subdued
appearance, and posture and gait abnormalities. One female
was humanely killed on day 2 and the top dose level was
reduced to 300 mg/kg/day in both males and females from day
4 or 3 respectively. At 300 mg/kg/day, clinical signs were
again evident in females and 2 further animals were humanely
killed on day 3. The remaining females in this group were
also terminated on day 3 because insufficient animals
remained for a meaningful evaluation of any effects. With
the exception of salivation, which was observed in males and
females at all dose levels there were very few clinical
abnormalities recorded after day 4 of the study.

Laboratory findings:
At 300/400 mg/kg/day, bodyweights were slightly lower in
males. There were no adverse effects on food consumption at
any dose level.


For males, group mean landing foot splay was higher than
controls at 300/400 mg/kg/day and motor activity was lower
than controls at both 150 and 300/400 mg/kg/day. In the
absence of any treatment-related effects on other functional
observation battery parameters or any associated pathology
changes the toxicological significance of these differences
from control values is unclear.


Differences in urine clinical chemistry parameters were
limited to higher urine volume in males at 300 mg/kg/day.
In the absence of any effects on other urine clinical
chemistry parameters or associated pathology findings this
difference from concurrent controls is considered not to be
of toxicological significance.


Group mean neutrophil count was statistically significantly
lower for males at 300/400 and at 150 mg/kg/day compared to
controls. The toxicological significance of this isolated
difference in white blood cell counts is unclear.


There were treatment-related differences in a small number
of blood clinical chemistry parameters in males and females
at 150 and in males at 300/400 mg/kg/day. These differences
included higher plasma urea in males at 300/400 mg/kg/day,
higher cholesterol in males at 300/400 and in females at 150
mg/kg/day, lower bilirubin in males at 150 and 300/400
mg/kg/day and higher gamma-glutamyl transferease and alanine
aminotransferase activities in males only at 300/400
mg/kg/day. The higher plasma cholesterol and higher plasma
enzyme activities may indicate an effect on liver function.

Effects in organs:
Treatment-related effects on organ weights were limited to
higher liver weights in males at all dose levels and in
females at 150 mg/kg/day and lower spleen weight in females
only at 150 mg/kg/day. In males at 300/400 mg/kg/day the
higher liver weights were associated with pathology findings
in the liver. In the absence of any related pathology
findings, the higher liver weights at lower dose levels are
considered to be of limited toxicological significance. In
the absence of any associated pathology findings in the
spleen the slightly lower spleen weights in females are
considered not to be of toxicological significance.


Administration of 300/400 mg/kg/day UL125 resulted in liver
lesions characterised by centrilobular (males) and diffuse
(females) hypertrophy. Findings in the non-glandular
stomach of female rats dosed at 300 mg/kg/day and terminated
early were suggestive of an irritant effect of the test
material.

Effect levels

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
150 mg/kg bw/day (nominal)
Basis for effect level:
other: original NCD unit is mg/kg/day.
Key result
Dose descriptor:
NOEL
Effect level:
150 mg/kg bw/day (nominal)
Basis for effect level:
other: original NCD unit is mg/kg/day.

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The no observed adverse effect level (NOAEL) for systemic toxicity in this study is considered to be 150 mg/kg/day

Classified as: Not classified
Executive summary:

Oral adminisation of 400/mg/kg/day UL125 for up to 3 days resulted in clinical signs of general toxicity. At the reduced top dose level of 300 mg/kg/day, clinical signs of toxicity were again evident in females resulting in early termination of this group. Oral adminisation of up to 300 mg/kg/day to makes and up to 150 mg/kg/day to females was generally well tolerated. At 300/400 mg/kg/day, bodyweights were slightly lower in males compared to controls.

At 300/400 mg/kg/day, hepatocyte hypertrophy was observed in the liver of both males and females. this finding was associated with changes in plasma biochemistry and increased liver weight. A small number of difference in clincial chemistry parameters were observed at 150 mg/kg/day together with higher liver weights, however, these differences were not associated with pathological changes and were considered to be of limited toxicological significance.

On this basis, the no observed adverse effect level (NOEL) for systematic toxicity in this study is considered to be 150 mg/kg/day.

Categories Display