Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2019-02-11 to 2019-04-10
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Cross-reference
Reason / purpose for cross-reference:
reference to same study
Reference
Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
From 2019-02-11 to 2019-04-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to other study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
Deviations:
yes
Remarks:
only 14 days of exposure (performed as a preliminary study to OECD 422)
Qualifier:
according to guideline
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Deviations:
yes
Remarks:
only 14 days of exposure (performed as a preliminary study to OECD 422)
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
Wistar
Remarks:
Han:WIST rat of Wistar origin
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Toxi-Coop Zrt. 1103 Budapest, Cserkesz u. 90
- Females (if applicable) nulliparous and non-pregnant: no data
- Age at study initiation: 49-54 days (males), 36-41 days (females)
- Weight at study initiation: 216-231 g for males, 132-147 g for females
- Fasting period before study: no data
- Housing: 5 animals of the same sex per cage (Type IV polypropylene/ polycarbonate) with Certified laboratory wood bedding
- Diet: ssniff® SM R/M-Z+H complete diet for rats and mice produced by ssniff Spezialdiäten GmbH, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30 - 70 %
- Air changes: Above 10 air-exchanges/ hour
- Photoperiod: Artificial light, from 6 a.m. to 6 p.m.

IN-LIFE DATES: from February 07, 2019 to February 25, 2019
Route of administration:
oral: gavage
Vehicle:
water
Remarks:
Distilled water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulations were prepared not longer than for three days and stored at 5 ± 3 °C until use.

VEHICLE
- Concentration in vehicle: 20, 60 and 180/150 mg/mL
- Amount of vehicle: 5 mL kg/bw
- Lot/batch no. (if required): 181001
- Purity: distilled water
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analytical dose verification of the formulations was performed once during this DRF study.
Measured concentrations of formulations applied in the study varied in the acceptable range (between 98 % and 101 % of the nominal concentrations) and all formulations were homogenous, thereby confirming proper dosing.
Duration of treatment / exposure:
14 days
Frequency of treatment:
once daily
Dose / conc.:
0 mg/kg bw/day (nominal)
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
300 mg/kg bw/day (nominal)
Dose / conc.:
750 mg/kg bw/day (nominal)
Remarks:
900, then reduced to 750 on Day 4
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: in agreement with the Sponsor and based on the oral LD50 value of 2040 mg/kg bw/day
- Fasting period before blood sampling for clinical biochemistry: yes (food deprivation for approximately 16 hours)
- Post-exposure recovery period in satellite groups: none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once a day, after treatment at approximately the same time.

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: on Day 0 (prior to study start) and twice weekly on Days 0, 3, 7, 10 and 13

FOOD CONSUMPTION AND COMPOUND INTAKE:
Food consumption was determined with the measurement of non-consumed diet once weekly


WATER CONSUMPTION AND COMPOUND INTAKE: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on Day 14 of treatment
- Anaesthetic used for blood collection: Yes (Isofluran CP®)
- Animals fasted: Yes
- How many animals: all
- Parameters checked: WBC, RBC, HGB, MCV, MCH, MCHC, PLT, RET, differential white blood cell count, blood clotting time (APTT, PT).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on Day 14 of treatment
- Animals fasted: Yes
- How many animals: all
- Parameters checked: ALT, AST, GGT, ALP, TBIL, CREA, UREA, GLUC, CHOL, Pi, Ca++, Na+, K+, Cl-, ALB, TPPROT, A/G ratio.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table)
The external appearance (surface of the body, all orifices) was examined, cranium, thoracic and abdominal cavities were opened and the appearance of the tissues and organs was observed macroscopically for each animal.
The following organs/tissues were removed and preserved in 4 % formaldehyde solution, except testes and epididymides, which were preserved in modified Davidson solution and then stored in 4 % formaldehyde solution:
Adrenal glands, Aorta, Bone with bone marrow and joint (femur), Brain (representative regions: cerebrum, cerebellum and pons and medulla oblongata), Eyes (lachrymal gland with Harderian glands), Mammary gland, Heart, Kidneys, Large intestines (caecum, colon, rectum), Liver, Lungs (with main stem bronchi; inflation with fixative and then immersion), Lymph nodes (submandibular, mesenteric), Muscle (quadriceps), Esophagus, Pancreas, Pituitary, Prostate, Salivary glands (submandibular), Sciatic nerve, Seminal vesicle with coagulating gland, Sexual organs (testes with epididymides, seminal vesicles with coagulating gland, ovaries, uterus with cervix and oviducts, vagina), Skin, Small intestines (duodenum, ileum, jejunum, rectum, including Peyer’s patches), Spinal cord (at three levels: cervical, mid-thoracic and lumbar), Spleen, Sternum, Stomach, Thymus, Thyroid + parathyroid, Trachea, Urinary bladder
HISTOPATHOLOGY: No
Statistics:
Statistical analysis was done with SPSS PC+ software for the following data: Body weight, Hematology and blood coagulation, Clinical chemistry, Organ weight.
The heterogeneity of variance between groups was checked by Bartlett's homogeneity of variance test. Where no significant heterogeneity was detected, a one-way analysis of variance was carried out. If the obtained result was positive, Duncan's Multiple Range test was used to assess the significance of inter-group differences.
Where significant heterogeneity was found, the normal distribution of data was examined by Kolmogorov-Smirnov test. In case of a none-normal distribution, the non-parametric method of Kruskal-Wallis One-Way analysis of variance was used. If there was a positive result, the inter-group comparisons were performed using the Mann-Whitney U-test.
Frequency of clinical signs, ophthalmoscopy, pathological and histopathological findings by sex and dose was calculated.
Significance was judged at a probability value of p < 0.05 and < 0.01. Male and female rats were evaluated separately.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
2,5-Dimethoxytetrahydrofuran caused clinical signs in slight or moderated degree at 900 mg/kg bw/day (decreased activity, squatting position, incoordination and prone position) and at 750mg/kg bw/day (decreased activity incoordination) in male and female animals.
The behavior and physical condition of all animals were normal in male and female animals in the control group and at 100 and 300 mg/kg bw/day during the course of 14-day administration.
At 900 mg/kg bw/day, slight or moderate decreased activity, squatting position, incoordination and prone position were detected in male (5/5) and female (5/5) animals 5-60 minutes after the administration on Days 0, 1 and 2.
After the dose reduction to 750 mg/kg bw/day, decreased activity and incoordination were noted for each animal during the remaining days of treatment period (5/5 male and 5/5 female).
All animals recovered – were normal – on Day 3 (washout day).
Mortality:
no mortality observed
Description (incidence):
There was no mortality in the control, 100, 300 or 900/750 mg/kg bw/day groups during the 14-day treatment period (male and female).
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Significant body weight loss was detected in male and female animals administered with 900 mg/kg bw/day between Days 0 and 3.
The body weight development was undisturbed in male and female animals after the dose reduction to 750 mg/kg bw/day (between Days 4 and 13).
The body weight and body weight gain of the male and female animals were unaffected at 100 mg/kg bw/day and in female animals at 300 mg/kg bw/day throughout the entire observation period.
In the male animals at 300 mg/kg bw/day, the mean body weight gain was significantly lower than in the control group between Days 0 and 3 resulting in significantly lower mean body weight from Day 3 up to the termination of the study (-5 %, -7 %).
At 900 mg/kg bw/day, the body weight decreased in each male and female animal between Days 0 and 3.
After the dose reduction, the mean body weight gain exceeded the control value reaching statistical significance between Days 3 and 7 (male and female) and between Day 7-10 (female). However, the summarized body weight gain remained significantly lower than in the control group in male animals and was lower – no statistical significance – than in the control group in female animals.
As a consequence, the mean body weight was lower than in the control in male animals from Day 3 up to the end of the study (minus 22 % – minus 13 %) and in female animals on Days 3 and 7 (-16, -7 %). The mean body weight of female animals at 900/750 mg/kg bw/day was similar to their control by the end of the treatment period (Day 13).
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
The mean daily food consumption was reduced in male and female animals at 900/750 mg/kg bw/day during the first week of the study in full compliance with the body weight changes.
The mean daily food consumption was comparable in the control and 100, 300 mg/kg bw/day (male and female) during the 14-day observation period.
At 900/750 mg/kg bw/day, the daily mean food intake was significantly lower than in the control in male and female animals during week 1 and it was similar to the control during week 2 (male and female).
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Test item related elevation in the mean percentage of neutrophil granulocytes (NEU), monocytes (MONO) and reticulocytes (RET) were observed in male and female animals at 900/750 mg/kg bw/day along with lowered mean percentage of lymphocytes (LYM).
In the male animals at 100 and 300 mg/kg bw/day, the examined hematological parameters were comparable to their control.
In the female animals, statistical significances were detected at the higher mean white blood cell count (WBC) and percentage of reticulocytes at 100 mg/kg bw/day and at the higher mean corpuscular volume (MCV) and mean corpuscular hemoglobin content (MCH) at 300 mg/kg bw/day with respect to their control.
At 900/750 mg/kg bw/day, statistically significant differences were observed with respect to the appropriate control at the higher mean percentage of neutrophil granulocytes, monocytes and reticulocytes, at the lower mean percentage of lymphocytes in male and female animals as well as at the higher mean white blood cell count in female animals.
Additionally, statistical significance was noted for the lower mean hematocrit value (HCT) and shorter mean prothrombin time (PT) in male animals at 900/750 mg/kg bw/day.
The slight, sporadic statistical differences compared to the control (HCT, PT in male animals at 900/750 mg/kg bw/day; WBC, RET and MCV, MCH in female animals at 100 and 300 mg/kg bw/day, respectively) were with minor degree and values remained within the historical control ranges. Therefore, these findings were judged to be toxicologically not relevant.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Slight elevation in activity of alanine aminotransferase (ALT) in male animals and elevated cholesterol concentration (CHOL) in male and female animals at 900/750mg/kg bw/day and in male animals at 300 mg/kg bw/day suggest an effect on the hepatic function.
At 100 mg/kg bw/day, statistical significance was detected at the slightly higher mean concentration of chloride (Cl-) in male animals and all examined parameters were comparable to their control in female animals.
At 300 mg/kg bw/day, higher mean concentrations of cholesterol, sodium (Na+) and chloride were observed in male animals and lower mean concentration of creatinine (CREA) and higher mean concentration of glucose (GLUC) were detected in female animals when compared to their control.
Compared to their control, statistical significances were noted for the higher mean activity of alanine aminotransferase in male animals, higher mean concentration of cholesterol in male and female animals and total protein (TPROT) in female animals. Lower mean level of chloride and creatinine and lower mean albumin: globulin ratio (A/G) were also detected in female animals at 900/750 mg/kg bw/day when compared to their control.
Statistically significant differences in some parameters were considered to be of little or no biological significance as the mean values correlated well with the historical control values (creatinine, glucose, total protein, A/G, Na+, Cl), the profile of change has no biological significance (creatinine) or findings were only detected at the lower doses (glucose, Cl, Na+).
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Evaluation of absolute and relative organ weights revealed slight elevation of kidneys weight in female animals and of liver weight in male and female animals at 900/750 mg/kg bw/day, which were judged to be treatment related. Histopathological examinations are needed to reveal the nature of these findings nevertheless, these might be an indication of the adaptation process.
There were no statistically or biologically significant differences between the control and 100 mg/kg bw/day treated male or female animals in the weights of the examined organs.
In the male animals at 300 mg/kg bw/day, statistically significant difference with respect to the control was detected at the slightly higher mean liver weight relative to body weight
In the female animals at 300 mg/kg bw/day, the liver weight relative to body and brain weights and thymus weight relative to body weight exceeded the control value.
At 900/750 mg/kg bw/day, statistically significant difference with respect to the control was detected at the lower mean body weight (absolute and relative to brain weight), at the higher mean liver weight (absolute and relative to body and brain weights), at the lower mean weights of heart (absolute) and seminal vesicles with coagulating gland and prostate (absolute and relative to brain weigh) and at the higher weights of brain and adrenal gland (both relative to body weight) in male animals.
In the female animals at 900/750 mg/kg bw/day, the mean weights of liver (absolute and relative to body and brain weights), kidneys (relative to body and brain weights) and thymus (relative to body and brain weights) were higher than in the control group.
Changes in the liver weights in male and female animals and in kidney weights in female animals at 300 or 900/750 mg/kg bw/day might be related to a test item influence on hepatic and renal function taking into account the changes in some clinical chemistry parameters (ALT, cholesterol). The degree of all of these changes was small therefore these might be considered to be indication of the adaptation process.
Statistical significances at the thymus weight was due to the relative low control value in female animals and all individual values remained well within the historical control ranges.
Statistical significances noted for some organs (brain, heart, seminal vesicles, adrenal glands) in male animals were with small degree and were originated from the low fasted body weight.
Therefore, these findings in organ weights (adrenal glands, brain, heart, seminal vesicles, thymus) were considered to be of little or no biological significance.
Gross pathological findings:
no effects observed
Description (incidence and severity):
Gross necropsy did not reveal any macroscopic changes, which were related to treatment with test item in male or female animals (100, 300 or 900/750 mg/kg bw/day).
Renal pyelectasia – right side or both sides – was observed in the control group (1/5 male, 1/5 female), at 100 mg/kg bw/day (1/5 male), at 300 mg/kg bw/day (1/5 male and 1/5 female) and at 900/750 mg/kg bw/day (1/5 female).
Pyelectasia is a common finding in this strain of experimental rats. There were no inflammatory or other pathological signs related to this finding and therefore it was not attributed to test item treatment.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
not examined
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
body weight and weight gain
clinical biochemistry
clinical signs
food consumption and compound intake
gross pathology
haematology
mortality
organ weights and organ / body weight ratios

see attached document

Conclusions:
Under the condition of the present study 2,5-Dimethoxytetrahydrofuran caused clinical signs, reduction in body weight development and food consumption after 13 days oral administration to male or female Han:WIST rats at 900/750 mg/kg bw/day.
At 900/750 mg/kg bw/day, a test item influence was observed in white blood cell parameters (NEU, MONO, LYM) and percentage of reticulocytes (male and female), in concentrations of cholesterol (male and female) and ALT activity (male), changes in in organ weights (liver, male and female; kidneys, female).
At 300 mg/kg bw/day, lesser but significant changes in some of these parameters were observed: body weight, cholesterol concentration in male animas, liver weight in male and female animals.
At 100 mg/kg bw/day, there were no test item related findings.
Executive summary:

In a subacute toxicity study 2,5-Dimethoxytetrahydrofuran was administered to 5 rats/sex/dose in water by gavage at dose levels of 0, 100, 300 and 900/750  mg/kg bw/day.

Detailed clinical observations were performed daily after the treatment. Body weights were recorded twice weekly in groups of control, 100 and 300 mg/kg bw/day and daily in high dose groups from Day 2. The food consumption was determined weekly to coincide with body weight measurements during the study. Clinical pathology (hematology, blood coagulation and clinical chemistry) and gross pathology examinations were conducted one day after the last treatment (on Day 14). Selected organs were weighed.

There was no mortality in control, 100, 300 or 900/750 mg/kg bw/day groups.

Test item related clinical signs were observed in slight or moderated degree at 900 mg/kg bw/day (decreased activity, squatting position, incoordination and prone position on Days 0, 1, 2) and at 750mg/kg bw/day (decreased activity incoordination, from Day 4 to Day 13) in male and female animals.

Significant body weight loss was detected in male and female animals administered with 900 mg/kg bw/day between Days 0 and 3. The body weight development was undisturbed in male and female animals after the dose reduction to 750 mg/kg bw/day – between Days 4 and 13.

The mean daily food consumption was reduced in male and female animals at 900/750 mg/kg bw/day during the first week of the study in full compliance with the body weight changes.

Test item related elevation in the mean percentage of neutrophil granulocytes (NEU), monocytes (MONO) and reticulocytes (RET) were observed in male and female animals at 900/750 mg/kg bw/day along with lowered mean percentage of lymphocytes (LYM).

Slight elevation in activity of alanine aminotransferase (ALT) in male animals and elevated cholesterol concentration (CHOL) in male and female animals at 900/750mg/kg bw/day and in male animals at 300 mg/kg bw/day suggest an effect on the hepatic function.

Necropsy examinations did not reveal any macroscopic changes, which were related to treatment with test item in male or female animals (100, 300 or 900/750 mg/kg bw/day).

Evaluation of absolute and relative organ weights revealed slight elevation of kidneys weight in female animals and of liver weight in male and female animals at 900/750 mg/kg bw/day, which were judged to be treatment related. Histopathological examinations are needed to reveal the nature of these findings nevertheless, these might be an indication of the adaptation process.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019
Report date:
2019

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
other: OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
yes only 14 days of exposure (performed as a preliminary study to OECD 422)
Qualifier:
according to guideline
Guideline:
other: EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Deviations:
yes
Remarks:
yes only 14 days of exposure (performed as a preliminary study to OECD 422)
GLP compliance:
no
Test type:
other: 14-day study
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Tetrahydro-2,5-dimethoxyfuran
EC Number:
211-797-1
EC Name:
Tetrahydro-2,5-dimethoxyfuran
Cas Number:
696-59-3
Molecular formula:
C6H12O3
IUPAC Name:
tetrahydro-2,5-dimethoxyfuran
Test material form:
liquid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Toxi-Coop Zrt. 1103 Budapest, Cserkesz u. 90
- Females (if applicable) nulliparous and non-pregnant: no data
- Age at study initiation: 49-54 days (males), 36-41 days (females)
- Weight at study initiation: 216-231 g for males, 132-147 g for females
- Fasting period before study: no data
- Housing: 5 animals of the same sex per cage (Type IV polypropylene/ polycarbonate) with Certified laboratory wood bedding
- Diet: ssniff® SM R/M-Z+H complete diet for rats and mice produced by ssniff Spezialdiäten GmbH, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30 - 70 %
- Air changes: Above 10 air-exchanges/ hour
- Photoperiod: Artificial light, from 6 a.m. to 6 p.m.

IN-LIFE DATES: from February 07, 2019 to February 25, 2019

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
Distilled water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulations were prepared not longer than for three days and stored at 5 ± 3 °C until use.

VEHICLE
- Concentration in vehicle: 20, 60 and 180/150 mg/mL
- Amount of vehicle: 5 mL kg/bw
- Lot/batch no. (if required): 181001
- Purity: distilled water
Doses:
0, 100, 300 and 750/900 (900, then reduced to 750 on Day 4) mg/kg bw/day during 14 days
No. of animals per sex per dose:
5
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14-day exposure
- Frequency of observations and weighing:
> clinical sings: once a day, after treatment at approximately the same time
> body weight: on Day 0 (prior to study start) and twice weekly on Days 0, 3, 7, 10
and 13
- Necropsy of survivors performed: yes
- Other examinations performed: fodd consumption, haematology, clinical chemistry (see section 7.5.1 for details)

Results and discussion

Effect levelsopen allclose all
Key result
Sex:
male/female
Dose descriptor:
LD0
Effect level:
900 mg/kg bw
Based on:
test mat.
Remarks on result:
other:
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 900 mg/kg bw
Based on:
test mat.
Remarks on result:
other: no mortality observed after 14 days of exposure
Mortality:
There was no mortality in the control, 100, 300 or 900/750 mg/kg bw/day groups during the 14-day treatment period (male and female).
Clinical signs:
2,5-Dimethoxytetrahydrofuran caused clinical signs in slight or moderated degree at 900 mg/kg bw/day (decreased activity, squatting position, incoordination and prone position) and at 750mg/kg bw/day (decreased activity incoordination) in male and female animals.
The behavior and physical condition of all animals were normal in male and female animals in the control group and at 100 and 300 mg/kg bw/day during the course of 14-day administration.
At 900 mg/kg bw/day, slight or moderate decreased activity, squatting position, incoordination and prone position were detected in male (5/5) and female (5/5) animals 5-60 minutes after the administration on Days 0, 1 and 2.
After the dose reduction to 750 mg/kg bw/day, decreased activity and incoordination were noted for each animal during the remaining days of treatment period (5/5 male and 5/5 female).
All animals recovered – were normal – on Day 3 (washout day).
Body weight:
Significant body weight loss was detected in male and female animals administered with 900 mg/kg bw/day between Days 0 and 3.
The body weight development was undisturbed in male and female animals after the dose reduction to 750 mg/kg bw/day (between Days 4 and 13).
The body weight and body weight gain of the male and female animals were unaffected at 100 mg/kg bw/day and in female animals at 300 mg/kg bw/day throughout the entire observation period.
In the male animals at 300 mg/kg bw/day, the mean body weight gain was significantly lower than in the control group between Days 0 and 3 resulting in significantly lower mean body weight from Day 3 up to the termination of the study (-5 %, -7 %).
At 900 mg/kg bw/day, the body weight decreased in each male and female animal between Days 0 and 3.
After the dose reduction, the mean body weight gain exceeded the control value reaching statistical significance between Days 3 and 7 (male and female) and between Day 7-10 (female). However, the summarized body weight gain remained significantly lower than in the control group in male animals and was lower – no statistical significance – than in the control group in female animals.
As a consequence, the mean body weight was lower than in the control in male animals from Day 3 up to the end of the study (minus 22 % – minus 13 %) and in female animals on Days 3 and 7 (-16, -7%). The mean body weight of female animals at 900/750 mg/kg bw/day was similar to their control by the end of the treatment period (Day 13).
Gross pathology:
Gross necropsy did not reveal any macroscopic changes, which were related to treatment with test item in male or female animals (100, 300 or 900/750 mg/kg bw/day).
Renal pyelectasia – right side or both sides – was observed in the control group (1/5 male, 1/5 female), at 100 mg/kg bw/day (1/5 male), at 300 mg/kg bw/day (1/5 male and 1/5 female) and at 900/750 mg/kg bw/day (1/5 female).
Pyelectasia is a common finding in this strain of experimental rats. There were no inflammatory or other pathological signs related to this finding and therefore it was not attributed to test item treatment.
Other findings:
Haematology, Clinical biochemistry, Organ weight: see details in section 7.5.1

Any other information on results incl. tables

see section 7.5.1

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
Under the condition of the present study 2,5-Dimethoxytetrahydrofuran does not caused mortality after 13 days oral administration at 900/750 mg/kg bw/day to male or female Han:WIST rats, but caused clinical signs, reduction in body weight development and food consumption.
rat oral gavage LD0 = 900 mg/kg bw
Executive summary:

In a subacute toxicity study 2,5-Dimethoxytetrahydrofuran was administered to 5 rats/sex/dose in water by gavage at dose levels of 0, 100, 300 and 900/750  mg/kg bw/day.

Detailed clinical observations were performed daily after the treatment. Body weights were recorded twice weekly in groups of control, 100 and 300 mg/kg bw/day and daily in high dose groups from Day 2. The food consumption was determined weekly to coincide with body weight measurements during the study. Clinical pathology (hematology, blood coagulation and clinical chemistry) and gross pathology examinations were conducted one day after the last treatment (on Day 14). Selected organs were weighed.

There was no mortality in control, 100, 300 or 900/750 mg/kg bw/day groups.

Test item related clinical signs were observed in slight or moderated degree at 900 mg/kg bw/day (decreased activity, squatting position, incoordination and prone position on Days 0, 1, 2) and at 750mg/kg bw/day (decreased activity incoordination, from Day 4 to Day 13) in male and female animals.

Significant body weight loss was detected in male and female animals administered with 900 mg/kg bw/day between Days 0 and 3. The body weight development was undisturbed in male and female animals after the dose reduction to 750 mg/kg bw/day – between Days 4 and 13.

The mean daily food consumption was reduced in male and female animals at 900/750 mg/kg bw/day during the first week of the study in full compliance with the body weight changes.

Necropsy examinations did not reveal any macroscopic changes, which were related to treatment with test item in male or female animals (100, 300 or 900/750 mg/kg bw/day).

The LD0 in rat by oral gavage is 900 mg/kg bw in this study.

No LD50 value can be calculated but as some adverse effects are observed at 900 mg/kg bw, 2,5-Dimethoxytetrahydrofuran is considered as classified as Acute Tox category 4 by oral route.