5-(dithiolan-3-yl)valeric acid

Repeated dose toxicity: other routes

Administrative data

Endpoint:

short-term repeated dose toxicity: other route

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1994-04-18 - 1995-03-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Study ower prepared study while seeking authorisation of the substance as active incredient for medical treatment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Comission Directive No. 91/507/EEC Council Recommendation No. 83/571/EEC

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

5-(dithiolan-3-yl)valeric acid

EC Number:

214-071-2

EC Name:

5-(dithiolan-3-yl)valeric acid

Cas Number:

1077-28-7

Molecular formula:

C8H14O2S2

IUPAC Name:

5-(1,2-dithiolan-3-yl)pentanoic acid

impurity 1

Reference substance name:

unknown

IUPAC Name:

unknown

impurity 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

dihydrogen oxide

Test material form:

solid: bulk

Details on test material:

This composition is the usual techical grade of AlzChem AG. It will be used when test substance has this composition (or is very closed) or no specific information is available

Test animals

Species:

dog

Strain:

Beagle

Sex:

male/female

Details on test animals or test system and environmental conditions:

Age: m 9 month, f 9 month
B.w. m 10.8 - 14.4 kg, f 10.2 - 13.0 kg
Caging: Boxes 6.0 m x 1.2 m
No of animals per box: 1 or 2 (group 2 - 4), 3 (group 1)
Diet: Standard dog diet ad libitum
Water: ad libitum in drinking water quality
Room temperature: 24 - 26 °C
Relative humidity: 21 - 49 %
Lighting: 6 a.m. - 6 p.m. artificial lighting, 6 p.m. - 6 a.m.natual dark rhythm

Administration / exposure

Route of administration:

intravenous

Vehicle:

water

Remarks:

NaCl 0.9 %

Details on exposure:

Before and after test substance administration approx. 1 ml physiological saline solution (0.9 %) were injected via three-way valve.
Duration of injection approx 1 min.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

Daily a.m. (7 days a week)

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

control

Doses / concentrations 2

Dose / conc.:

6.81 mg/kg bw/day (nominal)

Remarks:

low dose

Doses / concentrations 3

Dose / conc.:

9.09 mg/kg bw/day (nominal)

Remarks:

intermediate dose

Doses / concentrations 4

Dose / conc.:

12.1 mg/kg bw/day (nominal)

Remarks:

high dose

No. of animals per sex per dose:

3 m, 3 f

Control animals:

yes

Examinations

Observations and examinations performed and frequency:

Mortality: twice daily (a.m. and p.m.)
Behaviour and general condition: daily
Food consumption: daily, staring with 2nd pretest week
B.w.: Once a week, staring with 2nd pretest week
Reflexes: Pain, pupil, corneal and patella reflexes, once a week staring with 2nd pretest week
Heart rate, body temperature: once a week staring with 2nd pretest week, before administration each
Ophthalmology: before first administration and in week 4, all animals
ECG: before first subtance administrationand in week 4 before administration
Clinical chemistry and hematology: before first substance administration and in weeks 1 and 4
Urine: week 5 by punctation of the bladder during autopsy

Sacrifice and pathology:

Anesthesia: Rompun(R) and T61(R), exsanguination

Gross Necropsy: all animals -> external surface of body, orifices, cranial, toracic and abdominal cavities and their contents.
All gross lesions, adrenal glands (r/l), aorta, axillary lymph node, bone (femur and sternum), bone marrrow smear (from sternum), brain (cerebrum, cerebellum, medulla/pons), caecum, cervix, colon, duodenum, epididymides (r/l), gallbladder, heart, ileum, injection sites, jejunum, kidneys (r/l), liver, lungs, main stem bronchi, mammary gland, mesenteric lymph node, oesophagus, ovaries (r/l), pancreas, parathyrois glands (r/l), peripheral nerve, pituitary gland, prostate, rectum, salivary glands (parotid, submaxillary, sublingual), skeletal muscle, skin, spinal cord (cervical, thoracic, lumbar segments), spleen, stomach, testes (r/l), thymus, thyroid gland (both lobes), tongue, trachea, urinary bladder, uterus, vagina.

Organ weigths: Adrenals (r/l), brain, heart, kidneys (r/l), liver, lungs, ovaries (r/l), pituitary, prostate, spleen, testes (r/l), thyroids (r/l).
Expression as absolute values and relative to b.w. recoreded in week 4.

Fixation: All organes and tissues exept eyes and bone marrow smears -> 10 % formalin
Eyes -> SUSA fixative 4 - 16 h, thereafter 10 % formalin
Bone marrow smears -> air dried
Staining: All organs and tissues -> embedded in parafine wax, sectioned at 4 µm and stained with H&E
Additional sections of kidneys -> periodic acid Schiff reaction
Cryostate sections of liver and one kidney -> Oil red 0

Statistics:

Mean and SD: each group and sex
B.w. and organ weigts: DUNNET-Test
Clinical Parameters, ECG, hematology, clinical chemistry: DUNNETT-Test (normal distribution), otherwise STEEL-Test
Significances:
DUNNETT: * p < 0.05, ** p < 0,01
STEEL: + p < 0.05

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Low dose: Males -> diarreha and vomitus, one day in week 1
Females -> slight to moderate swellings of front legs during single days of treatment
Intermediate dose: Males -> diarreha during one day in week 3, one dog showed slight swelling of the front legsduring several days of the treating period
Females -> vomitus was noted one day in week 2 + 4, slight swelling of the front legs during single days
High dose: Males -> diarreha during one day in week 3, one animal showed vomitus during first day of treatment. Slight swelling of front legs during several days. One male showed skin reddening during three days of treatment.
Females -> vomitus in two animals during one day of week 2 and in one animal during one day in week 4.

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Statistically significant decrease in platelets was noted in low dose females during week 1 exmination.
During Week 4 in females the number of white blood cells (WBC) das decreased in treated animals compared to controls. No dose dependency.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Slightly increased glucose levels, 15 min after administration and more increased after 60 min in males and females. No statistical significance.
Males in group 4: Statistically significant increased Tot. Prot. in week 4
Females in group 4: Statistically significant increased Tot. Prot. in week 1 + 4, slightly but statistically significant increased ALAT in week 4

Males in group 2: increased AKP in week 4,
Males in group 3: decrease of Tot. Bili. in weekt 4
Males in group 2 + 3: decreased Na in week 4
Females in group 2: decreased CK in week 4

Not dose related, not reflecting toxic effect.

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Oral beningn papillomas in animals Nos. 12 and 18

Application site was thickend and/or had perivascular hemorrhages in many animals in all dose groups including control animals. => Traumatic character of daily i.v. injections.

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Kidneys showed a maginally higher severity of minimal to mild focal mineralization in some treated animals, especially females. No dose response relationship.

Injection sites showed inflammatory changes and hemorrhages. => Traumatic character of daily i.v. injections.

Effect levels

1

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 9.09 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

2

Key result

Dose descriptor:

LOAEL

Effect level:

ca. 12.1 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

Target system / organ toxicity

Key result

Critical effects observed:

no

Lowest effective dose / conc.:

9.09 mg/kg bw/day (nominal)

Applicant's summary and conclusion

Conclusions:

On the basis of the present 4-week toxicity study after daily i.v. administration in Beagle dogs it is concluded that alpha-Lipoic acid induced no specific toxic effects up to 12.1 mg/kg b.w.
As known from dose-range-finding studies, only slightly higher doses would have led to severe toxicity with even risk of deaths.
Diarrhea and/or vomitus, wich were present in single test substance treated animals during single days of the treatment period of the present study, are more considered to be incidental findings than to reflect a toxic effect.

Executive summary:

Under the assumption, that the findings of diarrhea and/or vomitus in single test substance treated animals during only single days of the treatment period are of no toxicological relevance, the dosage of 9.09 mg/kg b.w. is considered the NOEL in males and females during this 4 -week toxicity study after daily intravenous administration in beagle dogs.