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Description of key information

Oral (OECD 425), rat: LD50 > 5000 mg/kg bw
Dermal (OECD 402), rat: LD50 > 5000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
18 May - 06 June 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study
Qualifier:
according to
Guideline:
OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1100 (Acute Oral Toxicity)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
National GLP Compliance Monitoring Authority, Department of Science & Technology, New Delhi, India; Food and Consumer Product Safety Authority (VWA), The Hague, the Netherlands; Bundesinstitut für Risikobewertung, Berlin, Germany
Test type:
up-and-down procedure
Limit test:
yes
Species:
rat
Strain:
Wistar
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: inhouse bred (Outbred), Toxicology, Department of Safety Assessment, Advinus Therapeutics Limited, Bangalore 560 058, India
- Age at study initiation: 10-11 weeks
- Weight at study initiation: 177.3-180.3 g (range)
- Fasting period before study: yes, overnight (16-18 hours)
- Housing: the rats were housed individually in standard polysulfone cages (approximately L 425 mm x B 266 mm x H 175 mm) with stainless steel top grill, with facilities for pelleted food and water; steam sterilised corn cob bedding was used and changed along with the cage twice weekly
- Diet: Ssniff rats/mice pellet food, manitenance meal (Ssniff Spezialdiaten GmbH, Soest, Gemany), ad libitum
- Water: deep bore-well water passed through activated charcoal filter and exposed to UV-rays in Aquaguard on-line water filter-cum-purifier (Eureka Forbes Ltd., Mumbai, India), ad libitum
- Acclimation period: 5-10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-24
- Humidity (%): 58-68
- Air changes (per hr): 12-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 13 May 2011 To: 1, 3 and 6 June 2011
Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE
- Amount of vehicle (if gavage): 20 mL/kg bw
- Justification for choice of vehicle: the test substance forms a visibly homogenous solution in water

MAXIMUM DOSE VOLUME APPLIED: 20 mL/kg bw (3.5-3.6 mL absolute volume)
Doses:
5000 mg/kg bw
No. of animals per sex per dose:
3, dosed stepwise with a 2-day interval, according to the up-and-down procedure
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the animals were observed for mortality and clinical signs 1/2, 1, 2, 3 and 4 hours after administration on Day 1, and daily thereafter throughout the study period; the animals were weighed on Day 1 (prior to administration), 8 and 15
- Necropsy of survivors performed: yes, external surfaces of the body, all orifices, tissues and organs of the thoracic and abdominal cavities were examined, and all gross findings were recorded
Sex:
female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Based on:
test mat.
Mortality:
There was no mortality during the study period.
Clinical signs:
No clinical signs were observed during the study period.
Body weight:
No effect on body weight was noted.
Gross pathology:
Necropsy and histopathological examination revealed no substance-related findings.

Table 1: Mortality and clinical signs during the study period

 

Dose
[mg/kg bw]

Toxicological results*

Duration of clinical signs

Time of death

Mortality (%)

Females

5000

0/0/3

---

---

0

LD50 > 5000 mg/kg bw

                                                                                           

* first number = number of dead animals                                 

 second number = number of animals with clinical signs         

 third number = number of animals used                               

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: not classified
DSD: not classified
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13 May - 03 Jun 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
National GLP Compliance Monitoring Authority, Department of Science & Technology, New Delhi, India
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: in-house bred (Outbred); Toxicology, Department of Safety Assessment, Advinus Therapeutics Limited, Bangalore, India
- Age at study initiation: 11-12 weeks
- Weight at study initiation: 264.9-285.8 g (males), 203.6-211.5 g (females)
- Housing: the rats were housed individually in standard polysulfone cages (approximately L 425 mm x B 266 mm x H 175 mm), with a stainless steel top grill. Steam sterilized corn cob bedding was used and changed with the cage twice per week. The water bottles were changed weekly.
- Diet: Ssniff rats / mice pellet food - maintenance meal (Ssniff Spezialdiäten GmbH., Soest, Germany), ad libitum
- Water: deep bore-well water passed through activated charcoal filter and exposed to UV rays in Aquaguard on-line water filter-cum-purifier (manufactured by Eureka Forbes Ltd., Mumbai, India), ad libitum
- Acclimation period: males were acclimatised for 7 days, females were acclimatised for 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-24
- Humidity (%): 58-68
- Air changes (per hr): 12-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 18 May 2011 (females), 20 May 2011 (males) To: 03 Jun 2011
Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Remarks:
water was added to the test substance to form a paste
Details on dermal exposure:
TEST SITE
- Area of exposure: approximately 8 cm x 10 cm on the dorsolateral (back and side) thoracic part of the rats
- % coverage: approximately 10
- Type of wrap if used: the test substance was spread onto a 6-ply cotton gauze patch (9 cm x 5 cm for males, 8 cm x 5 cm for females), which was applied to the shaved skin area of the rats. The gauze patch was held in place with non-allergenic surgical tape that was wound around the torso.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the application sites were washed with water and wiped clean with a towel to remove any residual test substance
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 5000 mg/kg bw
- Constant volume or concentration used: no, the dose was calculated based on body weight
- For solids, paste formed: yes
Duration of exposure:
24 h
Doses:
5000 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
not required
Details on study design:
- Duration of observation period following administration: at least 15 days
- Frequency of observations and weighing: the animals were observed for mortality and clinical signs of toxicity 4 times on day 1 (the day exposure started) and once daily thereafter. The body weights were recorded on day 1 (prior to exposure), 8 and 15. The treated skin sites were assesed for local skin irritation daily after exposure ended.
- Necropsy of survivors performed: yes, the external surface of the body, all orifices, tissues and organs of the thoracic and abdominal cavities of all animals were examined
- Other examinations performed: clinical signs, body weight, local skin irritation
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Based on:
test mat.
Mortality:
There was no mortality during the study period.
Clinical signs:
No signs of toxicity were observed during the study period.
Body weight:
The body weight gains were within the normal ranges in males and females during the study period.
Gross pathology:
The necropsy and gross pathological examination revealed no substance-related findings.
Other findings:
- Other observations: there were no local skin irritation reactions
Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: not classified
DSD: not classified
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Additional information

Acute toxicity: oral

The acute oral toxicity of 2 -amino-2 -(hydroxymethyl)-1,3 -propanediol (trometamol) was assessed in a study performed according to the up-and-down procedure (OECD 425) in rats administered 5000 mg/kg bw (Mohan Kumar, 2011). Single animals were administered the limit dose stepwise, up to a total of 3 rats. There was no mortality, no clinical signs were observed during the 14-day observation period and no effects on the body weight were noted. There were no substance-related findings of the histopathological examination. The LD50 is considered to be > 5000 mg/kg bw.

 

In addition, several pre-guideline studies with rats (Giroux and Beaulaton, 1961), mice (Giroux and Beaulaton, 1961 and Rubenkoenig, 1955) and rabbits (Machle, 1940) are available confirming the low systemic acute oral toxicity of trometamol.

 

Acute toxicity: dermal

In a study performed according to OECD 402, 5000 mg/kg bw trometamol was applied to the shaved skin of rats and held under a semi-occlusive dressing for 24 hours (mohan Kumar, 2011). There was no mortality, and no signs of toxicity or effects on body weight were observed during the study period. No substance-related findings were noted during the gross pathological examination and the test substance did not cause skin irritation effects on the application site. The LD50 is considered to be > 5000 mg/kg bw.    

Acute toxicity: other routes

A number of studies were performed to determine the acute LD50 in several species and via several routes.

The LD50 (intravenous) of trometamol for rats varied from > 500 to 2300 and 3500-3600 mg/kg bw, (Darby and Anderson, 1966; Giroux and Beaulaton, 1961; Thompson, 1965). Severe dose-related damage to the kidneys was observed at the highest value (Giroux and Beaulaton, 1961). In mice, the LD50 (i.v.) ranged from 1044 – 1980 mg/kg bw, decreasinh inversely with the pH (Darby and Anderson, 1966; Giroux and Beaulaton, 1961;Thompson, 1965) The LD50 (i.v.) for rabbits was reported to be > 500 mg/kg bw; while for dogs the LD50 > 125 mg/kg bw, following a single dose (Giroux and Beaulaton, 1961), and approximately 500 mg/kg bw with a slow perfusion (Darby and Anderson, 1966). Lower blood glucose levels were observed following i.v. perfusions of non-lethal doses of trometamol in dogs and in humans; the latter also reporting transient discomfort. Temporary changes in respiration rate and depth were the only effects observed in dogs perfused with up to 10 mg/kg bw (Giroux and Beaulaton, 1961). The LD50 (intraperitoneal) values of trometamol reported for mice were 790 and 3350 mg/kg bw, respectively (Giroux and Beaulaton, 1961; Rubenkoenig, 1955). For dogs, the LD50 (i.p.) was > 2160 mg/kg bw (Darby and Anderson, 1966). Subcutaneous injections of 1000 mg/kg bw trometamol in rats and did not cause mortality (Giroux and Beaulaton, 1961).  

 

The test substance-related findings were comparable for oral and dermal routes of application in the acute toxicity studies, with the high LD50 -values indicating that trometamol has a very low potential to cause acute toxicity via these routes.

Justification for classification or non-classification

The available data on acute toxicity of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.