Adenosine

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 September 2017 - 05 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

17 December 2001

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Adenosine

EC Number:

200-389-9

EC Name:

Adenosine

Cas Number:

58-61-7

Molecular formula:

C10H13N5O4

IUPAC Name:

adenosine

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Oxidane

Test material form:

solid: particulate/powder

Details on test material:

Batch No.: 10004539
Storage at room temperature approx. 20°C

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Species and strain: Crl:(WI) rats
- Source: TOXI COOP ZRT. Cserkesz u. 90. 1103 Budapest, Hungary
- Hygienic level at arrival: SPF (Specific Pathogen Free)
- Hygienic level during the study: Good conventional
- Justification of strain: The Wistar rats as a rodent is one of the standard species of acute toxicity studies
- Number of animals: 3 animals/group
- Sex: Female, nulliparous and non pregnant animals
- Age of animals: Young adult rat, 8 weeks old in first and second step
- Body weight range at starting (first step): 192 - 194 g
- Body weight range at starting (second step): 198 - 200 g
- Acclimatization time: 5 days in first step and 6 days in second step

ENVIRONMENTAL CONDITIONS
- Animal health: Only healthy animals were used for the study. Health status was certified by the study director.
- Room: 13/2
- Housing: Group caging (3 animals/cage)
- Cage type: Type III polypropylene/polycarbonate.
- Light: Artificial light, from 6 a.m. to 6 p.m.
- Temperature: 22 ± 3 °C
- Relative humidity: 30 - 70 %
- Ventilation: above 10 air exchanges/hour by central air-condition system.
- The temperature and relative humidity were recorded daily during the study.
- Food and Water Supply: Animals received ssniff® SM R/M-Z+H complete diet for rats and mice produced by ssniff Spezialdiäten GmbH, D-59494 Soest Germany and tap water from municipal supply, as for human consumption from bottle ad libitum. The diet and drinking water are periodically analysed and are considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study. Copies of the relevant Certificates of Analysis are maintained in Toxi-Coop Zrt.’s archive.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

(1%)

Details on oral exposure:

VEHICLE
-Methyl cellulose
-Batch number: AX4380542
-Date of expiration: 18.09.2019
-Produced by: Molar Chemicals Kft.

- Aqua purificata Ph.Hg. VIII.
- Batch number: 1707-5506
- Date of expiration: 06.01.2018
- Produced by: Parma Produkt Kft.
- Formulation: All doses were formulated in the vehicle. Concentration of formulations was adjusted to maintain a treatment volume of 10 mL/kg bw. The test item was applied in a concentration of 200 mg/mL. Formulations were prepared just before the administration and stirred continuously during the treatment.

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

CLASS METHOD
- Justification of the doses: Starting dose was selected on the basis of the available information about the test item.
The acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, so treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of Annex 2d of OECD Guideline No. 423 was met.

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

3 females per dose (first step)
3 females per dose (second step)

Control animals:

no

Details on study design:

- Procedure: A single oral administration - followed by a fourteen-day observation period - was performed by gavage. The day before treatment the animals were fasted. The food but not water was withheld overnight. Animals were weighed before the application and the food was given back 3 hours after the treatment.
- Duration of the Experimental Period: 5 days in first step and 6 days in second step of acclimatization, treatment’s day, 14 days post-treatment observation period, necropsy on Day 15.
- Frequency of observations: Animals were observed individually after dosing at least once during the first 30 minutes, then 1 h, 2 h, 3 h, 4 h after the treatment and once each day for 14 days thereafter. Individual observations were performed on the skin and fur, eyes and mucous membranes and also respiratory, circulatory, autonomic and central nervous system, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.
- Body weight: The body weights were recorded on day 0 (just before the treatment), on day 7 and on day 15 with a precision of 1 g.
- Necropsy: At the end of the observation period all rats were sacrificed under isofluran anaesthesia. After examination of the external appearance, the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs were observed, and any abnormality was recorded with details of its location, colour, shape and size.

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No death occurred at 2000 mg/kg bw single oral dose of Adenosine. All female rats in step 1 and step 2 survived until the end of the 14-day observation period.

Clinical signs:

other: No treatment related symptoms were observed throughout the 14-day post-treatment period at any groups of the female animals.

Gross pathology:

All animals survived until the scheduled necropsy on Day 15.
Internal necropsy finding as pale kidneys was observed in two animals (No.: 7488, 7490) of group 1 and in all females of group 2.

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

No death occurred after the single 2000 mg/kg bw oral dose of Adenosine. The method used, was not intended for the precise calculation of a precise LD50 value.
The test item was ranked into classes of Globally Harmonized Classification System (GHS) described in the OECD Guideline No. 423 as Category 5.
The test item was ranked into classes of the current EU Regulation on classification, labeling and packaging (CLP) (EC) No 1272/2008 as not classified.
In conclusion, the LD50 of the test item Adenosine (CAS No 58-61-7) is higher than 2000 mg/kg bodyweight by oral route in the rat.

Executive summary:

General Information:

All criteria for the validity of the performed experiments have been met.

An acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw test item Adenosine (CAS No 58-61-7) as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, therefore treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of Annex 2d of OECD Guideline No. 423 (presented in Appendix VII) was met. Animals were weighed, observed for lethality and toxic symptoms for 14 days after the treatment. Gross pathological examination was carried out on the 15th day after the treatment.

Lethality, Clinical Symptoms and Body weight:

No death was noted at single oral dose of 2000 mg/kg bw.

No clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal.

The body weight development was undisturbed in all animals.

Gross Pathology:

All animals survived until the scheduled autopsy on Day 15. All organs of all experimental animals proved to be free of treatment related gross pathological changes.

Evaluation:

The method used is not intended to allow the calculation of a precise LD50 value.

The test item was ranked into classes of Globally Harmonized Classification System (GHS) described in the OECD Guideline No. 423 as below:

Dose (mg/kg bw)	Mortality (dead/treated)	LD50 (mg/kg bw)	GHS category
2000	0/6	between 2000 and 5000	5

The test item was ranked into classes of the current EU Regulation on classification, labeling and packaging (CLP) (EC) No 1272/2008 as below:

Dose (mg/kg bw)	Mortality (dead/treated)	LD50 (mg/kg bw)	CLP category
2000	0/6	above 2000	not classified

In conclusion, the LD50 of the test item Adenosine (CAS No 58-61-7) is higher than 2000 mg/kg bodyweight by oral route in the rat.