2-[4-(4-Alkoxyphenyl)-(pyridin-2-yl)-heteromonocyclyl]phenol

Endpoint summary

Description of key information

The acute oral LD50 of FAT 75637/B was determined to be greater than 2000 mg/kg body weight.

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:

Study initiation date - 24 February 2021; Experiment start date - 25 February 2021; Experiment completion date - 25 March 2021; Study completion date - 23 June 2021.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

yes

Remarks:

See "Any other information on materials and methods incl. tables"

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Specific details on test material used for the study:

Test Item: FAT 75637/B TE
Physical Appearance: Light yellow powder
Purity: 99.4 % all organic constituents; 95.0 % main constituent
Batch No: AT-0063765400
Manufactured Date: 21st April 2020
Expiry Date: May 27th, 2025

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Rats were housed under standard laboratory conditions, air conditioned with adequate fresh air supply (14.5 to 14.9 air changes/hour). Environment: temperature 21 to 24 °C, relative humidity 65 to 67 %, 12 hours light and 12 hours dark cycle. The maximum and minimum temperature and relative humidity in the experimental room were recorded once daily. The relative humidity in the experimental room was calculated from dry and wet bulb temperature recordings.

Route of administration:

oral: gavage

Vehicle:

other: Milli-Q water

Details on oral exposure:

Groups of animals of a single sex are dosed in a stepwise procedure using the fixed doses of 300 and 2000 mg/kg. The initial dose level was selected on the basis of a sighting study as the dose expected to produce some signs of toxicity without causing severe toxic effects or mortality. Further groups of animals were dosed at higher dose depending on the presence or absence of the signs of toxicity or mortality. This procedure continues until the dose causing evident toxicity or no more than one death is identified or when no effects are seen at the highest dose or when deaths occur at the lowest dose.

Doses:

As there was no complete available toxicology information about test item. Hence, the study was initiated with starting dose of 300 mg/kg body weight as sighting study. The test was started as per Annex 2 of the OECD Test guideline. Based on result of sighting study the main study was performed by using 4 animals of same sex.

Control animals:

no

Details on study design:

The dose formulation was prepared by using Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) female rat (G1-sighting study) at the dose of 300 mg/kg body weight. The rat was normal and there was no pre-terminal death observed. based on the treatemnt schedule, the treatment was started by dosing one female rat at the dose of 2000 mg/kg body weight (G2- sighting study). The rat was normal and there was no pre-terminal death observed. Hence, treatment was continued by dosing four additional female rats at the higher dose of 2000 mg/kg body weight (G2-main study). All rats were normal and there were no pre-terminal death observed. The prepared dose formulation was administered at the dose volume of 10 mL/kg bodyweight. The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Necropsy was performed for all the surviving rats. All surviving rats gained weight during experimental period. There were no gross pathological changes observed at necropsy.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no pre-terminal deaths.

Clinical signs:

other: There were no clinical signs

Gross pathology:

There were no gross pathological changes at necropsy in the terminal sacrifice rats

Body weight:

Group and Dose (mg/kg body weight)	Rat No.	Sex	Body weight (g)						No. dead/ No. tested	Pre-terminal deaths (%)
			Initial (Day 1)	8th day	Weight change (day 8 – Initial)	15th day	Weight change (day 15 – Initial)	At Death
G1(Sighting study) 300	Rw8001	F	230.1	245.4	15.3	260.1	30.0	NA	0/1	0
G2 (Sighting study) 2000	Rw8002	F	249.9	263.5	13.6	274.8	24.9	NA	0/1	0
G2 (Main study) 2000	Rw8003	F	240.1	252.8	12.7	268.4	28.3	NA	0/4	0
	Rw8004	F	229.8	240.7	10.9	257.3	27.5	NA
	Rw8005	F	227.0	238.8	11.8	256.8	29.8	NA
	Rw8006	F	239.2	250.1	10.9	265.8	26.6	NA

 

 

Summary of stability and homogeneity test

Stability results

Test Item Name: FAT 75637/B; Test Item Code:H009-1; Study No:G20923; Vehicle : Milli-Q Water

Experimental Period: 24 hours

 

Claimed Concentration (mg/mL)	Sampling Time Point (hour)	Analyzed Test Item Concentration (mg/mL)						Analyzed Test Item Conc(mg/mL) (Mean ± SD) %RSD	% Change over ‘0’ day
		Top		Middle		Bottom
		R 1	R 2	R 1	R 2	R 1	R 2
0.025	0	0.019	0.020	0.019	0.019	0.018	0.019	0.02 ± 0.001 (5.26)	NA
	24	0.019	0.017	0.017	0.017	0.019	0.019	0.02 ± 0.001 (5.36)	0.00
250.13	0	230.6	239.5	230.4	224.4	239.2	233.5	232.9 ± 5.79 (2.49)	NA
	24	254.0	251.3	254.0	252.2	263.2	254.4	254.9 ± 4.27 (1.67)	9.45
Acceptance criteria: Stability of the formulations was considered acceptable if mean results are within ± 15.0% from the mean initial stability (homogeneity) time point and formulations will be considered re-suspendable if mean %RSD is equal to or less than 10.0%

Where, R = replication, NA = Not applicable

Conclusion: The test item, FAT 75637/B was observed to be stable in the vehicle at dose concentrations of 0.025 and 250.13 mg/mL up to 24 hours when stored at room temperature.

 

 

Homogeneity results Test Item Name: FAT 75637/B

 

Claimed concentration (mg/mL)	Layer	Analyzed test item concentration (mg/mL)			Mean % agreement with claimed concentration in each layer	Overall mean ± s.d. of analyzed testitem concentration (mg/mL)	Accuracy of overall mean of each dose (%)	Overall %RSD
		R1	R2	Mean
0.0205	Top	0.019	0.020	0.02	95.1	0.019 ± 0.001	92.7	3.334
	Middle	0.019	0.019	0.02	92.7
	Bottom	0.018	0.019	0.02	90.3
250.13	Top	230.6	239.5	235.1	94.0	232.9 ± 5.79	93.1	2.490
	Middle	230.4	224.4	227.4	90.9
	Bottom	239.2	233.5	236.4	94.5

Note: R1, R2 denote replications

*Overall mean ± s.d. should be calculated using all the replicate values of all the layers.

Conclusion: The test item, FAT 75637/B was observed to be homogeneous in the vehicle at dose concentrations of 1.038 and 250.1 mg/mL

 

Dose Formulation Analysis Results

Study No: G20923                     Study Code : AOR                                  Date of analysis: 11 February 2021 

Claimed Conc. (mg/mL)	Sample code	Analyzed Conc. (mg/mL)	Mean Analyzed Conc. of each layer (mg/mL)	Concentration			% Agreement with Claimed Conc.	Mean % Agreement with Claimed Conc. in each layer	% Agreement
				Mean Analyzed Conc (mg/mL)	SD	% RSD			Mean of % Agreement with Claimed Conc.	SD	% RSD
200	G1TR1	191.7	1932	197.8	4.89	2.47	95.8	96.6	98.9	2.44	2.47
	G1TR2	194.8					97.4
	G1MR1	195.3	197.8				97.6	98.9
	G1MR2	200.3					100.1
	G1BR1	199.6	202.5				99.8	101.2
	G1BR2	205.4					102.7
Acceptance Criteria: Formulations will be considered acceptable if the mean results (calculated using all the replicate values) of all the layers and mean of each layer are within ±15.0 % of the claimed concentration and the relative standard deviation (% RSD, calculated using all the replicate values) of assay of top, middle and bottom layers (RSD) is equal to or less than 10.0 %.

Note: No peak was detected at the retention time of the analyte in the vehicle sample. The obtained results were within the acceptance criteria

 

Individual clinical signs, dose administration and necropsy findings

Group and Dose (mg/kg body weight)	Date and time of administration	Rat No.	Sex	Body weight (Day 1) (g)	Total volume administered (mL)	Day of observation
						Day 1
						30 min	1hour	2 hours	3 hours	4 hours
G1 (Sighting study) 300	03 March 2021 11:40 AM to 11:41 AM	Rw8001	F	230.4	2.3	N	N	N	N	N
G2 (Sighting study) 2000	09 March 2021 11:52 AM to 11:53 AM	Rw8002	F	249.9	2.5	N	N	N	N	N
G2 (Main study) 2000	11 March 2021 12:02 AM to 12:03 AM	Rw8003	F	240.1	2.4	N	N	N	N	N
		Rw8004	F	229.8	2.3	N	N	N	N	N
		Rw8005	F	227.0	2.3	N	N	N	N	N
		Rw8006	F	239.2	2.4	N	N	N	N	N

 

F: Female   N: Normal      min: minutes       mg: milligrams     kg: kilograms  mL: millilitre           NAD: No Abnormality Detected

 

Individual clinical signs, dose administration and necropsy findings: 

Group and Dose (mg/kg body weight)

Rat No.

Sex

Day of observation

NecropsyFindings

2

3

4

5

6

7

8

9

10

11

12

13

14

15

G1 (Sighting study) 300

Rw8001

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

G2 (Sighting study) 2000

Rw8002

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

G2 (Main study) 2000

Rw8003

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

Rw8004

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

Rw8005

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

Rw8006

F

N

N

N

N

N

N

N

N

N

N

N

N

N

N

NAD

F: Female   N: Normal      min: minutes       mg: milligrams     kg: kilograms  mL: millilitre           NAD: No Abnormality Detected

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the present study, the LD50 of test item, FAT 75637/B TE is greater than 2000 mg/kg body weight.

Executive summary:

The acute oral toxicity study with FAT 75637/B in Wistar rats was conducted to assess the toxicological profile of the test item. This study was conducted according to OECD test guideline 420 in a GLP certified laboratory. The dose formulation was prepared by using Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) female rat (G1-sighting study) at the dose of 300 mg/kg body weight. The rat was normal and there was no pre-terminal death observed. According to the treatment schedule, the treatment was started by dosing one female rat at the dose of 2000 mg/kg body weight (G2- sighting study). The rat was normal and there was no pre-terminal death observed. Hence, the treatment was continued by dosing four additional female rats at the higher dose of 2000 mg/kg body weight (G2-main study). All rats were normal and there were no pre-terminal death observed. The prepared dose formulation  was  administered  at  the  dose  volume of 10 mL/kg body weight. The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Necropsy was performed for all the surviving rats. All surviving rats gained weight during experimental period. There were no gross pathological changes observed at necropsy. The dose formulation analysis was performed for the G1-(300 mg/kg body weight) and G2-(2000 mg/kg body weight). The obtained results of dose formulation analysis for 30 mg/mL and 200 mg/mL were found to be with in the acceptable limit (85-115 %). Based on the results of the present study, The LD50 of test item, FAT 75637/B is greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Good quality database. Klimisch rating 1.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation)

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

The acute oral toxicity study with FAT 75637/B in Wistar rats was conducted to assess the toxicological profile of the test item. This study was conducted according to OECD test guideline 420 in a GLP-certified laboratory. The dose formulation was prepared by using Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) female rat (G1-sighting study) at the dose of 300 mg/kg body weight. The rat was normal and there was no pre-terminal death observed. The treatment was conducted by dosing one female rat at the dose of 2000 mg/kg body weight (G2- sighting study). The rat was normal and there was no pre-terminal death observed. Hence, the treatment was continued by dosing four additional female rats at the higher dose of 2000 mg/kg body weight (G2-main study). All rats were normal and there were no pre-terminal death observed. The prepared dose formulation  was  administered  at  the  dose  volume of 10 mL/kg body weight. The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Necropsy was performed for all the surviving rats. All surviving rats gained weight during experimental period. There were no gross pathological changes observed at necropsy. The dose formulation analysis was performed for the G1-(300 mg/kg body weight) and G2-(2000 mg/kg body weight). The obtained results of dose formulation analysis for 30 mg/mL and 200 mg/mL were found to be with in the acceptable limit (85-115 %). Based on the results of the present study, The LD50 of test item, FAT 75637/B is greater than 2000 mg/kg body weight.

Acute inhalation toxicity

Currently no study to assess the acute inhalation toxicity potential of HJP 2453 is available. The calculated value for vapour pressure was found to be 6.7E-7 Pa at 25 °C. Hence, the substance is considered to have low volatility. Synthesis and spray drying of this chemical is performed in a closed process; the final product consists of non-dusty granules. Hence, the use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalation route will be unlikely to occur. Based on column 2, ‘Specific rules for adaptation from column 1’ of the table given in REACH Annex VII, the study on acute inhalation toxicity only needs to be conducted if an exposure via inhalation is to be expected, based on vapour pressure and/or the likelihood of an exposure to aerosols, particles or droplets. Referring to the expected low volatility of the substance, the fact that the chemical is imported into the EU in a formulated form as a dust-free powder or as a granulate, the exposure via inhalation is considered to be unlikely. The chemical showed low toxicity potential in the available acute oral toxicity study (LD50: >2000 mg/kg bw), with no systemic toxicity being seen, hence it does not need to be classified STOT SE and low toxicity is expected for this chemical via the inhalation route. Taking into consideration the above arguments, low toxicity potential is expected on acute exposure of HJP 2453 via inhalation route and hence testing by the inhalation route was considered scientifically not necessary.

 

Acute dermal toxicity

Currently no study to assess the acute dermal toxicity potential of HJP 2453 is available. However, the molecular weight of HJP 2453 is 356.4 g/mol, indicating dermal absorption may be limited. It has water solubility of <50 microgram/L, indicating poorly solubility in water will further limit the partition from the stratum corneum into the epidermis. Hence, the dermal uptake for the substance will be low. The chemical showed low toxicity potential in the available acute oral toxicity study (LD50: >2000 mg/kg bw), with no systemic toxicity observed, hence, it does not need to be classified as STOT SE. Similarly, absence of systemic toxicity in skin irritation and sensitisation studies, further supports the conclusion that no adverse effects are expected for the chemical via the dermal route. Further, experience with similar chemical substances has demonstrated that it is very unlikely that toxicity related to the intrinsic properties of the chemical only show up upon dermal exposure and not after systemic application. Taking above arguments into consideration, low toxicity is expected on acute dermal exposure of HJP 2453 and testing by the dermal route was considered scientifically not necessary.

Justification for classification or non-classification

The substance does not need to be classified for acute toxicity according to CLP (Regulation (EC) No 1272/2008).