Benzamide, 3-amino-4-methoxy-N-methyl-

Endpoint summary

Description of key information

Compared to the relative absorbance value of the negative control the mean relative absorbance value was reduced irrelevantly to 87.8% after exposure of the skin tissues to the test item. This value is above the threshold for irritancy of ≤ 50%. Therefore, the test item is not considered to possess an irritant potential.

According to the findings in an in vivo eye irritation study, 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE does not meet the criteria for classification according to Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: UN GHS (2003, last rev. 2015)

Principles of method if other than guideline:

Based on a “Statement on the Scientific Validity of In Vitro Tests for Skin Irritation” of the European Commission (November 2008), official acceptance of the test method in the EU was achieved and implemented in EU, 2008a, Council Regulation (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to EC Regulation No 1907/2006 of the European Parliament and of the Council on REACH; 1st ATP 2009: EC Regulation No 761/2009 of 23 July 2009 amending, for the purpose of its ATP, EC Regulation No 440/2008 laying down test methods pursuant to EC Regulation No 1907/2006 of the European Parliament and of the Council on REACH, section B46.

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg (~ 39 mg/cm2 according to guideline)

Duration of treatment / exposure:

60 minutes.

Number of replicates:

3

Species:

other: reconstituted human epidermis model

Type of coverage:

other: Topical

Preparation of test site:

other: Not applicable

Vehicle:

other: No vehicle used

Controls:

yes

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
Each approximately 25 mg (~ 39 mg/cm2 according to guideline) of the test item were applied to each tissue, wetted with 25 µL DPBS, and spread to match the surface of the tissue for a complete treatment time of 60 minutes.


NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL DPBS (MatTek) were used as negative control per tissue.


POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL of a 5% SLS solution in deionised water (MatTek) were used as positive control per tissue.

Duration of treatment / exposure:

60 minutes

Observation period:

Not applicable

Number of animals:

Not applicable

Irritation / corrosion parameter:

other: % relative absorbance

Run / experiment:

1

Value:

93.5

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

other: % relative absorbance

Run / experiment:

2

Value:

90.9

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

other: % relative absorbance

Run / experiment:

3

Value:

79

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

other: % relative absorbance

Run / experiment:

mean

Value:

87.8

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Compared to the relative absorbance value of the negative control the mean relative absorbance value was reduced irrelevantly to 87.8% after exposure of the skin tissues to the test item. This value is above the threshold for irritancy of ≤ 50%. Therefore, the test item is not considered to possess an irritant potential.

Results after treatment with 3-Amino-4-methoxy-N-methylbenzamide and the controls (exposure interval of 60 minutes):

Dose	Tissue	Absorbance	Absorbance	Absorbance	Mean	Mean
Group	No.	570 nm	570 nm	570 nm	Absorbance	Absorbance
		Well 1	Well 2	Well 3	of	of three wells
					3 Wells	blank
	-	-	-	-	-	corrected
Blank	-	0.037	0.038	0.038	0.037	0.000
Negative Control	1	1.873	1.874	1.815	1.854	1.817
Negative Control	2	2.080	2.059	2.045	2.062	2.024
Negative Control	3	1.924	1.847	1.775	1.849	1.811
Positive Control	1	0.100	0.099	0.099	0.099	0.062
Positive Control	2	0.099	0.108	0.109	0.105	0.068
Positive Control	3	0.108	0.110	0.107	0.108	0.071
Test Item	1	1.886	1.763	1.748	1.799	1.762
Test Item	2	1.807	1.733	1.712	1.751	1.713
Test Item	3	1.566	1.516	1.496	1.526	1.488

Dose	Tissue	Mean Absorbance of 3 tissues	Relative	Relative	Mean
Group	No.	after blank	Absorbance [%]	Standard	Relative Absorbance
		correction*	Tissue 1, 2, 3 ***	Deviation	[% of Negative
				[%]	Control] ***
Negative Control	1		96.4
Negative Control	2	1.884	107.4	6.4	100.0
Negative Control	3		96.1
Positive Control	1		3.3
Positive Control	2	0.067	3.6	6.8	3.5
Positive Control	3		3.8
Test Item	1		93.5
Test Item	2	1.654	90.9	8.8	87.8
Test Item	3		79.0

*         Mean of three replicate wells after blank correction

**       relative absorbance per tissue [rounded values]

***     relative absorbance per treatment group [rounded values]

Interpretation of results:

other: not irritant

Conclusions:

In conclusion, it can be stated that in this study and under the experimental conditions reported, 3-Amino-4-methoxy-N-methylbenzamide is not irritant to skin according to UN GHS and EU CLP regulation.

Executive summary:

This in vitro study was performed to assess the irritation potential of 3-Amino-4-methoxy-N-methylbenzamide by means of the Human Skin Model Test.

The test item passed the MTT- and the Colour Interference pre-tests.

Approximately 25 mg of the test item were applied to each tissue, wetted with 25 µL of DPBS, and spread to match the surface of triplicate tissue.

30 µL of either the negative control (DPBS) or the positive control (5% SLS) were applied to triplicate tissue each.

The test item and the positive and negative controls were washed off the skin tissues after 60 minutes treatment. After further incubation for about 43 hours the tissues were treated with the MTT solution for 3 hours following about 3 hours extraction of the colorant from the cells. The amount of extracted colorant was determined photometrically at 570 nm.

After treatment with the negative control the absorbance values were well within the required acceptability criterion of mean OD³0.8 and ≤ 2.8 for the 60 minutes treatment interval thus showing the quality of the tissues.

Treatment with the positive control induced a decrease in the relative absorbance as compared to the negative control to 3.5% thus ensuring the validity of the test system.

The relative standard deviations between the % variability values of the test item, the positive and negative controls in the main test were below 9% (threshold of the "OECD Guideline for the Testing of Chemicals 439:In vitroSkin Irritation: Reconstructed Human Epidermis Test Method”: < 18%), thus ensuring the validity of the study.

Compared to the relative absorbance value of the negative control the mean relative absorbance value was reduced irrelevantly to 87.8% after exposure of the skin tissues to the test item. This value is above the threshold for irritancy of ≤ 50%. Therefore, the test item is not considered to possess an irritant potential.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

other information

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Animal Information
Two New Zealand White (Hsdlf:NZW) strain rabbits were supplied by Envigo RMS (UK) Limited, Leicestershire, UK. At the start of the study the animals weighed 2.24 or 3.43 kg and were 12 to 52 weeks old. After an acclimatization period of at least 5 days each animal was given a number unique within the study which was written with a black indelible marker pen on the inner surface of the ear and on the cage label.
Animal Care and Husbandry
The animals were individually housed in suspended cages. Free access to mains drinking water and food (2930C Teklad Global Rabbit diet supplied by Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study. The diet and drinking water were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.
The temperature and relative humidity were set to achieve limits of 17 to 23 °C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.
The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye remained untreated and was used for control purposes.

Amount / concentration applied:

0.1 mL of the test item, which was found to weigh approximately 89 mg

Duration of treatment / exposure:

Up to 1 hour

Observation period (in vivo):

72 hours

Number of animals or in vitro replicates:

2 rabbits

Details on study design:

Immediately before the start of the test, both eyes of the provisionally selected test rabbits were examined for evidence of ocular irritation or defect with the aid of a light source from a standard ophthalmoscope. Only animals free of ocular damage were used.
Initially, a single rabbit was treated. A subcutaneous injection of buprenorphine 0.01 mg/kg was administered 60 minutes prior to test item application to provide a therapeutic level of systemic analgesia. Five minutes prior to test item application, a pre dose anesthesia of ocular anesthetic (two drops of 0.5% proxymetacaine hydrochloride) was applied to each eye.
A volume of 0.1 mL of the test item, which was found to weigh approximately 89 mg (as measured by gently compacting the required volume into an adapted syringe) was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball. The upper and lower eyelids were held together for about one second immediately after treatment, to prevent loss of the test item, and then released. The left eye remained untreated and was used for control purposes. Immediately after administration of the test item, an assessment of the initial pain reaction was made according to the six point scale shown in Annex 2.
Eight hours after test item application, a subcutaneous injection of post dose analgesia, buprenorphine 0.01 mg/kg and meloxicam 0.5 mg/kg, was administered to provide a continued therapeutic level of systemic analgesia. The treated animal was checked for signs of pain and suffering approximately 12 hours later. No further analgesia was required.
After consideration of the ocular responses produced in the first treated animal, a second animal was similarly treated.
Assessment of ocular damage/irritation was made approximately 1 hour and 24, 48 and 72 hours following treatment, according to the numerical evaluation (Draize, J.H, 1977) given in Annex 3.
Any other ocular effects were also noted. Examination of the eye was facilitated by the use of the light source from a standard ophthalmoscope.
Any clinical signs of toxicity, if present, were also recorded.
Individual body weights were recorded on Day 0 (the day of dosing) and at the end of the observation period.

Irritation parameter:

cornea opacity score

Basis:

animal: 75686 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: No effects observed

Irritation parameter:

cornea opacity score

Basis:

animal: 75672 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: No effects observed

Irritation parameter:

iris score

Basis:

animal: 75686 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0

Max. score:

2

Reversibility:

fully reversible within: 48 hours

Irritation parameter:

iris score

Basis:

animal: 75672 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0

Max. score:

2

Reversibility:

other: No effects observed

Irritation parameter:

other: redness

Basis:

animal: 75686 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0.7

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

other: redness

Basis:

animal: 75672 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0.7

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

chemosis score

Basis:

animal: 75686 Female

Time point:

other: Mean 24, 48 and 72 hours

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Irritation parameter:

chemosis score

Basis:

animal: 75672 Female

Time point:

other: mean at 24, 48 and 72 hours

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Ocular Reactions
Individual and mean scores for ocular irritation are given in Appendix 1.
Blue colored staining of the fur around the treated eye, the inner eyelids and conjunctival membrane was noted in all animals at all observations.
No corneal effects were noted during the study.
Iridial inflammation was noted in one treated eye at the 24-Hour observation. No iridial effects were noted in two treated eyes during the study.
Moderate conjunctival irritation was noted in all treated eyes 1 hour after treatment and at the 24 and 48 Hour observations. Moderate conjunctival irritation was noted in one treated eye and minimal conjunctival irritation was noted in two treated eyes at the 72 Hour observation.
All treated eyes appeared normal at the 7 Day observation.
No corrosive effects were noted during the study. The test item did not induce significant or irreversible damage to the rabbit eye.

Other effects:

Body Weight
Individual body weights and body weight change are given in Appendix 2.
One animal showed body weight loss and the other two animals showed expected gain in body weight during the study.

Appendix 1     Eye Irritation Scores

Individual Scores for Eye Irritation

								Conjunctivae
Rabbit Number and Sex	IPR	Evaluation interval	Corneal Opacity	Area of Corneal Opacity	Iris	Redness	Chemosis		Discharge
75686 Female	0	1 Hour	0	0	1	2	1		2
75672 Female	0		0	0	1	2	1		1
75686 Female		24 Hour	0	0	0	1	1		1
75672 Female			0	0	0	1	1		1
75686 Female		48 Hour	0	0	0	1	0		0
75672 Female			0	0	0	1	0		0
75686 Female		72 Hour	0	0	0	0	0		0
75672 Female			0	0	0	0	0		0

IPR=Initial pain reaction

Mean Values after 24, 48 and 72 Hours

				Conjunctivae
Rabbit Number and Sex	Number of available data points	Corneal Opacity	Iris	Redness	Chemosis
75686 Female	3	0.0	0.0	0.7	0.3
75672 Female	3	0.0	0.0	0.7	0.3

Assessment According to Regulation (EC) No. 1272/2008

			Conjunctivae
Evaluated Intervals	Corneal Opacity	Iris	Redness	Chemosis
24 Hours	Not classified	Not classified	Not classified	Not classified
48 Hours	Not classified	Not classified	Not classified	Not classified
72 Hours	Not classified	Not classified	Not classified	Not classified

Appendix 2     Individual Body Weights and Body Weight Change

	Individual Body Weight (kg)
Rabbit Number and Sex	Day 0	Day 3	Body Weight Change (kg)
75686 Female	2.24	2.29	0.05
75672 Female	3.43	3.39	-0.04

Interpretation of results:

other: does not meet the criteria for classification according to Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008.

Conclusions:

According to the findings in this study, 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE does not meet the criteria for classification according to Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008.

Executive summary:

The primary eye irritation potential of 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE was investigated according to a method compatible with OECD test guideline No. 405 and Method B5. The test item was applied by instillation of 0.1 mL into the right eye of each of two young adult New Zealand White rabbits. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours after test item instillation. 

The mean score was calculated separately for each animal across three scoring times (24, 48 and 72 hours after instillation) for corneal opacity, iritis, redness and chemosis of the conjunctivae. The individual mean scores for corneal opacity and iritis was 0.0 for both animals. The individual mean scores for the conjunctivae were 0.7 for reddening and 0.3 for chemosis for both animals. 

The instillation of 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE into the eye resulted in conjunctival irritation. These effects were reversible and were no longer evident 72 hours after treatment in both animals (end of the observation period). No abnormal findings were observed in the cornea of any animal at any of the examinations. No corrosion was observed at any of the measuring intervals. No clinical signs of toxicity were observed.

Thus, the test item did not induce significant or irreversible damage to the rabbit eye.

According to the findings in this study, 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE does not meet the criteria for classification according to Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

No classification

According to the findings in the available studies, 3-AMINO-4-METHOXY-N-METHYLBENZAMIDE does not meet the criteria for classification according to Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008.