Amines, N-C12–14 (even numbered)-alkyltrimethylenedi-, reaction products with chloroacetic acid and diethylenetriamine, N-C12–14 (even numbered)-alkyl derivs.

Endpoint summary

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

basic toxicokinetics in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
- they are manufactured from similar or identical precursors under similar conditions
- they share structural similarities with common functional groups (corresponding to scenario 2 of the read-across assessment framework): both, the target and source substance, are aliphatic amines with C8-18 alkyl chains and acetate functions
- Two thirds (w/w) of the target substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid (excluding the solvent water) are composed of the source substance DOPA-Glycinate. The remaining third of Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid consists of other aliphatic amines and derivatives which are considered as structural analogues to those constituting the source substance DOPA-Glycinate and may therefore be expected to elicit comparable (eco)toxicological effects.

The read-across hypothesis is based on structural similarity of target and source substances. Based on available experimental data, including key physicochemical properties and data from acute toxicity, repeated dose toxicity, genotoxicity and short term ecotoxicity studies, the read-across hypothesis is supported by a quite similar toxicological profile of both substances.

(Eco)toxicological, physicochemical and environmental fate data are summarised in the data matrix; robust study summaries are included in the Technical Dossier in the respective sections.

Therefore, read-across from the existing ecotoxicity, environmental fate and toxicity studies conducted with the source substances is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

Further details are attached to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
For further details refer to IUCLID section 13.

3. ANALOGUE APPROACH JUSTIFICATION
For further details refer to IUCLID section 13.

4. DATA MATRIX
For further details refer to IUCLID section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across source

Preliminary studies:

The following no-effects levels were determined in an orientating experiment:
NOEL rat, i.v. = 125 mg/kg bw; NOEL rat, p.o = 400 mg/kg bw.
The administered radioactivity was distributed as follows: Approximately 55 %/19 % (p.o./i.v.) in the faeces, 6 %/23 % in urine, 0.6 %/0.9 % in cage wash, and 12 % (p.o.) in expired air. The mean of the highest plasma concentration was 0.04 %/0.25 % (p.o./i.v.). The fraction of radioactivity excreted in expired air indicated that this route of elimination is relevant.

Type:

absorption

Results:

34% oral absorption

Type:

distribution

Results:

throughout the body, with the highest levels in the residual carcass, in the liver, the kidneys, and the adipose tissue

Type:

metabolism

Results:

mainly oxidation (hydroxylation), to a minor extent dehydrogenation and acetylation

Type:

excretion

Results:

excreted rapidly within 24 hours; main elimination pathway: via the faeces, followed by expired air and urine

Metabolites identified:

yes

Details on metabolites:

In urine, the parent compounds N-C12 Gly, N’-C12 Gly, N’-C12 di Gly, C12 PDA and several metabolites were identified by mass spectrometry. Oxidation (hydroxylation) of the parent and some other metabolites like dehydrogenated and acetylated compounds, especially for C12 PDA, were identified. The most abundant compounds in urine were the oxidation products.
In plasma, only the unchanged parent compounds N-C12 Gly, N’-C12 Gly, N’-C12 di Gly, C12 PDA could be identified by mass spectrometry. For the radioactivity counting only N-C12 Gly, N’-C12 Gly were identified. The most abundant compounds in plasma were the parent substance N-C12 Gly and N’-C12 Gly.
In faeces, N-C12 Gly, N’-C12 Gly, N’-C12 di Gly, C12 PDA and several metabolites were identified by mass spectrometry. Oxidation (hydroxylation) of the parent and some other metabolites, like dehydrogenated and acetylated modifications, was demonstrated. The most abundant compounds in faeces were the oxidation products.

Conclusions:

Interpretation of results (migrated information): low bioaccumulation potential based on study results
The systemic bioavailability: 34% following oral administration.
The substance is mainly metabolised by oxidation (hydroxylation), and to a minor extent dehydrogenation and acetylation.
The vast majority of the administered radioactivity was excreted rapidly within 24 hours. The main elimination pathway was via the faeces, followed by expired air and urine.

Reference 2

Endpoint:

dermal absorption in vitro / ex vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
- they are manufactured from similar or identical precursors under similar conditions
- they share structural similarities with common functional groups (corresponding to scenario 2 of the read-across assessment framework): both, the target and source substance, are aliphatic amines with C8-18 alkyl chains and acetate functions
- Two thirds (w/w) of the target substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid (excluding the solvent water) are composed of the source substance DOPA-Glycinate. The remaining third of Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid consists of other aliphatic amines and derivatives which are considered as structural analogues to those constituting the source substance DOPA-Glycinate and may therefore be expected to elicit comparable (eco)toxicological effects.

The read-across hypothesis is based on structural similarity of target and source substances. Based on available experimental data, including key physicochemical properties and data from acute toxicity, repeated dose toxicity, genotoxicity and short term ecotoxicity studies, the read-across hypothesis is supported by a quite similar toxicological profile of both substances.

(Eco)toxicological, physicochemical and environmental fate data are summarised in the data matrix; robust study summaries are included in the Technical Dossier in the respective sections.

Therefore, read-across from the existing ecotoxicity, environmental fate and toxicity studies conducted with the source substances is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

Further details are attached to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
For further details refer to IUCLID section 13.

3. ANALOGUE APPROACH JUSTIFICATION
For further details refer to IUCLID section 13.

4. DATA MATRIX
For further details refer to IUCLID section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across source

Signs and symptoms of toxicity:

not examined

Dermal irritation:

no effects

Total recovery:

Test preparation 1, 20 % (w/w): 101.69 % (SD = 3.04%)
Test preparation 2, 0.2 % (w/w): 97.10 % (SD = 2.99%)

Time point:

24 h

Dose:

20%

Parameter:

percentage

Remarks:

potentially absorbable dose (sum of the absorbed dose, exposed skin and stratum corneum tape strips 3–20)

Absorption:

1.1 %

Time point:

24 h

Dose:

0.2%

Parameter:

percentage

Remarks:

potentially absorbable dose (sum of the absorbed dose, exposed skin and stratum corneum tape strips 3–20)

Absorption:

15.1 %

Key result

Time point:

24 h

Dose:

20%

Parameter:

percentage

Remarks:

Dermal delivery (exposed skin + absorbed dose)

Absorption:

0.6 %

Key result

Time point:

24 h

Dose:

0.2%

Parameter:

percentage

Remarks:

Dermal delivery (exposed skin + absorbed dose)

Absorption:

5 %

Test preparation 1, 20 % (w/w):99.76 % of the applied dose was removed by washing at 6 h post application. At 24 h post application, the total dislodgeable dose was 100.35 % of the applied dose. The stratum corneum retained 0.72 % of the applied dose, 0.37 % was removed with the first 5 tape strips.

Absorbed dose: 0.01 % (0.18 ng equivalent/cm²)

Dermal delivery: 0.62 % (13.17 ng equivalent /cm²)

Potentially absorbable dose: 0.97 % (20.53 ng equivalent /cm²)

Test preparation 2, 0.2 % (w/w):73.66 % of the applied dose was removed by washing at 6 h post application. At 24 h post application, the total dislodgeable dose was 75.30 % of the applied dose. The stratum corneum retained 16.08 % of the applied dose, 9.71 % was removed with the first 5 tape strips.

Absorbed dose: 0.11 % (0.02 ng equivalent /cm²)

Dermal delivery: 5.04 % (1.01 ng equivalent /cm²)

Potentially absorbable dose: 11.42 % (2.28 ng equivalent /cm²)

 

 

Table A6.2-4:Details on human skin.

Donor no.	Sex/age of donor	Site of sampling	Supplier	Membrane full-thickness (µm)	Membrane split-thickness (µm)
0164	F/28Y	Breast	St. Johns Hospital	1010–1150	380–390
0161	F/36Y	Abdomen	BUPA	1020–1080	390–400
0162	F/35Y	Abdomen	BUPA	700–1190	390–400
0179	F/84Y	Breast	Nottingham	1130	400
0169	F/82Y	Breast	Nottingham	1000	400
0180	F/74Y	Breast	Nottingham	940–1000	400
0166	F/33Y	Abdomen	Transkin	1240	400

 

 

Table A6.2-5:Summary of the results (mean values).

Test preparation	1		2
Target concentration of active substance	20 % (w/w)		0.2 % (w/w)
Active substance concentration in test preparation by radioactivity	21.016 % (w/w)		0.199 % (w/w)
Application rate of Test preparation	10.06 mg/cm²		10 µl/cm²
Application rate of test item	2114 µg equivalent/cm²		19.94 µg equivalent/cm²
Distribution	% applied dose	ng equivalent /cm²	% applied dose	ng equivalent /cm²
Dislodgeable dose 6 h (skin wash+tissue swab+pipette tips)	99.76	2108.47	73.66	14.69
Total dislodgeable dose (dislodgeable dose 6 h +stratum corneum + unexposed skin + cell wash)	100.35	2120.83	75.30	15.02
Unabsorbed dose	101.07	2136.17	92.06	18.36
Absorbed dose (cumulative receptor fluid + receptor rinse)	0.01	0.18	0.11	0.02
Dermal delivery (exposed skin + absorbed dose)	0.62	13.17	5.04	1.01
Potentially absorbable dose (dermal delivery + stratum corneum tape strips)	0.97	20.53	11.42	2.28
Mass balance (unabsorbed dose + dermal delivery)	101.69	2149.34	97.10	19.36

 

According to EFSA Guidance on Dermal Absorption (2012) as well as the EU Guidance Document

on Dermal Absorption (2004) only the first 2 tape strips should be discarded. On that basis dermal absorption for both low and high doses have been re-calculated.  

 

Recalculation disregarding 2 rather than 5 tape strips:

 

Prep 1 (20% a.i.)
	Cell 1	Cell 2	Cell 3	Cell 4	Cell 8	Cell 9	Cell 10	Cell 12	Cell 13	Cell 14	Mean	STDEV
1	0.008	0.019	0.08	0.068	0.18		0.282	0.12	0.023	0.144	0.103	0.090
2	0.003	0.011	0.141	0.099	0.093		0.295	0.063	0.01	0.201	0.102	0.098
Stratum total	0.04	0.1	0.99	0.69	0.95		1.58	0.62	0.16	1.33	0.718	0.549
minus 1+2	0.029	0.07	0.769	0.523	0.677		1.003	0.437	0.127	0.985	0.513	0.378
Dermal delivery	0.02	0.09	0.77	0.27	1.35		1.73	0.82	0.15	0.41	0.623	0.597
Absorbable Dose	0.049	0.16	1.539	0.793	2.027		2.733	1.257	0.277	1.395	1.137	0.907
Prep 2 (0.2% a.i.)
	Cell 16	Cell 17	Cell 18	Cell 19	Cell 24	Cell 25	Cell 26	Cell 28	Cell 29	Cell 30	Mean	STDEV
1	3.11	2.24	2.84	4.42	3.36	3.89	4.82	3.78	4.87	6.06	3.939	1.131
2	1.66	1.8	1.71	2.33	1.73	2.53	2.19	2.26	2.5	2.26	2.097	0.338
Stratum total	12.02	13.59	14.46	19.48	15.39	15.49	20.79	16.73	14.73	18.17	16.085	2.718
minus 1+2	7.25	9.55	9.91	12.73	10.3	9.07	13.78	10.69	7.36	9.85	10.049	2.052
Dermal delivery	2.56	2.52	3.84	3.15	8.21	9.37	6.12	7.47	3.15	4.02	5.041	2.538
Absorbable Dose	9.81	12.07	13.75	15.88	18.51	18.44	19.9	18.16	10.51	13.87	15.090	3.611

Conclusions:

The systemically available dose (= dermal delivery: exposed skin + absorbed dose): 0.6±0.6% for the high exposure scenario (20% a.i.), and 5.0±2.5% for the low exposure scenario (0.2% a.i.), respectively.
The potentially absorbable dose: 1.1±0.9% for the high exposure scenario (20% a.i.), and 15.1±3.6% for the low exposure scenario (0.2% a.i.), respectively.

Description of key information

The oral bioavailability was determined to be 34% (OECD guideline 417, GLP; rat).

The systemically available dose after dermal administration was determined to be 0.6±0.6% for the high exposure scenario (20% a.i.), and 5.0±2.5% for the low exposure scenario (0.2% a.i.), respectively (OECD guideline 428, GLP; human skin).

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

5

Absorption rate - inhalation (%):

100

Additional information

No experimental in vivo or in vitro data on oral, inhalation and dermal absorption, distribution, metabolism and excretion are available for the target substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid. However, toxicokinetic data are available for the source substance DOPA-Glycinate. A justification for read-across is attached to IUCLID section 13. Additionally, the toxicokinetic assessment is partially based on physicochemical properties.

 

Oral absorption

The physicochemical properties of the target substance are favourable for absorption (molecular weight < 500 g/mol, log Kow -0.55).

 

The systemic bioavailability of the source substance DOPA-Glycinate was 34% following oral administration. Based on the available experimental data and on physicochemical properties, the bioavailability after oral administration is set to 50% in accordance with the Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7c: Endpoint specific guidance.

 

Respiratory absorption

The extent of inhalation absorption deduced from the physico-chemical properties are expected to be high. For chemical safety assessment, a value of 100% is considered appropriate according to the Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7c: Endpoint specific guidance.

 

Dermal absorption

The physicochemical properties of the target substance are only partially favourable for dermal absorption (molecular weight < 500 g/mol, log Kow -0.55); the substance is expected to be too hydrophilic to easily cross the stratum corneum. On the other hand, the substance is corrosive, which may enhance penetration.

Experimental data are available for the source substance DOPA-Glycinate supporting the assumption of low dermal penetration.

The percutaneous absorption of [14C]-DOPA-Glycinate was tested according to OECD 428: Skin Absorption: In Vitro Method (2004).

The systemically available dose of DOPA-Glycinate (= dermal delivery: exposed skin + absorbed dose) was 0.6±0.6% for the high exposure scenario (20% a.i.), and 5.0±2.5% for the low exposure scenario (0.2% a.i.), respectively. For chemical safety assessment, a value of 5% is considered appropriate in accordance with the Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7c: Endpoint specific guidance.

 

Distribution

As a small molecule with high water solubility, a wide distribution of substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid can be expected. This assumption is further supported by in vivo data on the source substance DOPA-Glycinate.

DOPA-Glycinate was distributed throughout the body, with the highest levels in the residual carcass, in the liver, the kidneys, and the adipose tissue.

The recovery of radioactivity was greatest in the residual carcass (12–19 %), followed by the liver (approx 4 %). In all other tissues the radioactive recovery was low (≤ 1.00 %) and quite uniformly distributed, with no tissue storage in brain, heart, ovaries and spinal cord. There was no relevant difference in the tissue distribution of radioactivity between animals treated orally or intravenously with a single or repeated dose of the test substance.

A similar distribution can be assumed for the target substance, based on comparable physicochemical properties.

 

Metabolism/ Elimination

No experimental data are available or the target substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid. An ADME study was conducted with the closely related substance DOPA-Glycinate. In plasma, only parent substances but no transformation products could be identified. A first-pass effect following intestinal absorption is therefore unlikely. In urine and faeces, parent substances as well as transformation products were detected. Metabolites in both urine and faeces were characterised by oxidation (hydroxylation) of the parent and some other metabolites like dehydrogenated and acetylated compounds. The most abundant compounds in urine were the oxidation products.

Upon oral administration, radioactivity was predominantly eliminated via faeces (approx. 60 %) and via expired air (approx. 18 %). A lower proportion was excreted via urine (approx. 9 %) and less than 20 % of the administered dose was found in the carcass.

Based on close structural similarity, similar metabolism is expected for the target substance Reaction product of lauryl-PDA/lauryl-DETA with chloroacetic acid.