Alcohols, C12-14, ethoxylated, sulfates, sodium salts

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Remarks:

Liver S9 metabolic stability

Adequacy of study:

key study

Study period:

2022-2023

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Reason / purpose for cross-reference:

other: Composition of specific tested batch

Reference

Name:

SLES (PSL 1EO)

Type of composition:

legal entity composition of the substance

State / form:

liquid

Related composition:

Alcohols, C12-14, ethoxylated, sulfates, sodium salts - Consortium boundary

Alcohols, C12-14, ethoxylated, sulfates, sodium salts - Unilever

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Reference substance:

SLES (PSL 1EO)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2023

Report date:

2023

Materials and methods

Objective of study:

other: Metabolic stability in liver S9

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In this study the metabolic stability of SLES C12-14, Linear (hereafter referred to as SLES) was assessed. Pooled human liver S9 fractions were exposed to SLES at different concentrations. Samples were taken after incubation for 0, 10, 30 and 60 min at 37°C and processed for quantitative analysis by LC-MS. Blank controls were included and Midazolam and verapamil were used as positive controls. Negative control incubations were performed in line with all experiments using incubation fraction with test and reference items in the presence of heat-inactivated hepatocytes.
The amount of compound in the samples was expressed as percentage of remaining compound compared to time point zero (=100%). These percentages were plotted against the corresponding time points to determine In vitro intrinsic clearance (CLint S9) and half-life (t1/2) estimates.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Alcohols, C12-14, ethoxylated, sulfates, sodium salts

EC Number:

500-234-8

EC Name:

Alcohols, C12-14, ethoxylated, sulfates, sodium salts

Cas Number:

68891-38-3

Molecular formula:

not applicable, UVCB

IUPAC Name:

Alcohols, C12-14(even numbered), ethoxylated < 2.5 EO, sulfates, sodium salts

Test material form:

liquid: viscous

Remarks:

Very viscous liquid

Details on test material:

Molecular weight: 367 g/mol
Expiry Date: 01/10/2023

Results and discussion

Main ADME results

Main ADME results 1

Type:

other: t1/2 (in vitro human liver S9 metabolism)

Results:

21.33-43.77 minutes (all SLES components; 10 μM test concentration)

Main ADME results 2

Type:

other: In vitro intrinsic clearance (CLint S9)

Results:

7.92-16.25 µL/min/my protein (all SLES components; 10 µM test concentration)

Toxicokinetic / pharmacokinetic studies

Details on absorption:

SLES (at 0.1, 1 and 10 μM) was subjected to metabolism with human liver S9 fractions, resulting in clear turnover. Nevertheless, values of 1 and 0.1 μM SLES are all below the limit of quantification (BLQ) and therefore not usable for quantification. With 10 μM SLES, however, all components were quickly metabolised resulting in 14.1-39.5% remaining compound after 60 min of incubation (see Table 3 below and Figure 5 attached).

Negative controls containing heat-inactivated human liver S9 served as a monitoring system for non-enzymatic degradation or non-specific binding effects of the test item. The concentrations of test item remained relatively stable over the investigated time of 60 min of incubation in the negative controls (see Table 3).

Midazolam and verapamil were metabolised by human liver S9 preparations resulting in 1.9% and 34.5% remaining compound after 30 min of incubation, respectively. Propantheline, a reference for esterase activity showed only low turnover demonstrated by remaining percentage of 70.2%. In prospective assays, a different reference control for esterase activity might be recommended (see Table 4 below and Figure 6 attached).

All components of SLES were rapidly metabolised resulting in half-lives in the range of 21.33 to 43.77 min (10 μM test concentration). Corresponding in vitro intrinsic clearance rates (CLint S9) were in the range of 7.92 to 16.25 μL/min/mg protein (see Table 5 below). Results implicate that Phase I liver metabolism is involved in test item degradation.

Any other information on results incl. tables

Table 3 - Metabolism of SLES (at 0.1, 1 and 10 μM) with human liver S9: measured concentration and calculated percentage of remaining test item after incubation with human liver S9 fractions for different time points, (n=3), with respective negative control using heat-inactivated human liver S9, strikethrough values are BLQ

SLES (10 µM)
Remaining C12AS concentration				% remaining C12AS of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	2724.4	54.4	2	100	2
10	2348.5	89.1	3.8	86.2	3.3
30	1472	127.7	8.7	54	4.7
60	763.1	63	8.3	28	2.3
Negative control
0	2774.8	37.8	1.4	100	1.4
60	1996.6	22.4	1.1	72	0.8
Remaining C12AE1S concentration				% remaining C12AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	1268.8	21.5	1.7	100	1.7
10	860.7	17.6	2	67.8	1.4
30	417.2	30	7.2	32.9	2.4
60	179.1	17.9	10	14.1	1.4
Negative control
0	1283.7	23.9	1.9	100	1.9
60	1256.8	18.9	1.5	97.9	1.5
Remaining C12AE2S concentration				% remaining C12AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	590.4	4.8	0.8	100	0.8
10	442.9	18.3	4.1	75	3.1
30	224.1	19.6	8.8	38	3.3
60	105.1	6.8	6.5	17.8	1.2
Negative control
0	602.9	10.8	1.8	100	1.8
60	438.8	9.8	2.2	72.8	1.6
Remaining C12AE3S concentration				% remaining C12AE3S of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	267	4.5	1.7	100	1.7
10	198	6.3	3.2	74.2	2.4
30	98.1	9.4	9.6	36.8	3.5
60	46.4	2.1	4.4	17.4	0.8
Negative control
0	271.9	5.8	2.1	100	2.1
60	197.7	5.3	2.7	72.7	2
Remaining C12AE4S concentration				% remaining C12AE4S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	86.7	1.9	2.2	100	2.2
10	66.3	1.7	2.6	76.6	2
30	35.8	2.6	7.1	41.3	2.9
60	18.4	1	5.5	21.2	1.2
Negative control
0	88.2	1.3	1.5	100	1.5
60	63.5	1.8	2.8	72	2
Remaining C14AS concentration				% remaining C14AS of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	1004.5	30.4	3	100	3
10	903.7	33.6	3.7	90	3.3
30	634.1	51.5	8.1	63.1	5.1
60	396.4	30.8	7.8	39.5	3.1
Negative control
0	1023.6	14.3	1.4	100	1.4
60	746.9	8.4	1.1	73	0.8
Remaining C14AE1S concentration				% remaining C14AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	464.1	5.7	1.2	100	1.2
10	395.7	15.4	3.9	85.3	3.3
30	260	19.7	7.6	56	4.3
60	152.5	9	5.9	32.9	1.9
Negative control
0	471.3	5.5	1.2	100	1.2
60	384.5	12	3.1	81.6	2.5
Remaining C14AE2S concentration				% remaining C14AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	212.3	0.9	0.4	100	0.4
10	166.1	5.9	3.6	78.2	2.8
30	87.8	5.5	6.2	41.3	2.6
60	42.3	4	9.4	19.9	1.9
Negative control
0	215.3	0.8	0.4	100	0.4
60	163.4	2.6	1.6	75.9	1.2
SLES (1 µM)
Remaining C12AS concentration				% remaining C12AS of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	273	7	2.6	100	2.6
10	223.2	34.9	15.6	81.7	12.8
30	127.4	5.3	4.2	46.7	2
60	55.7	5.5	9.8	20.4	2
Negative control
0	301	26.5	8.8	100	8.8
60	240.1	129.4	53.9	79.8	43
Remaining C12AE1S concentration				% remaining C12AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	127.2	1.8	1.4	100	1.4
10	76.1	3.3	4.3	59.8	2.6
30	30.1	3	9.9	23.7	2.3
60	9.2	2.2	24.2	7.2	1.7
Negative control
0	136.9	10.1	7.4	100	7.4
60	121.6	55.8	45.9	88.8	40.8
Remaining C12AE2S concentration				% remaining C12AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	72.1	1.3	1.9	100	1.9
10	53.1	2.6	4.8	73.7	3.6
30	33.6	1.2	3.4	46.6	1.6
60	23.1	1	4.2	32	1.3
Negative control
0	74	4.9	6.6	100	6.6
60	57.1	18.9	33.2	77.1	25.6
Remaining C12AE3S concentration				% remaining C12AE3S of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	33.6	0.2	0.6	100	0.6
10	24.8	1.1	4.6	74	3.4
30	15.4	0.8	5	46	2.3
60	11.2	0.2	1.4	33.5	0.5
Negative control
0	35	2	5.7	100	5.7
60	27.2	9.6	35.2	77.7	27.4
Remaining C12AE4S concentration				% remaining C12AE4S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	11.5	0.1	0.6	100	0.6
10	8.7	0.4	4.7	75.3	3.6
30	6.3	0.2	3	54.2	1.6
60	4.6	0.1	2.4	40.1	1
Negative control
0	11.9	0.8	6.9	100	6.9
60	9.9	3.4	34.1	83.8	28.6
Remaining C14AS concentration				% remaining C14AS of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	99.7	0.6	0.6	100	0.6
10	83.9	23.1	27.5	84.1	23.2
30	41.2	3.7	8.9	41.3	3.7
60	7.8	3.6	45.7	7.8	3.6
Negative control
0	123.7	15.8	12.8	100	12.8
60	103.5	71.3	68.9	83.7	57.6
Remaining C14AE1S concentration				% remaining C14AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	62.8	1.7	2.7	100	2.7
10	52.4	2.7	5.2	83.4	4.3
30	40.1	1.5	3.8	63.8	2.4
60	39.5	0.6	1.4	62.8	0.9
Negative control
0	69.3	5	7.3	100	7.3
60	59.8	14.8	24.8	86.3	21.4
Remaining C14AE2S concentration				% remaining C14AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	18.9	3.3	18.9	100	17.3
10	17.3	1.6	17.3	92	8.6
30	16.3	0.5	16.3	86.5	2.7
60	16.7	0.3	16.7	88.7	1.8
Negative control
0	26.9	4.8	18	100	18
60	20.9	6.1	29.3	77.6	22.7
SLES (0.1 µM)
Remaining C12AS concentration				% remaining C12AS of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	24.6	9.8	39.9	100	39.9
10	29.2	24.6	84.3	118.6	100
30	0	0	n.a.	0	0
60	0	0	n.a.	0	0
Negative control
0	16.6	3.7	22.2	100	22.2
60	9.5	8.5	89.4	57.3	51.2
Remaining C12AE1S concentration				% remaining C12AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	7.3	4.8	65.7	100	65.7
10	4	3.6	88.1	55.4	48.9
30	0	0	n.a.	0	0
60	0	0	n.a.	0	0
Negative control
0	6.2	2.1	34.1	100	34.1
60	11.1	4.4	39.5	178.6	70.5
Remaining C12AE2S concentration				% remaining C12AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	21.3	2.5	11.8	100	11.8
10	19.5	2.4	12.5	92	11.5
30	15.8	0.8	5.4	74.5	4
60	15.2	0.3	1.8	71.4	1.3
Negative control
0	20.3	1.9	9.3	100	9.3
60	20.4	1.9	9.1	100.4	9.1
Remaining C12AE3S concentration				% remaining C12AE3S of initial concentration
Time [min]	Mean (nM)	SD (nM)	%CV	Mean [%]	SD [%]
0	10.8	1.8	16.6	100	16.6
10	8.6	0.6	6.5	79.7	5.2
30	7.7	0.1	1.9	71.3	1.4
60	7.3	0.2	2.9	66.9	1.9
Negative control
0	11.1	0.8	7.1	100	7.1
60	10.8	1	8.9	97.9	8.8
Remaining C12AE4S concentration				% remaining C12AE4S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	3.7	1	26.9	100	26.9
10	3.3	0.7	21.5	88.1	18.9
30	2.9	0.1	4.2	76.2	3.2
60	2.8	0.1	2.1	75.9	1.6
Negative control
0	3.9	0.7	18	100	18
60	4	0.3	8.5	102.5	8.7
Remaining C14AS concentration				% remaining C14AS of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	2.3	4	173.2	100	173.2
10	2.8	4.8	173.2	122.6	212.3
30	0	0	n.a.	0	0
60	0	0	n.a.	0	0
Negative control
0	3	3.5	117.1	100	117.1
60	0	0	n.a.	0	0
Remaining C14AE1S concentration				% remaining C14AE1S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	39	0.1	0.2	100	0.2
10	39	0.2	0.4	100.1	0.4
30	39	0.1	0.3	100	0.3
60	38.9	0.1	0.2	99.8	0.2
Negative control
0	39	0.2	0.5	100	0.5
60	39	0.1	0.2	99.9	0.2
Remaining C14AE2S concentration				% remaining C14AE2S of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	16.3	0.1	0.5	100	0.5
10	16.1	0.4	2.2	98.6	2.2
30	17	0.7	4.2	103.9	4.4
60	16.1	0.3	2	98.5	1.9
Negative control
0	15.9	0.1	0.8	100	0.8
60	16.5	0.9	5.5	103.8	5.7

Table 4 - Remaining reference items (nominal initial concentration: 1 μM): measured concentration and calculated percentage of remaining reference item after incubation with human liver S9 fractions for different time points, (n=3)

Remaining midazolam concentration				% remaining midazolam of initial concentration
Time [min]	Mean [nM]	[nM]	%CV	Mean [%]	SD [%]
0	695.9	68.8	9.9	100	9.9
30	13.5	0.7	5.5	1.9	0.1
Remaining verapamil concentration				% remaining verapamil of initial concentration
Time [min]	Mean [nM]	[nM]	%CV	Mean [%]	SD [%]
0	701.6	14.4	2	100	2
30	242.2	17.7	7.3	34.5	2.5
Remaining propantheline concentration				% remaining propantheline of initial concentration
Time [min]	Mean [nM]	SD [nM]	%CV	Mean [%]	SD [%]
0	948	84.6	8.9	100	8.9
10	851.3	26.9	3.2	89.8	2.8
30	839.9	116.8	13.9	88.6	12.3
60	665.7	49.9	7.5	70.2	5.3

Table 5 - Intrinsic clearance in vitro (CIint S9), prediction parameters and results for the test and reference items (n=3) with human liver S9 (2 mg/mL)

Component	Slope	r2	Range (min)	Half life in vitro (min)	Clint in vitro (µL/min/mg protein)
C12AS	-0.022	0.998	0-60	32.07	10.81
C12AE1S	-0.033	0.995	0-60	21.33	16.25
C12AE2S	-0.029	0.995	0-60	23.88	14.51
C12AE3S	-0.029	0.994	0-60	23.57	14.71
C12AE4S	-0.026	0.994	0-60	26.6	13.03
C14AS	-0.016	0.997	0-60	43.77	7.92
C14AE1S	-0.019	0.999	0-60	36.9	9.39
C14AE2S	-0.027	0.997	0-60	25.46	13.61
Midazolam	-0.131	1	0-30	5.27	65.74
Verapamil	-0.035	1	0-30	19.55	17.72
Propantheline	-0.005	0.925	0-60	> 60	2.71

Applicant's summary and conclusion

Conclusions:

Based on the measurement of metabolic breakdown of the components of SLES in an in vitro system with human liver S9, calculated half-life and in vitro intrinsic clearance rates were in the range of 21.33-43.77 minutes and 7.92-16.25 μL/min/mg protein, respectively, indicating moderate metabolism.

Executive summary:

The metabolic stability of SLES was assessed in human liver S9. Pooled fractions were exposed to SLES at 0.1, 1 or 10 μM in triplicate and samples were taken after 0, 10, 30 and 60 min of incubation at 37°C and processed for quantitative analysis by LC-MS. Blank controls were included and midazolam and verapamil were used as positive con
trols. Negative control incubations were performed in line with all experiments using incubation medium with test and reference item in the presence of heat-inactivated hepatocytes. The amount of each SLES component compound in the samples was expressed as percentage of remaining compound compared to time point zero (=100%). These percentages were plotted against the corresponding time points to determine In vitro intrinsic clearance (CL_{int S9}) and half-life (t_1/2) estimates.

SLES was subjected to metabolism with human liver S9 fractions, resulting in clear turnover. Nevertheless, values of 1 and 0.1 μM SLES were all below the limit of quantification and therefore not usable. The components of SLES were moderately metabolised at 10 μM, resulting in 14.1-39.5% remaining parental compound (after 60 min of incubation). Calculated half-lives (t_1/2) and in vitro intrinsic clearance rates (CL_{int S9}) were in the range of 21.33-43.77 minutes and 7.92-16.25 μL/min/mg protein.