Reaction mass of sodium 1-methoxy-1-oxohexadecane-2-sulphonate and sodium methyl 2-sulphooctadecanoate

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

other: theoretical assessment

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is not according to GLP. The study is based on expert judgement.

Objective of study:

toxicokinetics

Principles of method if other than guideline:

A theoretical approach of the toxicokinetic properties of the substance based on the available physico-chemical properties and toxicological data.

GLP compliance:

no

Type:

absorption

Results:

For risk assessment purposes, the oral and inhalation absorption is set at 100% and the dermal absorption is set at 10%.

In general, a compound needs to be dissolved before it can be taken up from the gastro-intestinal tract after oral administration. The molecular weights are below 500, the moderate log P values (between -1 and 4) of sodium methyl-2 -sulphohexadecanoate (C16MES) and sodium methyl 2 -sulphooctadecanoate (C18MES), and the high water solubility (>10 g/L) of C16MES, are favorable for absorption by the gastro-intestinal tract. For risk assessment purposes oral absorption of MIZULAN FL 80 is set at 100%.

 

Since the molecules are lipophilic (log P values>0) MIZULAN FL 80 is likely to distribute into cells and the intracellular concentration may be higher than extracellular concentration particularly in fatty tissues, and higher concentrations may occur in breast milk than in blood/plasma. However, with log P values less than 3, MIZULAN FL 80 is unlikely to accumulate. As amphipathic lipids with relatively high molecular weights (~400), the molecules may be excreted in the bile and may potentially undergo enterohepatic circulation.

 

Due to the low vapor pressure of the substances it is not to be expected that MIZULAN FL 80 will reach the nasopharyncheal region or subsequently the tracheobronchial or pulmonary region. On the other hand, the moderate log P values (between -1 and 4) of sodium methyl-2-sulphohexadecanoate (C16MES) and sodium methyl 2 -sulphooctadecanoate (C18MES) are favourable for absorption directly across the respiratory tract epithelium by passive diffusion. Overall, although it is unlikely that MIZULAN FL 80 will be available to a high extent after inhalation via the lungs due to low vapor pressure, for risk assessment purposes the inhalation absorption of MIZULAN FL 80 is set at 100%.

 

Dry particulates will have to dissolve into the surface moisture of the skin before uptake can begin. The log P values (between 1 and 4) and high water solubility (>10 g/L) of C16MES favor dermal absorption. However, the molecular weight of 372.5-400.55 indicates moderate or low dermal absorption. The criteria for reduced dermal absorption as given in the REACH guidance (MW>500, log Pow is smaller than -1 or higher than 4) are not met, therefore 100% dermal absorption of C16MES should be considered for risk assessment purposes. However, the potentially ionisable groups of C16MES might limit diffusion across biological membranes. In addition, the surface tension of 39mN/m is not favorable for dermal absorption. Furthermore, the lower oral LD50 compared to the dermal LD50 suggests a dermal absorption lower than oral absorption, in addition, the substance is neither skin irritating nor skin sensitizing. For risk assessment purposes the dermal absorption of MIZULAN FL 80 is set at 10%.

 

 

Conclusions:

Interpretation of results: bioaccumulation potential cannot be judged based on study results
For risk assessment purposes, the following absorptions were set:
oral 100%
inhalation 100%
dermal 10%

Description of key information

The bioaccumulation potential cannot be judged based on study results.

For risk assessment purposes, the following absorptions were set:

oral 100%

inhalation 100%

dermal 10%

Key value for chemical safety assessment

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

100

Additional information

In general, a compound needs to be dissolved before it can be taken up from the gastro-intestinal tract after oral administration. The molecular weights are below 500, the moderate log P values (between -1 and 4) of sodium methyl-2 -sulphohexadecanoate (C16MES) and sodium methyl 2 -sulphooctadecanoate (C18MES), and the high water solubility (>10 g/L) of C16MES, are favorable for absorption by the gastro-intestinal tract. For risk assessment purposes oral absorption of MIZULAN FL 80 is set at 100%.

 

Since the molecules are lipophilic (log P values>0) MIZULAN FL 80 is likely to distribute into cells and the intracellular concentration may be higher than extracellular concentration particularly in fatty tissues, and higher concentrations may occur in breast milk than in blood/plasma. However, with log P values less than 3, MIZULAN FL 80 is unlikely to accumulate. As amphipathic lipids with relatively high molecular weights (~400), the molecules may be excreted in the bile and may potentially undergo enterohepatic circulation.

 

Due to the low vapor pressure of the substances it is not to be expected that MIZULAN FL 80 will reach the nasopharyncheal region or subsequently the tracheobronchial or pulmonary region. On the other hand, the moderate log P values (between -1 and 4) of sodium methyl-2-sulphohexadecanoate (C16MES) and sodium methyl 2 -sulphooctadecanoate (C18MES) are favourable for absorption directly across the respiratory tract epithelium by passive diffusion. Overall, although it is unlikely that MIZULAN FL 80 will be available to a high extent after inhalation via the lungs due to low vapor pressure, for risk assessment purposes the inhalation absorption of MIZULAN FL 80 is set at 100%.

 

Dry particulates will have to dissolve into the surface moisture of the skin before uptake can begin. The log P values (between 1 and 4) and high water solubility (>10 g/L) of C16MES favor dermal absorption. However, the molecular weight of 372.5-400.55 indicates moderate or low dermal absorption. The criteria for reduced dermal absorption as given in the REACH guidance (MW>500, log Pow is smaller than -1 or higher than 4) are not met, therefore 100% dermal absorption of C16MES should be considered for risk assessment purposes. However, the potentially ionisable groups ofC16MESmight limit diffusion across biological membranes. In addition, the surface tension of 39mN/m is not favorable for dermal absorption. Furthermore, the lower oral LD50 compared to the dermal LD50 suggests a dermal absorption lower than oral absorption, in addition, the substance is neither skin irritating nor skin sensitizing. For risk assessment purposes the dermal absorption of MIZULAN FL 80 is set at 10%.