Sulfonic acids, C16-alkane hydroxy and C16-alkene, sodium salts

Endpoint summary

Description of key information

Absorption, Distribution, Metabolism, Excretion:

 

The metabolic fate of 14C-AOS (a mixture of 14C-sodium alkenyl(2) sulfonate and 14C-sodium 3-hydroxy alkane sulfonate) has been studied in rats by a single oral and intravenous injection of 100 mg (50 μCi)/kg and 10 mg (5 μCi)/kg, respectively.

 

Oral absorption:

Absorption via the gastrointestinal tract after oral application was found to equal 80% of the radioactivity administered (Inoue et al., 1982).

 

After oral administration, 14C-AOS was rapidly absorbed from the gastrointestinal tract. The blood level of 14C-activity reached its peak 3 hours after dosing and then declined. Twenty-four hours after the dose, about 0.8%/g of the 14C-AOS given was detected in cecum content, but in other tissues the figures were under 0.02% dose/g. Within 24 hours after the dose, 72% of the dose was excreted in the urine and 22% in the feces, while the excretion in the bile was 4.3% within 12 hours. The administered radioactivity was rapidly eliminated from the whole body within 24 hours (Inoue et al., 1982).

 

Metabolites were accounting for most of the radioactivity found in liver, kidney, urine and bile. In blood the activity of intact Alpha Olefin Sulfonate was one third of that of the metabolites, in the gastrointestinal tract metabolites accounted for one third of the activity. The metabolites were more polar than intact Alpha Olefin Sulfonate and included hydroxylated, carboxylated and sulfonated forms.

 

Dermal absorption:

 

Percutaneous absorption of α-olefin sulfonate (AOS) through intact skin was found to be very low (below 1% based on experimental data).

 

After application of 14C-AOS to the intact skin 60 - 70% of total radioactivity was recovered by skin washes, 0.62% of the applied dose was absorbed, and 0.298% of the applied dose was detected in urine (Minegishi et al., 1977).

 

Radioactivity could be detected in bile and urine within 1 hour after application to intact skin, but in very low amounts. Among the organs liver and kidney showed the highest amounts of radioactivity (0.123% and 0.059% of applied dose, respectively) 24 hours after application. Total recovery from urine, bile and main organs was about 0.62% of the applied dose after 24 hours (Minegishi et al., 1977).

 

 

Distribution

 

After oral and dermal application most of the radioactivity was found in liver (bile) and kidneys (urine).

 

Metabolism /Excretion

Metabolites were accounting for most of the radioactivity found in liver, kidney, urine and bile. In blood the activity of intact Alpha Olefin Sulfonate was one third of that of the metabolites, in the gastrointestinal tract metabolites accounted for one third of the activity. The metabolites were more polar than intact Alpha Olefin Sulfonate and included hydroxylated, carboxylated and sulfonated forms.

 

No intact 14C-AOS was detected in any of the urine samples after oral and intravenous doses. The metabolite was apparently more polar than intact 14C-AOS, and results from data of electrophoresis and equilibrium dialysis indicated that in fact 14C-AOS can bind with proteins, while the metabolites cannot. The metabolite was found to contain alcoholic, unsaturated and sulfonic acid functionalities. It is suggested that the metabolite may be a hydroxylated or polyhydroxylated sulfonic acid of shorter chain length than AOS. These results suggest that 14C-AOS is rapidly absorbed, metabolized and excreted, therefore, no accumulation of 14C-AOS is expected (Minegishi et al., 1977).

Inoue, S. et al. 1982: Metabolism of alpha-olefin sulfonate (AOS) in rats. Fundamental and applied toxicology 2(3): 130-138

Minegishi, K. et al. 1977: Percutaneous absorption of α-olefin sulfonate (AOS) in rats. Chem Pharm Bull 25(4): 821-825

 

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

80

Absorption rate - dermal (%):

1