Reaction mass of bis(N-decyl-N,N-dimethyldecan-1-aminium) carbonate and N-decyl-N,N-dimethyldecan-1-aminium hydrogen carbonate

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

- Reliability: GLP study according to international guidelines - Read-across justification: As both source (Didecyldimethylammonium chloride, DDAC) and target chemicals (Didecyldimethylammonium carbonate, DDA carbonate) have identical organic cations with hydrophobic side chains - the only difference is the inorganic anion carbonate or chloride with negligible contribution to the hazard properties- both substances can be predicted to have similar movement and fate characteristics.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1989

Materials and methods

Objective of study:

absorption

distribution

excretion

metabolism

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 85-1 (Metabolism and Pharmacokinetics)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

liquid: viscous

Details on test material:

- Name of test material: Didecyldimethylammonium chloride (DDAC)

Radiolabelling:

yes

Remarks:

14-C

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks
- Weight at study initiation: 236-262 g
- Fasting period before study: Approx. 18 hours prior to administration
- Housing: Metal cages/glass metabolism cages
- Individual metabolism cages: Yes
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: Approx. two weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 70 +/- 5
- Photoperiod (hrs dark / hrs light): 12 hour cycle

Administration / exposure

Route of administration:

other: oral: gavage and feed

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS
- Vehicle:
Distilled water
Rodent diet (Experiment 2)

- Concentration in vehicle:
Experiment 1: 0.5 mg/mL
Experiment 2: 34 ppm in diet followed by single dose of 0.5 mg/mL
Experiment 3: 5.0 mg/mL
Experiment 4: 5.0 mg/mL
- Amount of vehicle (if gavage): 10 mL of dosing solution per kg of body weight

HOMOGENEITY AND STABILITY OF TEST MATERIAL:
The non-radiolabelled a.s., DDAC, is hydrolytically and photolytically stable under the conditions of this study and has been shown to be stable in aqueous, alcohol and alcohol/aqueous solutions for extended periods, e.g. at least seven years under standard laboratory conditions

Duration and frequency of treatment / exposure:

Experiment 1: Single dose
Experiment 2: 14 day in diet followed by single dose
Experiment 3: Single dose
Experiment 4: Single dose

Doses / concentrations

Remarks:

Doses / Concentrations:
Experiment 1: 5 mg/kg bw
Experiment 2: 34 ppm in diet followed by single 5 mg/kg bw dose
Experiment 3: 50 mg/kg bw
Experiment 4: 50 mg/kg bw

No. of animals per sex per dose / concentration:

- Experiment 1: 10 (5/sex)
- Experiment 2: 10 (5/sex)
- Experiment 3: 10 (5/sex)
- Experiment 4: 10 (5/sex)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection:
Experiment 1: Oral gavage – single low dose
Experiment 2: Dietary – repeated low oral dose followed by oral gavage - single low dose
Experiment 3: Oral gavage – single high dose
- Post exposure period: 7 days after single doses or 14 days for dietary exposure
Experiment 4: Oral gavage – single high dose (metabolism phase)

Details on dosing and sampling:

SAMPLE COLLECTION (Experiment 1 - 3)
- Urine, Feces and Cage Washings: Urine, feces and urine/feces separator washing samples were collected at the following time intervals: 0-4, 4-8, 8-12, 12-24, 24-36, 36-48, 48-72, 72-96, 96-120, 120-144 and 144-168 hours. The urine was freeze-trapped to avoid oxidation, evaporation and bacterial degradation. Feces were collected at the same time intervals as the urine and was frozen upon collection. All urine, wash and fecal samples were stored at -15 °C until analysis. Upon collection, the urine, cage wash and fecal sample weights were determined and recorded. At the end of the study, the cages were rinsed with water and the weight of water was determined.
- Tissues and Organs: Seven days after dosing, the animals were anesthetized and euthanized by exsanguination following heart puncture. An aliquot of the blood was taken and centrifuged to separate the plasma. The following tissues and organs were harvested: gastrointestinal tract (stomach, small intestine, large intestine); gastrointestinal tract contents; bone; brain; fat; gonads (testes, seminal vesicles, prostate, ovaries, uterus); heart; kidneys; adrenal glands; thyroid glands; liver; lungs; blood; muscle; spleen; pancreas; any tissues which displayed pathology and residual carcass. Each tissue was individually weighed and stored at -15 °C until subjected to radioassay.

METABOLISM PHASE (Experiment 4)
The results of the definitive study showed that the majority of orally administered radioactivity (89-99 %) was excreted in the feces and only a small amount (2.5 %) was excreted in the urine. Therefore, the metabolism phase of this study was confined to the identification and quantification of fecal 14C residues.
The metabolism phase of this study was undertaken in two steps. First, additional male rats were orally dosed with 14C-DDAC at the high dosage level used in the definitive study, i.e., 50 mg/kg b.w. Feces were collected from these animals in order to obtain sufficient mass of 14C residues.
Following extraction and clean-up procedures, the metabolic profile of these 14C residues was determined using preparative thin layer chromatography, high pressure liquid chromatography and mass spectroscopy. The second step involved the determination of the metabolic profile of the 14C residues in fecal samples from the animals in the definitive study.

ANALYSIS
- Method of analysis: Radioactivity counting, TLC, HPLC and MS
- From how many animals: Samples were analysed per animal

Results and discussion

Preliminary studies:

PRELIMINARY EXPERIMENT
Four rats (2 males and 2 females) were fasted for 18 hours before the oral administration of 5 mg/kg 14C DDAC. The average amounts of radioactivity administered to the males and females were 18.2 µCi and 12.7 µCi, respectively. Immediately after dosing, the animals were transferred to individual glass metabolism cages (Roth cage). The cages were assembled to enable the separate collection of urine, feces and C02. Expired C02 was collected in 2:1 ethanolamine/cellusolve at intervals of 2, 4, 6, 8, and 24 hours. Five ml aliquots of the ethanolamine/cellusolve mixture were counted directly in
Carbon 14 liquid scintillation cocktail (Harvey Instrument, Hillsdale, NJ). Four hours after dosing the animals were fed ad libitum for the remainder of the test.
Urine and feces were collected at the same time intervals as the ethanolamine/cellusolve in order to reduce the chance of any volitization of 14C from these materials. The urine was freeze trapped as it was collected for the same reason. Following their collection, the urine and feces were discarded.

RESULTS
The average body weight for the males and females were 193.5 g and 137.0 g, respectively. The average amount of DDAC and radioactivity administered to the male rats were 4.8 mg/kg bw and 18.2 µCi, respectively. The corresponding figures for females are 4.7 mg/kg bw and 12.7 µCi.
The males expired an average of 0.045 % of dosed radioactivity as volatiles which were trapped in the ethanolamine/cellusolve mixture and designated as 14C02. The females expired on average of 0.053 % of dosed radioactivity. The results clearly indicate that an insignificant amount of 14C02 is expired. There is no difference in the expiration of 14C02 between males and females. Since no significant amount of volatiles were found, the rest of the studies were performed in hanging metal cages.

Main ADME results

Main ADME results 1

Type:

absorption

Results:

Low absorption after oral administration

Main ADME results 2

Type:

distribution

Results:

Residual 14C in tissues was negligible

Main ADME results 3

Type:

excretion

Results:

Majority excreted in the feces, less in the urine

Main ADME results 4

Type:

metabolism

Results:

Limited metabolism, different in males and females (dose dependent in females)

Toxicokinetic / pharmacokinetic studies

Details on absorption:

- Experiment 1: All rats dosed at the low dose of 5 mg/kg DDAC survived the experiment and no signs of toxicity were observed.
- Experiment 2: Rats were fed rat meal containing 34 ppm non-radiolabeled DDAC ad libitum for 14 days followed by oral administration of 5 mg/kg 14C radio labeled DDAC. All rats survived the experiment and showed no signs of toxicity.
- Experiment 3: All male rats dosed at the high dose of 50 mg/kg bw DDAC appeared normal and showed no sign of toxicity. Three of five female rats dosed at 50 mg/kg bw DDAC passed soft fecal material during the first collection interval.

Details on distribution in tissues:

- Experiment 1: Total residue in tissue and carcass ranged between 0.003 % and 0.135 % of dosed radioactivity for all rats studied
- Experiment 2: Total residue in tissue and carcass, which ranged between 0.004 % and 0.061 % of dosed radioactivity for all rats studied
- Experiment 3: Total residue in tissue and carcass, which ranged between 0.074 % and 0.675 % of dosed radioactivity for all rats studied

Details on excretion:

- Experiment 1:
Males: 1.65 % urine; 89.11 % faeces
Female: 1.42 % urine; 92.13 % faeces
Total Recovery: 90.82 +/- 7.30 % - males; 93.56 +/- 6.96 % females
- Experiment 2:
Males: 1.19 % urine; 93.88 % faeces
Female: 1.74 % urine; 90.11 % faeces
Total Recovery: 95.09 +/- 1.92 % - males; 91.88 +/- 4.98 % females
- Experiment 3:
Males: 1.17 % urine; 99.46 % faeces
Female: 2.36 % urine; 91.93 % faeces
Total Recovery: 100.94 +/- 2.68 % - males; 94.47 +/- 4.62 % females

Metabolite characterisation studies

Metabolites identified:

yes

Details on metabolites:

- Experiment 4: The results of the metabolism phase of this study indicates that there is a sex difference in the metabolism of DDAC in all dosing regimens. The metabolism of DDAC in female rats was more extensive than that of the male rats. In addition, a dose dependent metabolism was observed in the female rat, i.e., more parent was metabolized in the single low oral dose than in the single high oral dose. Approximately 90 - 100 % of the recovered radioactivity was found in the faeces. The metabolic process was found to involve oxidation of the two decyl side chains to form to a variety of oxidative products. The evidence seems to favor initial hydroxylation of the carbon next to the terminal carbon. This metabolite then proceeds to a ketone hydroxylated in the terminal carbon to form a hydroxy ketone.
Many attempts to develop two-dimensional TLC systems for the separation and/or quantitation of metabolites gave no improvement over the TLC/HPLC systems used in this study.
Four major metabolites have been identified. All four metabolites were more polar and can be presumed to be less toxic than parent compound. Oxidative modification on the decyl side chains is the dominant pathway. No modification on the methyl substituents was evidenced.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results
The majority of orally administered Didecyldimethylammonium Chloride is excreted via the faeces and appears to be metabolised in the gut of rats, apparently by microflora. Metabolism in females was greater than in males and lower doses were more extensively metabolised than higher doses in females. No tissue accumulation of the test substance was observed. Repeated dosing did not alter the uptake, distribution or metabolism of Didecyldimethylammonium Chloride.

Executive summary:

A study was carried out according to EPA OPP 85-1 (Metabolism and Pharmacokinetics) using the structural analog Didecyldimethylammonium chloride (DDAC). In view of the chemical and structural similarities (the relevant chemical part of both, DDAC and DDACarbonate, under the conditions of this test is the common quaternary ammonium cation Didecyldimethylammonium+), it is considered that the data are adequate for DDACarbonate. A total of 10 Sprague Dawley rats (5 male and 5 female per experiment) were dosed with radiolabelled test substance. The study was conducted in three phases: Experiment 1 – single low dose (5 mg/kg bw); Experiment 2 – 14-day repeated dietary exposure followed by single high dose (50 mg/kg bw); Experiment 3 - single high dose (50 mg/kg bw). Following the single doses urine and faeces were collected for 7 days. A preliminary study had indicated that no 14CO2 was generated. Tissues, urine and faeces were collected and analyzed for radioactivity and faeces were analyzed by TLC, HPLC and MS for metabolites and parent compound.

In all of the experiments approximately 89 – 99 % of the recovered radioactivity was found in the feces and less than 2.5 % in the urine. Tissue residues of 14C were less than 1 % of the administered dose in all groups. No significant differences were noted in any of the A, D or E patterns between males and females in rats dosed orally with 14C DDAC. The majority of orally administered Didecyldimethylammonium chloride appears to be metabolized in the gut of rats, apparently by microflora. Metabolism in females was greater than in males and lower doses were more extensively metabolized than higher doses in females. The metabolic profile showed that the only metabolism which occurred involved oxidation of the two decyl side chains to form hydroxy and hydroxyketo derivatives. Mass spectral data confirmed that both methyl substituents remained unmodified. While the exact position of the hydroxyl and/or keto functions on the decyl side chains could not be elucidated, the data strongly suggest that they are located at or near the terminal end. No tissue accumulation of the test substance was observed. Repeated dosing did not alter the uptake, distribution or metabolism of Didecyldimethylammonium chloride.