Silicic acid, lithium magnesium sodium salt

Toxicity to reproduction

Administrative data

Endpoint:

reproductive toxicity, other

Remarks:

summary of existing tox results on substance

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1973-4

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Work carried out by recognised toxicology laboratory by qualified laboratory personnel using calibrated equipment and recognised methods of test. But the work was done in 1974 and not to GLP standards at that time

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1974

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

100 rats, 50 of each gender divided into four groups, were orally dosed by intubation with a dispersion concentration of 10ml/kg of the test material in deionised water over a period of 100 consecutive days. The rats were grouped by weight and dosed according to a recorded schedule. Group 1 was the control group and had just distilled water administered. Group 2 had a low dose (5mg/kg), group 3 had a medium dose (50mg/kg) and group 4 had a high dose (500mg/kg). The rats were observed daily for signs of toxicity and mortality. All rats were weighed on day 1 and weekly thereafter and at sacrifice. Blood analysis was carried out after 6 weeks and at the end of the test period. All organs were examined after sacrifice

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, lithium magnesium sodium salt

EC Number:

258-476-2

EC Name:

Silicic acid, lithium magnesium sodium salt

Cas Number:

53320-86-8

Molecular formula:

Na0.7[Li0.3Mg5.5Si8O20(OH)4]

IUPAC Name:

magnesium(2+) lithium(1+) sodium bis(oxosilanebis(olate))

Test animals

Species:

rat

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

The rats were 28 days old when received for the start of the testing.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

not specified

Results and discussion

Results: P0 (first parental generation)

Effect levels (P0)

Dose descriptor:

dose level:

Effect level:

>= 50 - <= 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

Remarks on result:

not determinable due to absence of adverse toxic effects

Target system / organ toxicity (P0)

Critical effects observed:

yes

Lowest effective dose / conc.:

500 mg/kg bw/day (actual dose received)

System:

gastrointestinal tract

Organ:

oesophagus

stomach

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

no

Results: F1 generation

Effect levels (F1)

Remarks on result:

other: see Remarks

Remarks:

test was a 90-day repeated dose study, no data on F1

Applicant's summary and conclusion

Conclusions:

No effects were observed in the 90 day study to indicate effects on gonads. Furthermore, Laponite exhibited no toxicity in acute testing (oral, dermal, inhalation), mutagenicity and cytogenicity (See submitted studies) or any other toxicological relevant pathway. In addition Laponite is currently being explored as a potential drug delivery mechanism for angiogenesis (Page DJ, Clarkin CE, Mani R, Khan NA, Dawson JI, Evans ND. (2019) Injectable nanoclay gels for angiogenesis. Acta Biomater. 2019 Dec;100:378-387. doi: 10.1016/j.actbio.2019.09.023. Epub 2019 Sep 19), in implantable medical devices (Hsu, Wei-Hsin, Lee, Ya-Lun, Prasannan, A., Hu, Chien-Chieh, Wang, Jun-Sheng, et al., Biodegradable polymer-nanoclay composites as intestinal sleeve implants installed in digestive tract for obesity and type 2 diabetes treatment. 2020/05/01 Materials Science and Engineering: C 10.1016/j.msec.2020.110676). Laponite is a synthetic clay based on hectorite a naturally occurring clay mineral. There have been no epidemiological or toxicologically relevant studies on hectorite that found potential risk from hectorite exposure. Laponite is a synthetic clay with the same functional chemical composition as hectorite. Any nanoform exposures from laponite would be comparable to background exposure from the nanoform compartment of hectorite (Kahn , 1957).

Executive summary:

No effects were observed in the 90 day study to indicate effects on gonads.  Furthermore, Laponite exhibited no toxicity in acute testing (oral, dermal, inhalation), mutagenicity and cytogenicity (See submitted studies) or any other toxicological relevant pathway.