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Toxicological information

Toxicity to reproduction

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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

Constituent 1
Chemical structure
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+ [(Si8Mg5.5Li0.3) O20(OH)4]0.7-
IUPAC Name:
Silicic acid, lithium magnesium sodium salt

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.