[No public or meaningful name is available]

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Effects of Nano Calcium Carbonate and Nano Calcium Citrate on Toxicity in ICR Mice and on Bone Mineral Density in an Ovariectomised Mice Model

Author:

Huang S, Ching Chen J, Wei Hsu C and Chang WH

Bibliographic source:

Nanotechnology 20:375102 (7pp)

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study examined whether the bioavailability of calcium carbonate and calcium citrate could be improved by reducing the particle size. Because nanoscale supplements are novel formulas in health foods, the acute toxicity, sub-chronic toxicity (see separate IUCLID entry) and bioavailability (see separate IUCLID entry) needs to be determined in both sexes of mice in advance.
Standard acute toxicological evaluations of the ICR mice were performed in the initial assessment of the effects of nanoscale calcium carbonate internalisation. Micro calcium carbonate and nano calcium carbonate were administered in a single dose by gavage using a gastric intubation tube. The animals were then observed for a period of 7 days.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Calcium carbonate

EC Number:

207-439-9

EC Name:

Calcium carbonate

Cas Number:

471-34-1

Molecular formula:

CH2O3.Ca

IUPAC Name:

calcium carbonate

Test material form:

solid: nanoform, no surface treatment

Details on test material:

Calcium carbonate was nanoscaled with the aid of a pulsed air-flow pulveriser.
The morphology of nano calcium carbonate was characterised by:

1). Dynamic laser-light scattering (DLS): The diameters of the micro and nano calcium carbonate particles were 3773 ± 759 nm and 151 ± 19 nm, respectively.

2). Field emission scanning electron microscopy (FE-SEM): The images revealed the smooth surface morphology of nano calcium carbonate. The diameter of the particles ranged from 100 to 200 nm and were spherical in shape. Aggregates were also seen in the images.

3). Transmission electron microscopy (TEM): The particles have a spherical-to-oval morphology with a diameter of 100 to 200 nm.

The measurements made using DLS, FE-SEM and TEM were comparable.

Specific details on test material used for the study:

Uncoated nano calcium carbonate

Test animals

Species:

mouse

Strain:

ICR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: National Taiwan University Hospital, Taipei, Taiwan
- Age at study initiation: 8-10 weeks
- Fasting period before study: Animals were fasted overnight
- Diet: Pelleted mouse feed available ad libitum
- Water: Reverse osmosis water available ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-25 °C
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12 h/12 h day/night cycle


Sham surgery (n = 6, SHAM) or bilateral ovariectomy (n = 30, OVX) was performed from a dorsal approach at 6 to 8 week old mice. Surgical removal of the ovaries is a well-represented approach to mimic the postmenopausal condition in mice. In the sham operation, ovaries were exteriorised and then replaced.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

The test materials were administered in a single dose by gavage using a gastric intubation tube.

Doses:

Vitamin D3 (261 U/ kg bw) plus micro calcium carbonate: 1.3 g/kg bw
Vitamin D3 (261 U/ kg bw) plus nano calcium carbonate: 1.3 g/kg bw

No. of animals per sex per dose:

8 animals/sex/dose

Control animals:

yes

Details on study design:

On day seven, all the animals were weighed and any signs of toxicity were noted.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

other: NOAEL

Effect level:

1 300 mg/kg bw

Mortality:

No mortality was observed.

Clinical signs:

other: Throughout the study, no unusual behaviour or differences between groups were observed (i.e. no laboured breathing, difficulty moving, hunching or unusual interactions with cage mates were observed).

Any other information on results incl. tables

Table 1: Body weight and mortality during the 7-day acute toxicity test

Dose	Sex (n)	Initial body weight (g)	Final body weight (g)	Mortality dead/treated
Control	Male (8) Female (8)	33.2 ± 3.3 32.5 ± 3.7	35.3 ± 3.9 34.2 ± 3.8	0/8 0/8
Micro calcium carbonate (1.3 g/kg bw)	Male (8) Female (8)	33.4 ± 3.2 32.7 ± 3.4	34.9 ± 3.2 34.3 ± 3.6	0/8 0/8
Nano calcium carbonate (1.3 g/kg bw)	Male (8) Female (8)	32.5 ± 3.6 33.1 ± 2.9	33.7 ± 4.1 34.9 ±3.8	0/8 0/8

Data are mean ± SE values

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No mortality or unusual behaviour were observed during the course of the study. The NOAEL for both micro calcium carbonate and nano calcium carbonate were reported to be 1.3 g/kg bw.