6-methyl-1,2,3-oxathiazin-4(3H)-one 2,2-dioxide, potassium salt

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically reliable study with sufficient information for evaluation and assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

application GD 6 - 15

GLP compliance:

no

Remarks:

Study performed prior to implementation of GLP

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

6-methyl-1,2,3-oxathiazine-4(3-H)-one-2,2-dioxide potassium salt

IUPAC Name:

6-methyl-1,2,3-oxathiazine-4(3-H)-one-2,2-dioxide potassium salt

Constituent 2

Reference substance name:

6-methyl-1,2,3-oxathiazin-4(3H)-one 2,2-dioxide, potassium salt

EC Number:

259-715-3

EC Name:

6-methyl-1,2,3-oxathiazin-4(3H)-one 2,2-dioxide, potassium salt

Cas Number:

55589-62-3

Molecular formula:

C4H5NO4S.K

IUPAC Name:

potassium 6-methyl-2,2,4-trioxo-3,4-dihydro-1,2λ⁶,3-oxathiazin-3-ide

Constituent 3

Reference substance name:

Acesulfame potassium

IUPAC Name:

Acesulfame potassium

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Hoe 0-95 K
- Substance type: sweetener
- Physical state: crystalline powder
- Analytical purity: 99.8%
- Lot/batch No.: VP 528 G 511
- Stability under test conditions: stable

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands
- Age at study initiation: adult
- Weight at study initiation: mean: 165 - 167 g
- Fasting period before study: no
- Housing: individually in wire-bottom cages
- Diet: ad libitum (standard laboratory stock diet)
- Water: ad libitum (tap water)
- Acclimation period: at least 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): controlled
- Humidity (%): controlled
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES:
From: no data
To: no data

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: diet

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): no data
- Mixing appropriate amounts with (Type of food): institutute' stock diet
- Storage temperature of food: room temperature

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

Not applicable

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:4
- Length of cohabitation: overnight, until positive vaginal smears
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: sperm in vaginal smear referred to as day 0
- Any other deviations from standard protocol: no

Duration of treatment / exposure:

Gestation days 6 - 15

Frequency of treatment:

Daily

Duration of test:

From maing until necropsy on gestation day 20.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 other: %

Doses / concentrations 2

Dose / conc.:

0.3 other: %

Doses / concentrations 3

Dose / conc.:

1 other: %

Doses / concentrations 4

Dose / conc.:

3 other: %

No. of animals per sex per dose:

20

Control animals:

yes, plain diet

other: Positive control: Vitamin A palmitate (75000 IU/day)

Details on study design:

- Dose selection rationale: At request of sponsor based on low subchronic toxicity

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: days 0, 6, 16, 21

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No
- Time schedule for examinations:

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: complete necropsy
- organ weights: ovaries

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:
- pre-/post implantation loss

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: third per litter
- Skeletal examinations: Yes: two third per litter
- Head examinations: No data

Statistics:

Student's t-test: mean maternal body weights, mean food consumption, mean litter data
Chi-square test: skeletal and visceral anomalies

Indices:

Pre-/post-implantation loss,

Historical control data:

Yes

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not specified

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

effects observed, non-treatment-related

Description (incidence and severity):

A decreased in the number of live foetuse/litter in the low (0.3%) dose group only which was attributed to an increased number of embryonal resoptions in two dams. However, this low number of live foetuses/litter is within the normal range of control findings. it did not occurr in the high dose group.

Total litter losses by resorption:

effects observed, non-treatment-related

Description (incidence and severity):

An increased number of embryonal resoptions in two dams in the low dose group within the normal range in controls. However, this low number of live foetuses/litter was within the normal range of control findings. It did not occurr in the high dose group.

Early or late resorptions:

not specified

Dead fetuses:

no effects observed

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
Not applicable

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

> 30 000 ppm (nominal)

Based on:

test mat.

Basis for effect level:

other: lack of maternal toxicity

Maternal abnormalities

Abnormalities:

no effects observed

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

The foetal weight increased with increasing feeding level and slightly higher but not significantly highter than the controls.

Reduction in number of live offspring:

not specified

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Not applicable

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

3 other: %

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Any other information on results incl. tables

Summary of data:

 

Parameter/Concentration % (diet)	0	0.3	1.0	3.0	Vit. A 75000 IU/rat/day
Number of females mated	20	20	20	20	11
Number of females pregnant	18	16	17	13	8
Number of females with live fetuses	18	16	17	13	5
Number of live fetuses	185	141	170	131	31
Mean number of live fetuses/ litter	10	8.8**	10	10	5...
Pre-implantation loss %	6.1	11.2	8.0	8.9	6.5
Post-implantation loss %	2.0	10.6*	7.8	3.3	64.0***
Mean ovary weight/dam (g)	0.07	0.07	0.07	0.07	0.06*
Mean empty uterus weight/dam (g)	4.03	3.63*	3.78	3.66	1.97***
Mean number of corpora lutea/dam	11.2	11.2	11.4	11.5	10.4
Mean number of implantation sites/dam	10.5	9.9	10.6	10.5	9.6
Mean number of embryonic resorption/dam	0.17	0.81*	0.35	0.38	2.4**
Mean number of fetal resorption/dam	0.06	0.19	0.24	0	3.3**
Mean number of dead fetuses/dam	0	0.06	0	0	0.1
Mean fetal weight/dam (g)	5.07	5.26	5.32**	5.42**	4.52*
Number of litters with externally visible malformed fetuses	3	0	0	1	5
Number of fetuses with externally visible malformations	3	0	0	1	19
Number of fetuses with visceral anomalies	9	-	-	8	21
Number of fetuses with skeletal anomalies	22	-	-	16	10
- = not examined, * p<0.05, ** 0.01 >p>0.001; *** p<0.001

 

Applicant's summary and conclusion

Conclusions:

Acesulfame potassium was administered to pregnant Wistar rats orally via the diet at 0, 0.3%, 1.0% and 3.0 % from implantation at gestation day (GD) 6 through GD 15 (counting from day 0 of pregnancy).

All dose levels were tolerated without maternal or developmental toxicity and especially without morphological alterations in the fetuses.

The no observed adverse effects level (NOAEL) for maternal toxicity as well as for developmental toxicity including teratogenicity was 3.0% in the diet (30000 ppm corresponding to about 1500 mg/kg bw/day) and was thus clearly above the current limit dose of 1000 mg/kg bw/day.

Executive summary:

The prenatal developmental toxicity of Acesulfame potassium was investigated in pregnant female Wistar rats. Each 20 pregnant females received dietary dose levels of 0, 0.3%, 1.0% and 3.0% from implantation at gestation day (GD) 6 through GD 15 (counting from day 0 of pregnancy). A positive control group received 75000 IU Vitamin A palmitate/day dissolved in soybean oil.

 

This study is assessed as appropriate and valid since it was performed similar to internationally accepted testing guideline and reporting, assessment and data presentation in the study report was considered as appropriate.

 

Signs of maternal toxicity did not occur and food consumption and body weight/body weight gain was not adversely affected. Increased food consumption was noted but this can not be considered as adverse effects.

The oral administration of the test substance to the dams at all 3 dose levels had no influence on the gestational parameters.

 

Signs of prenatal developmental toxicity including morphological alterations were not observed at any concentration. The mean fetal weights were slightly increased but this can not be considered as adverse effect.

 

The positive control group showed a wide range of known abnormalities and demonstrated the sensitivity of the test system.

 

Conclusion:

Acesulfame potassium administered to pregnant Wistar rats orally via the diet at 0, 0.3%, 1.0% and 3.0 % from implantation at gestation day (GD) 6 through GD 15 (counting from day 0 of pregnancy) did not lead to any maternal or developmental toxicity and especially to no morphological alterations in the fetuses.

 

The no observed adverse effects level (NOAEL) for maternal toxicity as well as for developmental toxicity including teratogenicity was 3.0% in the diet (30000 ppm corresponding to about 1500 mg/kg bw/day) and was thus clearly above the current limit dose of 1000 mg/kg bw/day.