Retinyl palmitate

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented study which meets basic scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Retinyl acetate

EC Number:

204-844-2

EC Name:

Retinyl acetate

Cas Number:

127-47-9

IUPAC Name:

O~15~-acetylretinoic acid

Constituent 2

Reference substance name:

Vitamin-A-acetate

IUPAC Name:

Vitamin-A-acetate

Details on test material:

Vitamin A acetate (CAS No. 127-47-9) (dry powder), technical grade; purity was 535000 IU Vitamin A/g (ca. 180 mg/g or 18%)
composition:
gelatine, 31%
Vitamin A acetate, 20%
water, 3%
BHT, 1%
sodium aluminium silicate, max. 1%
dioctyl sodium sulfosuccinate, 0.04%
glucose sirup, ad 100%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: MUS Rattus, Brunnthal
- Age at study initiation: 42 days
- Weight at study initiation: 179  (150 - 205) g for males and 143 (114 - 172) g for females
- Acclimation period: 7 days (unsupplemented diet and water ad libitum)
- Fasting period before study: no
- Housing: Cage Typ D3, BECKER & CO ., Castrop-Rauxel, 3 or 2 animals per cage
- Diet: ad libitum: Ssniff-R-Mehl; SSNIFF Versuchstierdiäten GmbH, Soest
- Water ad libitum: tap water
The test article was mixed into the diet. The normal, unsupplemented diet already contained 8200 and 11400 IE Vitamin A/kg diet. 

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-2
- Humidity (%): 55 +/- 5
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: food

Details on oral exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): Experimental diets were prepared once weekly.

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

3 months

Frequency of treatment:

continuously in the diet

Doses / concentrations

Remarks:

Doses / Concentrations:
28, 112, 318 ppm in the diet; see freetext
Basis:

No. of animals per sex per dose:

20

Control animals:

yes, concurrent no treatment

Details on study design:

The experimental diets contained the basal level of Vitamin A plus the test substance at 15000 IE/kg feed (28 ppm),  60000 IE/kg feed (112 ppm), and 170000 IE/kg feed (318 ppm). Control rats  were fed the basal diet. One hundred and sixty rats were assigned to 4 groups of 20 male and 20  female rats each. Three groups of rats were fed the experimental diets supplemented with Vitamin A at 28, 112 and 318 ppm. The fourth group served as control; these animals were fed the basal diet, which already  contained Vitamin A at average levels of 8200 and 11400 IU.

Post-exposure period: none

Positive control:

not applicable

Examinations

Observations and examinations performed and frequency:

Food consumption was recorded daily. 
Body weights were determined weekly;  
Substance intake has been calculated from mean daily food intake and body weight change within one study week.
Animals were observed for clinical signs and mortality daily.
Clinical-chemical examinations were performed prior to dosing and two times during the course of the study:
total bilirubin
creatinine
urea
sodium
potassium
total protein
glucose
anorganic phosphate
calcium
chloride
triglyceride
cholesterol
albumin
globulines
lactate-dehydrogenase
glutamate-pyruvate-transaminase
alkaline phosphatase
glutamate-oxalacetate-transaminase

Hematological examinations were performed prior to dosing and two times during the course of the study:
erythrocytes
mean cell volume
thrombocytes
leukocytes
hematocrit
hemoglobin content of erythrocytes
mean corpuscular hemoglobin concentration
differential blood count

Urinalyses were made two times during the course of the study. 
pH
protein
glucose
ketones
bilirubin
blood
nitrite
urobilinogen
sediment
An ophthalmoscopic examination was made on half of  the animal of each group at the end of the study. 

Sacrifice and pathology:

After 3 months of  treatment, all surviving animals were sacrificed and evaluated grossly. Organs were removed, weighed and prepared for histological examination.  An X-ray examination of the cranium, the left front limb and the right hind limb was made on each animal.

Organ weights:
heart
liver
spleen
kidney
adrenal glands
testes/ovaries
brain

Histophathology:
heart, trachea, lung with bronchae, tongue, esophagus, fore/stomach, duodenum, colon, glandula submandibularis, liver, pancreas, spleen, thymus, sternum, kidney, urinary bladder, testes, epididymides, ovaries, prostata, uterus, pituitary gland, adrenal glands, thyroid gland, brain, eye, skeletal muscle, bone, all macroscopic lesions

Other examinations:

Liver samples have been taken from 10 males and 10 female animals per dose group for determination of vitamin A content.

Results and discussion

Results of examinations

Details on results:

Dose levels:
The uptake of the test substance varied during the course of the study. Generally, the average dose level decreased from the 1st to the 13th study week. Average weekly uptake of the test substance, males:
318-ppm group: 15.98 - 36.74 mg/kg bw/d
112 ppm group: 5.77 - 12.97 mg/kg bw/d
28-ppm group: 1.43 - 3.32 mg/kg bw/d
Average weekly uptake of the test substance, females:
318-ppm group: 18.55 - 35.79 mg/kg bw/d
112 ppm group: 6.40 - 12.57 mg/kg bw/d
28-ppm group: 1.62 - 3.07 mg/kg bw/d

Body weights:
Body weight and body weight gain was similar in all groups.
Food consumption:
Food consumption was similar in all groups.
Mortality:
No deaths occurred.
Clinical symptoms:
Clinical symptoms, if any, were unspecific in nature. The test substance  was well tolerated without any effects on behaviour.
Ophthalmoscopy.
Ophthalmoscopy revealed no substance-related changes.

Toxicologically relevant findings:
The following findings were considered to be statistically significant  and substance-related:
318 ppm group: - increased plasma triglyceride levels (both sexes) - slightly increased activity of glutamate pyruvate transaminase and glutamate oxalacetate transaminase in the plasma (males) - proteinuria (first urinalysis, one male) - increased absolute and relative liver weights (females) - brightened livers (both sexes) - lipid accumulation in Kupffer cells and decrease of   the intrahepatocellular lipid droplets in the peripheral  areas of the liver lobules (both sexes) - lipid accumulation in individual cells of the duodenal  lamina propria

112 ppm group: - slightly increased activity of glutamate pyruvate  transaminase and glutamate oxalacetate transaminase in  the plasma (males) - brightened livers (2/20 females) - lipid accumulation in the Kupffer cells of the liver  (both sexes)

28 ppm group: No substance-related changes were observed.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

28 ppm

Sex:

male/female

Basis for effect level:

other: corresponding  to 1.43-3.32 mg/kg bw/d (males) and  1.62-3.07 mg/kg bw/d (females).

2

Dose descriptor:

LOAEL

Effect level:

112 ppm

Sex:

male/female

Basis for effect level:

other: Hypervitaminosis A

Target system / organ toxicity

Critical effects observed:

not specified