Retinyl acetate

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Objective of study:

distribution

Principles of method if other than guideline:

The aim of the study was to determine the bioavailability of four stabilized products of Vitamin A acetate using the liver accumulation  test. 
Male and female Sprague-Dawley rats, depleted of vitamin A, were administered the different products in the diet for 7 and 14 days and the Vitamin A content in liver was determined.
and the vitamin A level of their livers was determined.

GLP compliance:

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

Molecular formula:

C22H32O2

IUPAC Name:

(2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-en-1-yl)nona-2,4,6,8-tetraen-1-yl acetate

Details on test material:

Four commercial samples of stabilised Vitamin A acetate (CAS No. 127-47-9):

- substance codes: 78/337 and C1
Vitamin A Acetate dry powder 500000 IE: Vitamin A acetate
(500000 IU/g, ca. 170 mg/g or 17%); matrix: gelatin,
glucose, corn starch
manufacturer: BASF AG

- substance codes: 78/338 and C2
Microvit A 750 Super: Vitamin A acetate; 750000 IU/g (ca.
260 mg/g or 26%); matrix: gelatin, dextrin, lactose,
glycerol
manufacturer: external supplier

- substance codes: 78/339 and C3
Vitamin A Acetate dry powder 650000 IE: Vitamin A acetate
(650000 IU/g, ca. 220 mg/g or 22%); matrix: gelatin,
glucose, corn starch
manufacturer: BASF AG

- substance codes: 78/340 and C4
Vitamin A Acetate 650000 IE: Vitamin A acetate (650000
IU/g, ca. 220 mg/g or 22%); matrix: gelatin, sugar,
modified starch
manufacturer: external supplier

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wiga, Sulzfeld
- Housing: individual housing in Typ D2/3 cages
- Diet : ad libitum
- Water: ad libitum

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: in feed

Details on exposure:

Male and female Sprague-Dawley rats depleted of vitamin A were 
administered the different products in the  diet for 7 and 14 days. 

Duration and frequency of treatment / exposure:

diet for 7 and 14 days

Doses / concentrations

Remarks:

Doses / Concentrations:
Approx. 1.7 - 2.6 ppm in the diet (5670 - 7640 IU/kg diet)

No. of animals per sex per dose / concentration:

Males: 80 Females: 80

Control animals:

no

Positive control reference chemical:

not applicable

Details on study design:

Pregnant rats were administered normal diet until day 15 of gestation.  Thereafter, the rats were offered vitamin-A-depleted diet until weanling 
 of their pups. The livers of 25 neonates were analysed for vitamin A  content. One hundred male and 100 female weanlings were fed  
vitamin-A-depleted diets until the onset of clinical signs of  vitamin-A-deficiency. Following parameters were determined:
- Body weight/ body weight gain
- Food consumption
- Mortality/ clinical signs of toxicity
- Vitamin A concentration in the liver

Thereafter, the rats were allocated to 8 groups of  10/sex and fed the different samples of vitamin A acetate as indicated in  the table (see freetext ). Groups 1-4 and 5-8 were treated for 7 and 14 days, respectively.  The following parameters were determined for each animal:
- body weight / body weight gain
- food consumption during exposure
- Mortality/ clinical signs of toxicity
- gross pathology
- organ weight of liver, heart, kidneys, spleen, testes
- skeletal assessment by X ray
- Vitamin A concentration in the liver

Statistics:

statistical evaluation (t-test and Duncan test); 
statistical  significance was set at p = 0.05 and p = 0.01.

Results and discussion

Toxicokinetic / pharmacokinetic studies

Transfer into organs

Transfer type:

other: accumulation in liver

Observation:

distinct transfer

Metabolite characterisation studies

Metabolites identified:

no

Any other information on results incl. tables

General results:
================
Body weight, body weight gain and food consumption was unaffected. During  the 

period of vitamin A depletion (feeding of a vitamin A deficient  diet), signs 

indicative of a hypovitaminosis (swollen eyelids and swollen  limbs) were 

observed. These symptoms were reversible within the first  days of vitamin A 

feeding. No animal died during the test period. Gross  pathology revealed no 

alterations of the internal organs and skeleton.

The ranking of Vitamin A resorption from the four products was as follows:
Microvit A 750 Super (external supplier), substance code C2 > Vitamin A  Acetate

 dry powder 500000 IE (BASF), substance code C1 = Vitamin A  Acetate dry powder 

650000 IE (BASF), substance code C3 >  Vitamin A  Acetate 650000 IE (external 

supplier), substance code C4.

Details of the statistical evaluation:
======================================

Comparison of 7-day and 14-day exposure:
----------------------------------------
The following changes were observed for the different vitamin A  compounds, 

regarding the vitamin A concentration per gram liver after 14  days compared to 

those after 7-day exposure:

substance code C1 (groups 1 and 5):
vitamin A content after 14 days less than 2-fold those after 7 days

substance code C2 (groups 2 and 6):
vitamin A content after 14 days approximately 2-fold those after 7 days

substance code C3 (groups 3 and 7):
vitamin A content after 14 days approximately 3-fold those after 7 days  in 

males and approximately 2-fold those after 7 days in females

substance code C4 (groups 4 and 8):
vitamin A content after 14 days approximately 3-fold those after 7 days

Tables 1-4:
-----------
FOOD CONSUMPTION, LIVER WEIGHT, AND BODY WEIGHT of males and females  after 7 

and 14 days of exposure. Values are given as mean +/- standard  deviation (SD),

 mean of n = 10.

Table 1: 7-day exposure, males
group  food cons.       liver wt.        body wt.
no.    [g]              [g]              [g]   
---------------------------------------------------------
  1    145.1+/-8.87     11.71+/-1.276    264.4+/-16.10
  2    151.1+/-9.32     11.57+/-1.181    268.1+/-18.48
  3    150.3+/-12.08    11.27+/-1.294    365.5+/-21.14
  4    146.4+/-13.06    11.15+/-1.568    364.8+/-20.80

Table 2: 7-day exposure, females
group  food cons.        liver wt.       body wt.
no.    [g]               [g]             [g]   
---------------------------------------------------------
  1    113.1+/-8.30      7.48+/-0.630    189.4+/-11.09
  2    115.7+/-9.32      7.47+/-0.517    190.8+/-12.79
  3    115.6+/-9.51      7.41+/-0.630    191.6+/-11.05
  4    116.3+/-10.38     7.39+/-0.628    191.8+/-9.75

Table 3: 14-day exposure, males
group  food cons.       liver wt.        body wt.
no.    [g]              [g]              [g]   
---------------------------------------------------------
  5    295.5+/-17.85    11.89+/-1.252    298.2+/-23.47
  6    303.5+/-23.49    12.57+/-1.633    302.8+/-21.85
  7    288.5+/-28.41    11.58+/-1.723    294.4+/-28.89
  8    298.6+/-13.04    12.25+/-1.130    298.4+/-18.31

Table 4: 14-day exposure, females
group  food cons.       liver wt.        body wt.
no.    [g]              [g]              [g]   
---------------------------------------------------------
  5    239.0+/-13.16    7.66+/-0.835     207.6+/-8.77
  6    240.3+/-19.70    7.81+/-0.943     206.3+/-16.01
  7    226.4+/-17.40    7.65+/-0.979     205.2+/-16.51
  8    227-2+/-11.63    7.96+/-0.805     205.4+/-9.17


Tables 5-8:
-----------
VITAMIN A CONCENTRATIONS in the livers of males and females, both after 7  and 

14 days of feeding.
The parameter "Vit. A [IE/g liver]" (3rd column) is defined as IE vitamin  

A per 1 gram of liver (remark: 1 IE = 0.344 ug vitamin A acetate).
The parameter "% Vit. A" (4th column) is defined as Vitamin A in liver  per 

Vitamin in food consumption * 100.
All values are given as mean +/- standard deviation (SD), mean of n = 10.

Table 5: 7-day exposure, males
group   subst.  Vit A              % Vit A
no.     code    [IE/g liver]
-------------------------------------------------------
  1      C1     37.8 +/- 12.84     53.4 +/- 17.91
  2      C2     50.6 +/- 6.88      54.3 +/- 5.25
  3      C3     28.1 +/- 10.53     28.0 +/- 8.63
  4      C4     24.0 +/- 8.78      26.1 +/- 10.39

Table 6: 7-day exposure, females
group   subst.  Vit A             % Vit A
no.     code    [IE/g liver]
-------------------------------------------------------
  1      C1     46.5 +/- 13.10     54.2 +/- 15.55
  2      C2     67.1 +/- 13.03     61.0 +/- 11.49
  3      C3     48.3 +/- 13.43     41.0 +/- 10.06
  4      C4     29.3 +/- 10.76     26.0 +/- 9.36

Table 7: 14-day exposure, males
group   subst.  Vit A              % Vit A
no.     code    [IE/g liver]
-------------------------------------------------------
  5      C1     56.6 +/- 12.03     42.1 +/- 10.09
  6      C2     106.8 +/- 9.48     62.0 +/- 5.38
  7      C3     83.7 +/- 15.43     45.8 +/- 9.18
  8      C4     69.4 +/- 8.33      40.5 +/- 4.99

Table 8: 14-day exposure, females
group   subst.  Vit A              % Vit A
no.     code    [IE/g liver]
-------------------------------------------------------
  5      C1     91.9 +/- 24.24     45.8 +/- 11.96
  6      C2     130.3 +/- 23.13    59.3 +/- 9.00
  7      C3     93.7 +/- 19.22     40.9 +/- 7.44
  8      C4     93.0 +/- 10.30     46.1 +/- 4.34