Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Non-validated methods used

Data source

Reference
Reference Type:
publication
Title:
Studies on the biological value of inorganic phosphates
Author:
Gillis MB, Norris LC & Heuser GF
Year:
1954
Bibliographic source:
J. Nutr., Jan 1954; 52: 115 - 125

Materials and methods

Objective of study:
other: testing the availability of different phosphates from feed for chicks
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
chicks were feed with one of two defined diets. Diet one contains only a basal concentration of 0.04 % (400 ppm) phosphorus which support life in young chicks for only a few days. Diet 2 contained a basal phosphorus concentration of about 0.35 % (3500 ppm) which was enough to keep chicks alive for at least 4 weeks. Both diets were supplemented by different purified orthophosphates, pyrophosphates, bone meals as well as deflourinated phosphates, raw rock phosphates and metaphosphates to give relative phosphorus concentrations of 0.25, 0.3 and 0.35 % (2500, 3000, 3500 ppm). The diets were feed to 1 day old male White Leghorn chicks for 4 weeks. Subsequently animals were sacrifices and the left tibiae excised, incinerated and the ash weighted as a parameter for bone calcification.
GLP compliance:
no

Test material

Test material form:
solid
Radiolabelling:
no

Test animals

Species:
other: chicken
Strain:
other: White Leghorn
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Housing: animals were individually housed in wire floored electrically heated battery brooders
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
no data
Duration and frequency of treatment / exposure:
continuous (via feed) for 4 weeks
Doses / concentrations
Remarks:
Doses / Concentrations:
equivalent of 0.25, 0.30 and 0.35 % (2500, 300, 3500 ppm) phosphorus in feed
No. of animals per sex per dose / concentration:
>= 10 per dose and substance
Control animals:
not specified
Positive control reference chemical:
no data
Details on study design:
no data
Details on dosing and sampling:
no data
Statistics:
no data

Results and discussion

Preliminary studies:
no

Toxicokinetic / pharmacokinetic studies

Details on absorption:
see table 1 for results of the bone calcification as a parameter for phosphate absorption
Details on distribution in tissues:
no data
Details on excretion:
no data

Metabolite characterisation studies

Details on metabolites:
no data

Any other information on results incl. tables

Table 1: Comparative biological values of inorganic phosphates

Reagent grade orthophosphates

Beta-tricalcium phosphate

100

Dicalcium phosphate

98

Monocalcium phosphate

113

Potassium acid phosphate

109

Sodium acid phosphate

101

Bone products

Steamed bone meal

 

  Sample A

100

  Sample B

100

  Sample C

100

  Sample D

95

  Sample E

94

  Sample F

90

  Sample G

70

Foreign bone meal

87

Spent bone char

84

Bone ash

89

Pyrophosphates

Alpha Ca pyrophosphate

0

Beta Ca pyrophosphate

0

Gamm Ca pyrophosphate

0

Vitreous ca pyrophosphate

20

Na pyrophosphate, decahydrate

57, partly toxic

Feed grade dicalciumphosphates

Sample A

97

Sample B

97

Sample C

96

Sample D

89

Defluorinated phosphates

Calcined

94

Fused

82

Precipitated

99

Raw Rock Phosphates

Curacao Is. Phosphate

87

Fla. Land pebble rock

50

Tennese brown rock

25

Colloidal phosphate

25

Acid pyrophosphates

Calcium acid pyrophosphate A

67

Calcium acid pyrophosphate B

50

Metaphosphates

Beta Ca metaphosphate

0

Gamma Ca metaphosphate

0

Vitreous Ca metaphosphate

45

Sodium metaphosphate

28

Potassium metaphosphate

0

in italics: values were determined with diet 2 as with diet 1 the bioavailability of phosphates was to low leading to a drastic mortality

- based in these results the following conclusions were drawn by the authors:

- The pure orthophosphates had a high bioavalability.

- Feed grade materials with bioavailability of phosphate were dicalcium phosphate, defluorinated phosphate and steamed bone meal. The bioavailability of phosphate from spent bone char, bone ash and inported bone meal was lower but sufficient.

- The bioavailability of phosphate from pyrophosphates and metaphosphates was low to zero

- Of the rock products only Curacao Island phosphate had a satisfactory bioavailability.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): no data
The bioavaiability of phosphate from different phosphates was tested in a bioassay where young male Leghorn White chicks were fed for 28 diet a defined diet that was low in phosphate with a defined supplement of the respective phosphate. The ash of the tibiae was weighted as parameter for bone calcification and hence the bioavailability of phosphate.
- The pure orthophosphates had a high bioavalability.
- Feed grade materials with bioavailability of phosphate were dicalcium phosphate, defluorinated phosphate and steamed bone meal. The bioavailability of phosphate from spent bone char, bone ash and inported bone meal was lower but sufficient.
- The bioavailability of phosphate from pyrophosphates and metaphosphates was low to zero
- Of the rock products only Curacao Island phosphate had a satisfactory bioavailability.
Executive summary:

In the present study (Gillis 1954) the bioavaiability of phosphate from different phosphates was tested in a bioassay where young male Leghorn White chicks were fed for 28 diet a defined diet that was low in phosphate with a defined suppment of the respective phosphate. The ash of the tibiae was weighted as parameter for bone calcification and hence the bioavailability of phosphate.

- The pure orthophosphates had a high bioavalability.

- Feed grade materials with bioavailability of phosphate were dicalcium phosphate, defluorinated phosphate and steamed bone meal. The bioavailability of phosphate from spent bone char, bone ash and inported bone meal was lower but sufficient.

- The bioavailability of phosphate from pyrophosphates and metaphosphates was low to zero

- Of the rock products only Curacao Island phosphate had a satisfactory bioavailability.