ETHYLHYDROXYETHYL CELLULOSE
EXPLANATION
This substance was considered at the twenty-seventh meeting of
the Committee (Annex 1, reference 62). At that time, the Committee,
after reviewing general data available on modified celluloses and some
specific studies on ethylhydroxyethyl cellulose, decided to include it
on a temporary basis, in the group ADI of 0-25 mg/kg b.w. for modified
celluloses, pending the results of a 90-day feeding study by 1985.
Because the study was known to be in progress, the Committee extended
the temporary ADI for ethylhydroxyethyl cellulose to 1986 (Annex 1,
reference 70).
BIOLOGICAL DATA
Biochemical aspects
No information available.
Toxicological studies
Acute toxicity
No information available.
Short-term studies
Rats
Ethylhydroxyethyl cellulose was administered to Charles River CD
rats (20 males and 20 females/group) by continuous dietary
incorporation at dose levels of 0, 250, 1375, or 2500 mg/kg b.w./day
for 90 consecutive days. All the animals were observed daily and all
signs of toxicity or behavioural changes were recorded. Body weights
and food consumption were recorded weekly. Ophthalmoscopy and
haematology analyses were carried out prior to termination. After 90
days of treatment the animals were killed and macroscopic examination
was carried out on all tissues from animals in the control and
high-dose groups. A statistically-significant (P < 0.01) increase in
cumulative food consumption was recorded in male rats of the high-dose
group throughout the study (weeks 1, 4, 8, and 12) and in female rats
of the high-dose group (P < 0.05) at weeks 4, 8, and 12. The
increased food consumption was considered to represent a compensation
for the dietary inclusion of the test substance. A corresponding
marginal decrease in the efficiency of food utilization was noted in
rats of this treatment group throughout the study. After adjustment
for final body weight, a small decrease in liver weight (P < 0.05)
was apparent in male rats of the high-dose group in comparison with
control values. No morphological changes in the livers of these rats
were apparent on histological examination. In all other respects,
including general health, body weight, ophthalmoscopy, haematology,
biochemistry, and macroscopic and microscopic pathology, rats
receiving ethylhydroxyethyl cellulose were similar to the controls
(Elliot et al., 1985).
Long-term studies
No information available.
Observations in man
No information available.
Comments
The 90-day study provided sufficient information on the apparent
lack of toxicity of ethylhydroxyethyl cellulose when fed at high
dietary levels to permit the Committee to include it in the group ADI
with modified celluloses.
EVALUATION
Estimate of acceptable daily intake for man
0-25 mg/kg b.w. (group ADI for modified celluloses)
REFERENCE
Elliot, P.H., Smith, P.A., Street, A.E., Gibson, W.A., Begg, S.E.,
Otter, J.M., & Shillam, K.W.G. (1985). The effects of continuous
dietary administration of ethylhydroxyethyl cellulose to rats for
ninety days. Unpublished report from Huntingdon Research Centre,
Huntingdon, England. Submitted to WHO by Huntingdon Research
Centre.