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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
5/19/1988 to 7/25/1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: meets generally accepted scientific standards, well-documented, and acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 452 (Chronic Toxicity Studies)
GLP compliance:
no
Remarks:
The final report was reviewed by the Quality Assurance unit of Coulston International Inc and accurately reflects the raw data generated during the conduct of the study.
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test article was identified in this study as follows:
[14C]-AMP (molecular weight = 91.1 g/mol; specific activity = 25 mCi/mmol)


[14C]-AMP was provided by The Dow Chemical Company prepared in three formulations, identified in this study as follows:

1. AMP (Batch No. TA074801Z1) – Contains 94.85 mg AMP/g and 0.27 mg 14C-AMP/g, for a total calculated value of 95.12 mg AMP/g (Paste)

2. 40% aqueous solution (w/v, pH 9.5) prepared from AMP - Contains 0.26 mg 14C-AMP/g (Liquid)

3. Control Lotion B with pure AMP (Lot BP200500759.06) – Contains 40 mg AMP/g and 0.26 mg 14C-AMP/g, for a total calculated value of 40.26 mg AMP/g (equivalent to the level of AMP in cosmetic lotions)


Pure AMP, 40% aqueous, and Neat Control Lotion B formulations were evaluated for radiochemical concentration, which was determined to be, respectively, 79.3, 86.2, or 87.6% in a first shipment of formulations, and 80.3, 88.9, or 92.4% in a second shipment of formulations.
Specific details on test material used for the study:
Hydrochloride salt of AMP - AMP-HCl (~AMP 47.1%)

Test animals

Species:
dog
Strain:
Beagle
Sex:
male/female
Details on test animals and environmental conditions:
Twenty nine male and 29 female beagle dogs were received from Laboratory Research Enterprises, Kalamazoo, MI, and 25 of the healthiest of each sex were used for study. The animals were selected based on criteria of the US FDA (1982). The dogs were 4 months of age at arrival to the testing laboratory. Animals were identified by an assigned identification number on a collar, housed singly for an acclimation period, and were examined by a laboratory veterinarian for general health status. Animals were stratified by body weight, and assigned randomly to their treatment groups.

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other: test material was dissolved in ethanol and then mixed into the feed
Details on oral exposure:
Animals were dosed via the diet, which was tested by the supplier (Purina) for contaminants. The test article was incorporated into the diet on a weight/weight basis using a premix. Fresh food was prepared with the test article weekly. The animals were offered 400g of the diets daily. Any uneaten food was weighed and recorded.
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
1 year
Frequency of treatment:
continuous
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 1.1, 11, 110 ppm
Basis:
nominal in diet
(approximately 0.029/0.031, 0.31/0.31, and 2.6/3.0 mg/kg-bw/day AMP in females/males)
Remarks:
Doses / Concentrations:
0, 0.031, 0.31, 2.8 mg/kg bw/day AMP
Basis:
nominal in diet
No. of animals per sex per dose:
6/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
Animals were dosed via the diet, which was tested by the supplier (Purina) for contaminants. The test article was incorporated into the diet on a weight/weight basis using a premix. Fresh food was prepared with the test article weekly. The animals were offered 400g of the diets daily. Any uneaten food was weighed and recorded. Drinking water was provided throughout the study ad libitum. Six males and six females were assigned to each of 4 dose groups (0, 1.1, 11, 110 ppm).
Daily observations were made of the general appearance, behavior, the presence of any signs of toxicity or pharmacologic effects and mortality. Body weights were recorded prior to dosing, and weekly thereafter. The fasting terminal body weight was also recorded. While weighing, the animals were examined for lesions or other signs of toxicity. Each animal had an ophthalmoscopic examination once pre-study, weeks 1, month 3,6,9,12 by a veterinarian.
Blood samples were obtained pre-study, and at 3, 6, 9, 12 months via venipuncture of fasted animals. The following parameters were recorded: hematocrit, hemoglobin, erythrocyte count, leukocyte count, platelet count, prothrombin time, MCH, MCHC, and MCV, Calcium, Phosphorous, Chloride, Sodium, Potassium, glucose, serum alkaline phosphatase, serum aspartate aminotransferase, serum analine aminotransferase, gamma glutamyl, transpeptidase, blood urea nitrogen, total protein, albumin, globulin, creatinine, bilirubin, and serum protein. Urine was examined for pH, specific gravity, volume and appearance, protein, glucose, acetone bodies, creatinine, and microscopic sediment.
Post-mortem examinations included a complete gross examination of the external surfaces, all orifices, the cranial cavity, the external surface of the brain, the thoracic, pelvic, and abdominal cavities and their viscera, cervical tissues and organs, and the carcass. Two animals per sex per dose were sacrificed at 6 months, with the remainder at 12 months. Organ weights were recorded for the liver, kidneys, testes, thyroids, adrenals, and brain. Tissues that were removed and preserved are the same as current OECD guidelines
Positive control:
no

Examinations

Observations and examinations performed and frequency:
Daily observations were made of the general appearance, behavior, the presence of any signs of toxicity or pharmacologic effects and mortality. Body weights were recorded prior to dosing, and weekly thereafter. The fasting terminal body weight was also recorded. While weighing, the animals were examined for lesions or other signs of toxicity. Each animal had an ophthalmoscopic examination once pre-study, weeks 1, month 3,6,9,12 by a veterinarian.
Sacrifice and pathology:
Blood samples were obtained pre-study, and at 3, 6, 9, 12 months via venipuncture of fasted animals. The following parameters were recorded: hematocrit, hemoglobin, erythrocyte count, leukocyte count, platelet count, prothrombin time, MCH, MCHC, and MCV, Calcium, Phosphorous, Chloride, Sodium, Potassium, glucose, serum alkaline phosphatase, serum aspartate aminotransferase, serum analine aminotransferase, gamma glutamyl, transpeptidase, blood urea nitrogen, total protein, albumin, globulin, creatinine, bilirubin, and serum protein. Urine was examined for pH, specific gravity, volume and appearance, protein, glucose, acetone bodies, creatinine, and microscopic sediment.
Post-mortem examinations included a complete gross examination of the external surfaces, all orifices, the cranial cavity, the external surface of the brain, the thoracic, pelvic, and abdominal cavities and their viscera, cervical tissues and organs, and the carcass. Two animals per sex per dose were sacrificed at 6 months, with the remainder at 12 months. Organ weights were recorded for the liver, kidneys, testes, thyroids, adrenals, and brain. Tissues that were removed and preserved are the same as current OECD guidelines
Statistics:
yes

Results and discussion

Results of examinations

Clinical signs:
no effects observed
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:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
Test material intake is estimated based on week 36 body weights and food consumption.

Males
estimated (mg/kg/day)
Control 0
1.1ppm .031
11ppm 0.31
110ppm 2.98


Females

estimated (mg/kg/day)
Control 0
1.1ppm .029
11ppm 0.31
110ppm 2.55

There were no general in-life observations made for any treated or control animal. Likewise, there were no ophthalmoscopic observations noted for any animal. Neither an ANOVA or a Kruskal-Wallis non-parametric ANOVA revealed any statistical significance in food consumption patterns for any dose level in either sex. There was no statistically significant differences in body weights for any of the animals throughout the study. Clinical chemistry findings for males revealed a slight decrease in the low and mid-dose groups' albumin-globulin ratio. Since there was no dose-response (the high dose group was not different than the control), it was judged to be a spurious finding and not treatment-related. High-dose males at 9 and 12 months showed differences in serum albumin via serum electrophoresis, but was not corroborated by actual clinical chemistry measurements, and was not considered by the authors to be biologically-significant. Throughout the study, findings for females included differences in serum sodium, serum ALT, and serum AST, but were transient, did not appear dose-related, and were judged by the authors to be not related to the administration of AMP. There was no effect of AMP administration on hematology, and likewise the urinalysis revealed no treatment-related effects. There were no effects on organ weights or organ/body weight ratios that were attributed to test material administration by the authors.
At necropsy, evaluation of the tissues revealed several isolated observations, none of which were attributed to the administration of the test material. There were no neoplastic observations in any of the dogs sacrificed at either 6 months or one year of administration in their diets.

Effect levels

Dose descriptor:
NOAEL
Effect level:
> 110 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Dose equivalent to 2.8 mg/kg bw/day based on average male and femal test material consumption

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Based on the findings under these study conditions, there is no effect at any dose level on general appearance, behavior, body weight, food consumption, ophthalmoscopic exams, clinical chemistry, hematology, organ weights, or tissue histopathology. Based on the absence of statistically and biologically significant findings in dose-response patterns, the No-Observed Effect Level for AMP HCl in the diets of Beagle dogs in greater than 110 ppm (>2.8 mg/kg bw AMP).