Lysine hydrochloride

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Augustus 2002 - December 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with OECD guideline 408 (1998) and Directive 87/302/EEC No L133 (1988)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Directive 87/302EEC No L133

Deviations:

yes

Remarks:

there were a number of minor deviations that were not considered to have affected the validity of the study

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Lysine hydrochloride

EC Number:

211-519-9

EC Name:

Lysine hydrochloride

Cas Number:

657-27-2

Molecular formula:

C6H14N2O2.ClH

IUPAC Name:

lysine hydrochloride

Details on test material:

- Name of test material (as cited in study report): Lys HCl crystals
- Physical state: white to pale yellow crystals
- Analytical purity: 99%
- Lot/batch No.: CP trial 13-14 November 2001
- Expiration date of the lot/batch: 1 November 2004
- Storage condition of test material: ambient temperature, under dry conditions

Test animals

Species:

rat

Strain:

other: Wistar Crl (WI) WU BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland (Sulzfeld, Germany)
- Age at study initiation: 6-7 weeks
- Weight at study initiation:138-195 and 106-151 g for males and females, respectively
- Fasting period before study: no
- Housing: 5 animals per cage in macrolon cages with sterilized wood shavings as bedding material
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30-70
- Air changes (per hr): ~10
- Photoperiod (hrs dark / hrs light): 12 hr/12 hr

IN-LIFE DATES: From: 28 August, 2002 To: 13 December, 2002

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: diet

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: not applicable

DIET PREPARATION
- Rate of preparation of diet (frequency): monthly
- Mixing appropriate amounts with (Type of food): powdered diet
- Storage temperature of food: in a freezer (≤ 18◦ C) until use

VEHICLE
- Justification for use and choice of vehicle (if other than water): not applicable
- Concentration in vehicle: not applicable
- Amount of vehicle (if gavage): not applicable
- Lot/batch no. (if required): not indicated (test compound)
- Purity: 99% (test compound)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

stability, homogeneity, and concentration

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

continuous, via dietary admixture

Doses / concentrations

Remarks:

Doses / Concentrations:
-Dose/concentration: 0, 0.5%, 1.5% and 5% in diet
Basis:
nominal in diet

No. of animals per sex per dose:

Treated animals: 10 males & 10 females; Control animals: 20 males & 20 females

Control animals:

yes

Details on study design:

- Dose selection rationale: results of a range-finding study
- Rationale for animal assignment (if not random): not applicable
- Rationale for selecting satellite groups: not applicable
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): not applicable

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily on working days, once daily on Saturdays and Sundays
- Cage side observations checked in table [No.?] were included. Not applicable

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly up to week 11-12

BODY WEIGHT: Yes
- Time schedule for examinations: before allocation to groups, on the first day of treatment, and weekly, thereafter until the end of the study, and on the day of necropsy

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

FOOD EFFICIENCY:
- gram weight gain per gram food: Yes

WATER CONSUMPTION : Yes
- Time schedule for examinations: week 1, 6 and 12

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to the start of treatment and towards the end of treatment (day 87)
- Dose groups that were examined: all animals prior to the start of treatment; control and high dose animals towards the end of treatment (day 87)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at necropsy
- Anesthetic used for blood collection: Yes (CO2/O2)
- Animals fasted: Yes
- How many animals: all animals
- Parameters checked in table [No.?] were examined. Standard parameters

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at necropsy
- Animals fasted: Yes
- How many animals: all animals
- Parameters checked in table [No.?] were examined. Standard parameters

URINALYSIS: Yes
- Time schedule for collection of urine: days 85 (males) and 87 (females)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked in table [No.?] were examined. Standard parameters

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: week 12-13
- Dose groups that were examined: all groups (10 animals/group and sex)
- Battery of functions tested: Functional Observational Battery (WHO/IPCS) + motor activity

OTHER: none

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Other examinations:

Organ weights were determined. Feces were collected in weeks 2, 7 and 13 of the study and shipped to the sponsor on dry-ice

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

Description (incidence and severity):

at compound intakes of 307, 914, 3002 mg/kg bw/day for males and 323, 968, 3173 mg/kg bw/day for females at low-, mid- and high dose, respectively

Food efficiency:

effects observed, treatment-related

Water consumption and compound intake (if drinking water study):

effects observed, treatment-related

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Description (incidence and severity):

(see overall remarks)

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY: No treatment-related clinical signs observed and no mortalities

BODY WEIGHT AND WEIGHT GAIN: Similar in both control and treated animals

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Similar in both control and treated animals. Average compound intake: 307, 914, 3002 mg/kg bw/day for males and 323, 968, 3173 mg/kg bw/day for females at low-, mid- and high dose, respectively

FOOD EFFICIENCY: Similar in both control and treated animals, but lower in high-dose females in the first study week

WATER CONSUMPTION: increased in all treated groups except low-dose females, which was not considered to be of toxicological significance

OPHTHALMOSCOPIC EXAMINATION: no treatment-related changes

HAEMATOLOGY: No relevant differences from controls

CLINICAL CHEMISTRY: No relevant differences from controls

URINALYSIS: No relevant differences from controls (see overall remarks)

NEUROBEHAVIOUR: no indications of neurotoxicity

ORGAN WEIGHTS: decreased spleen weights at high dose in males were considered to be related to treatment and toxicologically significant

GROSS PATHOLOGY: No treatment-related findings

HISTOPATHOLOGY: NON-NEOPLASTIC: No treatment-related findings

HISTOPATHOLOGY: NEOPLASTIC (if applicable) : not applicable

HISTORICAL CONTROL DATA (if applicable) : not applicable

OTHER FINDINGS: none

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

914 mg/kg bw/day (actual dose received)

Sex:

male

Basis for effect level:

other: organ weights

2

Dose descriptor:

NOAEL

Effect level:

968 mg/kg bw/day (actual dose received)

Sex:

female

Basis for effect level:

other: organ weights

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

none

Applicant's summary and conclusion

Conclusions:

The concentration of 1.5% in dietary admixture corresponding to a mean achieved dosage of 914 and 968 mg/kg bw/day for males and females, respectively, was considered a No-Observable-Adverse-Effect-Level (NOAEL) in this 90-day study in Wistar rats.

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