(R)-α-phenylethylammonium (-)-(1R, 2S)-(1,2-epoxypropyl)phosphonate monohydrate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 23, 1994 - July 29, 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(R)-α-phenylethylammonium (-)-(1R, 2S)-(1,2-epoxypropyl)phosphonate monohydrate

EC Number:

418-570-8

EC Name:

(R)-α-phenylethylammonium (-)-(1R, 2S)-(1,2-epoxypropyl)phosphonate monohydrate

Cas Number:

25383-07-7

Molecular formula:

C11H20NO5P

IUPAC Name:

(R)-α-phenylethylammonium (-)-(1R, 2S)-(1,2-epoxypropyl)phosphonate monohydrate

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Fosfomycin PEA salt
- Physical state: white crystalline powder
- Lot/batch No.: 4177
- Expiration date of the lot/batch: at least 3 years from the manufacturing date
- Stability under test conditions: at least 3 years
- Storage condition of test material: plastic bag in a cartboard box, at room temperature protected from the light.
- Other: manufacturing date: June 10, 1994

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Italia S.p.A.
- Age at study initiation: 7/9 weeks
- Weight at study initiation: Males: 225-250 g. Females: 200-225 g
- Fasting period before study: 16 hours
- Housing: 5 animals/sex/cage in T11C air-conditioned room in grill cages 40.5x38.5x18h cm with stainless feeder.
- Diet (e.g. ad libitum): Ad libitum (GLP 4RF21 top certificate pellet diet)
- Water (e.g. ad libitum): Ad libitum (from the municipal water main system, filtered).
- Acclimation period: Five days before the start of the test

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2 ºC
- Humidity (%): 55 ± 10 %
- Air changes (per hr): 20 per hour (filtered on HEPA 99.97 %)
- Photoperiod (hrs dark / hrs light): 12 h dark/12 h light (7 a.m - 7 p.m)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Methocel (methylcellulosae aqueous solution)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 100 mg/ml

MAXIMUM DOSE VOLUME APPLIED: 20 ml/kg

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Clinical signs and mortality: at 30 minutes, 2, 4 and 6 hours on the first day after the administration (day 1) and then twice a day up to termination of the observation period.
Weighing: twice pre-trial (at randomization and on day 1 just before administration) and on days 3, 8 and 14.
- Necropsy of survivors performed: Yes. All surviving animals (fasted overnight) were killed by excision of the femoral arteries, after i.p. overdosage anesthesia with 5% sodium pentobarbital.
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: Clinical signs and behaviour, body weight and gross pathology examinations.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No animals died during the observation period.

Clinical signs:

Signs involving the CNS (hypoactivity, muscular tremors, palpebral closure and hypothermia), the respiratory apparatus (shallow breathing) and piloerection, hunched posture and salivation were clinically observed in the treated rats starting from 30 minutes - 4 hours and lasting up to 6-24 hours after the test article administration. Sporadic cases of ataxia, reddish nasal discharge and chromodacryorrhea were also observed in some animals during the first days of the study. Recovery of all treated rats was achieved within 24 (females) - 48 hours (males) of treatment.

Body weight:

Low body weight gain was observed in some animals only at the day 3 weighing. Body weight gain returned to normal at the subsequent weighings.

Gross pathology:

No appreciable macroscopic findings were evident in any treated rat.

Any other information on results incl. tables

Table 1. Clinical signs frequency (cumulative)

Clinical signs	No. of rats affected	Signs observed (time)
		From*	To**
Hypoactivity	10	30 m	6 h
Ataxia	2	2 h	6 h
Reddish nasal discharge	2	2 d	-
Shallow breathing	3	2 h	2 d
Piloerection	10	30 m	2 d
Hunched posture	10	30 m	2 d
Muscular tremors	6	30 m	6 h
Salivation	6	30 m	6 h
Chromodacryorrhea	1	2 d	-
Palpebral closure	4	4 h	6 h
Hypothermia	3	2 h	2 d
Recovery	10	2 d	3 d

* first observation in one or more animals; ** last observation in one or more animals.

(day of treatment = day 1)

 

Table 2. Body weight (g). Dose: 2000 mg/kg.

Day	1 M	2 M	3 M	4 M	5 M	6F	7F	8F	9F	10F
Pre-trial	269	260	269	274	267	242	228	224	228	236
1*	247	235	248	250	238	220	209	209	210	214
3	258	251	269	260	249	226	209	214	215	224
8	298	287	305	285	301	248	229	236	261	248
14	362	344	352	353	344	263	252	253	281	270

 

Table 3. Gross pathology examination.

Dose (mg/kg)	Animals	Macroscopic findings
2000	Males No. 1-5	No appreciable macroscopic findings
	Females No. 6-10	No appreciable macroscopic findings

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

EU criteria.

Conclusions:

The oral LD50 of the test article in rats was higher than 2000 mg/kg bw.

Executive summary:

A toxicity study in Sprague Dawley Crl:CD (SD) rats (5 males and 5 females) with a single oral administration of the test article Fosfomycin PEA salt at the dosage of 2000 mg/kg bw (limit dose) was performed in accordance with EU Method B.1 and OECD Guideline 401. The test article was administered as a suspension in 0.4% methylcelllulosae aqueous solution at the constant volume of 20 ml/kg. All rats were treated after a 16 hour fasting period. The day of treatment was considered day 1 of the study. The animals were weighed twice before treatment (at randomization and on day 1 just before treatment) and on days 3, 8 and 14. They were clinically observed for 14 days following the treatment. On day 15 all treated rats were killed by excision of the femoral arteries, after i.p. overdosage anesthesia with 5% sodium pentobarbital and they were submitted to a thorough autopsy.

No animals died during the observation period.

The main clinical signs observed were: hypoactivity, muscular tremors, palpebral closure and hypothermia), the respiratory apparatus (shallow breathing) and piloerection, hunched posture starting from 30 minutes - 4 hours and lasting up to 6-24 hours after the test article administration. Sporadic cases of ataxia, reddish nasal discharge and chromodacryorrhea were also observed in some animals during the first days of the study. Recovery of all treated rats was achieved within 24 (females) - 48 hours (males) of treatment.

Low body weight gain was observed in some animals only at the day 3 weighing. Body weight gain returned to normal at the subsequent weighings. No appreciable macroscopic findings were evident in any treated rat.

In conclusion, the oral LD50 of the test article in rats was higher than 2000 mg/kg bw and transient clinical signs involving the CNS and the respiratory apparatus were the main findings.