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

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 13, 1994 - July 28, 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.3 (Acute Toxicity (Dermal))

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal 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 catboard 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
- Housing: Individual caging in air-conditioned rooms. Grill cages 40.5x38.5x18h cm with stainless steel feeder.
- Diet (e.g. ad libitum): Ad libitum (GLP 4 RF21 top certificate pelleted diet).
- Water (e.g. ad libitum): Ad libitum (from the municipal water main system, filtered).
- Acclimation period: 5 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

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 6x5 cm of the body dorsal surface.
- % coverage: 10 %
- Type of wrap if used: the treated area was covered with a porous gauze dressing fixed to the skin with hypoallergenic non-irritation tape. The test side was further covered in a suitable manner in order to ensure that the animals could not ingest the test substance.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period the residual test substance was wiped off.
- Time after start of exposure: about 24 h.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000mg/kg bw. Individual dosages were based on body weight taken just before treatment.
- For solids, paste formed: No, the test article was administrated by uniform application onto the cleared area.

Duration of exposure:

About 24 hours.

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 on exposure day and then twice a day up to termination of the observation period.
Weighing: twice pre-trial (at randomization and on day 1 just before treatment), on days 8 and 15.
- Necropsy of survivors performed: Yes, animals (fasted overnight) were killed by excision of the femoral arteries, after i.p. overdosage anesthesia with 5 % sodium pentobarbital, at the end of the observation period.
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: clinical signs and behaviour, body weight and gross pathology.

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 study.

Clinical signs:

No clinical signs nor behavioural alterations were observed in any treated rat. Slight erythema was observed at the application site during the first days of the study in two male and one female rats.

Body weight:

Body weight gain of all treated animals was considered within normal limits.

Gross pathology:

No changes were observed in the animals killed at the end of the study.

Any other information on results incl. tables

Table 1. Clinical signs frequency (cumulative)

Clinical signs	No. of rats affected	Signs observed (time)
		From*	Toº
Treatment site: erythema	3	2d	3d
Recovery	3	3d	4d

*) First observation in one or more animals

º) Last observation in one or more animals

d) Days

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	270	273	271	268	255	237	229	220	233	214
1*	280	285	282	288	279	241	243	235	250	225
8	333	342	341	324	323	253	248	250	256	227
15	379	400	388	366	378	277	264	284	278	238

*pre-dosing.

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:

LD50 value of test article in rats by dermal route at 24 h exposure period is 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 dermal administration of the test article Fosfomycin PEA salt at the dosage of 2000 mg/kg bw (24 hours exposure) was performed in accordance with EU Method B.3 and OECD Guideline 402. The test article was administered by uniform application on the cleared area and covered for the exposure period of 24 hours. 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 8 and 15. They were clinically observed for 24 days after patch removal. 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 deaths occurred as a result of treatment.

No clinical signs or behaviour alterations were observed during the study.

Slight transient erythema was occasionally observed at the application site in some animals during the first day of the study.

The body weight gain appeared normal.

No changes were found at the gross pathology examination performed at the end of the observation period.

In conclusion, the test article Fosfomycin PEA salt, when administrated by dermal route to rat, under the conditions adopted in this experiment, did not cause mortality nor show systemic toxic effects at the limit dose of 2000 mg/kg bw. The LD50 by dermal route is higher than 2000 mg/kg bw.