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Description of key information

Acute toxicity: oral. Key study: Test method according to EU Method B.1 and OECD Guideline 401. GLP study. The oral LD50 of the test article in Sprague-Dawley rats was > 2000 mg/kg bw.

Acute toxicity: dermal. Key study: Test method according to EU Method B.3 and OECD Guideline 402. GLP study. The LD50 value of test article in Sprague-Dawley rats by dermal route at 24 h exposure period is > 2000 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
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
Qualifier:
according to guideline
Guideline:
EU Method B.1 (Acute Toxicity (Oral))
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
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)
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.
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.

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

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.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
discriminating dose
Value:
2 000 mg/kg bw
Quality of whole database:
The study is GLP compliant and has a Klimisch score 1.

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Link to relevant study records
Reference
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
Qualifier:
according to guideline
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
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.)

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.
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.

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

 

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.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
discriminating dose
Value:
2 000 mg/kg bw
Quality of whole database:
The study is a GLP compliant and has a Klimisch score 1.

Additional information

Acute toxicity: oral. Key study: Test method according to EU Method B.1 and OECD Guideline 401. GLP study. The oral LD50 of the test article in Sprague-Dawley rats was > 2000 mg/kg bw.

Acute toxicity: dermal. Key study: Test method according to EU Method B.3 and OECD Guideline 402. GLP study. The LD50 value of test article in Sprague-Dawley rats by dermal route at 24 h exposure period is > 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint

Only one study available.

Justification for selection of acute toxicity – dermal endpoint

Only one study available.

Justification for classification or non-classification

Based on the available data oral and dermal acute toxicity, the substance is not classified for acute toxicity.