Naltrexone

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Naltrexone

EC Number:

240-649-9

EC Name:

Naltrexone

Cas Number:

16590-41-3

Molecular formula:

C20H23NO4

IUPAC Name:

(1S,5R,13R,17S)-4-(cyclopropylmethyl)-10,17-dihydroxy-12-oxa-4-azapentacyclo[9.6.1.0^{1,13}.0^{5,17}.0^{7,18}]octadeca-7(18),8,10-trien-14-one

Sampling and analysis

Analytical monitoring:

yes

Remarks:

HPLC-UV

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna were aged of < 24 hours old.
The culture was originally obtained from Smithers Viscient, Shawbury, UK.

Study design

Test type:

static

Water media type:

other: Elendt M4 medium

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

After 24 and 48 hours, the Daphnia magna in each test vessel were observed for evidence of immobility. The observations differentiated between mobile and immobile daphnids. An individual was considered immobile if, when the contents of the test vessel were briefly agitated, it did not swim during a 15-second period of observation. In addition, Daphnia magna submerged in the body of the test media and those that were held at the surface of the test media were also recorded.

Test conditions

Hardness:

Not specified

Test temperature:

20.0-20.5 °C (test start)
20.7-20.8°C (test end)

pH:

7.59-8.64 (test start)
7.57-7.83 (test end)

Dissolved oxygen:

8.98-9.43 mg/L (test start)
9.02-9.15 mg/L (test end)

Nominal and measured concentrations:

Nominal: 4, 9, 20, 45 and 100 mg/L
Measured: 3.87, 8.92, 20.2, 47.0 and 100.5 mg/L (at 0 hour)

Details on test conditions:

Fluorescent lighting
Photoperiod: 16h light/8h dark

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

All analytical results were within 80-120% of nominal concentrations. Therefore, the results were based on nominal concentrations.
After 48 hours, the concentration at which no significant (=< 10%) dose related immobility occurred was 100 mg/L. The NOEC was therefore 100 mg/L.
The 48-h EC50 value was determined to be > 100 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The validity criteria for control immobility (=< 10%) and dissolved oxygen (>= 3 mg/L) were both satisfied. The test is therefore considered valid.
Based on nominal concentrations, the 48-h EC50 value was determined to be > 100 mg/L. The corresponding NOEC and LOEC were considered to be 100 mg/L and > 100 mg/L respectively.