3'H-Cycloprop[15,16]androsta-6,15-dien-17-one, 15,16-dihydro-3,5-dihydroxy-, (3.beta.,5.beta.,15.alpha.,16.alpha.)-

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

Study period:

Jan - Jul 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

EC guideline 92/69/EEC

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

82543-15-5

Test material form:

solid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples for concentration analysis were taken at 0 and 48 h.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The nominal loading of the unfiltered suspension was 100 mg/L which is the highest concentration to be tested according to the guideline. The test concentrations were a saturated solution and 4 dilutions thereof, selected according to a limit and range-finding test where 75% immobilization were found in the saturated solution and no immobilization in 1:100 dilution. For the stock solution 100 mg ZK 38700 were suspended in 1000 mL tap water. Thereafter, the suspension was kept for 1 hours in an ultrasonic bath and stirred for 24 hours. Thereafter, the suspension was filtered through a glassfibre filter. This solution was used as the highest test concentration. Aliquots of the solution were further diluted 1 :2, 1 :4, 1:8 and 1 :16 with tap water in order to prepare the appropriate test concentrations.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation (mean and range, SD): 0-24 h
- Source: Schering AG, Exp. Toxicology, Berlin, Germany
- Feeding during test: no

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test conditions

Test temperature:

19.6 - 21.1 °C

pH:

7.0 - 8.7

Dissolved oxygen:

8.1 - 9.2 mg/L

Nominal and measured concentrations:

measured: 4.4, 8.4, 16.6, 33.5, 66.3 mg/L

Details on test conditions:

TEST SYSTEM
- Material, size, headspace, fill volume: 100 mL test vessels
- Volume of solution: 45 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 12 h light/12 h darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Mobility after 24 and 48 h

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

48.9 mg/L

95% CI:

>= 38.2 - <= 59.5

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Reported statistics and error estimates:

The EC50 for the compound was calculated by the computer program "LogW 1.5, IPDR,
Schering AG, Berlin, Germany.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48 h) of Endiol to Daphnia magna was calculated to be 48.9 mg/L [95% confidence limits 38.2-59.5 mg/L] on the basis of measured concentrations.

Executive summary:

The purpose of the study was to determine the acute toxicity (immobilization, EC/48 hours) of Endiol (ZK 38700) with Daphnia magna in order to evaluate the aquatic toxicity. Endiol is an intermediate of the synthesis of drospirenone. The study was conducted as a definitive test according to the following guidelines of the OECD, no 202 and the EC guideline 92/69/EEC.

20 juvenile Daphnia magna were used for each test solution of Endiol and 20 for the tap water control. The Daphnia were exposed for a period of 48 hours under static conditions. Immobilization was recorded at 24 hours and 48 hours. Samples for the concentration analysis by HPLC in combination with UV detection were taken at 0 and 48 hours after start of exposure. The analytical result gave a mean concentration of 66.3 mg/L (saturated solution).

Immobilized Daphnia were observed at test concentrations of 33.5 and 66.3 mg/L. The EC50/48 hours of Endiol to Daphnia magna was calculated to be 48.9 mg/L (measured). The highest concentration with no effects on mobility was 16.6 mg/L.