Pregna-1,4-diene-3,20-dione, 6-fluoro-11-hydroxy-16-methyl-21-[(1-oxopentyl)oxy]-, (6.alpha.,11.beta.,16.alpha.)-

Endpoint summary

Description of key information

The acute oral toxicity (LD50, rat) of fluocortolone-21-valerate is 245 mg/kg bw based on an acute rat study with the read-across substance fluocortolone (Günzel and Richter, 1965).

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:

1965

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not applicable

Remarks:

pre-guideline study

Principles of method if other than guideline:

- Principle of test: The test item was once orally applied to male and female Wistar rats in doses of 45 mg/kg, 125 mg/kg, 180 mg/kg, 250 mg/kg, 360 mg/kg, 500 mg/kg, 720 mg/kg, and 2000 mg/kg. The animals were observed for further 8 days. At the end of the observation period the animals were sacrificed if no premature death occurred and the exterior and interior appearance was recorded regardless wheter the animals died before the end of the observaqtion period or not.

GLP compliance:

no

Remarks:

study conducted prior to implementation of the respective OECD test guideline

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Tierzüchter Wulf (not further specified)
- Weight at study initiation: 80-110 g
- Fasting period before study: 16- 18 hours
- Housing: conventional (1 animal per cage) in macrolon cages
- Diet (ad libitum): Altromin R, ad libitum
- Water (ad libitum): tap water, ad libitum
- Acclimation period: 4-5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23
- Humidity (%): 55-65
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

other: gummi arabicum ad aqua dest.

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 620mg, 2.5g and 10g in 100 mL
- Amount of vehicle (if gavage): dependent on concentration, for 45 mg/kg : 0.72 mL/100g bw; for 125 mg/kg: 0.5 mL/100 g bw; for 180 mg/kg: 0.72 mL/100 g bw; for 250 mg/kg: 1.0 mL/100g bw; for 360 mg/kg: 1.4 mL/100 g bw; for 500 mg/kg: 2.0 mL/100 g bw; for 720 mg/kg: 2.8 mL/100 g bw; for 2.0 g/kg: 2.0 mL/100 g bw.


DOSAGE PREPARATION (if unusual): suspension

Doses:

45, 125, 180, 250, 360, 500, 720 and 2000 mg/kg bw

No. of animals per sex per dose:

5/sex/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 8 days
- kind of observations: clinical signs, mortality
- Necropsy of survivors performed: yes

- Other examinations performed: clinical signs, gross pathology

Statistics:

The LD50 was determined by the method of Litchfied and Wilcoxon.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

245 mg/kg bw

Based on:

test mat.

95% CL:

>= 173 - <= 347

Mortality:

Animals of the dose level of 125 mg/kg bw and above died between 2 and 8 days after application (details see table 1).

Clinical signs:

other: After single oral administration animals developed apathy from 125 mg/kg upwards.

Gross pathology:

At autopsy, hydrops ascites and fibrinous peritonitis, changes in the gastrointestinal tract such as ulcers, erosions and thickening of the gastric mucous membrane were observed. Also haemorrhagic mesenteric lymph nodes, necrobiosis of the liver, abscesses and subacute pneumonia in the lungs were noted. Adhesions of organs contained in the abdominal cavity were found.

Table 1: Number of dead animals per dose group after single oral application of fluocortolone (ZK 10445) to rats (males and females combined):

 

Dose [mg/kg]	No of dead animals/ No of treated animals
50	0/10
125	3/10
180	5/10
250	7/10
360	7/10
500	8/10
720	8/10
2000	9/10

 

 

Calculation of LD50 (Litchfield and Wilcoxon)
Dose (mg/kg)	T/E	%W	%E	D	Chi²	t
45	0/10	0	3	2.0	0.013	-----
125	3/10	30	23	7.0	0.025	5-7d
180	5/10	50	37	13.0	0.072	3-7d
250	7/10	70	51	19.0	0.140	4-8d
360	7/10	70	67	3.0	0.004	4-8d
500	8/10	80	79	1.0	-----	3-7d
720	8/10	80	88	8.0	0.060	4-7d
2000	10/10	100	99.1	0.6	0.004	2-5d

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute oral toxicity (LD50) of fluocortolone in male and female rats was determined to be 245 mg/kg.
From 125 mg / kg onwards sporadically, and in higher doses more accumulated, partly considerable apathy observed. The death occurred between 2 and 8 days after application. In those animals that prematurely died or were killed at 125 mg / kg miliary gray-white foci found in the liver at autopsy.
In higher doses severe gastrointestinal alterations (ulcers, bleeding, hyperemia, bloody infiltration of the mesenterial lymph nodes) and liver dystrophies) (color and consistency changes, multiple gray-white foci) were observed. As consequences hydrops ascites and fibrinous peritonitis was observed. The pathological anatomical findings primarily point to the damaging effects of the substance in the gastrointestinal tract and suggest that secondary diseases and autointoxications are a major contributor to the cause of death. This considerably limits the informative value of the LD50 p.o. as indicator for the actual lethal effect of the substance. However, based on the calculation according to Litchfield and Wilcoxon the oral LD50 for rats is 245 mg/kg bw (173 – 347 mg/kg bw).

Executive summary:

In an acute oral toxicity study similar to OECD test guideline 401 (the study was conducted prior to implementation of this guideline), groups of fasted, Wistar rats (5/sex) were given a single oral dose of  Fluocortolon in 5% gummi arabicum at doses of  45, 125, 180, 250, 360, 500, 720 and 2000 mg/kg bw and observed for 8 days.

Oral LD50 Females/Males = 245 mg/kg bw (95% C.I. 173 – 347 mg/kg)

 

After single oral administration of fluocortolone in doses of 45, 125, 180, 250, 360, 500, 720 and 2000 mg/kg bw to male and female rats (5/sex/group) apathy was found as clinical sign. At autopsy, hydrops ascites and fibrinous peritonitis were observed. Furthermore, changes in the gastrointestinal tract such as ulcers, erosions and thickening of the gastric mucous membrane were detected. Haemorrhagic mesenteric lymph nodes, necrobiosis of the liver, abscesses and subacute pneumonia in the lungs were noted. Adhesions of organs contained in the abdominal cavity were found. Animals of the dose level of 125 mg/kg bw and above died between 2 and 8 days after application.

Fluocortolon is of MODERATE Toxicity based on the LD50 in female and male Wistar rats, thus, Fluocortolon is classified in Category 3 for acute oral toxicity according to Regulation (EU) No. 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS).                                                                          

 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

245 mg/kg bw

Quality of whole database:

The study is of sufficient quality (Klimisch score = 2)

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

For fluocortolone-21-valerate (CAS No. 36130-02-6) no acute toxicity data are available. Therefore, acute oral toxicity data of fluocortolone (CAS No. 152-97-6) were used since these data are regarded as representative as most likely ester cleavage of fluocortolone-21-valerate occurs under physiological conditions. A search for structure-analogue substances using the QSAR OECD Toolbox 3.4 recommended fluocortolone as one out of 4 category substances for a read-across approach (for additional information see QSAR OECD Toolbox Report on Fluocortolon-21-Valerat in "Attached justification").

In the key study on acute oral toxicity the single administration of the test item fluocortolone in oral doses of 45, 125, 180, 250, 360, 500, 720 and 2000 mg/kg bw to male and female rats (5/sex/group) caused apathy in all animals at 125 mg/kg and above. At autopsy, hydrops ascites and fibrinous peritonitis were observed. Furthermore changes in the gastrointestinal tract such as ulcers, erosions and thickening of the gastric mucous membrane were detected. Haemorrhagic mesenteric lymph nodes, necrobiosis of the liver, abscesses and subacute pneumonia in the lungs were noted. Adhesions of organs contained in the abdominal cavity were found. Animals of the dose level of 125 mg/kg bw and above died between 2 and 8 days after application. The acute oral toxicity (LD50) of fluocortolone in male and female rats is 245 mg/kg bw (Günzel and Richter, 1965).

Further information on acute toxicity after oral administration to mice and dogs as well as after subcutaneous or intraperitoneal application to mice:

The single oral administration of fluocortolone in the doses of 360, 500, 720, 1000, 1440 and 2000 mg/kg bw to mice (10 male/group) was harmful. Apathy and convulsion were found as clinical signs. At autopsy, changes in the gastrointestinal tract such as ulcers, internal bleeding and enteritis were detected. Furthermore thickening of the gastric mucous membrane, grey-yellowish foci in the kidneys, grey-reddish discoloration of the liver, adhesion of liver and diaphragm, and abscesses in the kidneys were noted. Animals of dose group 720 mg/kg bw and above died between 3 hours and 15 days after application. The acute oral toxicity (LD50) of fluocortolone in male mice is 1500 mg/kg bw (Günzel and Richter, 1969).

The single oral administration of fluocortolone in the doses of 360, 500, 720, 1000, 1440 and 2000 mg/kg bw to mice (10 female/group) was harmful. Apathy and convulsion were found as clinical signs. At autopsy, changes in the gastrointestinal tract such as ulcers, internal bleedfing and enteritis were detected. Furthermore grey-white or grey-reddish foci in the liver were noted. Animals of dose group 720 mg/kg bw and above diedbetween 3 hours and 12 days after application. The acute oral toxicity (LD50) of fluocortolone in female mice is 1300 mg/kg (Günzel and Richter, 1969).

The single subcutaneous administration of fluocortolone in the doses of 360, 500, 720 1000, 1440 and 2000 mg/kg bw to male mice (10/group) was harmful. Apathy was found as clinical sign. At autopsy, a part of the test substance remained in the subcutis at the application side, also bleeding and abscesses in the subcutis were detected. In the gastrointestinal tract, changes such as ulcers and bleeding in the gastric mucous membrane were noted. Furthermore discoloration, bleeding and grey-white foci in the liver were observed. Animals of dose group 500 mg/kg and above died between 3 and 18 days after application. The acute subcutanous toxicity (LD50) of fluocortulone in male mice is 811 mg/kg bw (Günzel and Richter, 1969).

The single subcutaneous administration of fluocortolone in the doses of 360, 500, 720, 1000, 1440 and 2000 mg/kg bw to female mice (10/group) was harmful. Apathy was found as clinical sign. At autopsy, a part of the test substance remained in the subcutis at the application side, also bleeding and abscesses in the subcutis were detected. In the gastrointestinal tract, changes such as erosions, ulcers, enteritis and thickening of the gastric mucous membrane were noted. Furthermore marbling of the surface of the liver was observed. Animals of dose group 720 mg/kg and above died between 5 and 10 days after application. The acute subcutaneous toxicity (LD50) of fluocortolone in female mice is 840 mg/kg (Günzel and Richter, 1969).

The single i.p. administration of fluocortolone in the doses of 300, 400, 500, 600, 700 and 800 mg/kg bw to male mice was harmful. Apathy and convulsion were seen as clinical signs. At autopsy, the test substance was found intraperitoneally. In the gastrointestinal tract, changes such as ulcers and bleeding and erosions in the gastric mucous membrane were noted. Furthermore a grey-reddish marbling of the surface of the kidneys, grey-white foci in the liver and a congested urinary bladder were observed. Animals of dose group 400 mg/kg bw and above died between 4 hours and 4 days after

application. The acute ip toxicity (LD50) of fluocortolone in male mice is 395 mg/kg (Günzel and Richter, 1969).

The single ip administration of fluocortolone in the doses of 300, 400, 500, 600 and 700 mg/kg bw to female mice was harmful. Apathy was found as clinical sign. At autopsy, the test substance was found intraperitoneally. Furthermore bleeding in the lungs and a conspicuous lobular structure of the liver were observed. The ovarian were filled with a red aqueous fluid. Animals of the dose group 500 mg/kg bw and above died between 4 hours and 2 days after application. The acute ip toxicity (LD50) of fluocortolone in female mice is 510 mg/kg (Günzel and Richter, 1969).

Single oral administration of 100 mg/kg bw fluocortolone to fed and fasted male and female dogs (3/sex/group ) was applied. One of three animals of the fasted group and one of three animals of the fed group vomited the test substance between 1.5 and 2 hours after application. No clinical sings were found. no animal died. The acute oral toxicity (LD50) of fluocortolone in male and female dogs is >100 mg/kg (Günzel, 1965).

Single oral administration of 200 mg/kg bw fluocortolone was applied to 3 male and 1 female dogs. One of four animals vomited the test substance between 6 and 20 hours after application. No clinical sings were found and no animal died. The animals were not sacrificed. The acute oral toxicity (LD50) of fluocortolone in male and female dogs is > 200 mg/kg (Günzel, 1971).

Justification for classification or non-classification

Due to the results of the acute oral toxicity study in rats with the read-across substance fluocortolone classification of fluocortolone-21-valerate with Acute Toxicity Cat. 3 (H301: Toxic if swallowed) is required according to Regulation (EC) No. 1272/2008 (CLP).