5H-Cyclopenta[h]quinazoline, 6,7,8,9-tetrahydro-7,7,8,9,9-pentamethyl-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Jul 2013 to 20 Aug 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

1

Reference substance name:

(8S)-7,7,8,9,9-pentamethyl-5H,6H,7H,8H,9H-cyclopenta[h]quinazoline

EC Number:

801-093-8

Cas Number:

1315251-11-6

Molecular formula:

C16H22N2

IUPAC Name:

(8S)-7,7,8,9,9-pentamethyl-5H,6H,7H,8H,9H-cyclopenta[h]quinazoline

Test material form:

solid

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd.
- Age at study initiation: Eight to twelve weeks of age.
- Weight at study initiation: No data.
- Fasting period before study: Overnight fast immediately before dosing and for approximately three to four hours after dosing.
- Housing: in groups of up to three in suspended solid-floor polypropylene cages furnished with woodflakes.
- Diet: 2014C Teklad Global Rodent Diet (Harlan Laboratories UK Ltd) ad libitum.
- Water: Mains drinking water ad libitum.
- Acclimation period: At least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Set to achieve limits of 19 to 25 °C. Any deviations were considered not to have affected the purpose or integrity of the study.
- Humidity (%): Set to achieve limits of 30 to 70 %. Any deviations were considered not to have affected the purpose or integrity of the study.
- Air changes (per hr): At least 15 changes per hour.
- Photoperiod (hrs dark / hrs light): Twelve hours continuous light and twelve hours darkness.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

Test item was freshly prepared, as required, as a suspension in arachis oil BP. Arachis oil BP was used because the test item did not dissolve/suspend in distilled water.
The test item was formulated within two hours of being applied to the test system. It is assumed that formulation was stable for this duration.
No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation.

Doses:

300 and 2000 mg/kg

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

In the absence of data regarding the toxicity of the test item, 300 mg/kg was chosen as the starting dose.
All animals were dosed once only by oral gavage, using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to the fasted body weight at the time of dosing. Treatment of animals was sequential. Sufficient time was allowed between each group to confirm the survival of the previously dosed animals.
The animals were observed for deaths or overt signs of toxicity 0.5, 1, 2 and 4 hours after dosing and subsequently once daily for up to 14 days. Individual body weights were recorded prior to dosing and seven and fourteen days after treatment or at death.
At the end of the observation period, the surviving animals were killed by cervical dislocation. All animals were subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities for examination of major organs. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

500 mg/kg bw

Based on:

test mat.

Mortality:

The animals treated at a dose level of 2000 mg/kg were killed for humane reasons, four hours after dosing, due to the occurrence of clinical signs of toxicity that exceeded the severity limit set forth in the UK Home Office Project Licence. There were no deaths at a dose level of 300 mg/kg bw

Clinical signs:

other: Signs of systemic toxicity noted in animals treated at a dose level of 2000 mg/kg bw were hunched posture, ataxia, lethargy, body tremors or occasional body tremors, hypothermia, decreased respiratory rate, clonic and tonic convulsions, splayed gait and p

Gross pathology:

White liquid present in the stomach was noted in animals treated at a dose level of 2000 mg/kg bw. No abnormalities were noted at necropsy of treated animals at a dose level of 300 mg/kg bw.

Any other information on results incl. tables

Mortality data

Dose level mg/kg	Sex	No. of animals treated	Deaths during day of dosing (h)				Deaths during period after dosing (days)								Deaths
			0.5	1	2	4	1	2	3	4	5	6	7	8-14
300	Female	3	0	0	0	0	0	0	0	0	0	0	0	0	0/3
	Female	3	0	0	0	0	0	0	0	0	0	0	0	0	0/3
2000	Female	3	0	0	0	3*									3/3

* = Animals killed for humane reasons due to the occurrence of clinical signs of toxicity that exceeded the severity limit set forth in the UK Home Office Project Licence

 

Individual clinical observations

Dose level mg/kg	Animal No. & sex	Effects noted after dosing (h)				Effects noted during period after dosing (days)
		0.5	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
3000	1-0 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-1 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-2 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-0 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-1 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-2 female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
2000	2-0 female	HAToL	HATL	HATL HoRd (ct)	HALHo RdCcX*
	2-1 female	HAL	HAToLWs	HATL HoRdWs	HATLHo RdWsX*
	2-2 female	HA	HATo	HATo LHoRd	HATLHo WsPtX*

H = Hunched posture

A = Ataxia

L = Lethargy

T = Body tremors

To = Occasional body tremors

Ho = Hypothermia

Rd = Decreased respiratory rate

Cc = Clonic convulsion

Ct = Tonic convulsions

Ws = Splayed gait

Pt = Ptosis

( ) = Observation noted approximately 3 hours after dosing

X* = Animals killed for humane reasons due to the occurrence of clinical signs of toxicity that exceeded the severity limit set forth in the UK Home Office Project Licence

 

Individual body weights and body weight changes – 300 mg/kg

Dose level mg/kg	Animal No. & sex	Body weight (g) at Day			Body weight gain (g) during week
		0	7	14	1	2
300	1-0 female	168	170	188	2	18
	1-1 female	147	163	182	6	19
	1-2 female	154	165	179	11	14
	3-0 female	185	202	222	17	20
	3-1 female	172	186	206	14	20
	3-2 female	166	190	202	24	12

 

Individual body weights and body weight changes – 2000 mg/kg

Dose level mg/kg	Animal No. & sex	Body weight (g) at Day			Body weight (g) at death	Body weight gain (g) during week
		0	7	14		1	2
2000	2-0 female	151	-	-	140	-	-
	2-1 female	160	-	-	150	-	-
	2-2 female	171	-	-	162	-	-

-         Animal dead

 

Individual necropsy findings

Dose level mg/kg	Animal No. & sex	Time of Death	Macroscopic Observations
300	1-0 female	Killed Day 14	No abnormalities detected
	1-1 female	Killed Day 14	No abnormalities detected
	1-2 female	Killed Day 14	No abnormalities detected
	3-0 female	Killed Day 14	No abnormalities detected
	3-1 female	Killed Day 14	No abnormalities detected
	3-2 female	Killed Day 14	No abnormalities detected
2000	2-0 female	Humanely killed Day 0	Stomach: White liquid present
	2-1 female	Humanely killed Day 0	Stomach: White liquid present
	2-2 female	Humanely killed Day 0	Stomach: White liquid present

 

Applicant's summary and conclusion

Interpretation of results:

other: Harmful in accordance with EU CLP (EC no 1272/2008 and its amendments)

Conclusions:

The acute oral median lethal dose (LD50) of the substance in the female Wistar strain rat was approximately 500 mg/kg body weight. Based on this result, the substance will be classified for acute oral toxicity and is acute toxic 4, using the phrase: Harmful if swallowed.

Executive summary:

The study was performed according to OECD TG 423, conducted in compliance with GLP, to assess the acute oral toxicity of the substance in the Wistar strain rat. A group of three fasted females was treated with the substance at a dose level of 300 mg/kg body weight. Based on the results from this dose level, further groups of fasted females were treated at dose levels of 300 and 2000 mg/kg body weight. Dosing was performed sequentially. The substance was administered orally as a suspension in arachis oil BP. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

The animals treated at a dose level of 2000 mg/kg were killed for humane reasons, four hours after dosing, due to the occurrence of clinical signs of toxicity that exceeded the severity limit set forth in the UK Home Office Project Licence. There were no deaths at a dose level of 300 mg/kg. Signs of systemic toxicity noted in animals treated at a dose level of 2000 mg/kg were hunched posture, ataxia, lethargy, body tremors, or occasional body tremors, hypothermia, decreased respiratory rate, clonic and tonic convulsions, splayed gait and ptosis. There were no signs of systemic toxicity at a dose level of 300 mg/kg. Surviving animals showed expected gains in body weight. White liquid present in the stomach was noted in animals treated at a dose level of 2000 mg/kg. No abnormalities were noted at necropsy of animals treated at a dose level of 300 mg/kg.

In conclusion, the acute oral median lethal dose (LD50) of the substance in the female Wistar strain rat was approximately 500 mg/kg body weight.