Quinidine

Endpoint summary

Description of key information

According to the publication and calculation, quinidine is not irritating or corrosive to skin. In the in vitro BCOP test, quinine showed effects on the cornea of the bovine eye. A mean IVIS of 18.15 was calculated. Therefore, we assumed that quinine base anhydrous is mildly irritating to eyes and quinidine which is a  stereoisomer of quinine is also mildly irritating to eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is not done according to OECD guideline, but it is a well documented study.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Guinea pig maximisation test as described by Magnusson Kligman (1969, 1970) was used, under the same conditions as reported earlier (Wahlberg and Boman, 1978). At intradermal induction 0.25 % of the drug in distilled water was used. At epicutaneous induction 20 % of the drug in petrolatum was used with previous SLS treatment. Challenge is by topical application. Provided there is no irritation. Challenge testing was performed on control and exposed animals on day 21 with 1, 5, and 10 % of the drugs in petrolatum. The challenge site is evaluated 24 h and 48 h after removal of the patch. The statistical method was chi-squared analysis.

GLP compliance:

not specified

Species:

guinea pig

Strain:

not specified

Type of coverage:

occlusive

Preparation of test site:

other: clipped and shaved

Vehicle:

other: petrolatum

Controls:

yes

Amount / concentration applied:

TEST MATERIAL- Concentration: 25 % (epicutaneous induction in petrolatum)- Concentration: 1, 5 and 10 % (challenge test)

Number of animals:

39 animal (20 animals test group and 19 animals control group)

Details on study design:

Epicutaneous induction:- Test groups: 20- Control group: 19- Concentrations: 25 % epicutaneous induction of the drugs in petrolatumChallenge test:- Control group: 19 animals- Concentrations: 1, 5 and 10 % of the drugs in petrolatum- Exposure period: 24h - other: readings were taken 24 h and 48h after removal of the test chambers

Irritant / corrosive response data:

During the challenge test no control animals showed a reaction on 10 % quinidine sulphate. Furthermore, in the publication it is not described that during the first epicutaneous induction with 25% quinidine sulphate animals showed a reaction. Thus, we assumed that there were no irritation.

Interpretation of results:

not irritating

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

According to this study, quinidine sulphate (25%) is not irritating to skin. In conclusion, quinidine should not cause skin irritation, too.

Executive summary:

In the study published by Wahlberg, 1981 the skin irritation/corrosion was experimentally determined in guinea pigs. In the publication it is not described that during the first epicutaneous induction with 25% quinidine sulphate animals showed a reaction. Thus, we assumed that no irritations occurred. Furthermore, during the challenge test no control animals showed a reaction on 10 % quinidine sulphate after 24 h and 48 h. In these two tests no skin irritation occurred. Therefore, it can be conclude that quinidine sulphate is not irritating to skin and does

not need to be classified.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was done according to OECD guideline 437.

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Qualifier:

according to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Principles of method if other than guideline:

Test System:Fresh bovine eyes were obtained from the slaughterhouse Müller Fleisch GmbH, Enzstr. 2 - 4, 75217 Birkenfeld, Germany, on the day of the test. The cattle were between 12 and 60 months old. The eyes were transported to the test facility in Hank’s balanced salt solution (supplemented with 0.01 % streptomycin and 0.01 % penicillin). Then, the corneas were dissected and incubated in medium at 32 ± 1 °C in an incubation chamber for 1 hour. Preparations:After having carefully cleaned and sterilised the cornea holders, they were kept in the incubation chamber at 32 °C. On the day of the assay, the MEM without phenol red was supplemented with sodium bicarbonate, L-glutamine and 1 % fetal calf serum (= complete MEM) and stored in a water bath at 32 °C ± 1 °C. The same was performed with the MEM with phenol red. After the arrival of the corneas they were examined and only corneas which were free from defects were used. The corneas were excised with a scalpel and cut from the globe with a 2-3 mm ring of sclera around the outside. Each cornea was transferred to a cornea holder in which pre-warmed cMEM without phenol red was filled. The holders were then incubated for one hour in the incubation chamber at 32 °C.Method Description:After the initial incubation, the medium was changed and the baseline opacity for each cornea was recorded. None of the corneas showed tissue damage; therefore, all corneas were used. The baseline opacity was measured by placing the holder with the cornea in a spectral photometer and recording the absorption at 570 nm. Opacity is calculated from the measured absorption. For each treatment group (negative control solution, test item suspension and positive control solution), three replicates were used. After removal of the pre-incubation medium, 750 μL negative control solution resp. test item suspension resp. positive control solution were applied to each replicateAccording to the characteristics of the test item, the following treatment procedure was performed: Open Chamber Method:The “open chamber-method” is used for solid substances. In order to apply the test item, the nut was unscrewed to remove the glass disc. The test item could be applied directly on the cornea now. 750 μL of the test item were tested as suspension at 20 % concentration in 0.9 % sodium chloride solution. The test item suspension was given on the epithelium in such a manner that as much as possible of the cornea was covered with test item suspension. Exposition time on the corneas was 4 h ± 5 min. at 32 °C. After thorough rinsing with cMEM with phenol red and final rinsing with cMEM without phenol red, both chambers were filled with cMEM without phenol red, and the final opacity value of each cornea was recorded at once (again by measurement at 570 nm). The cMEM without phenol red was then removed from the front chamber, and 1 mL sodium fluorescein solution (concentration5 mg/mL) was added to the front chamber. The chambers were then closed again and incubated for 90 ± 5 min at 32 ± 1 °C. After incubation, the content of the posterior chamber was thoroughly mixed. Then, the permeability of the cornea was measured as optical density of the liquid at 490 nm.

GLP compliance:

yes (incl. QA statement)

Species:

other: Bos primigenius Taurus (Fresh bovine corneas)

Vehicle:

physiological saline

Remarks:

0.9 % sodium chloride solution

Amount / concentration applied:

TEST MATERIAL- Concentration (if solution): 20% in 0.9 % sodium chloride solution

Duration of treatment / exposure:

Incubation time: 4 hours at 32 ± 1 °C

Details on study design:

Negative Control: Sodium chloride solution: 0.9 % NaCl (CAS-No. 7647-14-5), dissolved in demin. water.Positive Control: Imidazole solution: 20 % C3H4N2 (CAS-No. 288-32-4), dissolved in 0.9 % NaCl.The test item is a non-surfactant solid substance. It was tested as a suspension at a concentration of 20 % in 0.9 % sodium chloride solution.

Irritation parameter:

in vitro irritation score

Run / experiment:

mean

Value:

18.15

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Mean value of 3 experiments. standard deviation: 11.4 %

Opacity and Permeability Values

The absorption (570 nm) and opacity values which were measured before and after exposition are given in the following table:

A) Absorption and Opacity Values Negative Control:

Parameter	Negative Control
Absorption before exposition	0.1534	0.1456	0.1523
Absorption after exposition	0.2548	0.1948	0.2557
Opacity before exposition	1.4236	1.3983	1.4200
Opacity after exposition	1.7980	1.5660	1.8018
Opacity Difference	0.3744	0.1677	0.3817

Mean opacity difference of the negative control is 0.3080.

B) Absorption and Opacity Values Test Item and Positive Control:

Parameter	Test Item Quinine Base Anhydrous			Positive Control
Absorption before exposition	0.1916	0.2158	0.1423	0.1539	0.1389	0.1598
Absorption after exposition	0.6452	0.5839	0.5777	1.5211	1.7040	1.5634
Opacity before exposition	1.5545	1.6436	1.3877	1.4253	1.3769	1.4448
Opacity after exposition	4.4177	3.8362	3.7818	33.1971	50.5825	36.5932
Opacity Difference	2.8632	2.1926	2.3941	31.7718	49.2056	35.1484

For the permeability measurement, three replicates for each treatment group were measured. The optical density values at 490 nm are given in the following table:

C) Optical density at 490 nm:

Repl.	Negative Control			Test Item Quinine Base Anhydrous			Positive Control
Meas.	0.0074	0.0059	0.0099	0.2255	0.2459	0.1908	0.5096	0.3197	0.3642
Corr.	0.0370	0.0295	0.0495	1.1275	1.2295	0.9540	2.5480	1.5985	1.8210
Mean	0.0387			--

Note: In order to correct the path length, a factor of 5 was taken into account when calculating the IVIS.

IVIS Values

IVIS was calculated using the values in tables A, B and C and the equation IVIS = (opacity difference – mean opacity difference of the negative controls) + [15 * (corr.OD490 – mean corr. OD490 of the negative controls)]

The calculated IVIS for each replicate and the corresponding means are presented in the following table:

D) IVIS:

Test Group	IVIS	Mean IVIS	Relative Standard Deviation IVIS
Negative Control 0.9% NaCl	0.929
	0.610	0.888	29.2 %
	1.124
Test Item Quinine Base Anhydrous	18.887
	19.747	18.150	11.4 %
	15.816
Positive Control 20% imidazole	69.103
	72.295	67.658	8.1 %
	61.575

Interpretation of results:

Category 2B (mildly irritating to eyes)

Remarks:

Migrated information Criteria used for interpretation of results: other: UN GHS

Conclusions:

According to the study report, quinine base anhydrous showed effects on the cornea of the bovine eye. The calculated IVIS (in vitro irritancy score) is 18.15. Therefore, quinidine which is a stereoisomer of quinine should be mildly irritating to eyes, too.

Executive summary:

This in vitro study was performed to assess serious eye damage of the read across substance quinine base anhydrous by quantitative measurements of changes in opacity and permeability in a bovine cornea. Two experiments were performed. The first experiment was cancelled, because the value of the positive control was not within the range of the historical data. The second experiment was valid. The test item quinine base anhydrous was brought onto the cornea of a bovine eye which previously had been incubated with cMEM without phenol red at 32 ± 1 °C for one hour and whose opacity had been determined. A 20% quinine base anhydrous solution was incubated on the cornea for four hours at 32 ± 1 °C. After removal of the test item, opacity and permeability values were measured. Physiological sodium chloride solution was used as negative control and imidazole (20 % solution in 0.9 % sodium chloride solution) was used as positive control. The negative control showed no irritation effects and no serious eye damage, mean IVIS was 0.888. The positive control induced serious eye damage on the cornea, mean IVIS was 67.658. Under this test condition, quinine base anhydrous showed effects on the cornea of the bovine eye. A mean IVIS of 18.150 was calculated. The mean IVIS of quinidine should be approximately 18.150, too.

According to OECD Guideline no. 437 (Jul. 2013), a substance with an IVIS > 3 and ≤ 55 induces effects on the cornea, that cannot be classified in a UN GHS Category. But according to the Background Review Document Current Status of In Vitro Test Methods for Identifying Mild/Moderate Ocular Irritants: Bovine Corneal Opacity and Permeability Test Method, 2010 a substance with an IVIS of 3.1 - 25 is mild irritant. Therefore, we assumed that quinidine base anhydrous is mildly irritating to eyes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The skin irritating/corrosive properties of quinidine were calculated via ChemProp and ToxPredict. Both calculations showed that quinidine is not corrosive to skin since no structural alerts were observed. But it could not be excluded that quinidine is irritating to skin based on the results on bioavailability. To exclude skin irritation, the publication on skin sensitisation were taken into account. In the study published by Wahlberg, 1981 the skin irritation/corrosion was experimentally determined in guinea pigs. In the publication it is not described that during the first epicutaneous induction with 25% quinidine sulphate animals showed a reaction. Thus, we assumed that no irritations occured. Furthermore, during the challenge test non of the control animals showed a reaction to 10 % quinidine sulphate after 24 h and 48 h. In these two tests no skin irritation occurred. In conclusion, quinidine is not irritating to skin and does not need to be classified.

To assess serious eye damage of quinidine a study report of quinine base anhydrous was consulted. In this study report an in vitro test (BCOP) was performed. A 20 % suspension of quinine base anhydrous was brought onto the cornea of a bovine eye for four hours at 32 ± 1 °C. After removal of quinine base anhydrous, opacity and permeability values were measured. In this study report, quinine base anhydrous showed effects on the cornea of the bovine eye. A mean IVIS of 18.15 was calculated. According to OECD Guideline no. 437 (Jul. 2013), a substance with an IVIS > 3 and ≤ 55 induces effects on the cornea, that cannot be classified in a UN GHS Category. But according to the Background Review Document Current Status of In Vitro Test Methods for Identifying Mild/Moderate Ocular Irritants: Bovine Corneal Opacity and Permeability Test Method, 2010 a substance with an IVIS of 3.1 - 25 is mild irritant. Therefore, we assumed that quinine base anhydrous is mildly irritating to eyes. Furthermore, to exclude the eye irritation properties case reports were consulted. In both case reports a 2 % quinine bisulphate ointment was used for eyes as a clarifier of corneal opacities. No patients showed an irritating reaction after applying of the quinine bisulfate ointment. Furthermore, experiments have shown that quinine is one of the most effective antiseptics. The antiseptic properties of quinine were determined, using quinine bisulphate powder to improve granular ophthalmia. In all five case reports, no patients showed an irritating reaction after applying of the quinine bisulphate powder. Thus, we conclude that quinidine which is a stereoisomer of quinine is not irritating to eyes and does not need to be classified.

Justification for selection of skin irritation / corrosion endpoint:
It is a well documented study. Study is done similar to OECD guideline 406.

Justification for selection of eye irritation endpoint:
The study was done according to OECD guideline 437.

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

According to the Globally Harmonized System of Classification and Labelling of Chemicals, 2011 of the United Nation a substance which is mildly irritating to eyes have to be classified in Eye Irrit Cat 2B. This classification is not considered according to EU-Regulation (EC) No 1272/2008. Therefore, quinidine is not irritating / corrosive to the skin or eyes and does not need to be classified.