Phenylsuccinic acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-04-13 - 2018-05-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

Test was sponsored by supplier in India. Since no other data is available no new animal study was performed.

Test material

Test material information

Constituent 1

Reference substance name:

Phenylsuccinic acid

EC Number:

211-238-1

EC Name:

Phenylsuccinic acid

Cas Number:

635-51-8

Molecular formula:

C10H10O4

IUPAC Name:

2-phenylbutanedioic acid

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Molecular formula:
C10H10O4
Molecular Mass:
194.18
Characteristics (Physical Appearance):
White Crystalline powder
CAS No.:
[635-51-8]
Batch Number:
123
Purity:
100%

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

Source:
Sri Raghavendra Enterprises, Bangalore, India
Age at the start of the study:
13 weeks
Sex:
Female; females were nulliparous and non-pregnant.
Body weight range (Day -1):
387 g to 511 g
Number of animals used:
Pilot Study - 2 animals;
Main study - 30 animals;
(Treatment group - 20 animals; Control group - 10 animals)
Veterinary Examination:
Prior to final assignment to the study, the animals were subjected to a veterinary examination to ensure that the selected guinea pigs were in a good state of health.
Accommodation : Animals were housed in room number AR-09, in the experimental animal facility of INTOX PVT. LTD., maintained under appropriate barriers. Animals were housed singly in solid bottom polypropylene cages [size: 42 cm (L) x 29 cm (W) x 19 cm (H)] with stainless steel grill tops, facilities for food and water bottle, and bedding of clean and sterilized paddy husk. The cages were suspended on stainless steel racks.
Environmental conditions : The room was climatically controlled with 10 to 15 air changes per hour. The room was air conditioned with temperature between 17 to 23 °C, relative humidity 30 to 70% and illumination cycle set to 12 hours light and 12 hours dark. Diet : ‘Amrut’ brand pelleted guinea pig feed manufactured Krishna Valley Agrotech LLP, Sangli, was provided ad libitum. Certificates of nutrient analysis for each batch of diet used have been retained in the facility records. The diet has been tested and certified for proximate analysis and has been verified to be free from undesired levels of contaminants. This diet was supplemented by a dose of Vitamin C administered orally. Water : Potable water, passed through ‘Aquaguard’ water filter, and subjected to ultra violet irradiation, was provided ad libitum in sterilized bottles with stainless steel sipper tubes. The drinking water has been tested and certified for potability and the water source has been verified to be free from undesired levels of contaminants.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

other: 0.2% Tween 80

Concentration / amount:

For induction : 53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80
For challenge : 53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80

Day(s)/duration:

14 days

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

other: analytical grade water with 0.2% Tween 80

Concentration / amount:

fully loaded

Day(s)/duration:

14

Adequacy of induction:

other: negative control

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: For induction : 53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80 For challenge : 53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80

Concentration / amount:

53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80

Day(s)/duration:

28 days

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20

Details on study design:

The induction and challenge was made by epidermal (topical) application of the test item, employing a patch under occlusive dressing, on the clipped skin of the flanks.
The sites and days of application were as follows.
Induction : Topical application on the clipped skin of the left flank,
On days 0, 7 and 14 of the study.
Challenge : Topical application on the clipped skin of the right flank.
On day 28 of the study.
Approximately 24 hours before treatment, the hair on the left flank was closely clipped with an electric clipper exposing an area of approximately 80 cm2 (8 x 10 cm). The gauze patch (occlusive dressing) admeasuring about 4 to 6 cm2 (at least 2 cm x 2 cm), fully loaded with formulated test item (treatment group) and vehicle control group (Analytical grade water with 0.2% Tween 80) was applied to the prepared area and was covered with an aluminum foil and secured in position with an adhesive tape wound around the torso for a period of 6 hours. After 6 hours contact period the test patch was removed and skin was wiped with analytical grade water and dried. The skin reaction was evaluated at 24 and 48 hours after removal of the skin patch by Magnusson and Kligman grading scale.
Treatment group and control group were challenged at 4 weeks after first induction application. The untreated flanks of animals were cleared of hair by close-clipping. The gauze patch fully loaded with 0.5 ml of test item was applied to the posterior part of the untreated (right) flanks of treatment and control group animals. The procedure of application and the exposure period was same as that during the induction.

Positive control substance(s):

yes

Remarks:

α-Hexylcinnamaldehyde

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

28

Group:

test chemical

Dose level:

53% w/v of 2-PHENYLSUCCINIC ACID, in analytical grade water with 0.2% Tween 80

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Results 2

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

10

Results 3

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

positive control

Dose level:

10% α-Hexylcinnamaldehyde

No. with + reactions:

5

Total no. in group:

10

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The allergic contact sensitisation potential of 2-PHENYLSUCCINIC ACID was assessed in guinea pigs as per the method described by Buehler E. V., in compliance with the Organization for Economic Co-operation and Development (OECD) Guidelines for Testing of Chemicals, Section 4, No. 406 - Skin sensitisation, adopted by the council on 17 July 1992.
In this test, induction of sensitisation was attempted by exposing the guinea pigs to 53% w/v of 2-PHENYLSUCCINIC ACID in analytical grade water with 0.2% Tween 80 on days 0, 7 and 14 by epidermal route on the clipped left flank area, there was no evidence of erythema and / or swelling at the site of application. After an induction period of 14 days, the animals were similarly subjected to a ‘challenge application’ with 53% w/v of 2-PHENYLSUCCINIC ACID in analytical grade water with 0.2% Tween 80 on day 28 of the study, on their right flank.
In absence of a sensitisation response in any of the treated animals to challenge by the test item, 2-PHENYLSUCCINIC ACID is classified as non sensitiser to guinea pigs as per the criteria of classification for the Buehler test (Kimber et. al., 1990).

Executive summary:

The allergic contact sensitisation potential of 2-PHENYLSUCCINIC ACID was assessed in guinea pigs as per the method described by Buehler E. V., in compliance with the Organization for Economic Co-operation and Development (OECD) Guidelines for Testing of Chemicals, Section 4, No. 406 - Skin sensitisation, adopted by the council on 17 July 1992.

In this test, induction of sensitisation was attempted by exposing the guinea pigs to 53% w/v of 2-PHENYLSUCCINIC ACID in analytical grade water with 0.2% Tween 80 on days 0, 7 and 14 by epidermal route on the clipped left flank area, there was no evidence of erythema and / or swelling at the site of application. After an induction period of 14 days, the animals were similarly subjected to a ‘challenge application’ with 53% w/v of 2-PHENYLSUCCINIC ACID in analytical grade water with 0.2% Tween 80 on day 28 of the study, on their right flank.

In absence of a sensitisation response in any of the treated animals to challenge by the test item, 2-PHENYLSUCCINIC ACID is classified as non sensitiser to guinea pigs as per the criteria of classification for the Buehler test (Kimber et. al., 1990).