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Toxicological information

Sensitisation data (human)

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Administrative data

Endpoint:
sensitisation data (humans)
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: well documented study report

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Type of sensitisation studied:
skin
Study type:
study with volunteers
Principles of method if other than guideline:
The purpose of this study was to evaluate the potential of p-methoxybenzaldehyde, as a result of repeated applications, to induce dermal sensitization in human subjects.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): p-Methoxybenzaldehyde
No additional data provided

Method

Type of population:
general
Ethical approval:
not specified
Subjects:
- Number of subjects exposed: 120 subjects inducted in the study; 109 subjects completed the study, 11 subjects discontinued (not due to test substance reactions)
- Sex: 36 males and 73 females
- Age: 18 to 70 years
Clinical history:
No subject exhibited dermatological or other medical or physical condition which would preclude test substance application.
Controls:
Each subject was patched with saline and 1:3 EtOH:DEP
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: patch test (epicutaneous test)

ADMINISTRATION
- Type of application: occlusive (left side of the back during induction; right side of the back at challenge)
- Description of patch: a webril/adhesive patch (25 mm Hill Top Chamber System) was used
- Vehicle / solvent: 1:3 ethanol:diethyl phthalate was applied to each designated patch
- Concentrations: 5.5% (6496 ug/cm2) test substance in vehicle
- Volume applied: 0.3 ml
- Testing/scoring schedule: patches remained in place and were kept dry for approximately 24 hours, after which time they were removed. A 24 hour period, during which no test materials were applied, followed the removal of the Monday and Wednesday patch applications; a 48 hour period followed the Friday patch applications. On Mondays, Wednesdays and Fridays, the test sites were observed and any reactions scored and recorded. The identical test site was then repatched until 9 induction patchings were completed over a period of approximately 3 weeks. A rest period of approximately 2 weeks followed the last induction patching. No test materials were applied during the rest period. At the challenge phase, the original induction test sites were observed and each subject queried as to whether any reaction was experienced during the rest period. The right side of the back was used for the virgin test site for the challenge phase. Patches were applied as in the induction phase and kept in place for 24 hours after which time they were removed and the challenge site scored. The original test sites were also observed.
- Other: the vehicles, 1:3 ethanol/diethyl phthalate and saline, were tested separately in the same manner as the test material

EXAMINATIONS
- Grading/Scoring system: scoring of the test sites was done at 24 (patch removal) 48, 72, and 96 hours post-patching using the modified scoring scale of the International Contact Dermatitis Research Group System, 1986: no visible reaction 0; faint, minimal erythema +/-; erythema-1; intense erythema, induration-2; intense erythema, induration, vesicles-3; severe reaction with erythema, induration, vesicles, pustules-4.

RECHALLENGES:
A first (1male and 1female subject; TS concentration: 5.5%) and a second (only the female subject with reaction at first rechallenge; TS concentrations: 5.5, 7.0 and 11.0%) rechallenges were conducted to evaluate the potential of the original test material under occlusive (25 mm Hill Top Chamber) conditions, to elicit dermal sensitization in the two human subjects (1 male and 1 female) who exhibited edematous reactions during the original repeated insult patch test. The test materials were volatilized for at least 15 minutes but no longer than 40 minutes. 0.3 ml of the test material in 1:3 ethanol:diethyl phthalate was applied to a 25 mm Hill Top Chamber. Reactions were scored at 24, 48, 72 and 96 hours post-patching.

Results and discussion

Any other information on results incl. tables

INDUCTION

Test substance:

1 subject exhibited a 1-level plus edema reaction during the induction phase and the test site was changed. The new test site exhibited a 1-level plus edema reaction and patching of this test material on this subject was discontinued for the remainder of the induction phase. The etiology of this reaction is unknown. One other subject exhibited a low-level, transient (+/-) reaction.

Saline:

Two subjects exhibited low-level, transient (+/-) reactions and 1 subject showed a continuous (+/- or 1 incl. dryness) reaction to saline.

Vehicle:

One subject exhibited a (+/- or 1) reaction to the vehicle 1:3 EtOH:diethyl phthalate at all induction patches exept the first and 8th patch.

CHALLENGE

Test substance:

One female subject exhibited a 1-level reaction at all timepoints investigated (incl. edema reaction 72 and 96h after challenge). This subject had not exhibited a significant reaction during the induction phase. After patching , 1-level plus edema on the original (induction) test site was observed at all timepoints investigated.

One male subject showed a 1 -level reaction at the challenge test site at all timepoints investigated. This subject showed reactions also in the induction phase (see above)

Two other subjects exhibited sporadic low-level (+/-) reactions on the challenge test sites at single timepoints only.

Saline:

One subject exhibited (+/- or 1) reactions at all timepoints invertigated to saline. This subject showed reactions also in the induction phase (see above)

One other subject exhibited sporadic low-level (+/-) reactions at single timepoints only.

Vehicle:

One subject exhibited 1 -level reactions at all timepoints invertigated with the vehicle 1:3 EtOH:diethyl phthalate at the induction site but no reaction at the challenge site. This subject showed reactions also in the induction phase (see above).

RECHALLENGES

First rechallenge:

5.5% test material in 1:3 ethanol:diethyl phthalate produced an 1-level plus edema reaction in the female subject only.

The male subject exhibited a low-level (+/- 1) reaction to saline only.

No reactions were exhibited to the vehicle 1:3 ethanol:diethyl phthalate in either subject tested.

Second rechallenge:

The female subject exhibited a 1-level plus edema reaction with 5.5, 7.0 or 11.0% TS in vehicle, whereas a 1-level plus edema reaction was also observed with the vehicle alone. No reactions were exhibited with saline.

Applicant's summary and conclusion