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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:
key study
Study period:
Not reported
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Inhibitory effect of zinc oxide on contact allergy due to colophony
Author:
Soderburg T A, Elemros T, Gref R and Hallmans G
Year:
1990
Bibliographic source:
Contact Dermatitis: 23: 346-351

Materials and methods

Type of sensitisation studied:
skin
Study type:
study with volunteers
Test guideline
Qualifier:
according to
Guideline:
other: Internationally accepted methods cited in Fregert S (1981)
Deviations:
not applicable
Principles of method if other than guideline:
This study was conducted in patients for the determination of inhibitory effect of of Zinc oxide on contact allergy due to colophony
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Zinc oxide (Merck, Darmstadt. FRG)
- Analytical purity: > 99 %

Method

Type of population:
other: Patients with suspected contact allergy
Ethical approval:
confirmed, but no further information available
Remarks:
Approved by the local ethical committee
Subjects:
- Number of subjects exposed: 14
- Sex: 13 females and one male
- Age: Females mean age: 40 yr; Male: 49 yr
- Race: No data
- Demographic information: No data
- Other: Patients with strong test reactions to colophony were not included.
Clinical history:
- History of allergy or casuistics for study subject or populations: Earlier verIfied moderate patch test reactions to colophony, were included in the study.
- Symptoms, onset and progress of the disease: No patient had signs of active dermatitis at the time of the study.
Controls:
- Colophony (10 and 60 %)
- Zinc oxide in white petrolatum (10 %)
- Adhesive mass (10 %)
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: Patch test

ADMINISTRATION
- Type of application: Other
- Description of patch: Portuguese colophony 10 % was mixed with zinc oxide 0.01, 0.1, 1.0 and 10 % (w/w white petrolatum) and patch tested on the same patients. 200 mg of the substance to be tested was dissolved in 99.5 % ethanol. Thereafter, the ethanol was evaporated in a steady stream of N2 until 0.2 mL remained. White petrolatum (1.8 g) was thereafter added.
- Vehicle / solvent: 99.5 % ethanol
- Concentrations: 0.01, 0.1, 1.0 and 10 % (w/w in white petrolatum)

EXAMINATIONS
- Grading/Scoring system:
(-) Negative
(+) Erythema and infiltration or erythema, infiltration and papules
(++) Erythema, infiltration and vesicles

- Statistical analysis: No data

Results and discussion

Results of examinations:
SYMPTOMS
- Frequency, level, duration of symptoms observed: The patch pieces were applied directly on the back and removed together with the other patches after 2 days, assessment of the reactions being made 3 d after application.

NO. OF PERSONS WITH/OUT REACTIONS COMPARED TO STUDY POPULATION
- Number of subjects with negative reactions: 14
- Total number of subjects: 14

Any other information on results incl. tables

For details see the reference for:

- Occlusive adhesive zinc-medicated tapes evaluated for inhibitory effect of Zinc oxide on contact allergy.

Applicant's summary and conclusion

Conclusions:
Under the test conditions, Zinc oxide (10 %) applied alone did not cause any erythema, infiltration or papules (patch test reactions)
Executive summary:

A study was conducted in patients for the determination of inhibitory effect of of Zinc oxide on contact allergy due to colophony.

14 patients with verified moderate contact allergy to colophony were patch tested with adhesive mass (10%), Portuguese colophony (10%), zinc oxide (10%), purified resin acids (10%), and Portuguese colophony (10%), in combination with zinc oxide.

Only 3 patients reacted to the adhesive mass, whereas all patients showed a positive patch test reaction to Portuguese colophony. A combination of zinc oxide (10%) with Portuguese colophony (10%) provoked a positive patch test reaction in only 5 of these 14 patients. However, negative

patch test reaction in all 14 patients was observed with Zinc oxide (10%).

Under the test conditions, Zinc oxide (10 %) applied alone did not cause any erythema, infiltration or papules (patch test reactions).