Registration Dossier

Administrative data

Endpoint:
sensitisation data (humans)
Type of information:
experimental study
Adequacy of study:
other information
Study period:
From Jan. 12, 1970 to Sept. 04, 1970
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable study report which meets basic scientific principles
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1971
Report Date:
1970

Materials and methods

Type of sensitisation studied:
skin
Study type:
study with volunteers
Principles of method if other than guideline:
A repeated insult patch test (HRIPT) was performed on 81 subjects to study the effect of repeated application of test material to human skin. The study was conducted in two phases 1) Induction phase and 2) Challenge phase. In the induction phase patches were applied on the same site in a vertical row on the upper arm of the subject and left in place 24 hr at each of nine applications over a period of three weeks. After 2 wk the treatment sites were challenged with two set of patches at the original treatment sites and one set at fresh site on alternate arm. The reactions were scored 48 h after each patch application in the induction phase and at 48 and 72 h after patch application in the challenge phase.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material: Monoethanolamine salt of alkyl benzene sulfonic acid; MEA-LAS
- TSIN: XTW-369
- Substance type: Pure active substance
- Physical state: Solid
- Stability under test conditions: Not reported
- Storage condition of test material: Not reported

Method

Type of population:
general
Ethical approval:
not specified
Subjects:
- Number of subjects exposed: 81 panelists were exposed in total (14 in pilot study and 67 in the main study)
- Sex: Male and Female
- Age: 16 to >60 y
- Race: Not reported
- Demographic information: Not reported
Clinical history:
Not reported
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: Human repeated insult patch test (HRIPT)

ADMINISTRATION
- Type of application: Occlusive
- Description of patch: The test patch consisted of a 3/4 x 1 inch Webril swatch affixed to the centre of a 1.5 x 2 inch Duke elastic bandage.
- Vehicle / solvent: Water
- Concentrations: 0.5 mg/mL (induction phase) and 0.1 mg/mL (challenge phase)
- Volume applied: 0.5 mL
- Application of patches: The study was conducted in following two phases:
Induction phase: Patches were applied on the same site on upper arm of the subject at each nine application for three weeks unless severity of a reaction made the application inadvisable.
Challenge phase: After 2 wk the treatment sites were challenged with duplicate set of patch at the old site and a single set at adjacent fresh site.
Make up session: A make up session was arranged after the last induction application for the panelists with earlier absence.
- Testing/scoring schedule: In induction phase, treatment sites were scored for reactions at 48 h after patch application for each of 9 exposures. Challenge sites were scored at 48 and 96 h after patch application. For details please refer to ‘Table 1’ provided under ‘Any other information on results incl. tables’ section.
- Removal of test substance: 24 h after application of each of the 9 induction patches and the challenge patches.

EXAMINATIONS
- Grading/Scoring system: The reactions were scored on the following scale:
No evidence of irritation - 0
Slight erythema - 1
Marked erythema - 2
Few small papules, little or no erythema - 3 min
Scattered small petechial erosions and/or scabs – III
Erythema and papules - 3
Erythema and edema – E
Erythema, edema and papules - 4
Vesicular eruption - 5
Strong reaction spreading beyond test site – 6
Effects on superficial layers of skin were scored as follows:
Slight glazed appearance - A
Marked glazing - B
Glazing with peeling and cracking – C
Glazing with deep fissures - F
Numerous small scabs covering most or all of patch site - G

Results and discussion

Results of examinations:
NO. OF PERSONS COMPLETED THE STUDY: The study was initiated on 81 panelists, however only 75 completed the study. 6 subjects were dropped from the study due to excessive absence.

SYMPTOMS
- Frequency, level, duration of symptoms observed: Serial application of test material produced little or no irritation in 5 subjects (No. 60-64 out of 75 subjects). Varying degrees of primary irritation was observed in the remaining subjects. The incidence of significant primary irritation (Grade 2 or greater) was observed in 8 individuals.
One subject (No. 2) reacted strongly to the challenge application of test material. However, did not react to the test solution when reapplied in a rechallenge.

NO. OF PERSONS WITH/OUT REACTIONS COMPARED TO STUDY POPULATION
- Number of subjects with positive reactions (sensitizing reaction): 0/75; one subject reacted strongly to the challenge application, however did not react when reapplied in re-challenge. The initial reaction was probably because of skin-fatigue or temporary hyper-reactivity.
- Number of subjects with negative reactions: 5/75
- Number of subjects with irritating reactions: 70/75; Varying degrees of primary irritation observed
8/70; Significant primary irritation (Grade 2 or greater)

Applicant's summary and conclusion

Conclusions:
Monoethanolamine salt of alkyl benzene sulfonic acid (MEA-LAS) did not produce skin sensitization in humans repeated insult patch test (HRIPT).
Executive summary:

A human repeated insult patch test (HRIPT) of Monoethanolamine salt of alkyl benzene sulfonic acid (MEA-LAS) was performed to study the effect of repeated applications of MEA-LAS to human skin.

A total of 81 subjects participated in the study. Subjects were exposed to 9 induction patches containing 0.5 mL of 0.05% test material under a pattern of 3 induction exposure per wk for a period of 3 wks. Patches were removed 24 h after each application and patch sites were graded at 48 h after patch application prior to the next patch application. After a two week rest period, subjects were challenged with 0.5 mL of 0.05% test material (24 h patch exposure) with duplicate patch at the original site and a fresh site on the other arm. Challenge patch sites were graded at 48 and 96 h after patch application.

In this study, 75/81 subjects completed the study. Serial application of test material produced little or no irritation in 5/75 subjects. Varying degrees of primary irritation were observed in the remaining subjects. The incidence of significant primary irritation (Grade 2 or greater) was observed in 8 individuals.

Only 1 subject reacted strongly to the challenge application of test material. However, the subject did not react to the test solution when reapplied at 0.05% concentration at original site and 0.01% at opposite arm in a re-challenge. The initial reaction was probably due to skin-fatigue or temporary hyper-reactivity.

Based on above, it was concluded that Monoethanolamine salt of alkyl benzene sulfonic acid (MEA-LAS) did not produce skin sensitization in human repeated insult patch test (HRIPT).