Hydroxyoctadecanoic acid, monoester with glycerol

Sensitisation data (human)

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Administrative data

Endpoint:

sensitisation data (humans)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

secondary source

Title:

Unnamed

Year:

2007

Materials and methods

Type of sensitisation studied:

skin

Study type:

case report

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: Human Patch test

Principles of method if other than guideline:

Human volunteers are patched with test material, and the results in the skin are evaluated after 24-48 hours by a trained expert and reported.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Test material form:

solid

Details on test material:

As per the 2007 CIR Final Report on Ricinus communis, Hydrogenated Castor Oil consists primarily of glyceryl-tri-hydroxystearate (Nikitis and McEwen, 1990). The National Formulary (Committee of Revision of the United States Pharmacopeial Convention 2004b) has published the following requirements for Hydrogenated Castor Oil: free fatty acids (free fatty acids in 20 g require for neutralization not more than 11.0 ml of 0.1 N sodium hydroxide), heavy metals (0.001%), hydroxyl value (between 154 and 162), iodine value (not more than 5), and saponification value (between 176 and 182).

Specific details on test material used for the study:

no data

Method

Type of population:

occupational

Ethical approval:

not specified

Subjects:

Test subjects were three human patients who had occupational sensitivity to castor bean extract.

Controls:

Seven laboratory personnel

Route of administration:

dermal

Details on study design:

Lehrer et al. (1980) evaluated the sensitivity of three human subjects (with occupational hypersensitivity to castor allergens) to castor bean extract and four Castor Wax extracts (solvent = SLS, PBS, urea-NaCl, or Triton X-100). Seven normal laboratory personnel served as controls. The test substances were applied to the skin using both patch and prick tests. Only the castor bean extract and the SLS extract of Castor Wax were evaluated in the prick test; the four Castor Wax extracts were evaluated in the patch test.

In the prick test (to detect IgE-mediated hypersensitivity), a drop of allergen extract was applied to the skin. Following application to the skin, the underlying superficial layer of the skin was pricked with a 25-gauge needle. Reactions were scored 15 min after application of the allergen. A positive prick test reaction was defined as a wheal and flare reaction with edema >5 mm. Castor bean extract was tested at concentrations up to 1000 µg/ml and, SLS Castor Wax extract, at concentrations up to 22,000 µg/ml. Results from the prick test indicated no immediate skin reactivity to castor bean extract or the SLS Castor Wax extract.

In patch tests (to detect cell-mediated hypersensitivity), a semiocclusive patch containing either of the four Castor Wax extracts (concentration not stated) or paraffin (control) was applied to the skin for 24 and 48 h. Reactions were scored at 24 and 48 h post removal.

Results and discussion

Results of examinations:

The three patients were highly sensitive to castor allergen in the prick test (positive skin reaction to 1.0 or 0.1 µg/ml castor bean extract). The patients also had a positive skin reaction to the SLS Castor Wax extract, where the level of sensitivity was 100- to 100,000-fold less than that induced by castor bean extract. None of the seven normal subjects had a delayed reaction to any of the four Castor Wax extracts that were tested. Prick test results (normal subjects) indicated no immediate skin reactivity to castor bean extract or the SLS Castor Wax extract.

Because immediate hypersensitivity to Castor Wax was observed in the three patients who were sensitive to castor bean, additional tests (prick tests) were performed to determine whether Castor Wax solubilized in different organic solvents or an underarm deodorant stick containing Castor Wax would induce irritation and elicit a positive immediate hypersensitivity reaction in these three patients. Positive skin reactions to Castor Wax (in different solvents or in a deodorant stick) were not detected.

The four Castor Wax extracts and paraffin (control) were evaluated in patch tests for cell-mediated hypersensitivity. None of the three patients had a delayed reaction to any of the four Castor Wax extracts (test concentration not stated).

Applicant's summary and conclusion

Conclusions:

In three patients with documented occupational sensitivity to castor bean, all patients showed positive skin prick test reactions to 0.1 to 1.0 µg/ml castor allergen. In addition, there were positive skin prick tests to the SLS Castor Wax extract, but at a level of sensitivity 100- to 100,000-fold less than that induced by castor bean extract. There were no positive results reported for the patch tests in patients or in controls.