3-(2-hydroxyethyl)-p-phenylenediammonium sulphate

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 428 (Skin Absorption: In Vitro Method)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3-(2-hydroxyethyl)-p-phenylenediammonium sulphate

EC Number:

298-995-1

EC Name:

3-(2-hydroxyethyl)-p-phenylenediammonium sulphate

Cas Number:

93841-25-9

Molecular formula:

C8H12N2O.H2O4S

IUPAC Name:

2-(2,5-Diaminophenyl)ethanol sulfate (1:1)

Specific details on test material used for the study:

INCI name : Hydroxyethyl-p-phenylenediamine sulfate
Raw material name : Betoxol II
Trade name : Jarocol BTX
Batch number : 36/37
Purity by HPLC : 99.8a/a%
Assay by NMR : 99.9%

Radiolabelling:

yes

Results and discussion

Any other information on results incl. tables

The results of the cutaneous absorption experiment with 6 pig skin samples treated with 1.5mg test item/cm2 (1.5% of hydroxyethyl-p-phenylenediamine sulfate (Betoxol II) in formulation in the presence of a reaction partner and 3% hydrogen peroxide) are prsented below.

	Skin number	Integrity test/[% dose]	1/[ug/cm2][% dose]	2/[ug/cm2][% dose]	3/[ug/cm2][% dose]	4/[ug/cm2][% dose]	Total/[ug/cm2][%dose]
1.5mg test item in 100mg of formulation per 1 cm2 skin	2	0.34	[1.27]/[0.10]	[7.30]/[0.56]	[0.76]/[0.06]	[960.9]/[74.3]	[1212.3]/[93.7]
	4	0.41	[1.09]/[0.09]	[5.31]/[0.41]	[0.71]/[0.06]	[1022.2]/[79.8]	[1283.1]/[100.1]
	6	0.39	[1.08]/[0.09]	[4.92]/[0.39]	[1.12]/[0.09]	[997.6]/[78.8]	[1273.7]/[100.6]
	8	0.26	[2.18]/[0.17]	[5.18]/[0.40]	[0.85]/[0.07]	[982.0]/[76.3]	[1238.7]/[96.2]
	10	0.42	[1.85]/[0.14]	[6.12]/[0.48]	[0.48]/[0.04]	[1001.3]/[78.0]	[1261.9]/[98.3]
	12	0.36	[0.66]/[0.05]	[7.31]/[0.57]	[0.86]/[0.07]	[1008.7]/[79.0]	[1276.1]/[99.1]
	mean	0.36	[1.36]/[0.11]	[6.02]/[0.47]	[0.80]/[0.06]	[995.5]/[77.7]	[1257.6]/[98.1]
	+/-sd	0.06	[0.56]/[0.04]	[1.07]/[0.08]	[0.21]/[0.02]	[21.5]/[2.04]	[27.1]/[2.7]

Integrity test : 3H2O permeation (4 hours cumulative)

1 :Receptor fluid (72 hours cumulative)

2: Epidermis (72 hours cumulative)

3: Upper dermis (72 hours cumulative)

4 : Rinsing solution (after 60 minutes)

Total : 1 +2 +3 +4

Applicant's summary and conclusion

Conclusions:

The cutaneous absorption of Betoxol II in formulation (a typical hair dye formulation for oxidative dyes in the presence of a reaction partner and hydrogen peroxide) was measured by scintillation counting with pig skins in vitro. After application of 100mg/cm2 formulation containing 1.5% of Betoxol II (=1.5mg test item/cm2) for 60 minutes on skin samples and subsequent rinse-off with water and shampoo, a maximal amount of 0.11 +/-0.04% of the applied dose (1.36 +/-0.56ug/cm2) could have passed through the skin barrier during the 72 hours permeation. In addition 0.06 +/-0.02% of the applied dose (0.80 +/-0.21ug/cm2) could be found in the upper dermis and 0.47 +/-0.08% of the applied dose (6.02 +/-1.07ug/cm2) in the epidermis (total recovery 98.1%). After 72 hours small amounts of Betoxol II were found in the receptor fluid, in upper dermis and epidermis. There is an indication of a depot effect with the kinetics observed. Under the present conditions of application (rinse off) and experimental time, as a worst case scenario an amount of the applied Betoxol II of 8.18 +/-1.22ug/cm2 (n=6, one donor; receptor fluid + upper dermis + epidermis) is considered as biologically available.

Executive summary:

The cutaneous absorption of Hydroxyethyl-p-phenylenediamine sulfate (Betoxol II) in formulation, a typical hair dye formulation was investigated in vitro using pig skin preparations measuring 0.89 +/- 0.04mm thickness, which were continuously rinsed from underneath with physiological receptor fluid at a temperature of 32 +/- deg C. After checking the skin integrity, the formulation containing 1.5% of test item, partially 14C labelled, was mixed with one volume of 6% Welloxon (6% hydrogen peroxide) and applied to the skin samples (1.5mg test item/cm2) in a practice relevant manner for 60 minutes and subsequently washed off with water and shampoo. The determination of the amount of test item in the washings was performed by scintillation counting. At 16, 24, 40, 48, 64 and 72 hours, the content of the test item in the receptor fluid as well as after 72 hours the content extracted from the skin (epidermis and upper dermis separated) was determined in the same way. the integrity of each skin preparation was demonstrated by examination of penetration characteristics with tritiated water resulting in 0.26 to 0.42% of the applied dose found in the receptor fluids, which was within the limit of acceptance (<=0.6%) for the skin samples. After 72 hours Betoxol II was found in the receptor fluid, in upper dermis and epidermis and the kinteics indicates a possible depot effect. Under the present conditions of application (rinse off) and experimental time, as a worst case scenario an amount of the applied Betoxol II of 8.18 +/-1.22ug/cm2 (n=6, one donor; receptor fluid + upper dermis + epidermis) is considered as biologically available.