Sodium N-chlorobenzenesulphonamide

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Although information on test material is limited, the study was performed according to valid methods; therefore it is considered adequate, relevant and reliable.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 428 (Skin Absorption: In Vitro Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC method No. 1907/2008

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

CAS 127-52-6 trihydrate

IUPAC Name:

CAS 127-52-6 trihydrate

Test material form:

solid: crystalline

Details on test material:

Substance arrived 4 August 2010, otherwise no data.

Radiolabelling:

no

Test animals

Species:

pig

Strain:

not specified

Sex:

not specified

Administration / exposure

Duration of exposure:

Skin preparation 1 (1h), preparation 2 (2h), preparation 3 (4h), preparation 4 (6h), preparation 5 (8h), preparation 6 (24h) at laboratory temperature (cell system maintained at 34°C).

Doses:

Application to the skin: 40 µL of the test sample was applied using an automatic pipette on the skin preparations. In each of the two independent runs 6 skin preparations were used.
Quantification of the applied dose: the applied dose was weighed up 3x, the average value was used for calculations.

Details on in vitro test system (if applicable):

Full-thickness porcine skin supplied by B+B Agro, 289 01 Číněves, without scalding, was used in the test. A sheet of skin from both sides of the backbone (cca 40 x 70 cm) was treated in the laboratory within 6 hours after slaughter. The subcutaneous fat was removed using electrical knife and blunt butcher knife.The skin was shaved by electrical shaver, washed with lukewarm water and let to dry. With a punching pin the skin was divided into disc-shaped pieces, (diameter 5cm), which were stored in vacuum bags with designated date of preparation and frozen (-18°). Prior to testing (2-3 hours) the skin preparations were defrozen on air at laboratory temperature.
Metabolic status: metabolically non-active.

Apparatus for skin absorption:
The used static Franz diffusion cells consisted of a donor chamber (in the form of a glass cap with an opening in the center) and receptor chamber double bottom glass diameter cca 2 cm,volume cca 5 mL).The receptor fluid was applied in the receptor chambers, the cells were connected by a system of tubes with a water bath and the temperature was maintained at 34°C. The system was placed on a magnetic stirrer (Variomag Poly, Labortechnik AG, Germany) set for 310 rPm.

Procedure of fractionation: at the end of exposure the skin surface was wiped using a metal spatula (fraction 1), the skin preparation was then cut into small pieces (fraction 2) and the receptor fluid was collected (fraction 3) .

Extraction: extraction vehicle 2-propanol (SIGMA-ALDRICH)
Fraction 1 from the spatula was washed with 4 mL of extraction vehicle. Fraction 2 (skin) was extraced in the extraction vehicle for 24 h at laboratory temperature, homogenized in an ultrasonic bath for 15 min and filtered using Spartan 3O/0,2 RC filters( Schleicher+Schuell).

Method for determination of the tested compound:
Fraction 1 and fraction 3 were analysed immediately after the end of exposure, fraction 2 was analyzed after the 24 hour extraction.
Determination of chloramine-B and its primary degradation product benzenesulfonamide was carried out by means of HPLC-UV method. The
method was used for determination of chloramine-B and benzensulfonamide in the 2-propanol extracts of the skin wipes, whole skin and in the receptor fluid. The resulting concentrations of tested compounds in the analyzed fractions were determined using a calibration curve.

Equipment, column, mobile phase:
HPLC chromatograph ECOM, two pumps LCP 4020, UV-VIS detector LCD
2083, mobile phase mixer Knauer, autosampler HT300L.
The parameters of HPLC analysis are listed below:
- Column: Chromolith performance R P-18E, 100-4.6, Merck
- Guard column: Chromolith RP-18E,10-4.6, Merck
- Mobile phase: 20% methanol in phosphate buffer (pH 3)
- Flow rate: 1 mL/min
- Detection wavelength: 220 nm
- Injection: 20 µl

Results and discussion

Absorption in different matrices:

Chloramine B was not found in any analyzed fraction in either experiment. Overall recovery of the degradation product of chloramine B (benzenesulfonamide) in both experiments is presented in table 1.

Total recovery:

In the receptor fluid, skin preparation and the on skin surface, only Benzenesulfonamide, the primary degradation product of Chloramine B, has been detected. The tested applied substance, Chloramine B, has not been found in any of the analysed fractions. The penetration of benzenesulfonamide is very low up to 6 hours after application (max.1.18%) and low after 24 hours after application (max.7 .98%).

Percutaneous absorption

Percutaneous absorption 1

Dose:

40 µL

Parameter:

percentage

Absorption:

0 %

Remarks on result:

other: 1, 2, 4, 6, 8, 24 h

Remarks:

Chloramine B trihydrate

Percutaneous absorption 2

Dose:

40 µL

Parameter:

percentage

Absorption:

>= 5.1 - <= 7.98 %

Remarks on result:

other: 24h

Remarks:

Benzenesulfonamide

Any other information on results incl. tables

Table 1. Recovery of benzenesulfonamide in the experiments

Duration of exposure	Recovery (%)
	Experiment 1			Experiment 2
	fraction 1	fraction 2	fraction 3	fraction 1	fraction 2	fraction 3
1h	16.84	61.43	0.08	14.61	75.60	0.00
2h	11.40	65.53	0.39	11.68	74.36	0.09
4h	10.18	93.29	0.83	8.95	83.36	0.18
6h	10.13	75.45	1.18	8.84	86.06	0.36
8h	6.45	69.83	3.36	5.87	85.58	2.18
24h	6.29	60.02	5.10	4.51	80.58	7.98

Applicant's summary and conclusion

Conclusions:

After application on skin, Chloramine B was not detected in any of the analysed fractions and receptor fluid, it is not absorbed in the skin and does not penetrate. Only the presence of its degradation product, benzenesulfonamide, was detected in the skin fractions and receptor fluid. After short-term exposure its penetration is negligible, after 24 h exposure its penetration is low.

Executive summary:

 Chloramine B was tested in vitro on full-thickness porcine skin according to OECD TG 428 method. Disc-shaped pieces, (diameter 5cm) were defrozen prior to testing (2-3 hours). Metabolic status was metabolically non-active. 40 µL was applied for different durations (1h, 2h, 4h, 6h, 8h and 24h). At the end of exposure the skin surface was wiped using a metal spatula (fraction 1), the skin preparation was then cut into small pieces (fraction 2) and the receptor fluid was collected (fraction 3) .

After application on skin, Chloramine B was not detected in any of the analysed fractions and receptor fluid, it is not absorbed in the skin and does not penetrate. Only the presence of its degradation product, benzenesulfonamide, was detected in the skin fractions and receptor fluid. After short-term exposure its penetration is negligible, after 24 h exposure its penetration is low.