Butylchlorodihydroxystannane

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

7 February 2018 to 9 May 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Objective of study:

other: hydrolysis as a function of pH

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Butylhydroxyoxostannane

EC Number:

218-880-1

EC Name:

Butylhydroxyoxostannane

Cas Number:

2273-43-0

Molecular formula:

C4H10O2Sn

IUPAC Name:

butyl(oxo)stannanol

Test material form:

solid

Details on test material:

- Appearance: white solid

Radiolabelling:

not specified

Results and discussion

Any other information on results incl. tables

HYDROLYSIS AT PH 4.0, 7.0, and 9.0:

- All samples did not show significant changes in the 119Sn-NMR Spectrum

- The half-life time of the substance under the conditions of the study was > 1 year.

- The substance is considered as hydrolytically stable at pH 4, 7, 9

- The signals propose a dimeric tetraorganodistannoxane structure. Those structures are formed following a stepwise hydrolysis of initially formed diorganotin hydroxides.

HYDROLYSIS AT PH 1.2

- The 119Sn-NMR spectrum of the organic extract shows a decrease of the products peak and an increase of the breakdown product, the monochloride of the substance DOT(-Neo)Cl.

- The 119Sn-NMR spectrum shows only one signal in pH 1.2 not any longer the typical signal for dimeric MBTO (distannoxane). The single signal can be assigned to monomeric monobutylstannonic acid.

Applicant's summary and conclusion

Conclusions:

The study shows that the test material is hydrolytically stable at pH 4, 7, 9. After 5 days of hydrolysis at 50°C less than 10% of the test material was hydrolysed (half life at 25°C > 1 year).
Under simulated gastric conditions (0.1 M HCl /pH 1.2 /40°C/ 4 h) the 119Sn-NMR spectrum shows only one signal in pH 1.2 not any longer the typical signal for dimeric MBTO (distannoxane). The single signal can be assigned to monomeric monobutylstannonic acid.

Executive summary:

The hydrolysis of the test material as a function of pH was investigated in accordance with the standardised guidelines OECD 111 and EU Method C.7.

The stability of the test material was investigated at pH 4, 7 and 9 and pH 1.2 using NMR spectroscopy.

The study shows that the test material is hydrolytically stable at pH 4, 7, 9. After 5 days of hydrolysis at 50°C less than 10% of the test material was hydrolysed (half life at 25°C > 1 year).

Under simulated gastric conditions (0.1 M HCl /pH 1.2 /40°C/ 4 h) the 119Sn-NMR spectrum shows only one signal in pH 1.2 not any longer the typical signal for dimeric MBTO (distannoxane). The single signal can be assigned to monomeric monobutylstannonic acid.