Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics in vitro / ex vivo
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:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Objective of study:
other: Hydrolysis of the test substance under gastric conditions
Principles of method if other than guideline:
Hydrolysis of the test substance (recording of 13C and 1H NMR spectra) was investigated immediately after adding aqueous test substance to pH 4 buffer (conc. = 0.1 %) and after incubation at 37 °C for 1, 2 and 6 hours. By spiking this solution with MEA (monoethanol amine), methanol, and formaldehyde, the decomposition of the test substance was investigated. Additionally, hydrolysis was investigated at pH 5, 7, and 9.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
No details.
Radiolabelling:
no

Administration / exposure

Details on study design:
For all NMR measurements 0.7 mL of each test solution had to be transfered into a 5-mm NMR-tube. Capillaries filled with D2O and Na-trimethylsilylpropionic acid served as lock purpose and reference.
1H NMR spectra of all samples were measured at 22 °C using a Bruker system operating at 360 MHz. The 1H NMR spectra were recorded immediately after the preparation of the sample, after 1, 2 and 6 hours. The spectra obtained were processed using a lb value of 1.
13C NMR spectra of all samples were measured at 22 °C using a Varian system operating at 600 MHz. The spectra obtained were processed using a lb value of 5.

Results and discussion

Main ADME results
Type:
other: hydrolysis
Results:
the test substance is instable under simulated gastric conditions (pH 4).

Any other information on results incl. tables

The test substance shows a dramatic instability in aqueous solution at pH values of 4 and 7. 1H NMR spectra recorded directly after preparation of the 0.1 % test substance solution showed only signals of monoethanol amine which was confirmed by recording additional 13C NMR spectra (due to sensitivity reasons recorded with a 0.5 % aqueous solution). The latter showed also the signal of formaldehyde which is also a decomposition product of the test substance. No traces of methanol were found.

An aqueous solution of the test substance at pH 9 showed immediately after preparation signals for a mixture of undecomposed test substance, monoethanol amine and formaldehyde. Again no methanol could be detected.

Applicant's summary and conclusion