# Commission Regulation (EU) No 544/2011 of 10 June 2011 implementing Regulation (EC) No 1107/2009 of the European Parliament and of the Council as regards the data requirements for active substances (Text with EEA relevance) (repealed), Division 2.9.1

Extent: E+W+S+N.I.

The hydrolysis rate of purified active substances (usually radiolabelled active substance, > 95 % purity), for each of the pH values 4, 7 and 9, under sterile conditions, in the absence of light, must be determined and reported in accordance with method C 7 of Regulation (EC) No 440/2008. For substances with a low rate of hydrolysis, the rate can be determined at 50 °C, or another appropriate temperature.
If degradation is observed at 50 °C, degradation rate at another temperature must be determined, and an Arrhenius plot must be constructed to permit an estimate to be made of hydrolysis at 20 °C. The identity of hydrolysis products formed and the rate constantly observed, must be reported. The estimated DT50 value must also be reported.

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Source: https://www.legislation.gov.uk/eur/2011/544/annex/part/A/division/2/division/2.9/division/2.9.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2011-544/annex/part-A/division-2/division-2.9/division-2.9.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.