diff --git a/ISO/ISO11238-Substances.rdf b/ISO/ISO11238-Substances.rdf
index 1c7de127..e0ca70b1 100644
--- a/ISO/ISO11238-Substances.rdf
+++ b/ISO/ISO11238-Substances.rdf
@@ -209,6 +209,7 @@
single substance that can be described as a stoichiometric or non-stoichiometric single molecular entity and is not a protein, nucleic acid or polymer substance
Chemical substances are generally considered 'small' molecules which have associated salts, solvates or ions and may be described using a single definitive or representative structure.
+
ISO 11238:2018 Health informatics - Identification of medicinal products (IDMP) - Data elements and structures for the unique identification and exchange of regulated information on substances, clause 3.11
@@ -510,6 +511,7 @@
The strength of a medicinal product is often based on what is referred to as the active moiety of the molecule, responsible for the physiological or pharmacological action of the drug substance. To avoid ambiguity, the free acid and/or free base should be used as the moiety upon which strength is based.
The active moiety of a stoichiometric or non-stoichiometrical substance molecule is considered that part of the molecule that is the base, free acid or ion molecular part of a salt, solvate, chelate, clathrate, molecular complex or ester.
The moiety subclause serves for the description of both the moiety and the other fragment constituting the substance. The Element Group Moiety is attached to the element class Chemical in order to describe a salt, solvate and co-crystal relationship to the active moiety in an unambiguous way with respect to the description of the molecular formula and sometimes the official names. The Element Group Amount is attached to Moiety. This will help to describe salts, solvates, hydrated substances and co-crystallising agents in a more unambiguous way with respect to the description of the molecular formula and sometimes official names. Each moiety within the chemical substance is to be identified and the composition range of the moieties when known is to be provided by means of the following data elements: If the numeric value of the element 'Number of Moieties' is equal to 1, the class Moiety should not be used; otherwise the class shall always be mandatory.
+
ISO 11238:2018 Health informatics - Identification of medicinal products (IDMP) - Data elements and structures for the unique identification and exchange of regulated information on substances, clause 3.45