description: Substance for marking the basis of strength. When the precise active ingredient is a salt, the strength is often provided for the active moiety (basis of strength). package_name: ihe.pharm.mpd.r4 derivation: constraint name: MedicationStrengthSubstance type: Extension elements: extension: {index: 0} url: pattern: {type: uri, value: 'https://profiles.ihe.net/PHARM/MPD/StructureDefinition/ihe-ext-medication-strengthsubstance'} type: uri index: 1 value: choices: [valueCodeableConcept] index: 3 valueCodeableConcept: {type: CodeableConcept, choiceOf: value, index: 4} package_version: 1.0.0-comment-2 extensions: {} class: extension kind: complex-type url: https://profiles.ihe.net/PHARM/MPD/StructureDefinition/ihe-ext-medication-strengthsubstance base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.0.0-comment-2 required: [value, valueCodeableConcept]