Compounded Preparation - KCl in D5W Admixture - includes a reference to a substance in the ingredient element

{
  "resourceType" : "Medication",
  "id" : "med0317",
  "doseForm" : {
    "coding" : [{
      "system" : "http://snomed.info/sct",
      "code" : "385219001",
      "display" : "Solution for injection"
    }],
    "text" : "Solution for injection"
  },
  "ingredient" : [{
    "item" : {
      "concept" : {
        "coding" : [{
          "system" : "http://www.nlm.nih.gov/research/umls/rxnorm",
          "code" : "8591"
        }],
        "text" : "Potassium Chloride"
      }
    },
    "strengthRatio" : {
      "numerator" : {
        "value" : 20,
        "system" : "http://unitsofmeasure.org",
        "code" : "meq"
      },
      "denominator" : {
        "value" : 1000,
        "system" : "http://unitsofmeasure.org",
        "code" : "mL"
      }
    }
  },
  {
    "item" : {
      "concept" : {
        "coding" : [{
          "system" : "http://www.nlm.nih.gov/research/umls/rxnorm",
          "code" : "313002",
          "display" : "sodium chloride 9 MG/ML Injectable Solution"
        }],
        "text" : "1000 ml glucost 50mg/ml Injection"
      }
    },
    "strengthRatio" : {
      "numerator" : {
        "value" : 5,
        "system" : "http://unitsofmeasure.org",
        "code" : "g"
      },
      "denominator" : {
        "value" : 100,
        "system" : "http://unitsofmeasure.org",
        "code" : "mL"
      }
    }
  }]
}