Request using Medication Code for Inhaler - Proventil - on hold with dispenseRequest and substitution

{
  "resourceType" : "MedicationRequest",
  "id" : "medrx0326",
  "identifier" : [{
    "use" : "official",
    "system" : "http://www.bmc.nl/portal/prescriptions",
    "value" : "12345689"
  }],
  "status" : "on-hold",
  "intent" : "order",
  "medication" : {
    "concept" : {
      "coding" : [{
        "system" : "http://www.nlm.nih.gov/research/umls/rxnorm",
        "code" : "746763",
        "display" : "NDA020503 200 ACTUAT albuterol 0.09 MG/ACTUAT Metered Dose Inhaler [Proventil]"
      }]
    }
  },
  "subject" : {
    "reference" : "Patient/pat1",
    "display" : "Donald Duck"
  },
  "authoredOn" : "2015-01-15",
  "requester" : {
    "reference" : "Practitioner/f007",
    "display" : "Patrick Pump"
  },
  "dosageInstruction" : [{
    "sequence" : 1,
    "text" : "Use two sprays twice daily",
    "additionalInstruction" : [{
      "text" : "Shake Well"
    }],
    "timing" : {
      "repeat" : {
        "frequency" : 2,
        "period" : 1,
        "periodUnit" : "d"
      }
    },
    "doseAndRate" : [{
      "type" : {
        "coding" : [{
          "system" : "http://terminology.hl7.org/CodeSystem/dose-rate-type",
          "code" : "ordered",
          "display" : "Ordered"
        }]
      },
      "doseQuantity" : {
        "value" : 1,
        "unit" : "ea",
        "system" : "http://terminology.hl7.org/CodeSystem/v3-orderableDrugForm",
        "code" : "ORINHL"
      }
    }]
  }],
  "dispenseRequest" : {
    "validityPeriod" : {
      "start" : "2015-01-15",
      "end" : "2016-01-15"
    },
    "numberOfRepeatsAllowed" : 3,
    "quantity" : {
      "value" : 30,
      "unit" : "mL",
      "system" : "http://unitsofmeasure.org",
      "code" : "mL"
    },
    "expectedSupplyDuration" : {
      "value" : 30,
      "unit" : "days",
      "system" : "http://unitsofmeasure.org",
      "code" : "d"
    }
  },
  "substitution" : {
    "allowedBoolean" : true,
    "reason" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/v3-ActReason",
        "code" : "FP",
        "display" : "formulary policy"
      }]
    }
  }
}