No inactive_ingredient field when query for drug substance in Drug Label API

Question

I am looking for the inactive ingredients for a dozen of different drugs. However when querying in the Label API, most results return without an "inactive_ingredient" field. The field only exists in the Fields Reference Document: https://open.fda.gov/apis/drug/label/searchable-fields

Example1, Propofol search: https://api.fda.gov/drug/label.json?search=openfda.substance_name:propofol&limit=3

Examlpe2, Albuterol search: https://api.fda.gov/drug/label.json?search=openfda.substance_name:albuterol&limit=3

No inactive_ingredient field is found in any of these queries.

Answer 1

This means that the inactive ingredients section is missing from the drug label SPL file.