When you search SNOMED CT for a medication such as Ibuprofen, you will find many possible matches, two of which are: 
- Ibuprofen (substance) SCTID 387207008
- Product containing Ibuprofen (medicinal product) SCTID 38268001
There are two top-level domains of interest: Substance and Pharmaceutical/Biologic Product, as shown above. Thus, you should select the concept belonging to the right domain for your purpose. How do they relate?
Product containing Ibuprofen (medicinal product) SCTID 382
↓ Has active ingredient
Ibuprofen (substance) SCTID 387207008
Keep in mind that SNOMED CT distinguishes between Product containing Ibuprofen (medicinal product) SCTID 38268001 and Product containing only Ibuprofen (medicinal product) SCTID 776287003. The latter is a child of the former. We show part of the hierarchy here (you can look at the full hierarchy in the SNOMED CT browser):
Product containing Ibuprofen (medicinal product)
↓
Product containing only Ibuprofen (medicinal product)
↓
Product containing only Ibuprofen in oral dose form (medicinal product form)
↓
Product containing precisely Ibuprofen 200 milligram/1 each conventional release oral tablet (clinical drug)
The new SNOMED CT Pharmaceutical/Biologic Product model, released in 2018, has added clarity to make clear whether a concept is a product versus a substance. Prior to 2018, the concept Product containing Ibuprofen (pharmaceutical/biological product) had the Preferred Term Ibuprofen, which is also the Preferred Term for the Ibuprofen (substance) concept. Thus, it is possible for the user to select the wrong concept inadvertently in a quick search for that term. In the new pharmaceutical product model, the Preferred Term for this concept became Ibuprofen only product, making a distinction from the substance. Note that the concepts in the hierarchy shown above all have a “has active ingredient” relationship to the Ibuprofen (substance) concept.
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