If you use different concentrations of the same medication, then simply create a new medication label template with the same medication name and change the concentration.
For example, if the app has “Lidocaine 1%” already in the database, but you sometimes use “Lidocaine 2%” as well, then tap on Plus icon on the upper right of the “Edit Labels” view. Enter all of the pertinent drug information in each field. After this has been done, “Lidocaine 1%” and “Lidocaine 2%” will now appear in the list of drugs.