Good idea! That will certainly work better than "Other Income" as Blackriver proposed.
Let's see, first we'll have to name our business. How about Phreelance Pharmaceutical Enterprises, with a subsidiary, Whackmaster Service Company. Hmmm, that means two separate Form C's. Okay, then on Line A we'll have to describe the professional activities that provided the principal source of income reported on Line 1 (gross receipts). Let's see... Product Marketing and Distribution for the first, and maybe, Accounts Receivable Collections and Maintenance of Territorial Integrity for the second. There are other informational requirements, as well, which I am sure Blackriver will no trouble completing. Go for it, Blackriver! You're almost home free.