Personally I wouldn't venture into that business, but for the sake of argument, here's how I would approach it:
1. Find a niche ailment that has low competition but high enough demand to satisfy a small business's needs e.g anal boils.
2. Build a minimum viable product. No flashy stuff, don't waste your time with too much legal mumbo jumbo, just make a pill that works. To build this prototype shouldn't be too expensive. Fund this using friends, family and fools.
3. Test the market using this prototype. Get at least three retailers to place an order for your product.
4. Expand in your niche once you prove the viability of your product through sales(if it doesn't sell well, you can cut your losses at this point). Use the profits and orders off of that initial Minimum Viable Product to plead your case for financing for expansion. Become the anal boils go-to guy. Now you can do those legal things. There you go, you are now the proud owner of an anal boils pharmaceutical.