...400mg Ibuprofen, three times daily with meals.

<meta> keywords are thought nowadays to have little or no bearing on search engine indexing, because they have been so thoroughly abused by authors.

I suspect you're in for a difficult struggle, because those sound like competitive keywords to rank for. If you can be more specific to your area/niche, then you have better chances. Check out your keywords in a Google search: how many results do they return? This gives you a (very) crude estimate of the challenge you face.

There's no easy way to rank well for competitive keywords, I'm afraid.