That really depends a lot on the nature of the drug, where it needs to be to produce the appropriate effect, and how much SAR and development work you have done or are willing to do. This is an old problem with many different possible solutions and several books have been written about various techniques to solve it.
When solubility is the only issue, changing salt forms can sometimes get you the solubility you need. Since you also have metabolism issues, the second easiest answer would be to try to develop a pro-drug. Going up the technology scale, you can get into linking your drug to active transport targets, or even packaging in a wide variety of untargeted or targeted nanoparticles.
But unless you really have knife-edge SAR where there is no place on the molecule that you can alter properties without killing activity, the investment in targeted synthesis to try to develop a compound which is biologically active and has the physico-chemical properties you need to get it into the body nearly always pays off better than the investment in development required to get an otherwise intractable molecules delivered.