Disclosed herein are pharmaceutical compositions of 5-hydroxy-2- methylnaphthalene-l,4-dione. Also disclosed are methods of treating diseases and/or conditions associated with a cancer, such as prostate cancer with such pharmaceutical compositions of 5-hydroxy-2-methylnaphthalene-l,4-dione. The disclosed pharmaceutical compositions may provide improved dosage for oral administration to patients in the clinic. The disclosed pharmaceutical compositions may provide improved stability and/or shelf life.