"A very good indication of the success of the prodrug approach can be obtained by examining the prevalence of prodrugs on the market. It might come as a surprise to many people that currently approximately 10% of all globally marketed medicines can be classified as prodrugs, and in 2008 alone, 33% of all approved small-molecular-weight drugs were prodrugs (Rautio, 2010; Stella, 2010). Despite these impressive numbers, we have only begun to appreciate the full potential of the prodrug approach in modern drug development, and many novel prodrug innovations await discovery. "

from your link

http://m.pharmrev.aspetjournals.org/content/63/3/750.full

Go Prurisol! Go CTIX!