Generic drugs for the treatment of ocular conditions: changing the treatment landscape.

As global spending on medicinal products continues to rise, the availability of lower-cost generic substitutes is increasingly driving health care decision-making. US FDA does not require strict demonstration of human bioequivalence and/or therapeutic studies for the approval of generic ophthalmic compounds. Bioequivalence between generic and innovator compounds is presumed on the basis of matching active and inactive ingredient profiles. Generic compounds may differ from innovator agents with regards to performance under environmental stress, relative acidity and bottle size/rigidity. Matching ingredient profiles may therefore not result in consistently comparable drug compositions and clinical effects.