Aqueous formulations and ointments.

The development of ocular drug delivery systems has progressed greatly during the past four decades. This has resulted from better understanding of the pertinent physiological processes and from the availability of new synthetic polymers. More must be learned about the distribution of polymer solutions during the blink and their interactions with biosurfaces. In addition, awareness of the limitations placed on vehicle characteristics (e.g., viscosity, surface activity) by the variation in human eyes and more accurate extrapolation of data from relatively uncomplicated experimental models to the human eye will result in the development of even more effective ophthalmic vehicles designed for specific purposes and for particular drugs.