Development of microemulsions for ocular delivery. 
Microemulsions (MEs) are thermodynamic stable dispersion of oily phase and aqueous phase stabilized by surfactants and co-surfactants, and are a small droplet size of less than 100 nm.  MEs are appropriate systems for ocular drug delivery because they improve ocular drug retention, extended duration of action, high ocular absorption, permeation of loaded drugs and effortlessness of preparation and administration.  This review is an effort to summarize the recent development in the area of MEs, self-emulsifying drug delivery systems, which are examined in relation to their uses in ocular drug delivery.  The noteworthy patent, toxicity and stability issues related to these ME systems are also explored here.