Table 6.

Recent patents filed dealing with ocular MEs.

Recent patents	Drugs used	Surfactants	Co-surfactants	Other ingredients	Description and outcome of the study
Sergio et al., WO 154985A1, 2011 [49]	Steroids (difluprednate), prostaglandin (latanoprost) NSAID ( diclofenac), antioxidant, and pegaptanib	d-α-tocopheryl PEG 1000 succinate	Glycerol	Vitamin E, MCT, and disodium phosphate	The inventors developed o/w ME for encapsulation of water insoluble drugs for topical ophthalmic application. The developed ME carrier remained stable for a period of 6 months displaying a particle size of 15 nm without any signs of instability or separation
Gobel, European patent EP- 2485714A1, 2012 [50]	Tacrolimus	Lecithin, decyl glucoside, span 80 (sorbitan monooleate), and brij 30 (polyoxyethylene(4)lauryl ether)	Pentylene glycol, propylene glycol, and PEG-20	Dibutyl adipate, isopropyl myristate, and tartaric acid	The transparent o/w ME for delivery of immunosuppressant agent tacrolimus is subjected to HET-CAM test and claimed to be free from signs of irritation. The particle size range varied from 5 to 100 nm. Additionally, the tacrolimus ME was found to penetrate efficiently the stratum corneum tissue and reach the dermis due to presence of lymphocyte, which is the target for the active ingredient
Carli et al., US Patent US 8414904B2, 2013 [51]	Prostaglandin analogue (latanoprost, travoprost, and bimatoprost)	Tween 80, brij 52, 56, 58	Tween 20	Ethyl oleate, miglyol 812, ricinus oil sorbitol, glycerol, chlorobutanol, and buffer (pH 7.4)	o/w MEs composed of prostaglandin formulated with two nonionic surfactants and one oily component displayed a particle size not more than 700 nm and a low zeta potential of +2 to −2 due to the use of nonionic surfactants as emulsifying agents. The formulation was claimed to be free from any signs of irritation on rabbit eyes. The ME remained stable for a period of 12 months