Nanoemulsions are
considered as the most promising solution to
improve the delivery of ophthalmic drugs. The design of ophthalmic
nanoemulsions requires an extensive understanding of pharmaceutical
as well as technological aspects related to the selection of excipients
and formulation processes. This Review aims at providing the readers
with a comprehensive summary of possible compositions of nanoemulsions,
methods for their formulation (both laboratory and industrial), and
differences between technological approaches, along with an extensive
outline of the research methods enabling the confirmation of
in vitro
properties, pharmaceutical performance, and biological
activity of the obtained product. The composition of the formulation
has a major influence on the properties of the final product obtained
with low-energy emulsification methods. Increasing interest in high-energy
emulsification methods is a consequence of their scalability important
from the industrial perspective. Considering the high-energy emulsification
methods, both the composition and conditions of the process (e.g.,
device power level, pressure, temperature, homogenization time, or
number of cycles) are important for the properties and stability of
nanoemulsions. It is advisible to determine the effect of each parameter
on the quality of the product to establish the optimal process parameters’
range which, in turn, results in a more reproducible and efficient
production.