Table 8.

Features of nanosuspensions in ocular drug delivery.

Reasons for the Development of Ocular Nanosuspensions	Challenges to Be Overcome	Specific Studies
Increased saturation solubility and dissolution Increased permeation İncreased contact/retention time on the ocular site Increased transcorneal penetration Enhancement of specific effects on the ocular site Enhancement of ocular bioavailability Providing better drug stability The rapid formulation development process Using directly as liquid dosage form Convertibility to semi-solid dosage form (cream, ointment, gel, etc.) Possibility for controlled released systems Possibility of mucoadhesion on the ocular site Reduction in drug dose Reduction in side effects Reduction in toxicity	Challenging in selection of stabilizer type and ratio Challenging to design formulation for crossing the cornea and reaching the intraocular tissue Overcoming physical (Ostwald ripening, agglomeration) and chemical (hydrolysis) stability issues Usually requires some excipients such as viscosity enhancers, pH and charge modifiers, or a carrier to apply Requirement for sterilization	pH values Rheological/mechanical properties Surface tension Saturation solubility Stability Corneal residence time In vitro release/ex vivo ocular permeation In vitro transcorneal penetration Ocular irritation In vivo performance after ocular application Corneal bioavailability