Nanosuspension-based Ocular Therapeutics for Infection Control: Integrating Mucin Interactions and Tear Film Dynamics

Ocular infections can affect the ocular surface and adnexal structures, intraocular structures, or both. Infections of the ocular surface and adnexa often arise from the invasion of commensals when typical barriers are compromised, which includes infectious blepharitis, conjunctivitis, keratitis, dacryocystitis, and orbital infections, among others. Intraocular infections may develop due to localised trauma or as part of a systemic condition. A variety of viruses, bacteria, fungi, protozoa, and helminths can cause intraocular illness. Occasionally, ocular abnormalities are the only external clinical indications of systemic infectious diseases. Analyzing specimens from ocular tissues or fluids can aid in diagnosing ocular infectious diseases and may help identify systemic infections. The management of ocular illnesses generally involves the topical application of antimicrobials and anti-inflammatory agents, along with targeted therapy addressing the underlying etiologies. In some cases, systemic antibacterial agents or glucocorticoids may be necessary. Addressing an inflamed or infected eye in an emergency context poses a diagnostic and therapeutic challenge for the emergency physician, with aetiology and prognoses varying from benign, self-limiting conditions to organ-threatening diseases. To address these ocular infections, the market has evolved with various therapeutics-based eye drops that are instilled specifically into the lower precorneal pocket and are regarded as the most patient-compliant method of drug delivery. Nevertheless, the efficacy of this approach is significantly reduced by the blink reflex, resulting in the loss of most of the topical dose. In this regard, nanosuspensions, which disperse hydrophobic drugs in an aqueous medium stabilised by surfactants, offer a promising strategy for mitigating ocular infections. Overall, this review aims to thoroughly examine the applicability of nanosuspensions in ocular drug delivery to target and treat infections in the human eye.