Comparison of Consecutive Therapeutic Effects of Nanoemulsion and Emulsion Cyclosporin in Dry Eye Patients after Short-Term Treatment with Topical Fluorometholone

Purpose

To compare the consecutive therapeutic effects of 0.05% emulsion and nanoemulsion cyclosporine (CsA) in dry eye patients after short-term treatment with unpreserved 0.1% fluorometholone (FML).

Methods

A prospective, randomized, and double-blinded study of dry eye patients was conducted in a single center. Patients were assigned to the nanoemulsion CsA (group 1) and emulsion CsA (group 2) groups. To relieve discomfort, unpreserved 0.1% FML was used in both groups for 4 weeks and then changed to 0.05% CsA for the next 8 weeks. Symptom assessment in dry eye (SANDE) score, tear secretion, tear film breakup time (TBUT), corneal staining score (CSS), meibomian gland dysfunction (MGD) grade, and meibomian gland (MG) expression were evaluated at baseline and at 4 and 12 weeks after treatment.

Results

Twenty-four patients completed the treatment (9 and 15 patients in groups 1 and 2); in both the groups, SANDE score, TBUT, MGD grade, and MG expression were significantly improved after treatment with unpreserved 0.1% FML (each p < 0.005), and the therapeutic effects were enhanced with changes in nanoemulsion or emulsion CsA compared with baseline (each p < 0.001). TBUT and CSS after treatment in group 1 were significantly improved compared to those in group 2 (p=0.003 and 0.020, respectively).

Conclusion

Consecutive therapeutic effects of nanoemulsion or emulsion CsA after short-term treatment with unpreserved FML were excellent in patients with dry eyes. Topical nanoemulsion CsA showed better improvement in TBUT and OSS than CsA. This trial is registered with KCT0006070.

Novel Ocular Drug Delivery Systems: An Update on Microemulsions

Sufficient ophthalmic drug delivery is still challenging for pharmaceutical technologists, despite various scientific efforts. Several ocular drug carriers have been designed to enhance bioavailability by prolonging the drug retention time. One of the current encouraging approaches is the utilization of colloidal carriers with the characteristic submicron-nanometer size. Microemulsions (MEs) are such colloid systems that present sizes between 5 and 200 nm with significant thermodynamic stability and low surface tension. In addition, MEs as topical ocular carriers can lead to great ocular drug adsorption due to their enhanced retention time. Furthermore, considering that MEs are stable for long time and various temperatures, their ocular application is of great interest. The aim of this study is to cover basic physicochemical principals of ocular MEs such as their possible size, stability, and therapeutic efficacy against various eye disorders. Thus, a comprehensive review for ocular drug delivery systems in the form of MEs that show promising characteristics as their stability and therapeutic efficiency is performed.