Ocular delivery of cyclosporine A using dissolvable microneedle contact lens

The penetration of large molecular weight and poorly aqueous soluble drugs within the cornea has been a limiting factor in the treatment of ocular conditions. The objective of the present study was to fabricate rapidly dissolving polymeric microneedle ocular patch (MOP) to effectively deliver cyclosporine A (CsA) within the cornea. Microneedles were prepared using polyvinyl pyrrolidone by micromolding technique with contact lens design features. The model macromolecule, CsA, was loaded in MOP in a bilayered approach, where CsA was entrapped in 25 microneedles. CsA loaded MOP were characterized for physical and mechanical properties, CsA loading, dissolution, corneal insertion, and CsA distribution in excised porcine eye globe. The average height and base diameter of the conical microneedles were 535 ± 15.7 and 287 ± 2.00 μm, respectively. The average amount of CsA loaded in one MOP was found to be 50.3 μg. Microneedles were found to completely dissolve in the cornea within 60 s of application. MOP showed a compression strength of 57.3 ± 13.7 N, and an insertional force of 10.8 ± 0.91 N in the excised porcine cornea. The application of MOP for 5 min significantly (p < 0.05) enhanced the flux (9.04 ± 0.88 μg/cm2/h) and retention (81 ± 5.1 μg/g) of CsA in excised porcine cornea when compared with commercially available Cyclomune® eye drops (flux 2.11 ± 0.56 μg/cm2/h and amount retained 53 ± 1.1 μg/g). The porcine eye globe distribution studies showed a disposition of 45.5, 29.1, 8.3, 5.2, 3.0 and 0.2% of CsA within the cornea, aqueous humor, lens, vitreous humor, sclera and choroid-retinal complex, respectively. Taken together, MOP can be developed for effective ocular delivery of CsA.