Comparative evaluation of nanofiber and wafer-based systems for ophthalmic delivery of a water-soluble drug

Aimed at developing and comparing wafer and nanofibers as biocompatible and prolong release ophthalmic delivery systems, we have prepared various formulations of sulfacetamide-a soluble drug- and evaluate them.

Wafers were prepared using the casting and freeze-drying method, while nanofibers were fabricated via an electrospinning system. Various formulations containing polyvinyl alcohol (PVA) and sodium alginate (SA) were employed, with SA ratios ranging from 0 to 15%. Morphological characterization with SEM microscopy, thermal behavior, in vitro drug release, bio-adhesive strange, antibacterial activity and fibroblast cell cytotoxicity of various formulations of nanofiber and wafer were evaluated. Additionally, glutaraldehyde was used for cross-linking the formulations.

Wafers exhibited a porous structure with nanosized walls. In addition, various formulations of nanofibers were prepared with nano-sized thicknesses ranging from 420.55 to 153.42 nm. Wafers showed a slow-release profile lasting more than six hours, similar to that of nanofibers in most cases with kinetic of Higuchi order. Cross-linking both systems further sustained drug release for more than 7 h, particularly in formulations with higher sodium alginate content. The nanofiber exhibited higher antibacterial activity against Escherichia coli and Staphylococcus aureus, particularly when formulated 10% of SA. Additionally, nanofibers showed higher cell viability upon contact with fibroblast cells and higher bioadhesive strength ranging from 2.3 to 3.6 N/cm² in compare with wafers (ranging from 1.6 to 2.5 N/cm²).

Formulations of pharmaceutical wafers and nanofibers are interchangeable, and are suitable for prolonged delivery of sulfacetamide, a water-soluble drug; however, nanofibers showed higher biocompatibility, antibacterial activity and bioadhessiveness.