Extended Delivery of Pirfenidone with Novel, Soft Contact Lenses In Vitro and In Vivo

Purpose: The aim of this study was to fabricate pirfenidone (PFD)-loaded soft contact lenses (SCLs), explore their characteristics, and evaluate their efficiency on extended delivery of PFD in vitro and in vivo. Methods: PFD-loaded SCLs were fabricated by embedding an insert of PFD and polyvinyl alcohol (PVA) into 2 layers of silicone elastomer. The optical transparency, water content, and protein deposition were measured. Transformed human corneal epithelial cells were used to test the cytotoxicity of SCLs. The release rate of PFD by SCLs in vitro was evaluated by an ultraviolet-visible spectrophotometer. Toxicity of SCLs was assessed by inspection of ocular surface irritation in rabbits before and after contact lens wear. The concentrations of PFD in tears and aqueous humor of rabbits' eyes as a function of time were determined by high-performance liquid chromatography for SCLs and 30 mu L of 0.5% PFD eye drops. Results: SCLs possessed good light transmittance. Blank SCLs had poor water content (0.548% +/- 0.330), and an improved water content was found in PVA film-loaded SCLs (11.022% +/- 1.508, P = 0.010). No lysozyme and human serum albumin were found in SCLs. There was no significant toxicity of SCLs in vitro and in vivo. SCLs prolonged the residence time of PFD in tears and aqueous humor of rabbit eyes by 5 times compared with the eye drop instillation while around 1/10 of the eye drop dosage was loaded in SCLs. Conclusions: PFD-loaded SCLs can significantly prolong the residence time of PFD and may be a promising ocular drug delivery system.

Automated summary

This study aimed to develop PFD-loaded SCLs, evaluate their characteristics, and assess their efficiency in extended delivery of PFD. The results showed that PFD-loaded SCLs had good light transmittance and improved water content compared to blank SCLs. In vitro and in vivo tests indicated low toxicity of SCLs. SCLs significantly prolonged the residence time of PFD in tears and aqueous humor.