Comparative analysis of generic and brand NSAIDS toxicity in human corneal stromal fibroblasts

Abstract

Purpose : Topical NSAIDS drops are regularly used for the management of postoperative ocular inflammation after laser-refractive and cataract surgeries. Clinical research has documented the appearance of corneal pathologies such as red-eye, punctate keratopathy, stromal infiltrates, persistent epithelial defects, conjunctival ulceration, and scleral and corneal melting in patients after the use of ophthalmic NSAIDS drops. Using an in vitro model, we compared the impact of application dosage and preservative formula between generic and brand (Voltaren) NSAIDS, diclofenac.

Methods : Primary human stromal fibroblasts (hCSF) were generated from donor human corneas purchased from an eye bank. Primary cultures were grown by placing sectioned donor corneas on 35mm culture dishes and incubated in a humidified 5% CO₂ incubator at 37°C in MEM medium supplemented with 10% fetal bovine serum. hCSFs were expanded in 6-well culture plates by seeding cells at an initial density of 7.5x10⁴ cells/well in the presence or absence of 0.1% generic or brand (Voltaren) diclofenac. Voltaren contains preservatives sorbic acid and edetate sodium and has polyoxyl-35 as an emollient, whereas generic diclofenac contains polyquad polyquaternium-1 and tocophersolan as preservatives and mannitol as emollients. At 50% confluence, cells were treated with generic or brand diclofenac at a dosage of 1, 2, or 4 drops twice or four times a day. Changes in cellular phenotype, proliferation, apoptosis, and matrix metalloproteinase (MMP) expression were analyzed with microscopy, Ki67 staining, TUNEL assay, and qRT-PCR, respectively.

Results : A dosage of 2 drops twice a day caused no significant change in cellular toxicity or phenotype in the hCSFs for up to 48 hours. Furthermore, at this dosage, no notable cell death was observed for 72 hours. A dosage of 2 drops four times a day did cause a noticeable change in hCSF morphology and a 40% increase in cell death as compared to vehicle treated controls in both generic and brand treated TUNEL+ cells. qRT-PCR found no significant difference between mRNA levels of MMP -1, -2, -8, and -9 in cells treated with generic vs brand diclofenac.

Conclusions : No significant differences between brand vs generic diclofenac treated cells were observed. It appears that preservatives and emollients present in generic and brand diclofenac have little or no role in corneal toxicity.

This is a 2020 ARVO Annual Meeting abstract.