In Vitro Activity of a New Ophthalmic Spray Containing Biosecur® Citrus Extract (Oftasecur®) Against Candida auris and Candida albicans and Preformed Biofilm on Contact Lenses

We investigated the in vitro antifungal activity of a new commercial ocular spray containing Biosecur^® citrus extract (Oftasecur^®) against <i>Candida auris</i> and <i>C. albicans</i> and assessed its activity against preformed <i>Candida</i> biofilm on contact lenses and plastic lens cases. The <i>C. auris</i> isolate 12 (NCPF 8973) and the SC5314 <i>C. albicans</i> wild-type reference strain were used. Oftasecur^®'s effect on <i>C. auris</i> and <i>C. albicans</i> planktonic cells (1 × 10⁶ cells/mL) was tested in RPMI-1640 medium. The concentrations tested were 0.39%, 1.56%, 6.25%, 12.5%, and 25%. The living planktonic cell number was obtained using time-kill experiments. Antifungal activity against preformed <i>C. auris</i> and <i>C. albicans</i> biofilm on etafilcon A and senofilcon A contact lenses and plastic lens cases was also tested. A significant decrease was found in the living cell number of <i>C. albicans</i> after 8-48 h in the presence of Oftasecur^® concentrations ranging from 6.25% to 25% (<i>p</i> < 0.01-0.001). In the <i>C. auris</i> experiments, the cell number was significantly decreased after 8 h incubation in 25% Oftasecur^® (<i>p</i> < 0.05-0.001). Similarly, 12.5% Oftasecur^® was effective against preformed <i>C. auris</i> and <i>C. albicans</i> biofilm on contact lenses and plastic lens cases. The results suggest that the in vitro antifungal activity of Oftasecur^® against <i>C. albicans</i> and <i>C. auris</i> planktonic cells and preformed fungal biofilm on contact lenses and plastic cases is dependent on the concentrations used. Further research is warranted to establish whether Oftasecur^® may play a role in the prevention of contact lens-related <i>Candida</i> keratitis and other ocular-surface <i>Candida</i> infections.