Sustained release ciprofloxacin and diclofenac from a disposable contact lens

Purpose: To develop contact lens giving 24 hour sustained release of an anti-inflammatory (diclofenac) and an anti-biotic (ciprofloxacin). Methods 1) Preliminary Work: Solutions of sodium diclofenac were prepared and added to solutions of ciprofloxacin HCl. Mixing these solutions formed the insoluble codrug ciprodiclofenate. 1.5 ml of the suspensions were placed in microcentrifuge tubes and, after briefly spinning, 0.5 ml of the supernatant was removed for analysis. After replacement with fresh buffer, the codrug was resuspended by vortex mixing and the process repeated until no drug was detectable in the receptor. Methods 2) Preparation and Evaluation of Lenses: Disposable contact lenses (Acuvue, J&J) washed three times with deionized water and then immersed in a 1% sodium diclofenac solution for 3 hours. Lenses were then taken out of the solution, excess water removed, and immersed in a 5% ciprofloxacin HCl solution for 12 hours. The now cloudy lenses were then washed in deionized water and placed on a glass sphere (radius of curvature 8 mm.) Phosphate buffer (pH 7.4) was dripped onto the lens at 50 ul/min and collected for analysis by HPLC to determine drug release. Results 1: The serial dilution experiment showed that the codrug maintained supernatant concentrations of diclofenac between 0.1 and 0.2 mg/ml and of ciprofloxacin between 0.2 and 0.35 mg/ml despite 20 serial dilutions. Results 2: Ciprofloxacin and diclofenac were slowly released from the lens maintaining buffer concentrations of over 20 ug/ml and 5 ug/ml respectively for over 24 hours. Conclusion: This work suggests that codrug impregnated contact lenses can be used to maintain high concentrations of antibiotics and anti-inflammatories in the tear film for a prolonged period.

Duke Scholars

Author Hongtao Michael Guo Orthopaedic Surgery