Abstract
Purpose:
To analyze the release of two fluoroquinolones, ciprofloxacin and moxifloxacin, from conventional hydrogel (CH) and silicone hydrogel (SH) daily disposable commercial contact lenses (CLs) from a vial and an in vitro eye model.
Methods:
Four CH CLs (nelfilcon A, omafilcon A, etafilcon A, ocufilcon B) and three SH CLs (somofilcon A, narafilcon A, delefilcon A) were incubated in a solution containing either ciprofloxacin or moxifloxacin for 24 h. After the incubation period, the lenses were placed in two release conditions: (1) a vial containing 4.8 mL of PBS for 24 hours and (2) an in vitro eye model with a PBS flow rate at 4.8 mL over 24 h. The amount of drugs released was determined using spectrophotometric technique.
Results:
The release in the vial for both drugs was very rapid, and reached a plateau between 15 min and 2 h for all lens types. In contrast, under under physiological flow conditions, a constant and slow release was observed over 24 h. The amounts of ciprofloxacin released from the lenses ranged between 49.6±0.7 to 62.8±0.3 µg/lens in the vial, and between 35.0±7.0 to 109.0±5.0 µg/lens in the eye model. Moxifloxacin release ranged from 24.0±4.0 to 226.0±2.0 µg/lens for the vial, and between 13.0±2.0 to 151.0±10.0 µg/lens in the eye model. In both systems and for both drugs, HEMA-based CLs released significantly more drug than other materials.
Conclusions:
The parameters of the release system, in particular the volume of the release medium and flow rate, have a huge influence on release profiles. Under physiological flow conditions, release profiles were significantly slower and constant when compared with release in a vial model. The release is also affected by the material composition of the lens, and the water solubility of the drug.