Evaluation of 5-fluorouracil released from a foldable capsular vitreous body in vitro and in vivo.

BACKGROUND

Previously, we have confirmed that the foldable capsular vitreous body (FCVB) can serve as a drug delivery system (DDS) as well as a vitreous substitute. Here, we evaluated the characteristics of the release of 5-fluorouracil (5-Fu) from FCVB in vitro and in vivo.

METHODS

For the in-vitro study, various concentrations of 5-FU (50-200 μg/ml) were injected into FCVB capsules and immersed in cups of modified Franz diffusion cells, and liquid was aspirated at specific time intervals. In the in-vivo study, FCVB was folded and implanted into the vitreous cavity in the right eyes of five rabbits, and then 1.0 ml 5-Fu (200 μg/ml) was injected into the capsule. Another five rabbits that were used as the controls received intravitreal injections Aqueous humor was aspirated postoperatively at specific time intervals up to 56 days. The 5-Fu contents in vitro were detected by UV spectrophotometry and ultra performance liquid chromatography (UPLC), and the in-vivo 5-FU levels in the aqueous humour were detected by UPLC. The stock solution in the FCVB before-release study and the FCVB residue were collected for UPLC analysis.

RESULTS

UV spectrophotometry revealed that 5-FU was released from FCVB in vitro in a time-dependent manner from 20-360 min in vitro. UPLC analysis revealed that 5-FU was released sustainably from FCVB. The 5-FU concentration in the aqueous humour was detected until postoperative day 56 (D56), with sustained release from postoperative days 3-56. However, the 5-FU concentration in the control samples was detected until only D7, and could not be detected on D14. Finally, 48.8% of the 5-FU was released on D56 in the in-vivo experiment.

CONCLUSIONS

FCVB can release 5-Fu sustainably and mechanically, indicating that FCVB can be used as a common vehicle for the sustainable release of different drugs. FCVB is a potentially valuable pharmaceutical adjunct to conventional vitreous surgery for managing or preventing proliferative vitreoretinopathy.