Purpose: For an effective pharmaceutical treatment it is necessary in some cases to maintain a constant drug level over a certain period. This cannot be achieved by conventional eye drop application. Therefore, a new insert basically consisting of alginates with a different hydroxyethylcellulose (HEC) content was developed. The aim of this study was to evaluate the tolerance of these inserts applied to the conjunctival cul de sac.
Methods: 24 healthy volunteers received the insert containing different concentrations of hydroxyethylcellulose (0%, 5%, 30%) for 1 up to 5 days. The eyes have been examined several times (including visual acuity, ocular surface morphology, break-up-time, Schirmer-Tear-Test). Subjective parameters were pain sensations or daily life disturbance.
Results: After an initial conjunctival hyperemia and a mild foreign body sensation, the insert was well tolerated. No variations concerning the tolerance between the different concentrations of hydroxyethylcellulose were observed.
Conclusion: This study showed good tolerance of the new calcium-alginate-insert applied to the ocular surface for controlled drug release.