Curcumin in situ gelling polymeric insert with enhanced ocular performance

The search for an ocular drug delivery system that could provide long-acting e�ects without
a detriment to the anatomy and physiology of the eye remains a challenge. Polyphenolic compounds
(curcumin in particular) have recently gained popularity due to their powerful antioxidant properties;
yet curcumin su�ers poor stability and water solubility. A conventional eye drop formulation of
curcumin in the form of a suspension is likely to su�er a short duration of action requiring multiple
instillations. On the other hand, polymeric in-situ gelling inserts o�er the prospect of overcoming
these limitations. The aim of this study was to prepare, characterize and evaluate in vivo, polymeric,
in-situ gelling and mucoadhesive inserts for ocular surface delivery of curcumin. Di�erent types and
ratios of biocompatible polymers (HPMC, CMC, PL 127 and PVA) and three plasticizers along with
the solvent casting method were adopted to prepare curcumin inserts. The inserts were investigated
for their physicochemical characteristics, applicability, and suitability of use for potential placement
on the ocular surface. The prepared inserts revealed that curcumin was mainly dispersed in the
molecular form. Insert surfaces remained smooth and uniform without cracks appearing during
preparation and thereafter. Improved mechanical and mucoadhesive properties, enhanced in vitro
release (7.5- to 9-fold increases in RRT300 min) and transcorneal permeation (5.4- to 8.86-fold increases
in Papp) of curcumin was achieved by selected in-situ gelling inserts compared to a control curcumin
suspension. The developed inserts demonstrated acceptable ocular tolerability, enhanced corneal
permeability, and sustained release of curcumin along with retention of insert formulation F7 on the
ocular surface for at least two-hours. This insert provides a viable alternative to conventional eye
drop formulations of curcumin.