Abstract
Purpose :
The use of eye drops is known to lack efficiency. This is mainly due to patients' low adhesion to the treatment due to forgetfulness, difficult on application or incorrect application of the drops, but also due to the high amount of drug that is quickly eliminated from the eye by the drainage system.
To overcome this problem we developed a small spherical, pearl-like ocular insert based on low molecular weight polycaprolactone-polyethylene glycol block copolymers (PEG-PCL-PEG) to immobilise and release moxifloxacin (Mx) and Flurbiprofen (Flb).
Methods :
The PCL-PEG copolymers were synthetised by ring-opening polymerisation of ε-caprolactone in the presence of different amounts of PEG with distinct molecular weights.
Samples were incubated in the presence of rabbit corneal endothelial cells to evaluate their biocompatibility.
The surface energy, water absorption and mas loss of different ineye® were evaluated.
Two different immobilisation techniques were used, according to the intended release profiles - dispersion of Flb in the polymeric matrix and a central core of Mx surrounded by the polymer. Ineye® samples were incubated in ultrapure water at 37° Celsius and released drugs were quantified by UV-Vis spectrophotometry.
Results :
The results revealed an excellent biocompatibility for the PCL/PEG copolymers synthetised (Fig. 1). Surface energy of some of the materials was similar to lacrimal film’s surface tension, which means that, when placed in the eye, the ineye® is not going to cause itching or expose the cornea to air. The distinct strategies for immobilisation of Mx and Flb revealed to be a reasonable and accurate way to obtain the desired release profiles - a zero order release during 4 weeks for Mx and a Fickian release profile during 2 weeks for Flb (Fig. 2).
Conclusions :
It was possible to prepare copolymers with the right properties to obtain a biocompatible material that allowed the preparation of inserts containing two drugs using distinct immobilization strategies, in order to have distinct release profiles.
The ineye® is a very flexible formulation technology, suitable to release various drugs at distinct rates, making it suitable for other ocular diseases and conditions. In the present study it was demonstrated that a single ineye® can replace two bottles of eye-drops on preventing inflammation and infection before and after an ocular surgery.
This is a 2020 ARVO Annual Meeting abstract.