Treating allergic conjunctivitis using in situ polyelectrolyte gelling systems

We prepared 0.3% Carbopol/15.5% Pluronic and 0.1% Alginate/15.5% Pluronic solutions as the in situ gelling vehicles for ophthalmic drug delivery of cromolyn. The flow properties, in vitro release and in vivo pharmacological response of these polyelectrolyte solutions and of commercial eye drops were evaluated and compared. The polyelectrolyte solutions were free-flowing at pH 4.0 and 25°C, and they turned to strong gels at pH 7.4 and 37°C due to the in situ phase transition. The in vitro release and in vivo pharmacological response indicated that both vehicles retained cromolyn better than the commercial eye drops. The results demonstrated that both systems are usable as in situ gelling vehicles to increase ocular therapeutic efficacy in treating allergic conjunctivitis.