Corneal-PAMPA: A novel, non-cell-based assay for prediction of corneal drug permeability

The present study was aimed to develop an in vitro non-cell-based method, for the measurement of corneal permeability. To this avail, the parallel artificial membrane permeability assay (PAMPA) was used for studying the effects of composition of the artificial lipid membrane, the DMSO cosolvent content of the donor phase as well as different buffer solutions in the model. Based on experimental corneal permeability values of 25 active pharmaceutical ingredients (APIs), a final model with good predictive ability (R-2 = 0.880) was developed and validated. The optimized conditions for the Corneal-PAMPA were the following: iso-pH conditions using phosphate buffer saline (PBS pH 7.4) without cosolvent, phosphatidylcholine (10.7 w/v %; without cholesterol) dissolved in a mixture of hexane:dodecane:chloroform = 70:25:5 (v/v) as an artificial membrane, 4h incubation of the PAMPA plates at 35 degrees C. The model's applicability in the case of diluted solutions of eye drops was also demonstrated.