Abstract
Purpose: :
To generate an insilico prediction model for the intravitreal penetration of fluoroquinolones using controlled invivo cassette dosing (N-in-One) approach in rabbits and to evaluate its validity in predicting human intravitreal penetration.
Methods: :
Cassette dosing (N-in-One) approach was used and a cocktail intravenous formulation containing seven fluoroquinolones (ciprofloxacin, pefloxacin, ofloxacin, lomefloxacin, sparfloxacin, gatifloxacin and moxifloxacin) was prepared under sterile conditions. It was administered as a single i.v. bolus to rabbits at the concentration of each having 12µmol/kg body weight. The animal experiments were conducted in compliance with the ARVO statement for the use of animals in ophthalmic and vision research. Vitreous and plasma sample were taken under anesthesia 3hrs and 6hrs after administration and was subjected for HPLC analysis using photodiode array detection. Various molecular descriptors were generated using CaChe, ACD/Chemsketch and CLOGP softwares for all the fluoroquinolones. Multiple linear regression was employed to generate insilico prediction model to calculate logVP (vitreous to plasma). Additionally the vitreous and plasma levels in humans at 6hrs for above studied fluoroquinolones were pooled from various studies conducted previously in our laboratory. The insilico equations developed using different molecular descriptors for predicting intraocular penetration in rabbits was also subjected for prediction of human intravitreal concentration.
Results: :
The insilico model generated using parameters of invivo experiment in rabbit (plasma concentration) and descriptors i.e., band-gap, protein binding, ionization constant, logPow showed best prediction (r2=1). Where as the same molecular equation when subjected for the generation of intravitreal human penetration (logVP) from human plasma showed a weak correlation .
Conclusions: :
Cassette dosing (N-in-One) approach showed the predicted vitreous penetration data in rabbits. This approach can be well exploited for ophthalmic drug research. The insilico prediction model developed from intravitreal penetration data in rabbits was unable to predict human vitreous penetration
Keywords: antibiotics/antifungals/antiparasitics • endophthalmitis • vitreous