Preclinical Pharmacokinetic Evaluation of Gatifloxacin Mucoadhesive Formulations in Rabbit Eye using HPLC

In order to improve the frequent dosing regimen reported for the commercial aqueous gatifloxacin eye drops, two new ophthalmic mucoadhesive formulations based on high molecular weight sodium hyaluronate were prepared. The pharmacokinetic profiles outlined showed a strong bioavailability increase for gatifloxacin-hyaluronate formulations with respect to aqueous conventional eye drop. Gatifloxacin quantification in aqueous humor of albino rabbits was performed by an extremely simple, rapid, direct, sensitive and specific HPLC-UV method. Separations were obtained on an Adsorbosphere HS C18 column using CH3CN and an aqueous solution of 10 mM SDS, 10 mM TBAA and 25 mM citric acid (pH 2.5) (50∶50 v/v). Detection was performed at 293 nm using a flow rate of 1.0 ml/min. The developed method fulfills the validation requirements of FDA and EMEA and it is suitable for the pharmacokinetic study in rabbit eye.