Formulation and Evaluation of Ophthalmic Preparations Containing Econazole Nitrate-Cyclodextrin Complexes

Improvement of ocular delivery systems properties remains a major challenge to achieve a continued therapeutic effect of drugs. The aim of the present study was to improve the solubility, dissolution rate and hence the ocular bioavailability of econazole nitrate (EC). To achieve this goal, econazole nitrate was complexed with β-cyclodextrin (β-CyD) and hydroxypropyl-β-cyclodextrin (HP-β-CyD) using co-precipitation method. The influence of different CyDs on EC complexation was investigated by different methods as fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The present work includes the preparation of eye gels and ocuserts containing econazole nitrate-cyclodextrins complexes using different polymers. Physicochemical properties (pH, viscosity, uniformity of drug content, in-vitro release) of the preparations were studied by the appropriate methods. The obtained results revealed that, EC solubility increased as a function of CyDs concentration. All formulations possessed uniform drug content with pH and viscosity compatible with the eye. In-vitro release data of ophthalmic formulations showed a sustained release with the diffusion-controlled mechanism (Higuchi model). Ocular bioavailability of EC-CyD complexes from the selected formulations was significantly (p