Pharmacokinetic and toxicological studies of liposomal amphotericin B eye drops on the rabbit eye

Keratomycosis is a fungal infection of the cornea in tropical areas and the cause of corneal morbidity and blindness. This remains a problem in developing countries. Amphotericin B (AmB) is still considered the treatment of choice for fungal infection. Liposomal formulation of AmB (L-AmB) has demonstrated promising results with higher efficacy and lower toxicity. The aim of this study is to evaluate L-AmB eye drop penetration and toxicity on the rabbit eye. Seven New Zealand rabbits were divided into three groups. Six rabbits were used for the pharmacokinetic and toxicological studies (three rabbits treatment used L-AmB 0,15%, three rabbits treatment used L-AmB 0,5%) and one served as normal control. All treatment used two concentrations of L-AmB (0.15% and 0.5%) given as eye drops every hour for three days. The pharmacokinetic study measured AmB concentration in the tissues (cornea, aqueous, lens, vitreous, sclera) using high performance liquid chromatography (HPLC), and toxic reactions were evaluated in clinical signs and histopathological examination (cornea, iris, sclera, retina). In all tissues, L-AmB 0.5% had higher concentrations of AmB than 0.15%, reached MIC in both concentrations and showed no toxic effects. Liposomes are promising drug carriers for eye diseases that can penetrate to the anterior and posterior tissues of the eye.