RESUMO
This study was undertaken to establish experimentally whether the intravitreal application of liposomally-entrapped ganciclovir could prolong intraocular therapeutic levels when it is compared to the intravitreal injection of a simple solution of the drug. New Zealand white rabbits were given an intravitreal injection of the drug solution and of liposome-encapsulated ganciclovir. The intravitreal clearance of ganciclovir was determined after a single injection of either the drug solution (200 micrograms/0.1 mL) or the liposomally-entrapped (with 41% load; 82 micrograms drug load and 118 micrograms free) ganciclovir. The ganciclovir vitreal concentrations were measured at various time intervals for a period up to 43 days using an HPLC method. The results of this study clearly demonstrated that prolonged intravitreal drug levels (above the mean inhibitory dose of cytomegalovirus of 1 microgram/mL) after administration of the liposome-entrapped ganciclovir and estimated to continue beyond 30-43 days. The injection of the 200 micrograms/0.1 mL of drug solution showed a mean vitreous concentration which was higher than the ID50 only for 55 h. The disappearance rate constant for the liposome-encapsulated injections was approximately 22 x slower than simple drug solution injections (controls). No evidence of retinal toxicity was found by clinical or light microscopy examination of the treated eyes.
Assuntos
Antivirais/administração & dosagem , Antivirais/farmacocinética , Ganciclovir/administração & dosagem , Ganciclovir/farmacocinética , Corpo Vítreo/metabolismo , Animais , Antivirais/análise , Cromatografia Líquida de Alta Pressão , Portadores de Fármacos , Ganciclovir/análise , Meia-Vida , Injeções , Lipossomos , Masculino , Microscopia Eletrônica , Tamanho da Partícula , Coelhos , SoluçõesRESUMO
Keratomycosis due to Aspergillus fumigatus occurs most often in immuno-competent patients who live and work in a fungus-rich atmosphere. Previous trauma with epithelial lesion are reported by most authors. While the new antifungal drugs may be effective, corneal graft is the most effective solution in uncontrolled cases. When performed early, good visual recovery was observed in most cases as reported in the literature and in our case.
