RESUMEN
Dorzolamide ophthalmic drop is one of the most common glaucoma medications but it has a short residence time in the eye. The aim of this study is to develop ocular dorzolamide HCl nanoliposomes [DRZ - nanoliposomes] and to evaluate their potential use for the treatment of ocular hypertension. Nanoliposomes were prepared using Reverse-phase evaporation vesicle [REV] and thin layer hydration [TLH] method with 7:3 and 7:4 molar ratios of phosphatidylcholine:cholesterol. The physicochemical properties of the formulations were investigated. Formulations with 7:4 lipid ratio were evaluated in terms of drug release, physical stability and ex vivo permeation through the excised albino rabbit cornea. The rabbits in groups of 6 were treated with selected DRZ - nanoliposomes or dorzolamide solution or marketed dorzolamid preparation [Biosopt®] and intraocular pressure [IOP] was monitored. Formulations with 7:4 molar ratio entrapped greater amount of drug compared to those with 7:3 lipid components ratio. DRZ - nanoliposomes with 7:4 lipid ratio showed more transcorneal permeation than Dorzolamide solution [p<0.05]; and the formulation prepared by TLH method exhibited higher permeability than that prepared by REV method [p<0.05]. The selected DRZ - nanoliposomes showed greater IOP lowering activity and a more prolonged effect compared to dorzolamide solution and Biosopt®. DRZ - nanoliposomes prepared by TLH method with 7:4 ratio showed promising results as a candidate for the treatment of ocular hypertension