Ocular dorzolamide nanoliposomes for prolonged IOP Reduction: in-vitro and in-vivo evaluation in rabbits

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

Sulfur hexafluoride 20% versus lactated ringer's solution for prevention of early postoperative vitreous hemorrhage after diabetic vitrectomy

To compare the hemostatic effect of sulfur hexafluoride 20% [SF6 20%] with lactated Ringer's solution for prevention of early postoperative vitreous hemorrhage following diabetic vitrectomy. In a prospective randomized clinical trial, 50 eyes undergoing diabetic vitrectomy were divided into two groups. At the conclusion of surgery, in one group the vitreous cavity was filled with SF6 20% while in the other group lactated Ringer's solution was retained in the vitreous cavity. The two groups were compared for the rate of early postoperative vitreous hemorrhage. The incidence of vitreous hemorrhage was lower in the SF6 group than the Ringer's group 4 days [20% vs. 68%, P=0.001], 7 days [24% vs. 60%, O=0.01] and 4 weeks [16% vs. 40%, P=0.059] after vitrectomy. In comparison with lactated ringer's solution, SF6 20% had a significant hemostatic effect especially in the early postoperative period after diabetic vitrectomy and reduced the incidence of vitreous hemorrhage