Abstract
Purpose: :
Polyethylene glycol (PEG)-400 is a clear, colorless, viscous liquid that readily dissolves many hydrophobic drugs. It is a widely used commercial solvent and vehicle for many pharmaceutical and cosmetic products and safe for human oral consumption and topical application. To our knowledge, however, there are no reports on the intraocular safety of PEG-400. The purpose of this study is to investigate the intraocular safety of PEG 400 to determine its suitability as a potential vehicle for intraocular delivery of hydrophobic drugs.
Methods: :
Six healthy, male, Dutch Belted rabbits, weighing between 2.0 and 3.0 kg, were used for this experiment. The left eye of each animal received a single 0.1ml intravitreal injection of PEG-400. Complete eye exams and dark- and light-adapted electroretinograms (ERG) of both eyes were obtained at baseline and at 1 and 4 weeks after injection. After the 4-week ERG was completed, animals were euthanized and eyes were enucleated and analyzed with histology and transmission electron microscopy (TEM).
Results: :
Ophthalmic examinations demonstrated signs of retinal necrosis in all 6 left eyes injected with PEG-400 which was apparent at 1 week but more evident by 4 weeks. Photopic and scotopic ERG studies of left eyes injected with PEG-400 showed significantly reduced b-wave amplitudes at 1 and 4 weeks after injection compared to baseline (P < 0.01). Histopathological analysis of eyes demonstrated both inner and outer retinal atrophy and necrosis.
Conclusions: :
Our findings indicate that the intravitreal injection of polyethylene glycol-400 is toxic to retina and it should not be used as a vehicle in the eye.
Keywords: drug toxicity/drug effects • uveitis-clinical/animal model • electroretinography: non-clinical