Abstract
Stability of 4 commercial eye drop preparations mainly composed of dexamethasone or betamethasone packed in light-resistant pouches was investigated with Manasul Light which has a wavelength of 3, 650 Å. The method for the quantitative assay was based on the one reported from the manufacturers of eye drops to the Ministry of Health and Welfare. All the preparations kept in black pouches maintained pre-irradiation conditions; while among the products in orange pouches the content of main ingredients decreased in 1 preparation but the balance of ingredients showed no change in 3 preparations. All the preparations kept outside of the pouches were found to have reduced contents of their main ingredients.
