Several routes of absorption are possible for eye drops and their excess amounts can sometimes cause unwanted systemic bioavailability if they are not completely absorbed by the eye. Also, generally the concentration of the active ingredient in such drops is high so despite correct application, considerable amounts may get absorbed through various routes. This article gives an overview of various routes of absorption, factors which affect absorption of drugs and discusses pediatric considerations.
Topical therapy has been reported as effective in treating the conjunctiva, cornea, anterior chamber, and iris. This implies that the eye drops are on the surface of the eye only for a short time and hence, bioavailability must be classified as extremely low and is reported in the literature to be in the order of 5%–10% and there is systemic absorption of 50%+ dose via few major routes (like…
