[Nanocapsules of beta-blocking agents: a new drug carrier in ophthalmology. Application to medical treatment of glaucoma in rabbits].

In order to reduce the lacrimal elimination and to increase the intraocular penetration of betaxolol after ocular administration, we prepared a new drug carrier, polycaprolactone nanocapsules, containing betaxolol in the base form. The instillation of nanocapsules containing only 0.1% of betaxolol into glaucomatous rabbit eyes induced a greater decrease of IOP in intensity, time and stability compared to the reduction of IOP induced after instillation of the commercial eye drops (Betoptic) containing 5 times more betaxolol (0.56%). This new pharmaceutical dosage form produces very interesting therapeutic effects with much lower drug concentrations than that commonly used in aqueous commercial eye drops; thus, systemic and local side effects could be minimized. All drugs used in medical treatments of eye diseases should be able to be included in this carrier. In addition, effective drugs not used because of their toxicity will become suitable for use at lower and safer doses.