title: Comparative in vitro investigation of the forces exerted by eye drops and eye spray.
abstract: Topical administration of ophthalmic drugs is predominantly carried out in the form of eye drops. The application of an eye spray represents a feasible alternative to drop instillation with regard to the clinical efficacy. In this study the forces exerted during the application of eye drops and eye spray to a surface were measured in vitro and compared with each other. Whereas the maximal forces that occurred with a falling drop tended to increase with greater application distance, the forces decreased with spraying. From an application distance of 3 cm the eye spray proved to have a more favorable mechanical force effect than the eye drops. In view of the loss of experimental liquid caused by spray application as well as the diameter of the spray cone, a spray distance of from 4 cm to 5 cm can be deemed to be optimal.
authors.affiliation: Institute of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, Martin-Luther-University, Halle-Wittenberg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Wagner
authors.forename: R H H
authors.initials: RH
authors.lastname: Neubert
mesh_terms: D000287:Administration, Topical; D000336:Aerosols; D002626:Chemistry, Pharmaceutical; D004563:Electrochemistry; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D011312:Pressure
chemical_list: D000336:Aerosols; D009883:Ophthalmic Solutions