title: Influence of the physico-chemical properties of ophthalmic viscolysers on the weight of drops dispensed from a flexible dropper bottle.
abstract: The present study investigated the influence of the rheological behaviour, the viscoelasticity and surface tension of various viscolysers on the weight of drops dispensed from a commercially available flexible dropper bottle. Furthermore, the effect of the concentration and molecular weight of some viscolysers and the angle at which the dropper bottle is held, were studied. Up to a value of 25 mPa x s, the viscosity and the rheological behaviour of the solution had no significant influence on the drop weight under conditions simulating patient manipulation. The lower the dynamic surface tension of the solution, however, the lower the weight of drops delivered. The dispensing angle (90 or 45 degrees) of the dropper bottle, on the other hand, had an impact on the weight of drops dispensed.
authors.affiliation: Department of Pharmaceutical Sciences, Laboratory of Pharmaceutical Technology and Biopharmacy, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Antwerpen (Wilrijk), Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Van Santvliet
authors.forename: A
authors.initials: A
authors.lastname: Ludwig
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005079:Excipients; D009883:Ophthalmic Solutions / Q000737:chemistry*; D012212:Rheology; D013500:Surface Tension; D014783:Viscosity