title: Liquid penetration as a method of assessing the wettability and surface energy of pharmaceutical powders.
abstract: The use of a liquid penetration technique to assess the wettability and surface energy of a series of barbiturates, including the use of bicomponent systems, has been critically evaluated. Values of apparent contact angles (theta) obtained using the Washburn relationship (1921) and the Carli & Simioni correction (1979) were found to reflect the practically derived wettability of the powders. Values of gamma c obtained from modified Zisman plots and from Neumann's equation of state did not realistically describe the surface energies of the powders. The nature of alcohol-water mixtures has been examined to assist elucidation of the theoretical problems associated with the technique and to offer a possible explanation for the inadequacies of the surface energy results.
authors.forename: G
authors.initials: G
authors.lastname: Buckton
authors.forename: J M
authors.initials: JM
authors.lastname: Newton
mesh_terms: D001463:Barbiturates / Q000032:analysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D000431:Ethanol; D011208:Powders; D013499:Surface Properties; D014867:Water
chemical_list: D001463:Barbiturates; D011208:Powders; D014867:Water; D000431:Ethanol