title: Surface acidity of solid pharmaceutical excipients III. Excipients for solid dosage forms.
abstract: The surface acidities of pharmaceutical excipients are detected by color changes of acid-base indicators on the substrate's surface. To quantify the indicator's transition interval on the surface of hydrophilic excipients, as an organic solvent methanol is introduced for the preparation of indicator-excipient mixtures. The influence of the particle size on the determination of the surface acidity is investigated and particle size did not influence the determination within the particle size range investigated. Surface acidities of common excipients used in preparation of solid dosage forms are presented.
authors.affiliation: Department of Pharmaceutical Technology, Eberhard Karl University, Tübingen, Germany.
authors.forename: C A
authors.initials: CA
authors.lastname: Scheef
authors.forename: D
authors.initials: D
authors.lastname: Oelkrug
authors.forename: P C
authors.initials: PC
authors.lastname: Schmidt
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D004396:Coloring Agents; D004304:Dosage Forms; D005079:Excipients / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013012:Sorbitol / Q000737:chemistry*; D013053:Spectrophotometry; D013499:Surface Properties
chemical_list: D004396:Coloring Agents; D004304:Dosage Forms; D005079:Excipients; D013012:Sorbitol; D002482:Cellulose