title: Electrochemical determination of dissolution rates of lyophilized pharmaceutical formulations.
abstract: We present a method to measure dissolution times for rapidly dissolving lyophilized formulations. K4Fe(CN)6 was lyophilized in formulations containing sucrose, salts, and Tween 20. Dissolution of the lyophilized powders was measured by monitoring the time dependence of the oxidation of Fe(CN)6(4-) ion at the surface of a platinum rotating disk electrode. Reconstitution of lyophilized K4Fe(CN)6 formulations with aqueous solutions of 0.03% Tween 20 altered the time of dissolution for all cases. Salt and sucrose formulations without Tween 20 dissolved more slowly in a Tween 20 solution than in water alone. In contrast, formulations containing Tween 20 dissolved faster in the Tween 20 solution when compared to dissolution in water.
authors.affiliation: Department of Chemical Engineering, University of Colorado, Boulder 80309, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Webb
authors.forename: C A
authors.initials: CA
authors.lastname: Koval
authors.forename: C M
authors.initials: CM
authors.lastname: Randolph
authors.forename: T W
authors.initials: TW
authors.lastname: Randolph
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004563:Electrochemistry; D005612:Freeze Drying / Q000379:methods; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012995:Solubility
chemical_list: D004364:Pharmaceutical Preparations