title: The effect of ionotropic gelation residence time on alginate cross-linking and properties.
abstract: The ability to engineer biocompatible polymers with controllable properties is highly desirable. One such approach is to cross-link carbohydrate polymers using ionotropic gelation (IG). Previous studies have investigated the effect of curing time on alginate cross-linking. Herein, we discuss a novel study detailing the effect of IG residence time (IGRT) on the cross-linking of alginate with calcium ions (Ca2+) along with water migration (syneresis) and their subsequent impact on the pharmaceutical properties of alginate particles. IGRT was shown to have a significant effect on particle size, porosity, density, mechanical strength and swelling of calcium alginate particles as well as drug release mechanism. Furthermore, we describe a novel application of electron dispersive spectroscopy (EDS), in conjunction with Fourier Transform- infra red (FT-IR) spectroscopy, to analyze and monitor the changes in Ca2+concentration during cross-linking. A simple procedure to determine the concentration and distribution of the surface and internal Ca2+involved in alginate cross-linking was successfully developed.
authors.affiliation: Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN, United States.
authors.forename: Mitulkumar A
authors.initials: MA
authors.lastname: Patel
authors.affiliation: Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN, United States; Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
authors.forename: Mohamed H H
authors.initials: MH
authors.lastname: AbouGhaly
authors.affiliation: Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN, United States.
authors.forename: Jacqueline V
authors.initials: JV
authors.lastname: Schryer-Praga
authors.affiliation: Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN, United States. Electronic address: chadwick@purdue.edu.
authors.forename: Keith
authors.initials: K
authors.lastname: Chadwick
keywords: Attenuated total reflectance-Fourier transform IR; Calcium alginate; Electron dispersive spectroscopy; Ionotropic gelation residence time; Polymer cross-linking