title: Comparison of selected physico-chemical properties of calcium alginate films prepared by two different methods.
abstract: Sodium alginate (SA) is a naturally occurring, non-toxic, polysaccharide that is able to form gels after exposure to calcium. These gels have been used in food and biomedical industries. This is the first direct comparison of two different methods of calcium alginate film production, namely interfacial gelation (IFG) and dry cast gelation (DCG). IFG films were significantly thicker than DCG films, and were more extensively rehydrated in water and 0.1M HCl than the DCG films. During rehydration in 0.1M HCl almost all calcium ions were lost. Under scanning electron microscopy, IFG films appeared less dense than DCG films. IFG films were mechanically weaker than DCG films, and both types of film were weaker after rehydration in 0.1M HCl compared with deionized water. Permeation of theophylline (TPL) was evaluated in-vitro; the diffusion coefficient (D) of the TPL was almost 90 times lower in DCG films than IFG films when both were rehydrated in water. Although the 0.1M HCl rendered both gels more permeable to TPL, D of TPL was still about five times lower in DCG compared to IFG films. The evaluation of selected physico-chemical properties of films is important, since this information may inform the choice of gelation technique used to produce calcium alginate coatings on pharmaceutical products.
authors: School of Biomedical Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors: Yazmin J
authors: YJ
authors: Crossingham
authors: School of Biomedical Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors: Philip G
authors: PG
authors: Kerr
authors: School of Biomedical Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. Electronic address: rokennedy@csu.edu.au.
authors: Ross A
authors: RA
authors: Kennedy
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002118:Calcium / Q000032:analysis / Q000737:chemistry; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D013806:Theophylline / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D014867:Water; D020723:Glucuronic Acid; D013806:Theophylline; D006851:Hydrochloric Acid; D002118:Calcium
keywords: Calcium alginate gels; Drug diffusion; Films; Mechanical puncture tests; Theophylline