title: Using modified Kramers-Kronig relations to test transmission spectra of porous media in THz-TDS.
abstract: We show that modified Kramers-Kronig relations provide a useful tool to test the validity of the complex refractive index extracted from transmission terahertz spectra of porous matrices containing pharmaceutical materials. The role of scattering of terahertz radiation is qualitatively considered as a reason for the observed discrepancy between experimental data and the values extracted from the inverted complex refractive index. As an example we present an analysis of the terahertz spectra of carbamazepine and lactose alpha-monohydrate.
authors.affiliation: Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland. htuonone@gmail.com
authors.forename: H
authors.initials: H
authors.lastname: Tuononen
authors.forename: E
authors.initials: E
authors.lastname: Gornov
authors.forename: J A
authors.initials: JA
authors.lastname: Zeitler
authors.forename: J
authors.initials: J
authors.lastname: Aaltonen
authors.forename: K-E
authors.initials: KE
authors.lastname: Peiponen
mesh_terms: D003198:Computer Simulation; D004337:Drug Carriers / Q000737:chemistry*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D008422:Materials Testing; D008956:Models, Chemical; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D016062:Porosity; D055053:Terahertz Radiation; D055068:Terahertz Spectroscopy / Q000379:methods*
chemical_list: D004337:Drug Carriers; D004364:Pharmaceutical Preparations