We use terahertz time-domain spectroscopy (THz-TDS) to measure the absorption spectra of six drugs, atenolol,
furosemide, tropicamide, lobeline hydrochloride, propranolol hydrochloride, and promethazine hydrochloride, in the
frequency range of 0.3 THz to 2.0 THz. Furosemide, tropicamide, and promethazine hydrochloride show distinct
absorption features, whereas atenolol, lobeline hydrochloride, and propranolol hydrochloride exhibit no obvious
absorption peaks. The use of THz-TDS makes it possible to rapidly distinguish the drugs with characteristic absorption
peaks. Our results demonstrate that THz-TDS is highly sensitive to the structure and spatial arrangement of molecules.
As a result, THz-TDS will have potential exploitation in pharmaceutical fields.
Terahertz time-domain spectroscopy (THz-TDS) was utilized to study solid state reaction progress between α-naphthol(NP) and p-benzoquinone(BQ). Density functional theory (DFT) was employed to optimize the structure of the complex. The result shows that the reaction product is associated by hydrogen bonding between one of the oxygen atoms of BQ and one hydrogen atom of the hydroxyl group of NP; and FTIR spectra is presented as supporting evidence. Our work demonstrated that THz-TDS was a promising and complementary method in analyzing solid-state reaction between NP and BQ.
Absorption spectra and index of refraction of aminophenol compounds are obtained using Terahertz time-domain
spectroscopy (THz-TDS) in the frequency range between 0.3 and 2.0 THz at room temperature. Quantum chemical
calculations are performed to better understand the origin of the absorption features observed in experiments. Different
weight ratios of isomeric mixtures are analyzed by THZ-TDS with the help of linear regression technology. It is
concluded that THZ-TDS is able to identify the components and their relative percentage in isomeric mixtures.
Terahertz spectroscopy has tremendous potential for applications to evaluate the quality of the drugs including the TCM.
In this paper, the Terahertz Time-Domain Spectroscopy investigated two active ingredients: Andrographolide and
Dehydroandrographoline, isolated from Andrographis paniculata (Burm. f.) Nees. We also measured the mixtures of two
active ingredients at the different ratio and the quantitative analysis is also applied to determine the contents of
compound. The Terahertz spectroscopy is a potential and promising technique in identifying the components, evaluating
the drugs sanitation and inspecting the quality of medicine including TCM.