Abstract: Effective control of the pharmaceutical tablets is of great importance. This study that is based on terahertz spectroscopy aims to develop a fast, active, and non-destructive material characterization method. Terahertz Spectroscopy allow a structural analysis in a wide scan range of 5 to 700 cm -1. In this study, active pharmaceutical ingredients that are used in commercial drugs are characterized using fingerprint spectra in cm -1 range by THz-FTIR Spectroscopy. This study is supported by Tubitak. EXPERIMENTAL  Active pharmaceutical powders are ground in an agate mortar without further purification  Specified amount of the particles is mixed with high density polyetylene and compressed into a 1.3 cm diameter pellet with a pressure of 2 tons for 5 minutes.  Prepared pellets are directly placed in the sample compartment of the THz-FTIR instrument. References 1.Ajito, K.; Ueno Y.; Song H., NTT Technical Review, 2012,10(2) 2.Taday, P. F., Phil. Trans. R. Soc. London, 2004, 362, RESULTS AND DISCUSSION Terahertz Time Domain Spectrometer (THz-TDS) Terahertz Generation Crystal SAMPLE Wollaston Prism Ti:Sapphire Laser Broadband Dielectric Mirror Beam Splitter Beam Combiner Cubic Mirror Parabolic Mirror Terahertz Detection Crystal Working range: cm -1 THz Generation and Detection Crystal: ZnTe, 1mm MEASUREMENT OF MATRIX MATERIALS MEASUREMENT OF ACTIVE PHARMACEUTICALS Terahertz absorption images (commercial and test tablets) 4 Tablet surface ingredient distribution (near-IR imaging) 1 Infrared MicrowavesTerahertz Hz → low energy waves → non-destructive → penetrate into the material → transmit through nonpolar molecules (plastic, ceramics) Absorbance Spectra Raw Spectra  HDPE transmission in Far-IR region is very high due to its nonpolar characteristic. Therefore, HDPE forms a good matrix to disperse the active material. For easier comparison, the spectra are offset by one absorbance unit. 1. Benzydamine 2. Ibuprofen 3. Naproxen CONCLUSION  Strong absorption peaks are observed in THz region.  THz waves can be used as a tool to characterize active pharmaceuticals.  There are sufficient differences between the three active pharmaceuticals to make it possible to use for identification. FUTURE DIRECTIONS  Measurement of samples with THz-TDS  Assay of active pharmaceuticals in tablets  Investigation of tablet homogeneity MERVE DOĞANGÜN, ENİS ARIK, OKAN ESENTÜRK Chemistry Department, Middle East Technical University, Çankaya, Ankara Laser Spectroscop y Group METHOD DEVELOPMENT FOR ACTIVE PHARMACEUTICAL INGREDIENT ANALYSIS IN TERAHERTZ REGION INTRODUCTION The THz-waves provide important information about the low-frequency vibrational modes including hydrogen bonding, rotational modes of gases and crystal phonon modes. 1 IntensityAbsorbance APPLICATIONS BIOTECHNOLOGY 2 Determination of high order protein structures Genetic sensing Biomedical Imaging PHARMACEUTICS 2 Characterisation of tablet coating & polymorphism Inspection of tablet core Integrity SECURITY 3 Illicit Drug & Explosive Detection Inspection of biological and chemical agents BB Source Beam Splitter Delay Stage SAMPLE Detector Working range: cm -1 Source: ETC Beam Splitter: DTGS-PE Thermo Scientific Nicolet 6700 FTIR Spektrometer Central λ: 800nm 3.Kemp, M. C.; Taday, P. F.; Cole, B. E.; Cluff J. A.; Fitzgerald, A. J.; Tribe, W. R., Proc of SPIE, 2003, 5070, 8 4.Application of imaging analysis technology